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Sample records for higher mutation frequency

  1. Frequency and distribution of Notch mutations in tumor cell lines

    International Nuclear Information System (INIS)

    Mutvei, Anders Peter; Fredlund, Erik; Lendahl, Urban

    2015-01-01

    Deregulated Notch signaling is linked to a variety of tumors and it is therefore important to learn more about the frequency and distribution of Notch mutations in a tumor context. In this report, we use data from the recently developed Cancer Cell Line Encyclopedia to assess the frequency and distribution of Notch mutations in a large panel of cancer cell lines in silico. Our results show that the mutation frequency of Notch receptor and ligand genes is at par with that for established oncogenes and higher than for a set of house-keeping genes. Mutations were found across all four Notch receptor genes, but with notable differences between protein domains, mutations were for example more prevalent in the regions encoding the LNR and PEST domains in the Notch intracellular domain. Furthermore, an in silico estimation of functional impact showed that deleterious mutations cluster to the ligand-binding and the intracellular domains of NOTCH1. For most cell line groups, the mutation frequency of Notch genes is higher than in associated primary tumors. Our results shed new light on the spectrum of Notch mutations after in vitro culturing of tumor cells. The higher mutation frequency in tumor cell lines indicates that Notch mutations are associated with a growth advantage in vitro, and thus may be considered to be driver mutations in a tumor cell line context. The online version of this article (doi:10.1186/s12885-015-1278-x) contains supplementary material, which is available to authorized users

  2. EGFR mutation frequency and effectiveness of erlotinib

    DEFF Research Database (Denmark)

    Weber, Britta; Hager, Henrik; Sorensen, Boe S

    2014-01-01

    mutation (S768I), and two complex mutations. Seven percent of the patients were never smokers. The differences in median progression-free survival and overall survival between the mutated group and the wild-type group were 8.0 vs. 2.5 months, p...-1 vs. 2-3) and line of treatment (1st vs. 2nd and 3rd) had no influence on outcome in EGFR-mutated patients. CONCLUSION: We found a higher frequency of EGFR mutations than expected in a cohort with less than 10% never smokers. The outcome after treatment with erlotinib was much better in patients......OBJECTIVES: In 2008, we initiated a prospective study to explore the frequency and predictive value of epidermal growth factor receptor (EGFR) mutations in an unselected population of Danish patients with non-small cell lung cancer offered treatment with erlotinib, mainly in second-line. MATERIALS...

  3. The Oenothera plastome mutator: effect of UV irradiation and nitroso-methyl urea on mutation frequencies

    International Nuclear Information System (INIS)

    Sears, B.B.; Sokalski, M.B.

    1991-01-01

    Oenothera plants homozygous for a recessive plastome mutator allele (pm) showed spontaneous mutation frequencies for plastome genes that are 200-fold higher than spontaneous levels. Mutations occurred at high frequencies in plants grown in the field, in a glasshouse, or as leaf tip cultures under fluorescent light, indicating that the plastome mutator activity is UV-independent. However, the chlorotic sectors became visible at an earlier stage of development when seedlings were irradiated, compared to seedlings that were not exposed to UV. These results imply that the rate of sorting-out was increased by the irradiation treatment, possibly due to a decrease in the effective number of multiplication-competent plastids, or a reduction in the extent of cytoplasmic mixing. Nitroso-methyl urea treatment of seeds had a dramatic effect on mutation frequency in both wild-type and plastome mutator samples. When the background mutation rates were low, the combination of the plastome mutator nucleus and the chemical mutagenesis treatment resulted in a synergistic effect, suggesting that the plastome mutator may involve a cpDNA repair pathway. (author)

  4. Effect of combined mutagenic treatments on sensitivity and mutation frequency in rice

    International Nuclear Information System (INIS)

    Gopinathan Nair, V.

    1977-01-01

    Rice seeds were subjected to two sets of combination treatments of radiations and NMH. The effects of mutagenic treatments in the M 1 and M 2 generations were recorded and discussed. Mutation frequencies estimated as number of mutations per 100 M 1 years were not higher than the values expected on the basis of additive effects. When estimated as number of mutants per 100 M 2 plants, the frequencies revealed more than additive effects. The synergistic effect on mutant frequencies was due to increase in the segregation ratio of mutants. This effect was more pronounced at the higher dose combinations of fast neutrons and NMH. (author)

  5. Inherited and environmentally induced differences in mutation frequencies between wild strains of Sordaria fimicola from "Evolution Canyon".

    Science.gov (United States)

    Lamb, B C; Saleem, M; Scott, W; Thapa, N; Nevo, E

    1998-05-01

    We have studied whether there is natural genetic variation for mutation frequencies, and whether any such variation is environment-related. Mutation frequencies differed significantly between wild strains of the fungus Sordaria fimicola isolated from a harsher or a milder microscale environment in "Evolution Canyon," Israel. Strains from the harsher, drier, south-facing slope had higher frequencies of new spontaneous mutations and of accumulated mutations than strains from the milder, lusher, north-facing slope. Collective total mutation frequencies over many loci for ascospore pigmentation were 2.3, 3.5 and 4.4% for three strains from the south-facing slope, and 0.9, 1.1, 1.2, 1.3 and 1.3% for five strains from the north-facing slope. Some of this between-slope difference was inherited through two generations of selfing, with average spontaneous mutation frequencies of 1.9% for south-facing slope strains and 0.8% for north-facing slope strains. The remainder was caused by different frequencies of mutations arising in the original environments. There was also significant heritable genetic variation in mutation frequencies within slopes. Similar between-slope differences were found for ascospore germination-resistance to acriflavine, with much higher frequencies in strains from the south-facing slope. Such inherited variation provides a basis for natural selection for optimum mutation rates in each environment.

  6. The observed human sperm mutation frequency cannot explain the achondroplasia paternal age effect

    Science.gov (United States)

    Tiemann-Boege, Irene; Navidi, William; Grewal, Raji; Cohn, Dan; Eskenazi, Brenda; Wyrobek, Andrew J.; Arnheim, Norman

    2002-01-01

    The lifelong spermatogonial stem cell divisions unique to male germ cell production are thought to contribute to a higher mutation frequency in males. The fact that certain de novo human genetic conditions (e.g., achondroplasia) increase in incidence with the age of the father is consistent with this idea. Although it is assumed that the paternal age effect is the result of an increasing frequency of mutant sperm as a man grows older, no direct molecular measurement of the germ-line mutation frequency has been made to confirm this hypothesis. Using sperm DNA from donors of different ages, we determined the frequency of the nucleotide substitution in the fibroblast growth factor receptor 3 (FGFR3) gene that causes achondroplasia. Surprisingly, the magnitude of the increase in mutation frequency with age appears insufficient to explain why older fathers have a greater chance of having a child with this condition. A number of alternatives may explain this discrepancy, including selection for sperm that carry the mutation or an age-dependent increase in premutagenic lesions that remain unrepaired in sperm and are inefficiently detected by the PCR assay. PMID:12397172

  7. Modification of mutation frequency in Saccharomyces Cerevisiae

    International Nuclear Information System (INIS)

    Vashishat, R.K.; Kakar, S.N.

    1976-01-01

    In a reverse mutation system, using haploid, histidine-requirinq strain of Saccharomyces cerevisiae, the frequency of uv-induced prototrophs increased if the post-irradiation minimal medium was supplemented with limited amounts of histidine. Addition of natural amino acids or RNA bases in the post-irradiation minimal medium, with or without histidine, also increased the uv-induced mutation frequency. Thus, post-irradiation conditions favouring protein and RNA synthesis, are effective in increasing uv-induced mutations in yeast. As compared to uv light, nitrous acid was more effective in inducing reversions in this strain and the frequency increased if the treated cells were plated on minimal medium supplemented with limited amounts of histidine. However, the addition of amino acids or RNA bases decreased the number of revertants. An additional inclusion of histidine reversed the suppressive effect of these metabolites. The mutation induction processes are thus different or differently modifiable in uv and nitrous acid. (author)

  8. Frequencies of aneuploidy and dominant lethal mutations in young female mice induced by low dose γ-rays

    International Nuclear Information System (INIS)

    Yao Suyan; Zhang Chaoyang; Dai Lianlian; Gao Changwen

    1991-01-01

    Relationship between aneuploidy, dominant lethal mutations and doses in young feral mice induced by low dose γ-rays was examined. The results suggest that the frequencies of aneuploidy of embryos increased at 0.15 Gy, but increases at over 0.50 Gy after irradiation in groups. The frequencies of aneuploidy and dominant lethal mutations increased with increasing doses and fitted linear relationship. This dose-response relationship of trisomic was not significant. The frequency of dominant lethal mutations induced by 60 Co γ irradiation is 5.59%. The effect of dominant lethal mutation is higher than that of the aneuploidy

  9. Induced mutations in chickpea (Cicer arietinum L.) II. frequency and spectrum of chlorophyll mutations

    International Nuclear Information System (INIS)

    Kharkwal, M.C.

    1998-01-01

    A comparative study of frequency and spectrum of chlorophyll mutations induced by two physical (gamma rays, fast neutrons) and two chemical mutagens (NMU, EMS) in relation to the effects in M1 plants and induction of mutations in M2 was made in four chickpea (Cicer arietinum L.) varieties, two desi (G 130 & H 214) one Kabuli (C 104) and one green seeded (L 345). The treatments included three doses each of gamma rays (400, 500 & 600 Gy) and fast neutrons (5, 10 & 15 Gy) and two concentrations with two different durations of two chemical mutagens, NMU [0.01% (20h), & 0.02% (8h)] and EMS [0.1% (20h) & 0.2% (8h)]. The frequencies and spectrum of three different kinds of induced chlorophyll mutations in the order albina (43.5%), chlorina (27.3%) and xantha (24.2%) were recorded. Chemical mutagens were found to be efficient in inducing chlorophyll mutations in chickpea. Highest frequency of mutations was observed in green seeded var. L 345 (83% of M1 families and 19.9/1000 M2 plants). Kabuli var. C 104 was least responsive for chlorophyll mutations

  10. Spectrum and frequency of chlorophyll mutations in urdbean (Vigna mungo L. Hepper) induced by EMS and gamma rays

    International Nuclear Information System (INIS)

    Sharma, A.K.; Singh, V.P.; Sarma, M.K.

    2006-01-01

    In mutation breeding experiment, plants with altered characteristics such as chlorophyll changes, sterility, plant lethality etc. could be the marker of the mutability of a variety. In fact, spectrum and frequency of chlorophyll mutations have been studied in the great detail. The chlorophyll mutation is the clear-cut indication of non-directional nature of mutation and possibility of induction of useful mutations. The spectrum and frequency of chlorophyll mutation was estimated by using gamma rays (100, 200, 300 and 400 Gy doses), EMS (0.2, 0.4, 0.6 and 0.8%) and combination of gamma rays (100, 200, 300 400 Gy) with 0.2 % concentration EMS on two cultivars, namely, Pant Urd-19 and Pant Urd-30 of urdbean ( Vigna mungo L. Hepper). Five different types of chlorophyll mutations viz., albina, xantha, viridis, chlorina and maculata were identified in both the cultivars. Almost all the combination treatments produced maximum frequency and wider spectrum of chlorophyll mutations followed by single treatment of gamma rays or EMS. The frequency of chlorophyll mutation increased with higher doses of mutagens but decreased at highest dose. Proc. Nat. Acad. Sci. India. 76(8), I, 2006. 64-68. (author)

  11. Mutation direction by irradiation in rice

    International Nuclear Information System (INIS)

    Wang Cailian; Chen Qiufang; Jin Wei; Lu Yimei

    2001-01-01

    The mutation directions of rice were studied. The results indicated that the mutation directions of rice induced by 14 C were invert correlation to their genetic backgrounds of tested rice varieties, i.e. early mature and short stem varieties produced later mature and higher stem mutation; late mature and high stem varieties produced earlier mature and shorter stem mutation; the varieties of middle maturity and height produced both direction mutations of earlier and later maturity or shorter and higher stem. The mutation directions induced by 14 C were also related to treated doses and stages. Frequency of earlier maturity mutation by protons treatment were higher than those induced by other mutagens. Frequency of later maturity by γ-rays were higher than those induced by other mutagens. Frequency of short stem mutation by synchronous irradiation (soft X-rays) were higher than those induced by other mutagens. Frequency of beneficial mutation induced by proton treatment were higher than those induced by γ-rays

  12. Mutation Rate Variation is a Primary Determinant of the Distribution of Allele Frequencies in Humans.

    Directory of Open Access Journals (Sweden)

    Arbel Harpak

    2016-12-01

    Full Text Available The site frequency spectrum (SFS has long been used to study demographic history and natural selection. Here, we extend this summary by examining the SFS conditional on the alleles found at the same site in other species. We refer to this extension as the "phylogenetically-conditioned SFS" or cSFS. Using recent large-sample data from the Exome Aggregation Consortium (ExAC, combined with primate genome sequences, we find that human variants that occurred independently in closely related primate lineages are at higher frequencies in humans than variants with parallel substitutions in more distant primates. We show that this effect is largely due to sites with elevated mutation rates causing significant departures from the widely-used infinite sites mutation model. Our analysis also suggests substantial variation in mutation rates even among mutations involving the same nucleotide changes. In summary, we show that variable mutation rates are key determinants of the SFS in humans.

  13. Characterization of the factor VIII defect in 147 patients with sporadic hemophilia A: Family studies indicate a mutation type-dependent sex ratio of mutation frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Becker, J.; Schmidt, W.; Olek, K. [Univ. of Bonn (Germany)] [and others

    1996-04-01

    The clinical manifestation of hemophilia A is caused by a wide range of different mutations. In this study the factor VIII genes of 147 severe hemophilia A patients-all exclusively from sporadic families-were screened for mutations by use of the complete panel of modern DNA techniques. The pathogenous defect could be characterized in 126 patients (85.7%). Fifty-five patients (37.4%) showed a F8A-gene inversion, 47 (32.0%) a point mutation, 14 (9.5%) a small deletion, 8 (5.4%) a large deletion, and 2 (1.4%) a small insertion. Further, four (2.7%) mutations were localized but could not be sequenced yet. No mutation could be identified in 17 patients (11.6%). Sixteen (10.9%) of the P identified mutations occurred in the B domain. Four of these were located in an adenosine nucleotide stretch at codon 1192, indicating a mutation hotspot. Somatic mosaicisms were detected in 3 (3.9%) of 76 patients` mothers, comprising 3 of 16 de novo mutations in the patients` mothers. Investigation of family relatives allowed detection of a de novo mutation in 16 of 76 two-generation and 28 of 34 three-generation families. On the basis of these data, the male:female ratio of mutation frequencies (k) was estimated as k = 3.6. By use of the quotients of mutation origin in maternal grandfather to patient`s mother or to maternal grandmother, k was directly estimated as k = 15 and k = 7.5, respectively. Considering each mutation type separately, we revealed a mutation type-specific sex ratio of mutation frequencies. Point mutations showed a 5-to-10-fold-higher and inversions a >10-fold- higher mutation rate in male germ cells, whereas deletions showed a >5-fold-higher mutation rate in female germ cells. Consequently, and in accordance with the data of other diseases like Duchenne muscular dystrophy, our results indicate that at least for X-chromosomal disorders the male:female mutation rate of a disease is determined by its proportion of the different mutation types. 68 refs., 1 fig., 5 tabs.

  14. Studies on induced mutation frequency in Catharanthus roseus (L.) G. Don by gamma rays and EMS individually and in combination

    International Nuclear Information System (INIS)

    Venkateswarlu, M.; Susheelamma, B.N.; Kumar, P.; Subhash, K.

    1988-01-01

    Seeds of pink flowered (PF) and white flowered (WF) Catharanthus roseus were soaked in distilled water for 24 h and treated with gamma rays and 0.1% EMS separately and in combination. Six types of chlorophyll mutations, viz., xantha, albina, chlorina, viridis, maculata and tigrina were recovered to M 2 generation of both forms. The frequency of chlorophyll mutations was found to be dependent on the dose, of gamma rays and duration of treatment with EMS. Higher frequency of chlorophyll mutations was noticed in PF, which is mutagenically more sensitive than WF. It was also noticed that the combination treatments of gamma rays and EMS enhanced the frequency of chlorophyll mutations

  15. Estimating Exceptionally Rare Germline and Somatic Mutation Frequencies via Next Generation Sequencing.

    Directory of Open Access Journals (Sweden)

    Jordan Eboreime

    Full Text Available We used targeted next generation deep-sequencing (Safe Sequencing System to measure ultra-rare de novo mutation frequencies in the human male germline by attaching a unique identifier code to each target DNA molecule. Segments from three different human genes (FGFR3, MECP2 and PTPN11 were studied. Regardless of the gene segment, the particular testis donor or the 73 different testis pieces used, the frequencies for any one of the six different mutation types were consistent. Averaging over the C>T/G>A and G>T/C>A mutation types the background mutation frequency was 2.6x10-5 per base pair, while for the four other mutation types the average background frequency was lower at 1.5x10-6 per base pair. These rates far exceed the well documented human genome average frequency per base pair (~10-8 suggesting a non-biological explanation for our data. By computational modeling and a new experimental procedure to distinguish between pre-mutagenic lesion base mismatches and a fully mutated base pair in the original DNA molecule, we argue that most of the base-dependent variation in background frequency is due to a mixture of deamination and oxidation during the first two PCR cycles. Finally, we looked at a previously studied disease mutation in the PTPN11 gene and could easily distinguish true mutations from the SSS background. We also discuss the limits and possibilities of this and other methods to measure exceptionally rare mutation frequencies, and we present calculations for other scientists seeking to design their own such experiments.

  16. Comparison of somatic mutation frequencies at HGPRT locus induced by radiation and chemical pollutant from energy system

    International Nuclear Information System (INIS)

    Xu Honglan; Cao Yi; Duan Zhikai; Wu Qiqing; Chen Ying; Zhang Shuxian

    1998-12-01

    The somatic induction frequencies of mutation at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus induced by 60 Co γ-rays and Benzo-a-pyrene (B(a)P), which are representative of hazardous emission and pollutant from nuclear energy cycle and fossil-fuelled energy cycle respectively, were detected by using forward mutation assay and cloning technique in both V 79 Chinese hamster cells and human peripheral blood T-lymphocytes. Resistant mutants were selected with 6-thioguanine (6-TG). Dose-response curves and mathematical expressions were obtained for mutation frequencies and survival following γ-ray and B(a)P(+S 9 ) treatments. The dose ranges for the two mutagens were compared when they induced the same mutation frequencies. In V 79 /HGPRT assay system, when the mutation frequencies were 5∼35 mutants/10 6 cells the response of γ-rays in the dose range from 0.93∼4.96 Gy at dose rate of 1.16 Gy/min is nearly equivalent to that in the B(a)P dose range from 0.52∼4.27 μg/ml. By using cloning technique in T-lymphocytes, when the mutation frequencies were 1∼14 mutants/10 5 cells the response of γ-rays in the dose range from 0.05∼4.77 Gy at dose rate of 1.03 Gy/min is nearly equivalent to that in the B(a)P dose range from 0.15∼7.36 μg/ml. When the survival fraction is 37%, the mutation frequency induced by B(a)P is higher than that induced by 60 Co γ-rays

  17. The frequency pattern of dumpy mutations induced by x-rays in the successive stages of oocytes of Drosophila

    International Nuclear Information System (INIS)

    Miyamoto, Tomio; Nakao, Yoshio

    1978-01-01

    The frequency patterns of the different kinds of dumpy mutations induced by x-rays (1,500 and 3,000R) in the successive stages of oocyte development were investigated by transferring the inseminated females daily to fresh vials for 12 days. Under this transferring procedure, the first egg-laying period represents oocytes irradiated when they are at stage 14, and the subsequent ones represent progressively earlier stages of oocyte development at the time of irradiation. The results obtained indicate that (1) the overall yield of complete dumpy mutations recovered in the first six day egg-laying periods (1st-6th day) are relatively higher than that in the subsequent six day periods (7th-12th day), showing a response pattern with a higher mutation frequency in the early egg-laying periods and a lower frequency in the late egg-laying periods; (2) the frequency patterns for the exceptions of the ol and lv types and those of ov and olv types through the sampling periods are practically similar to those observed in the total dumpy mutations; (3) a somewhat peculiar frequency pattern, which seems to be variable by dose, is found in the yield of the o and v exceptions. At the exposure level of 1,500R, no definite difference in response pattern for these exceptions is found, though a response pattern which is practically similar to that observed in the total dumpy mutations is found at the exposure level of 3,000R. The foregoing findings seem to indicate that the different kinds of dumpy exceptions are affected at various degrees by the difference in the cell stages of oocyte. This may possibly suggest that these exceptions are different from each other in the nature of their mutations, that is to say, whether they are associated with chromosome breakage events or not. (auth.)

  18. High frequency of mutation G377S in Brazilian type 3 Gaucher disease patients

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    R. Rozenberg

    2006-09-01

    Full Text Available Gaucher disease (GD, the most prevalent lysosome storage disorder, presents an autosomal recessive mode of inheritance. It is a paradigm for therapeutic intervention in medical genetics due to the existence of effective enzyme replacement therapy. We report here the analysis of GD in 262 unrelated Brazilian patients, carried out in order to establish the frequency of the most common mutations and to provide prognostic information based on genotype-phenotype correlations. Among 247 type 1 GD patients, mutation N370S was detected in 47% of all the alleles, but N370S/N370S homozygosity was found in only 10% of the patients, a much lower frequency than expected, suggesting that most individuals presenting this genotype may not receive medical attention. Recombinant alleles were detected at a high frequency: 44% of the chromosomes bearing mutation L444P had other mutations derived from the pseudogene sequence, present in 25% of patients. Three neuronopathic type 2 patients were homozygous for L444P, all presenting additional mutations (E326K or recombinant alleles that probably lead to the more severe phenotypes. Six children, classified as type 1 GD patients, had a L444P/L444P genotype, showing that neuronopathic symptoms may only manifest later in life. This would indicate the need for a higher treatment dose during enzyme replacement therapy. Finally, mutation G377S was present in 4 homozygous type 1 patients and also in compound heterozygosity in 5 (42% type 3 patients. These findings indicate that G377S cannot be unambiguously classified as mild and suggest an allele-dose effect for this mutation.

  19. Frequency and spectrum of chlorophyll-deficient mutations in rice after treatment with radiation and alkylating agents

    International Nuclear Information System (INIS)

    Bhan, A.K.; Kaul, M.L.H.

    1976-01-01

    Three varieties of rice were treated with gamma rays and two alkylating agents EMS and DES, separately and in combinations, with a view to finding out the frequency and spectrum of chlorophyll mutations in relation to the genotype and the nature of the mutagen. Chlorophyll mutation frequency was enhanced with increasing dose but dropped at very high doses (doses that induced over 90% seeding lethality in M 1 ). The fall was attributed to either the increased mutated sector and diplontic selection after exposure to very high doses or relatively high resistance of some of the seeds. Among chlorophyll mutants in M 2 induced by radiations as well as alkylating agents, the albina type formed the majority class. EMS induced a significantly higher proportion of albinas than did gamma rays

  20. Frequency of common CFTR gene mutations in Venezuelan patients with cystic fibrosis

    OpenAIRE

    Sánchez, Karen; Arcia, Orlando; Matute, Xiorama; Mindiola, Luz; Chaustre, Ismenia; Takiff, Howard

    2014-01-01

    Mutations in the CFTR gene in Cystic Fibrosis (CF) patients have geographic differences and there is scant data on their prevalence in Venezuelan patients. This study determined the frequency of common CFTR gene mutations in these patients. We amplified and sequenced exons 7, 10, 11, 19, 20 and 21, which contain the most common CFTR mutations, from 105 Venezuelan patients in the National CF Program. Eleven different mutations were identified, four with frequencies greater than 1%: p.Phe508del...

  1. The effects of extremely low frequency magnetic fields on mutation induction in mice

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, James W. [Department of Genetics, University of Leicester, Leicester LE1 7RH (United Kingdom); Haines, Jackie; Sienkiewicz, Zenon [Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, Oxfordshire OX11 0RQ (United Kingdom); Dubrova, Yuri E., E-mail: yed2@le.ac.uk [Department of Genetics, University of Leicester, Leicester LE1 7RH (United Kingdom)

    2015-03-15

    Highlights: • The effects of 50 Hz magnetic fields on mutation induction in mice were analyzed. • The frequency of ESTR mutation was established in sperm and blood. • Exposure to 10–300 μT for 2 and 15 h did not result in mutation induction. • Mutagenic effects of 50 Hz magnetic fields are likely to be negligible. - Abstract: The growing human exposure to extremely low frequency (ELF) magnetic fields has raised a considerable concern regarding their genotoxic effects. The aim of this study was to evaluate the in vivo effects of ELF magnetic fields irradiation on mutation induction in the germline and somatic tissues of male mice. Seven week old BALB/c × CBA/Ca F{sub 1} hybrid males were exposed to 10, 100 or 300 μT of 50 Hz magnetic fields for 2 or 15 h. Using single-molecule PCR, the frequency of mutation at the mouse Expanded Simple Tandem Repeat (ESTR) locus Ms6-hm was established in sperm and blood samples of exposed and matched sham-treated males. ESTR mutation frequency was also established in sperm and blood samples taken from male mice exposed to 1 Gy of acute X-rays. The frequency of ESTR mutation in DNA samples extracted from blood of mice exposed to magnetic fields did not significantly differ from that in sham-treated controls. However, there was a marginally significant increase in mutation frequency in sperm but this was not dose-dependent. In contrast, acute exposure X-rays led to significant increases in mutation frequency in sperm and blood of exposed males. The results of our study suggest that, within the range of doses analyzed here, the in vivo mutagenic effects of ELF magnetic fields are likely to be minor if not negligible.

  2. The effects of extremely low frequency magnetic fields on mutation induction in mice

    International Nuclear Information System (INIS)

    Wilson, James W.; Haines, Jackie; Sienkiewicz, Zenon; Dubrova, Yuri E.

    2015-01-01

    Highlights: • The effects of 50 Hz magnetic fields on mutation induction in mice were analyzed. • The frequency of ESTR mutation was established in sperm and blood. • Exposure to 10–300 μT for 2 and 15 h did not result in mutation induction. • Mutagenic effects of 50 Hz magnetic fields are likely to be negligible. - Abstract: The growing human exposure to extremely low frequency (ELF) magnetic fields has raised a considerable concern regarding their genotoxic effects. The aim of this study was to evaluate the in vivo effects of ELF magnetic fields irradiation on mutation induction in the germline and somatic tissues of male mice. Seven week old BALB/c × CBA/Ca F 1 hybrid males were exposed to 10, 100 or 300 μT of 50 Hz magnetic fields for 2 or 15 h. Using single-molecule PCR, the frequency of mutation at the mouse Expanded Simple Tandem Repeat (ESTR) locus Ms6-hm was established in sperm and blood samples of exposed and matched sham-treated males. ESTR mutation frequency was also established in sperm and blood samples taken from male mice exposed to 1 Gy of acute X-rays. The frequency of ESTR mutation in DNA samples extracted from blood of mice exposed to magnetic fields did not significantly differ from that in sham-treated controls. However, there was a marginally significant increase in mutation frequency in sperm but this was not dose-dependent. In contrast, acute exposure X-rays led to significant increases in mutation frequency in sperm and blood of exposed males. The results of our study suggest that, within the range of doses analyzed here, the in vivo mutagenic effects of ELF magnetic fields are likely to be minor if not negligible

  3. Mutation induction by ion beams in higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Atsushi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2003-04-01

    This review mainly describes study results obtained in the Takasaki ion-beam (IB) irradiation facility (TIARA) on the mutation induction in higher plants. Biological effects like lethality and on budding of IBs (carbon, Ne and Ar) are discussed in relation with their linear energy transfer (LET), relative biological effectiveness and the developmental states in shepherd's-purse and tobacco. Induced mutation by IB are characterized by those findings that the mutation rate by C beam is 1.9 x 10{sup -6}, being 17 times higher than the electron beam, in the shepherd's-purse, that C beam induces larger structural changes than electron beam when examined by molecular mechanism of tt and gl gene mutations, and that mutation spectrum of IB is different from that of {gamma}-ray and is wider. Novel mutants are described on shepherd's-purse (pigment mutants, ultraviolet (UV)-resistant and sensitive ones, and flowering ones), disease-resistant rice, barley and tobacco plants, and flowering plants. IB mutation is possibly useful for solving the problems of environment and foods in future. (N.I.)

  4. Frequencies, Laboratory Features, and Granulocyte Activation in Chinese Patients with CALR-Mutated Myeloproliferative Neoplasms.

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    Haixiu Guo

    Full Text Available Somatic mutations in the CALR gene have been recently identified as acquired alterations in myeloproliferative neoplasms (MPNs. In this study, we evaluated mutation frequencies, laboratory features, and granulocyte activation in Chinese patients with MPNs. A combination of qualitative allele-specific polymerase chain reaction and Sanger sequencing was used to detect three driver mutations (i.e., CALR, JAK2V617F, and MPL. CALR mutations were identified in 8.4% of cases with essential thrombocythemia (ET and 5.3% of cases with primary myelofibrosis (PMF. Moreover, 25% of polycythemia vera, 29.5% of ET, and 48.1% of PMF were negative for all three mutations (JAK2V617F, MPL, and CALR. Compared with those patients with JAK2V617F mutation, CALR-mutated ET patients displayed unique hematological phenotypes, including higher platelet counts, and lower leukocyte counts and hemoglobin levels. Significant differences were not found between Chinese PMF patients with mutants CALR and JAK2V617F in terms of laboratory features. Interestingly, patients with CALR mutations showed markedly decreased levels of leukocyte alkaline phosphatase (LAP expression, whereas those with JAK2V617F mutation presented with elevated levels. Overall, a lower mutant rate of CALR gene and a higher triple-negative rate were identified in the cohort of Chinese patients with MPNs. This result indicates that an undiscovered mutant gene may have a significant role in these patients. Moreover, these pathological features further imply that the disease biology varies considerably between mutants CALR and JAK2V617F.

  5. Somatic mutation frequencies in the stamen hairs of stable and mutable clones of Tradescantia after acute gamma-ray treatments with small doses

    International Nuclear Information System (INIS)

    Ichikawa, Sadao; Takahashi, C.S.

    1977-01-01

    Young inflorescences of two different Tradescantia clones heterozygous for flower and stamen-hair color, one stable (KU 9) and the other spontaneously mutable (KU 20), were irradiated acutely with small doses (approx. 3 to 50 R) of 60 Co gamma-rays. Somatic mutation frequencies from blue to pink in the stamen hairs scored on post-irradiation days 10 to 16 increased essentially linearly with increasing gamma-ray dose in both clones. Despite about a 5-fold difference in spontaneous mutation frequency per hair found between the two clones, the dose-response curves of pink mutations determined were similar to each other, giving average mutation frequencies of 1.51 and 1.41 pink-mutant events per 1000 hairs per R for KU 9 and KU 20, respectively. These frequencies are comparable to earlier results obtained from acute irradiation treatments of other clones with higher doses. The doubling dose of pink mutation (the radiation dose making the mutation frequency double the spontaneous level) was calculated to be 2.09 R for KU 9, and this low doubling dose must be given full attention. On the other hand, the doubling dose for KU 20 (calculated to be 10.4 R) is of questionable value, being greatly subject to change because of the diversely variable spontaneous mutation frequency of this clone

  6. Pairwise and higher-order correlations among drug-resistance mutations in HIV-1 subtype B protease

    Directory of Open Access Journals (Sweden)

    Morozov Alexandre V

    2009-08-01

    Full Text Available Abstract Background The reaction of HIV protease to inhibitor therapy is characterized by the emergence of complex mutational patterns which confer drug resistance. The response of HIV protease to drugs often involves both primary mutations that directly inhibit the action of the drug, and a host of accessory resistance mutations that may occur far from the active site but may contribute to restoring the fitness or stability of the enzyme. Here we develop a probabilistic approach based on connected information that allows us to study residue, pair level and higher-order correlations within the same framework. Results We apply our methodology to a database of approximately 13,000 sequences which have been annotated by the treatment history of the patients from which the samples were obtained. We show that including pair interactions is essential for agreement with the mutational data, since neglect of these interactions results in order-of-magnitude errors in the probabilities of the simultaneous occurence of many mutations. The magnitude of these pair correlations changes dramatically between sequences obtained from patients that were or were not exposed to drugs. Higher-order effects make a contribution of as much as 10% for residues taken three at a time, but increase to more than twice that for 10 to 15-residue groups. The sequence data is insufficient to determine the higher-order effects for larger groups. We find that higher-order interactions have a significant effect on the predicted frequencies of sequences with large numbers of mutations. While relatively rare, such sequences are more prevalent after multi-drug therapy. The relative importance of these higher-order interactions increases with the number of drugs the patient had been exposed to. Conclusion Correlations are critical for the understanding of mutation patterns in HIV protease. Pair interactions have substantial qualitative effects, while higher-order interactions are

  7. Survey on the frequency of somatic mutations in A-bomb survivors

    International Nuclear Information System (INIS)

    Akiyama, Mitoshi

    1992-01-01

    Several methods have recently been established for quantitatively detecting somatic cell mutations on a specific locus using human blood cells. These methods have enabled the biological estimation of A-bomb radiation doses in surveys on somatic cell mutations. This paper outlines HPRT, GPA, and TCR assays used to measure somatic cell mutations, focusing on the outcome in A-bomb survivors. HPRT assay is based on colony formation with interleukin-2. The frequency of HPRT mutant cells was significantly increased with advancing age in A-bomb survivors and was positively correlated with the frequency of chromosomal aberrations in lymphocytes. There was also a significantly positive correlation between HPRT mutant cell frequencies and DS86 estimated doses, although the slope was slow. In GPA assay, flow cytometric measurements of fluorescence-labeled erythrocytes are used to detect somatic cell mutations. There was a positive correlation between GPA mutant cell frequencies and age in A-bomb survivors. The GPA mutant cell frequencies showed much more positive correlation with lymphocyte chromosomal aberration frequencies than the HPRT mutant cell frequencies. When anti-CD3 antibody and anti-CD4 antibody are labeled with different fluorescences and are analyzed by using flow cytometry, TCR mutant cells having CD3 - 4 + can be detected. When the frequency of TCR mutant cells was examined in 342 A-bomb survivors, it did not correlate with radiation doses. This implies that TCR assay may be unadequate for biological estimation of A-bomb radiation doses throughout a lifetime of A-bomb survivors, because TCR mutant cells seems to be unable to live for a long time due to national selection. (N.K.)

  8. Frequency and spectrum of hemoglobinopathy mutations in a Uruguayan pediatric population

    Directory of Open Access Journals (Sweden)

    Julio Da Luz

    2013-01-01

    Full Text Available Hemoglobinopathies are the most common recessive diseases worldwide but their prevalence in Uruguay has not been investigated. In this study, 397 unrelated outpatient children from the Pereira Rosell Hospital Center (CHPR, as well as 31 selected patients with microcytic anemia and 28 β-thalassemia carriers were analyzed for hemoglobinopathies by using biochemical and molecular biology methods. Parametric and non-parametric methods were used to compare the hematological indices between groups of genotypes. Of the 397 patients in the first group, approximately 1% (0.76% HbS and 0.25% β-thalassemia had a mutation in the HBB gene and 3.3% had α-thalassemia. These mutations had a heterogeneous distribution that varied according to individual ancestry. HbS was found exclusively in individuals with declared African ancestry and had a carrier frequency of 2.2%. The frequency of α-thalassemia carriers in outpatients of European and African ancestry was 1.2% and 6.5%, respectively. In contrast, the frequency of α-thalassemia carriers in patients with microcytic anemia was 25.8%, significantly higher (p < 0.01 than that observed in the sample as a whole and in Afro-descendants and Euro-descendants. Significant differences were observed in the hematological parameters between individuals with thalassemia genotypes and those with a normal genotype. These results indicate that hemoglobinopathies are a relevant health problem in Uruguay.

  9. The occurrence and frequency of genomic mutations that mediate ...

    African Journals Online (AJOL)

    The occurrence and frequency of genomic mutations that mediate Isoniazid and Rifampicin resistance in Mycobacterium tuberculosis isolates from untreated pulmonary Tuberculosis cases in urban Blantyre, Malawi.

  10. Different mosaicism frequencies for proximal and distal Duchenne muscular dystrophy (DMD) mutations indicate difference in etiology and recurrence risk

    Energy Technology Data Exchange (ETDEWEB)

    Passos-Bueno, M.R.; Takata, R.I.; Rapaport, D.; Bakker, E.; Kneppers, A.L.J.; Dunnen, J.T. den; Ommen, J.B. van

    1992-11-01

    In about 65% of the cases of Duchenne muscular dystrophy (DMD) a partial gene deletion or duplication in the dystrophin gene can be detected. These mutations are clustered at two hot spots: 30% at the hot spot in the proximal part of the gene and about 70% at a more distal hot spot. Unexpectedly the authors observed a higher frequency of proximal gene rearrangements among proved germ line' mosaic cases. Of the 24 mosaic cases they are aware of, 19 (79%) have a proximal mutation, while only 5 (21%) have a distal mutation. This finding indicates that the mutations at the two hot spots in the dystrophin gene differ in origin. Independent support for the different mosaicism frequency was found by comparing the mutation spectra observed in isolated cases of DMD and familial cases (ratio 1:1). The authors conclude from these data that proximal deletions most likely occur early in embryonic development, causing them to have a higher chance of becoming familial, while distal deletions occur later and have a higher chance of causing only isolated cases. Finally, the findings have important consequences for the calculation of recurrence-risk estimates according to the site of the deletion: a [open quote]proximal[close quote] new mutant has an increased recurrence risk of approximately 30%, and a [open quote]distal[close quote] new mutant has a decreased recurrence risk of approximately 4%. 28 refs., 2 figs., 2 tabs.

  11. Abiotic stress leads to somatic and heritable changes in homologous recombination frequency, point mutation frequency and microsatellite stability in Arabidopsis plants

    International Nuclear Information System (INIS)

    Yao Youli; Kovalchuk, Igor

    2011-01-01

    In earlier studies, we showed that abiotic stresses, such as ionizing radiation, heavy metals, temperature and water, trigger an increase in homologous recombination frequency (HRF). We also demonstrated that many of these stresses led to inheritance of high-frequency homologous recombination, HRF. Although an increase in recombination frequency is an important indicator of genome rearrangements, it only represents a minor portion of possible stress-induced mutations. Here, we analyzed the influence of heat, cold, drought, flood and UVC abiotic stresses on two major types of mutations in the genome, point mutations and small deletions/insertions. We used two transgenic lines of Arabidopsis thaliana, one allowing an analysis of reversions in a stop codon-containing inactivated β-glucuronidase transgene and another one allowing an analysis of repeat stability in a microsatellite-interrupted β-glucuronidase transgene. The transgenic Arabidopsis line carrying the β-glucuronidase-based homologous recombination substrate was used as a positive control. We showed that the majority of stresses increased the frequency of point mutations, homologous recombination and microsatellite instability in somatic cells, with the frequency of homologous recombination being affected the most. The analysis of transgenerational changes showed an increase in HRF to be the most prominent effect observed in progeny. Significant changes in recombination frequency were observed upon exposure to all types of stress except drought, whereas changes in microsatellite instability were observed upon exposure to UVC, heat and cold. The frequency of point mutations in the progeny of stress-exposed plants was the least affected; an increase in mutation frequency was observed only in the progeny of plants exposed to UVC. We thus conclude that transgenerational changes in genome stability in response to stress primarily involve an increase in recombination frequency.

  12. Frequency of CDH1 germline mutations in gastric carcinoma coming from high- and low-risk areas: metanalysis and systematic review of the literature

    International Nuclear Information System (INIS)

    Corso, Giovanni; Marrelli, Daniele; Pascale, Valeria; Vindigni, Carla; Roviello, Franco

    2012-01-01

    The frequency of E-cadherin germline mutations in countries with different incidence rates for gastric carcinoma has not been well established. The goal of this study was to assess the worldwide frequency of CDH1 germline mutations in gastric cancers coming from low- and high-risk areas. English articles using MEDLINE access (from 1998 to 2011). Search terms included CDH1, E-cadherin, germline mutation, gastric cancer, hereditary, familial and diffuse histotype. The study included all E-cadherin germline mutations identified in gastric cancer patients; somatic mutations and germline mutations reported in other tumors were excluded. The method of this study was scheduled in accordance with the 'PRISMA statement for reporting systematic reviews and meta-analyses'. Countries were classified as low- or middle/high risk-areas for gastric carcinoma incidence. Statistical analysis was performed to correlate the CDH1 mutation frequency with gastric cancer incidence areas. A total of 122 E-cadherin germline mutations have been identified; the majority (87.5%) occurred in gastric cancers coming from low-risk areas. In high-risk areas, we identified 16 mutations in which missense mutations were predominant. (68.8%). We verified a significant association between the mutation frequency and the gastric cancer risk area (p < 0.001: overall identified mutations in low- vs. middle/high-risk areas). E-cadherin genetic screenings performed in low-risk areas for gastric cancer identified a higher frequency of CDH1 germline mutations. This data could open new approaches in the gastric cancer prevention test; before proposing a proband candidate for the CDH1 genetic screening, geographic variability, alongside the family history should be considered

  13. Frequency and Prognostic Relevance of FLT3 Mutations in Saudi Acute Myeloid Leukemia Patients

    Directory of Open Access Journals (Sweden)

    Ghaleb Elyamany

    2014-01-01

    Full Text Available The Fms-like tyrosine kinase-3 (FLT3 is a receptor tyrosine kinase that plays a key role in cell survival, proliferation, and differentiation of hematopoietic stem cells. Mutations of FLT3 were first described in 1997 and account for the most frequent molecular mutations in acute myeloid leukemia (AML. AML patients with FLT3 internal tandem duplication (ITD mutations have poor cure rates the prognostic significance of point mutations; tyrosine kinase domain (TKD is still unclear. We analyzed the frequency of FLT3 mutations (ITD and D835 in patients with AML at diagnosis; no sufficient data currently exist regarding FLT3 mutations in Saudi AML patients. This study was aimed at evaluating the frequency of FLT3 mutations in patients with AML and its significance for prognosis. The frequency of FLT3 mutations in our study (18.56% was lower than many of the reported studies, FLT3-ITD mutations were observed in 14.4%, and FLT3-TKD in 4.1%, of 97 newly diagnosed AML patients (82 adult and 15 pediatric. Our data show significant increase of FLT3 mutations in male more than female (13 male, 5 female. Our results support the view that FLT3-ITD mutation has strong prognostic factor in AML patients and is associated with high rate of relapse, and high leucocytes and blast count at diagnosis and relapse.

  14. HPRT gene mutation frequency and the factor of influence in adult peripheral blood lymphocytes

    International Nuclear Information System (INIS)

    Zhao Jingyong; Zheng Siying; Cui Fengmei; Wang Liuyi; Lao Qinhua; Wu Hongliang

    2002-01-01

    Objective: To study the HPRT gene loci mutation frequencies and the factor of influence in peripheral blood lymphocytes of adult with ages ranging from 21-50. Methods: HPRT gene mutation frequency (GMf) were examined by the technique of multinuclear cell assay. Relation between GMf and years were fitted with a computer. Results: Relation could be described by the following equation: y = 0.7555 + 0.0440x, r = 0.9829. Smoking has influence on GMf and sex hasn't. Conclusion: HPRT gene mutation frequency increases with increasing of age. Increasing rate is 0.00440% per year

  15. Rich Medium Composition Affects Escherichia coli Survival, Glycation, and Mutation Frequency during Long-Term Batch Culture.

    Science.gov (United States)

    Kram, Karin E; Finkel, Steven E

    2015-07-01

    Bacteria such as Escherichia coli are frequently grown to high density to produce biomolecules for study in the laboratory. To achieve this, cells can be incubated in extremely rich media that increase overall cell yield. In these various media, bacteria may have different metabolic profiles, leading to changes in the amounts of toxic metabolites produced. We have previously shown that stresses experienced during short-term growth can affect the survival of cells during the long-term stationary phase (LTSP). Here, we incubated cells in LB, 2× yeast extract-tryptone (YT), Terrific Broth, or Super Broth medium and monitored survival during the LTSP, as well as other reporters of genetic and physiological change. We observe differential cell yield and survival in all media studied. We propose that differences in long-term survival are the result of changes in the metabolism of components of the media that may lead to increased levels of protein and/or DNA damage. We also show that culture pH and levels of protein glycation, a covalent modification that causes protein damage, affect long-term survival. Further, we measured mutation frequency after overnight incubation and observed a correlation between high mutation frequencies at the end of the log phase and loss of viability after 4 days of LTSP incubation, indicating that mutation frequency is potentially predictive of long-term survival. Since glycation and mutation can be caused by oxidative stress, we measured expression of the oxyR oxidative stress regulator during log-phase growth and found that higher levels of oxyR expression during the log phase are consistent with high mutation frequency and lower cell density during the LTSP. Since these complex rich media are often used when producing large quantities of biomolecules in the laboratory, the observed increase in damage resulting in glycation or mutation may lead to production of a heterogeneous population of plasmids or proteins, which could affect the

  16. Mutational jackpot events generate effective frequency-dependent selection in adapting populations

    Science.gov (United States)

    Hallatschek, Oskar

    The site-frequency spectrum is one the most easily measurable quantities that characterize the genetic diversity of a population. While most neutral models predict that site frequency spectra should decay with increasing frequency, a high-frequency uptick has been reported in many populations. Anomalies in the high-frequency tail are particularly unsettling because the highest frequencies can be measured with greatest accuracy. Here, we show that an uptick in the spectrum of neutral mutations generally arises when mutant frequencies are dominated by rare jackpot events, mutational events with large descendant numbers. This leads to an effective pattern of frequency-dependent selection (or unstable internal equilibrium at one half frequency) that causes an accumulation of high-frequency polymorphic sites. We reproduce the known uptick occurring for recurrent hitchhiking (genetic draft) as well as rapid adaptation, and (in the future) generalize the shape of the high-frequency tail to other scenarios that are dominated by jackpot events, such as frequent range expansions. We also tackle (in the future) the inverse approach to use the high-frequency uptick for learning about the tail of the offspring number distribution. Positively selected alleles need to surpass, typically, an u NSF Career Award (PoLS), NIH NIGMS R01, Simons Foundation.

  17. Low frequency of c-MPL gene mutations in Iranian patients with Philadelphia-negative myeloproliferative disorders.

    Science.gov (United States)

    Ghotaslou, A; Nadali, F; Chahardouli, B; Alizad Ghandforosh, N; Rostami, S H; Alimoghaddam, K; Ghavamzadeh, A

    2015-01-01

    Myeloproliferative disorders are a group of diseases characterized by increased proliferation of myeloid lineage. In addition to JAK2V617F mutation, several mutations in the c-MPL gene have been reported in patients with philadelphia-negative chronic myeloproliferative disorders that could be important in the pathogenesis of diseases. The aim of the present study was to investigate the frequency of c-MPL and JAK2V617F mutations in Iranian patients with Philadelphia-negativemyeloproliferative disorders. Peripheral blood samples were collected from 60 patients with Philadelphia-negative MPD) Subgroups ET and PMF) and 25 healthy subjects as control group. The mutation status of c-MPL and Jak2V617F were investigated by using Amplification-refractory mutation system (ARMS) and Allele-Specific PCR (AS-PCR), respectively. The results were confirmed by sequencing. Among 60 patients, 34 (56.6%) and 1(1.7%) had Jak2V617F and c-MPL mutation, respectively. Patients with Jak2V617F mutation had higher WBC counts and hemoglobin concentration than those without the mutation (p= 0.005, p=0.003). In addition, for all healthy subjects in control group, mutations were negative. The present study revealed that the c-MPL mutations unlike the Jak2V617F mutations are rare in Iranian patients with Ph-negative MPNs and the low mutation rate should be considered in the design of screening strategies of MPD patients.

  18. Somatic mutation frequency in the stamen hairs of Tradescantia KU 7 and KU 9 clones exposed to low-level gamma rays

    International Nuclear Information System (INIS)

    Ichikawa, S.; Nagashima, C.; Takahashi, C.S.

    1981-01-01

    Two triploid clones (KU 7 and KU 9) of Tradescantia heterozygous for flower color were exposed to 1 to 42.3R of gamma rays or the scattering radiation in the gamma field of the Institute of Radiation . Breeding. Occurrence of somatic pink mutations in the stamen hairs was investigated 10 to 16 (or 14) days after irradiation. The mutation frequency was found to increase linearly with increasing gamma-ray exposure in the both clones, and the frequencies of 0.437 and 0.468 pink mutant events per 10 3 hairs per R were determined for KU 7 and KU 9, respectively. When the data collected in the present study were analyzed together with those obtained in earlier experiments in the gamma field, linear relationships of the somatic mutation frequency with gamma-ray (2.1 to 201.6R) and scattering radiation (0.72 to 57.6R) exposures were confirmed. Scattering radiation was found to have a genetical efficiency more than two times higher than that of gamma rays. Variation of spontaneous mutation frequency observed in the present study and in earlier studies was inversely correlated to temperature variation

  19. Radiation-induced mutation at minisatellite loci

    International Nuclear Information System (INIS)

    Dubrova, Y.E.; Nesterov, V.N.; Krouchinsky, N.G.

    1997-01-01

    We are studying the radiation-induced increase of mutation rate in minisatellite loci in mice and humans. Minisatellite mutations were scored by multilocus DNA fingerprint analysis in the progeny of γ-irradiated and non-irradiated mice. The frequency of mutation in offspring of irradiated males was 1.7 higher that in the control group. Germline mutation at human minisatellite loci was studied among children born in heavily polluted areas of the Mogilev district of Belarus after the Chernobyl accident and in a control population. The frequency of mutation assayed both by DNA fingerprinting and by eight single locus probes was found to be two times higher in the exposed families than in the control group. Furthermore, mutation rate was correlated with the parental radiation dose for chronic exposure 137 Cs, consistent with radiation-induction of germline mutation. The potential use of minisatellites in monitoring germline mutation in humans will be discussed

  20. Mutation frequencies in male mice and the estimation of genetic hazards of radiation in men

    International Nuclear Information System (INIS)

    Russell, W.L.; Kelly, E.M.

    1982-01-01

    Estimation of the genetic hazards of ionizing radiation in men is based largely on the frequency of transmitted specific-locus mutations induced in mouse spermatogonial stem cells at low radiation dose rates. The publication of new data on this subject has permitted a fresh review of all the information available. The data continue to show no discrepancy from the interpretation that, although mutation frequency decreases markedly as dose rate is decreased from 90 to 0.8 R/min (1 R = 2.6 x 10/sup -4/ coulombs/kg) there seems to be no further change below 0.8 R/min over the range from that dose rate to 0.0007 R/min. Simple mathematical models are used to compute: (a) a maximum likelihood estimate of the induced mutation frequency at the low dose rates, and (b) a maximum likelihood estimate of the ratio of this to the mutation frequency at high dose rates in the range of 72 to 90 R/min. In the application of these results to the estimation of genetic hazards of radiation in man, the former value can be used to calcualte a doubling dose - i.e., the dose of radiation that induces a mutation frequency equal to the spontaneous frequency. The doubling dose based on the low-dose-rate data compiled here is 110 R. The ratio of the mutation frequency at low dose rate to to that at high dose rate is useful when it becomes necessary to extrapolate from experimental determinations, or from human data, at high dose rates to the expected risk at low dose rates. The ratio derived from the present analysis is 0.33

  1. Pre-thymic somatic mutation leads to high mutant frequency at hypoxanthine-guanine phosphoribosyltransferase gene

    Energy Technology Data Exchange (ETDEWEB)

    Jett, J. [Lawrence Livermore National Lab., CA (United States)

    1994-12-01

    While characterizing the background mutation spectrum of the Hypoxathine-guanine phosphoribosyltransferase (HPRT) gene in a healthy population, an outlier with a high mutant frequency of thioguanine resistant lymphocytes was found. When studied at the age of 46, this individual had been smoking 60 cigarettes per day for 38 years. His mutant frequency was calculated at 3.6 and 4.2x10{sup {minus}4} for two sampling periods eight months apart. Sequencing analysis of the HPRT gene in his mutant thioguanine resistant T lymphocytes was done to find whether the cells had a high rate of mutation, or if the mutation was due to a single occurrence of mutation and, if so, when in the T lymphocyte development the mutation occurred. By T-cell receptor analysis it has been found that out of 35 thioguanine resistant clones there was no dominant gamma T cell receptor gene rearrangement. During my appointment in the Science & Engineering Research Semester, I found that 34 of those clones have the same base substitution of G{yields}T at cDNA position 197. Due to the consistent mutant frequency from both sampling periods and the varying T cell receptors, the high mutant frequency cannot be due to recent proliferation of a mature mutant T lymphocyte. From the TCR and DNA sequence analysis we conclude that the G{yields}T mutation must have occurred in a T lymphocyte precursor before thymic differentiation so that the thioguanine resistant clones share the same base substitution but not the same gamma T cell receptor gene.

  2. Mutation frequencies in male mice and the estimation of genetic hazards of radiation in men: (specific-locus mutations/dose-rate effect/doubling dose/risk estimation)

    International Nuclear Information System (INIS)

    Russell, W.L.; Kelly, E.M.

    1982-01-01

    Estimation of the genetic hazards of ionizing radiation in men is based largely on the frequency of transmitted specific-locus mutations induced in mouse spermatogonial stem cells at low radiation dose rates. The publication of new data on this subject has permitted a fresh review of all the information available. The data continue to show no discrepancy from the interpretation that, although mutation frequency decreases markedly as dose rate is decreased from 90 to 0.8 R/min (1 R = 2.6 X 10 -4 coulombs/kg) there seems to be no further change below 0.8 R/min over the range from that dose rate to 0.0007 R/min. Simple mathematical models are used to compute: (a) a maximum likelihood estimate of the induced mutation frequency at the low dose rates, and (b) a maximum likelihood estimate of the ratio of this to the mutation frequency at high dose rates in the range of 72 to 90 R/min. In the application of these results to the estimation of genetic hazards of radiation in man, the former value can be used to calculate a doubling dose - i.e., the dose of radiation that induces a mutation frequency equal to the spontaneous frequency. The doubling dose based on the low-dose-rate data compiled here is 110 R. The ratio of the mutation frequency at low dose rate to that at high dose rate is useful when it becomes necessary to extrapolate from experimental determinations, or from human data, at high dose rates to the expected risk at low dose rates. The ratio derived from the present analysis is 0.33

  3. Frequency of rare mutations and common genetic variations in severe hypertriglyceridemia in the general population of Spain.

    Science.gov (United States)

    Lamiquiz-Moneo, Itziar; Blanco-Torrecilla, Cristian; Bea, Ana M; Mateo-Gallego, Rocío; Pérez-Calahorra, Sofía; Baila-Rueda, Lucía; Cenarro, Ana; Civeira, Fernando; de Castro-Orós, Isabel

    2016-04-23

    Hypertriglyceridemia (HTG) is a common complex metabolic trait that results of the accumulation of relatively common genetic variants in combination with other modifier genes and environmental factors resulting in increased plasma triglyceride (TG) levels. The majority of severe primary hypertriglyceridemias is diagnosed in adulthood and their molecular bases have not been fully defined yet. The prevalence of HTG is highly variable among populations, possibly caused by differences in environmental factors and genetic background. However, the prevalence of very high TG and the frequency of rare mutations causing HTG in a whole non-selected population have not been previously studied. The total of 23,310 subjects over 18 years from a primary care-district in a middle-class area of Zaragoza (Spain) with TG >500 mg/dL were selected to establish HTG prevalence. Those affected of primary HTG were considered for further genetic analysis. The promoters, coding regions and exon-intron boundaries of LPL, LMF1, APOC2, APOA5, APOE and GPIHBP1 genes were sequenced. The frequency of rare variants identified was studied in 90 controls. One hundred ninety-four subjects (1.04%) had HTG and 90 subjects (46.4%) met the inclusion criteria for primary HTG. In this subgroup, nine patients (12.3%) were carriers of 7 rare variants in LPL, LMF1, APOA5, GPIHBP1 or APOE genes. Three of these mutations are described for the first time in this work. The presence of a rare pathogenic mutation did not confer a differential phenotype or a higher family history of HTG. The prevalence of rare mutations in candidate genes in subjects with primary HTG is low. The low frequency of rare mutations, the absence of a more severe phenotype or the dominant transmission of the HTG would not suggest the use of genetic analysis in the clinical practice in this population.

  4. Deficiency of the DNA repair protein nibrin increases the basal but not the radiation induced mutation frequency in vivo

    International Nuclear Information System (INIS)

    Wessendorf, Petra; Vijg, Jan; Nussenzweig, André; Digweed, Martin

    2014-01-01

    Highlights: • lacZ mutant frequencies measured in vivo in mouse models of radiosensitive Nijmegen Breakage Syndrome. • Spontaneous mutation frequencies are increased in lymphatic tissue due to Nbn mutation. • Single base transitions, not deletions, dominate the mutation spectrum. • Radiation induced mutation frequencies are not increased due to Nbn mutation. - Abstract: Nibrin (NBN) is a member of a DNA repair complex together with MRE11 and RAD50. The complex is associated particularly with the repair of DNA double strand breaks and with the regulation of cell cycle check points. Hypomorphic mutation of components of the complex leads to human disorders characterised by radiosensitivity and increased tumour occurrence, particularly of the lymphatic system. We have examined here the relationship between DNA damage, mutation frequency and mutation spectrum in vitro and in vivo in mouse models carrying NBN mutations and a lacZ reporter plasmid. We find that NBN mutation leads to increased spontaneous DNA damage in fibroblasts in vitro and high basal mutation rates in lymphatic tissue of mice in vivo. The characteristic mutation spectrum is dominated by single base transitions rather than the deletions and complex rearrangements expected after abortive repair of DNA double strand breaks. We conclude that in the absence of wild type nibrin, the repair of spontaneous errors, presumably arising during DNA replication, makes a major contribution to the basal mutation rate. This applies also to cells heterozygous for an NBN null mutation. Mutation frequencies after irradiation in vivo were not increased in mice with nibrin mutations as might have been expected considering the radiosensitivity of NBS patient cells in vitro. Evidently apoptosis is efficient, even in the absence of wild type nibrin

  5. Deficiency of the DNA repair protein nibrin increases the basal but not the radiation induced mutation frequency in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Wessendorf, Petra [Institute of Medical and Human Genetics, Charité – Universitätsmedizin Berlin, Augustenburger Platz 1, D-13353 Berlin (Germany); Vijg, Jan [Albert Einstein College of Medicine, Michael F. Price Center, 1301 Morris Park Avenue, Bronx, NY 10461 (United States); Nussenzweig, André [Laboratory of Genome Integrity, National Cancer Institute, National Institute of Health, 37 Convent Drive, Room 1106, Bethesda, MD 20892 (United States); Digweed, Martin, E-mail: martin.digweed@charite.de [Institute of Medical and Human Genetics, Charité – Universitätsmedizin Berlin, Augustenburger Platz 1, D-13353 Berlin (Germany)

    2014-11-15

    Highlights: • lacZ mutant frequencies measured in vivo in mouse models of radiosensitive Nijmegen Breakage Syndrome. • Spontaneous mutation frequencies are increased in lymphatic tissue due to Nbn mutation. • Single base transitions, not deletions, dominate the mutation spectrum. • Radiation induced mutation frequencies are not increased due to Nbn mutation. - Abstract: Nibrin (NBN) is a member of a DNA repair complex together with MRE11 and RAD50. The complex is associated particularly with the repair of DNA double strand breaks and with the regulation of cell cycle check points. Hypomorphic mutation of components of the complex leads to human disorders characterised by radiosensitivity and increased tumour occurrence, particularly of the lymphatic system. We have examined here the relationship between DNA damage, mutation frequency and mutation spectrum in vitro and in vivo in mouse models carrying NBN mutations and a lacZ reporter plasmid. We find that NBN mutation leads to increased spontaneous DNA damage in fibroblasts in vitro and high basal mutation rates in lymphatic tissue of mice in vivo. The characteristic mutation spectrum is dominated by single base transitions rather than the deletions and complex rearrangements expected after abortive repair of DNA double strand breaks. We conclude that in the absence of wild type nibrin, the repair of spontaneous errors, presumably arising during DNA replication, makes a major contribution to the basal mutation rate. This applies also to cells heterozygous for an NBN null mutation. Mutation frequencies after irradiation in vivo were not increased in mice with nibrin mutations as might have been expected considering the radiosensitivity of NBS patient cells in vitro. Evidently apoptosis is efficient, even in the absence of wild type nibrin.

  6. Diversity and frequency of kdr mutations within Anopheles sinensis populations from Guangxi, China.

    Science.gov (United States)

    Yang, Chan; Feng, Xiangyang; Huang, Zushi; Li, Mei; Qiu, Xinghui

    2016-08-15

    Anopheles sinensis is a major vector of malaria in China and its control is under great threat as the development of insecticide resistance. Voltage-gated sodium channel (VGSC) is the target of several classes of insecticides. Genetic mutations of VGSC have been documented to confer knockdown resistance (kdr) to dichlorodiphenyltrichloroethane (DDT) and pyrethroids in mosquitoes. To control this vector efficiently, it is important to know the resistance-associated genetic mutations, their distribution frequencies and genealogical relations. Three hundreds and thirteen (313) adults of An. sinensis collected from nine locations across Guangxi Zhuang Autonomous Region were used. The partial sequence of the An. sinensis voltage gated sodium channel gene (AS-VGSC) containing codon 1014 was sequenced. PHASE2.1 was used to construct the haplotypes of each individual, and the accuracy of haplotypes was further confirmed by clone sequencing. The genealogical relations of kdr mutations in AS-VGSC was analysed using TCS 2.1 and Network 5.0. Sixteen AS-VGSC haplotypes including seven haplotypes carrying non-synonymous mutations at codon 1014, and fifty-five AS-VGSC genotypes were identified from 313 mosquitoes collected from nine geographical locations across Guangxi. The number of haplotypes in each of the nine populations ranged from 5 to 13. The frequency of haplotypes carrying kdr mutations ranged from 2.7 to 80.0 % within the nine populations, of which 1014C was unexpectedly high in the northeast of Guangxi. Genealogical analysis suggested multiple origins of kdr mutations in An. sinensis. Diverse haplotypes of AS-VGSC are distributed in Guangxi. The presence of haplotypes carrying mutations at codon 1014 indicates a risk of pyrethroid and DDT resistance. The kdr mutations show differential distribution geographically, with high frequencies occurred in the northeast of Guangxi. Genealogical analysis suggests multiple origins of kdr mutations in An. sinensis populations

  7. Frequency of CNKSR2 mutation in the X-linked epilepsy-aphasia spectrum.

    Science.gov (United States)

    Damiano, John A; Burgess, Rosemary; Kivity, Sara; Lerman-Sagie, Tally; Afawi, Zaid; Scheffer, Ingrid E; Berkovic, Samuel F; Hildebrand, Michael S

    2017-03-01

    Synaptic proteins are critical to neuronal function in the brain, and their deficiency can lead to seizures and cognitive impairments. CNKSR2 (connector enhancer of KSR2) is a synaptic protein involved in Ras signaling-mediated neuronal proliferation, migration and differentiation. Mutations in the X-linked gene CNKSR2 have been described in patients with seizures and neurodevelopmental deficits, especially those affecting language. In this study, we sequenced 112 patients with phenotypes within the epilepsy-aphasia spectrum (EAS) to determine the frequency of CNKSR2 mutation within this complex set of disorders. We detected a novel nonsense mutation (c.2314 C>T; p.Arg712*) in one Ashkenazi Jewish family, the male proband of which had a severe epileptic encephalopathy with continuous spike-waves in sleep (ECSWS). His affected brother also had ECSWS with better outcome, whereas the sister had childhood epilepsy with centrotemporal spikes. This mutation segregated in the three affected siblings in an X-linked manner, inherited from their mother who had febrile seizures. Although the frequency of point mutation is low, CNKSR2 sequencing should be considered in families with suspected X-linked EAS because of the specific genetic counseling implications. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

  8. The Frequency and Type of K-RAS Mutations in Mexican Patients With Colorectal Cancer: A National Study.

    Science.gov (United States)

    Cárdenas-Ramos, Susana G; Alcázar-González, Gregorio; Reyes-Cortés, Luisa M; Torres-Grimaldo, Abdiel A; Calderón-Garcidueñas, Ana L; Morales-Casas, José; Flores-Sánchez, Patricia; De León-Escobedo, Raúl; Gómez-Díaz, Antonio; Moreno-Bringas, Carmen; Sánchez-Guillén, Jorge; Ramos-Salazar, Pedro; González-de León, César; Barrera-Saldaña, Hugo A

    2017-06-01

    Current metastatic colorectal cancer (mCRC) therapy uses monoclonal antibodies against the epidermal growth factor receptor. This treatment is only useful in the absence of K-RAS gene mutations; therefore the study of such mutations is part of a personalized treatment. The aim of this work is to determine the frequency and type of the most common K-RAS mutations in Mexican patients with metastatic disease by nucleotide sequencing. We studied 888 patients with mCRC from different regions of Mexico. The presence of mutations in exon 2, codons 12 and 13, of the K-RAS gene was determined by nucleotide sequencing. Patients exhibited K-RAS gene mutations in 35% (310/888) of cases. Mutation frequency of codons 12 and 13 was 71% (221/310) and 29% (89/310), respectively. The most common mutation (45.7%) in codon 12 was c.35G>A (p.G12D), whereas the one in codon 13 was c.38G>A (p.G13D) (78.7%). Given the frequency of K-RAS mutations in Mexicans, making a genetic study before deciding to treat mCRC patients with monoclonal antibodies is indispensable.

  9. High frequency of PTEN mutations in nevi and melanomas from xeroderma pigmentosum patients.

    Science.gov (United States)

    Masaki, Taro; Wang, Yun; DiGiovanna, John J; Khan, Sikandar G; Raffeld, Mark; Beltaifa, Senda; Hornyak, Thomas J; Darling, Thomas N; Lee, Chyi-Chia R; Kraemer, Kenneth H

    2014-05-01

    We examined nevi and melanomas in 10 xeroderma pigmentosum (XP) patients with defective DNA repair. The lesions had a lentiginous appearance with markedly increased numbers of melanocytes. Using laser capture microdissection, we performed DNA sequencing of 18 benign and atypical nevi and 75 melanomas (melanoma in situ and invasive melanomas). The nevi had a similar high frequency of PTEN mutations as melanomas [61% (11/18) versus 53% (39/73)]. Both had a very high proportion of UV-type mutations (occurring at adjacent pyrimidines) [91% (10/11) versus 92% (36/39)]. In contrast to melanomas in the general population, the frequency of BRAF mutations (11%, 7/61), NRAS mutations (21%, 13/62), and KIT mutations (21%, 6/28) in XP melanomas was lower than for PTEN. Phospho-S6 immunostaining indicated activation of the mTOR pathway in the atypical nevi and melanomas. Thus, the clinical and histological appearances and the molecular pathology of these UV-related XP nevi and melanomas were different from nevi and melanomas in the general population. © 2014 Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  10. The molecular anatomy of spontaneous germline mutations in human testes.

    Directory of Open Access Journals (Sweden)

    Jian Qin

    2007-09-01

    Full Text Available The frequency of the most common sporadic Apert syndrome mutation (C755G in the human fibroblast growth factor receptor 2 gene (FGFR2 is 100-1,000 times higher than expected from average nucleotide substitution rates based on evolutionary studies and the incidence of human genetic diseases. To determine if this increased frequency was due to the nucleotide site having the properties of a mutation hot spot, or some other explanation, we developed a new experimental approach. We examined the spatial distribution of the frequency of the C755G mutation in the germline by dividing four testes from two normal individuals each into several hundred pieces, and, using a highly sensitive PCR assay, we measured the mutation frequency of each piece. We discovered that each testis was characterized by rare foci with mutation frequencies 10(3 to >10(4 times higher than the rest of the testis regions. Using a model based on what is known about human germline development forced us to reject (p < 10(-6 the idea that the C755G mutation arises more frequently because this nucleotide simply has a higher than average mutation rate (hot spot model. This is true regardless of whether mutation is dependent or independent of cell division. An alternate model was examined where positive selection acts on adult self-renewing Ap spermatogonial cells (SrAp carrying this mutation such that, instead of only replacing themselves, they occasionally produce two SrAp cells. This model could not be rejected given our observed data. Unlike the disease site, similar analysis of C-to-G mutations at a control nucleotide site in one testis pair failed to find any foci with high mutation frequencies. The rejection of the hot spot model and lack of rejection of a selection model for the C755G mutation, along with other data, provides strong support for the proposal that positive selection in the testis can act to increase the frequency of premeiotic germ cells carrying a mutation

  11. Molecular spectrum of KRAS, NRAS, BRAF, PIK3CA, TP53, and APC somatic gene mutations in Arab patients with colorectal cancer: determination of frequency and distribution pattern

    Science.gov (United States)

    Al-Shamsi, Humaid O.; Jones, Jeremy; Fahmawi, Yazan; Dahbour, Ibrahim; Tabash, Aziz; Abdel-Wahab, Reham; Abousamra, Ahmed O. S.; Shaw, Kenna R.; Xiao, Lianchun; Hassan, Manal M.; Kipp, Benjamin R.; Kopetz, Scott; Soliman, Amr S.; McWilliams, Robert R.; Wolff, Robert A.

    2016-01-01

    Background The frequency rates of mutations such as KRAS, NRAS, BRAF, and PIK3CA in colorectal cancer (CRC) differ among populations. The aim of this study was to assess mutation frequencies in the Arab population and determine their correlations with certain clinicopathological features. Methods Arab patients from the Arab Gulf region and a population of age- and sex-matched Western patients with CRC whose tumors were evaluated with next-generation sequencing (NGS) were identified and retrospectively reviewed. The mutation rates of KRAS, NRAS, BRAF, PIK3CA, TP53, and APC were recorded, along with clinicopathological features. Other somatic mutation and their rates were also identified. Fisher’s exact test was used to determine the association between mutation status and clinical features. Results A total of 198 cases were identified; 99 Arab patients and 99 Western patients. Fifty-two point seven percent of Arab patients had stage IV disease at initial presentation, 74.2% had left-sided tumors. Eighty-nine point two percent had tubular adenocarcinoma and 10.8% had mucinous adenocarcinoma. The prevalence rates of KRAS, NRAS, BRAF, PIK3CA, TP53, APC, SMAD, FBXW7 mutations in Arab population were 44.4%, 4%, 4%, 13.1%, 52.5%, 27.3%, 2% and 3% respectively. Compared to 48.4%, 4%, 4%, 12.1%, 47.5%, 24.2%, 11.1% and 0% respectively in matched Western population. Associations between these mutations and patient clinicopathological features were not statistically significant. Conclusions This is the first study to report comprehensive hotspot mutations using NGS in Arab patients with CRC. The frequency of KRAS, NRAS, BRAF, TP53, APC and PIK3CA mutations were similar to reported frequencies in Western population except SMAD4 that had a lower frequency and higher frequency of FBXW7 mutation. PMID:28078112

  12. Frequency of canine nt230(del4) MDR1 mutation in prone pure breeds, their crosses and mongrels in Israel - insights from a worldwide comparative perspective.

    Science.gov (United States)

    Dekel, Yaron; Machluf, Yossy; Stoler, Aviad; Aderet, Arava; Baumel, Daniel; Kellerman, Efrat; Plotsky, Yoram; Noked Partouche, Oshrat; Elhalal, Gal; Ben-Shlomo, Izhar; Bercovich, Dani

    2017-11-13

    Sensitivity to macrocyclic lactones, which are commonly used in veterinary clinics, was first found in Rough Collies, and was attributed in 2001 to a 4 bp deletion in the MDR1 gene. The list of affected breeds currently includes 13 breeds. Researchers from different countries and continents examined the allelic frequencies of the nt230(del4) MDR1 mutation, emphasizing the clinical importance of this test not only to mutation-prone dogs, but also to their crosses and mongrels, since treatment of a deletion carrier with these compounds may lead to its death. In this study, the allelic frequencies of nt230(del4) MDR1 mutation in affected breeds, their crosses, unrelated pure breeds and mongrels are reported for the state of Israel (n = 1416 dogs). The Israeli data were compared with reports from the US, Europe, UK, Australia and Japan. The allelic frequencies of nt230(del4) MDR1 mutation in Israel for Australian, Swiss and German Shepherds (31%, 17% and 2.4%, respectively) are similar to the corresponding frequencies worldwide, much higher for Border Collies (4.8%), twice lower for Rough Collies (28%, compared to 55% or more elsewhere), and ~1% for mongrels. The frequencies for crosses of Australian Shepherd and Border Collies in Israel are 4 and 1.6 times lower, respectively, compared to the frequencies for the respective pure breeds. This work, that for the first time presents the frequency of nt230(del4) MDR1 mutation in Israel, along with a worldwide survey, has implications for clinicians, owners and breeders of sheepdogs and their crosses and supports the need for extra care in treatment and in future breeding. Of note, the relative proportion of affected breeds, in the overall tested dogs, might be higher than their actual proportion in Israel due to directed samples collection by veterinarians for clinical purposes, as these are mainly limited to certain affected breeds or dogs that resemble them.

  13. Modification of radiation-induced sex-linked recessive lethal mutation frequency by tocopherol

    International Nuclear Information System (INIS)

    Beckman, C.; Roy, R.M.; Sproule, A.

    1982-01-01

    The present study evaluates the effect of supplementing culture medium with α-tocopherol acetate on the yield of sex-linked recessive lethal mutants induced by X-irradiation in mature sperm of Drosophila. Although tocopherol treatment of males had no impact on the yield of mutations, a drastic reduction in mutation frequency was observed when irradiated males were mated to females raised and subsequently maintained on tocopherol-enriched diet. (orig./MG)

  14. Frequency and spectrum of mutations induced by gamma irradiation in single, double and triple dwarf wheats

    International Nuclear Information System (INIS)

    Dhonukshe, B.L.

    1981-01-01

    Induced mutation studies were carried with three dwarf wheat varieties viz., ''Sonalika'', ''Chhoti Lerma'' and ''Hira'', considered to be single, double and trible dwarfs, respectively. Gamma-rays were used as a source of irradiation. Frequency of chlorophyll mutations were comparatively low and the spectrum was narrow. Chlorophyll mutations were altogether absent in the variety ''Sonalika''. A very wide spectrum of viable mutations affecting stem, leaf, ear growth habit, maturity and fertility characteristics was observed in the M 2 . The cumulative frequency of all the mutants together was quite high, which varied with the varieties. There were varietal differences in the composition and width of the spectrum induced by gamma-rays. The dwarf mutants having desirable leaf and spike characters were isolated in all the three varieties. (author)

  15. The Number of Overlapping AID Hotspots in Germline IGHV Genes Is Inversely Correlated with Mutation Frequency in Chronic Lymphocytic Leukemia.

    Science.gov (United States)

    Yuan, Chaohui; Chu, Charles C; Yan, Xiao-Jie; Bagnara, Davide; Chiorazzi, Nicholas; MacCarthy, Thomas

    2017-01-01

    The targeting of mutations by Activation-Induced Deaminase (AID) is a key step in generating antibody diversity at the Immunoglobulin (Ig) loci but is also implicated in B-cell malignancies such as chronic lymphocytic leukemia (CLL). AID has previously been shown to preferentially deaminate WRC (W = A/T, R = A/G) hotspots. WGCW sites, which contain an overlapping WRC hotspot on both DNA strands, mutate at much higher frequency than single hotspots. Human Ig heavy chain (IGHV) genes differ in terms of WGCW numbers, ranging from 4 for IGHV3-48*03 to as many as 12 in IGHV1-69*01. An absence of V-region mutations in CLL patients ("IGHV unmutated", or U-CLL) is associated with a poorer prognosis compared to "IGHV mutated" (M-CLL) patients. The reasons for this difference are still unclear, but it has been noted that particular IGHV genes associate with U-CLL vs M-CLL. For example, patients with IGHV1-69 clones tend to be U-CLL with a poor prognosis, whereas patients with IGHV3-30 tend to be M-CLL and have a better prognosis. Another distinctive feature of CLL is that ~30% of (mostly poor prognosis) patients can be classified into "stereotyped" subsets, each defined by HCDR3 similarity, suggesting selection, possibly for a self-antigen. We analyzed >1000 IGHV genes from CLL patients and found a highly significant statistical relationship between the number of WGCW hotspots in the germline V-region and the observed mutation frequency in patients. However, paradoxically, this correlation was inverse, with V-regions with more WGCW hotspots being less likely to be mutated, i.e., more likely to be U-CLL. The number of WGCW hotspots in particular, are more strongly correlated with mutation frequency than either non-overlapping (WRC) hotspots or more general models of mutability derived from somatic hypermutation data. Furthermore, this correlation is not observed in sequences from the B cell repertoires of normal individuals and those with autoimmune diseases.

  16. Detection of MPLW515L/K mutations and determination of allele frequencies with a single-tube PCR assay.

    Science.gov (United States)

    Takei, Hiraku; Morishita, Soji; Araki, Marito; Edahiro, Yoko; Sunami, Yoshitaka; Hironaka, Yumi; Noda, Naohiro; Sekiguchi, Yuji; Tsuneda, Satoshi; Ohsaka, Akimichi; Komatsu, Norio

    2014-01-01

    A gain-of-function mutation in the myeloproliferative leukemia virus (MPL) gene, which encodes the thrombopoietin receptor, has been identified in patients with essential thrombocythemia and primary myelofibrosis, subgroups of classic myeloproliferative neoplasms (MPNs). The presence of MPL gene mutations is a critical diagnostic criterion for these diseases. Here, we developed a rapid, simple, and cost-effective method of detecting two major MPL mutations, MPLW515L/K, in a single PCR assay; we termed this method DARMS (dual amplification refractory mutation system)-PCR. DARMS-PCR is designed to produce three different PCR products corresponding to MPLW515L, MPLW515K, and all MPL alleles. The amplicons are later detected and quantified using a capillary sequencer to determine the relative frequencies of the mutant and wild-type alleles. Applying DARMS-PCR to human specimens, we successfully identified MPL mutations in MPN patients, with the exception of patients bearing mutant allele frequencies below the detection limit (5%) of this method. The MPL mutant allele frequencies determined using DARMS-PCR correlated strongly with the values determined using deep sequencing. Thus, we demonstrated the potential of DARMS-PCR to detect MPL mutations and determine the allele frequencies in a timely and cost-effective manner.

  17. Detection of MPLW515L/K mutations and determination of allele frequencies with a single-tube PCR assay.

    Directory of Open Access Journals (Sweden)

    Hiraku Takei

    Full Text Available A gain-of-function mutation in the myeloproliferative leukemia virus (MPL gene, which encodes the thrombopoietin receptor, has been identified in patients with essential thrombocythemia and primary myelofibrosis, subgroups of classic myeloproliferative neoplasms (MPNs. The presence of MPL gene mutations is a critical diagnostic criterion for these diseases. Here, we developed a rapid, simple, and cost-effective method of detecting two major MPL mutations, MPLW515L/K, in a single PCR assay; we termed this method DARMS (dual amplification refractory mutation system-PCR. DARMS-PCR is designed to produce three different PCR products corresponding to MPLW515L, MPLW515K, and all MPL alleles. The amplicons are later detected and quantified using a capillary sequencer to determine the relative frequencies of the mutant and wild-type alleles. Applying DARMS-PCR to human specimens, we successfully identified MPL mutations in MPN patients, with the exception of patients bearing mutant allele frequencies below the detection limit (5% of this method. The MPL mutant allele frequencies determined using DARMS-PCR correlated strongly with the values determined using deep sequencing. Thus, we demonstrated the potential of DARMS-PCR to detect MPL mutations and determine the allele frequencies in a timely and cost-effective manner.

  18. Experiences from treatment-predictive KRAS testing; high mutation frequency in rectal cancers from females and concurrent mutations in the same tumor

    DEFF Research Database (Denmark)

    Jönsson, Mats; Ekstrand, Anna; Edekling, Thomas

    2009-01-01

    . METHODS: We used a real-time PCR based method to determine KRAS mutations in 136 colorectal cancers with mutations identified in 53 (39%) tumors. RESULTS: KRAS mutations were significantly more often found in rectal cancer (21/38, 55%) than in colon cancer (32/98, 33%) (P = 0.02). This finding...... was explained by marked differences mutation rates in female patients who showed mutations in 33% of the colon cancers and in 67% of the rectal cancers (P = 0.01). Concurrent KRAS mutations were identified in three tumors; two colorectal cancers harbored Gly12Asp/Gly13Asp and Gly12Cys/Gly13Asp and a third tumor...... carried Gly12Cys/Gly12Asp in an adenomatous component and additionally acquired Gly12Val in the invasive component. CONCLUSION: The demonstration of a particularly high KRAS mutation frequency among female rectal cancer patients suggests that this subset is the least likely to respond to anti...

  19. Mutation frequencies of the cytochrome CYP2D6 gene in Parkinson disease patients and in families

    Energy Technology Data Exchange (ETDEWEB)

    Lucotte, G.; Turpin, J.C. [CHR, Reims (France); Gerard, N. [INSERM, Paris (France)] [and others

    1996-07-26

    The frequencies of five mutations of the debrisoquine 4-hydroxylase (CYP2D6) gene (mutations D6-A, B, C, D, and T), corresponding to poor metabolizer (PM) phenotypes, were determined by restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR) in 47 patients with Parkinson disease, and compared with the findings in 47 healthy controls. These mutant alleles were about twice as frequent among patients as in controls, with an approximate relative risk ratio of 2.12 (95% confidence interval, 1.41-2.62). There seem to be no significant differences in frequencies of mutant genotypes in patients among gender and modalities of response with levodopa therapy; but frequency of the mutations was slightly enhanced after age-at-onset of 60 years. Mutations D6-B, D, and T were detected in 7 patients belonging to 10 Parkinson pedigrees. 25 refs., 1 fig., 2 tabs.

  20. Assessing the contribution of the herpes simplex virus DNA polymerase to spontaneous mutations

    Directory of Open Access Journals (Sweden)

    Leary Jeffry J

    2002-05-01

    Full Text Available Abstract Background The thymidine kinase (tk mutagenesis assay is often utilized to determine the frequency of herpes simplex virus (HSV replication-mediated mutations. Using this assay, clinical and laboratory HSV-2 isolates were shown to have a 10- to 80-fold higher frequency of spontaneous mutations compared to HSV-1. Methods A panel of HSV-1 and HSV-2, along with polymerase-recombinant viruses expressing type 2 polymerase (Pol within a type 1 genome, were evaluated using the tk and non-HSV DNA mutagenesis assays to measure HSV replication-dependent errors and determine whether the higher mutation frequency of HSV-2 is a distinct property of type 2 polymerases. Results Although HSV-2 have mutation frequencies higher than HSV-1 in the tk assay, these errors are assay-specific. In fact, wild type HSV-1 and the antimutator HSV-1 PAAr5 exhibited a 2–4 fold higher frequency than HSV-2 in the non-HSV DNA mutatagenesis assay. Furthermore, regardless of assay, HSV-1 recombinants expressing HSV-2 Pol had error rates similar to HSV-1, whereas the high mutator virus, HSV-2 6757, consistently showed signficant errors. Additionally, plasmid DNA containing the HSV-2 tk gene, but not type 1 tk or LacZ DNA, was shown to form an anisomorphic DNA stucture. Conclusions This study suggests that the Pol is not solely responsible for the virus-type specific differences in mutation frequency. Accordingly, it is possible that (a mutations may be modulated by other viral polypeptides cooperating with Pol, and (b the localized secondary structure of the viral genome may partially account for the apparently enhanced error frequency of HSV-2.

  1. The spontaneous chlorophyll mutation frequency in barley

    DEFF Research Database (Denmark)

    Jørgensen, Jørgen Helms; Jensen, Hans Peter

    1986-01-01

    A total of 1866 barley plants were progeny tested in the greenhouse. Twenty-five plants segregated for newly arisen, spontaneous chlorophyll mutant genes. Among the total of 470,129 seedlings screened there were 79 mutants (1.7 .+-. 0.6 .times. 10-4). The data are added to data from three similar...... materials and the resulting estimate of the chlorophyll mutant frequency is 1.6 .times. 10-4 in about 1.43 million seedlings. The estimate of the chlorophyll mutation rate per generation is close to 67.3 .times. 10-4 per diploid genome or in the order of 6 .times. 10-7 per locus and haploid genome....

  2. Mutation induction by ion beams in plants

    International Nuclear Information System (INIS)

    Tanaka, Atsushi

    2001-01-01

    The effect of ion beams such as C, He, and Ne ions was investigated on the mutation induction in plants with the expectation that ion beams of high linear energy transfer (LET) can frequently produce large DNA alternation such as inversion, translocation and large deletion rather than point mutation. Mutation frequency was investigated using Arabidopsis visible phenotype loci and was 8 to 33 fold higher for 220 MeV carbon ions than for electrons. Mutation spectrum was investigated on the flower color of chrysanthemum cv to find that flower mutants induced by ion beams show complex and stripe types rather than single color. Polymerase chain reaction analysis was performed to investigate DNA alteration of mutations. In conclusion, the characteristics of ion beams for the mutation induction are 1) high frequency, 2) broad mutation spectrum, and 3) novel mutants. (S. Ohno)

  3. Mutation induction by ion beams in plants

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Atsushi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2001-03-01

    The effect of ion beams such as C, He, and Ne ions was investigated on the mutation induction in plants with the expectation that ion beams of high linear energy transfer (LET) can frequently produce large DNA alternation such as inversion, translocation and large deletion rather than point mutation. Mutation frequency was investigated using Arabidopsis visible phenotype loci and was 8 to 33 fold higher for 220 MeV carbon ions than for electrons. Mutation spectrum was investigated on the flower color of chrysanthemum cv to find that flower mutants induced by ion beams show complex and stripe types rather than single color. Polymerase chain reaction analysis was performed to investigate DNA alteration of mutations. In conclusion, the characteristics of ion beams for the mutation induction are 1) high frequency, 2) broad mutation spectrum, and 3) novel mutants. (S. Ohno)

  4. HFE gene C282Y, H63D and S65C mutations frequency in the Transylvania region, Romania.

    Science.gov (United States)

    Trifa, Adrian P; Popp, Radu A; Militaru, Mariela S; Farcaş, Marius F; Crişan, Tania O; Gana, Ionuţ; Cucuianu, Andrei; Pop, Ioan V

    2012-06-01

    HFE-associated haemochromatosis is one of the most frequent autosomal recessive disorders in the Caucasian population. Although most of the cases are homozygous individuals for the C282Y mutation, another two mutations, H63D and S65C, have been reported to be associated with milder forms of the disease. This study was a first attempt to evaluate the distribution of these HFE gene mutations in the Transylvania region. Two-hundred and twenty-five healthy, unrelated volunteers originating from the Transylvania region, Romania, were screened for the HFE gene C282Y, H63D and S65C mutations, using molecular genetics assays (Polymerase Chain Reaction-Restriction Fragments Length Polymorphism). For the C282Y mutation, 7 heterozygotes (3.1%) were found, but no homozygous individual. In the case of the H63D mutation, 40 heterozygotes (17.8%) and 4 homozygotes (1.75%) for the mutant allele were evidenced. We found a compound heterozygous genotype (C282Y/H63D) in one individual (0.45%). Thus, the allele frequencies of the C282Y and H63D were 1.75% and 10.9%, respectively. Three individuals (1.3%) were found to harbour the S65C mutation in a heterozygous state, but none in a homozygous state: the allele frequency of the mutant allele was 0.75%. The distribution of the HFE gene C282Y, H63D and S65C mutations found in our group matches the tendencies observed in other European countries: a decreasing gradient from Northern to Southern Europe for the C282Y mutation; high frequency for the H63D mutation, and low frequency for the S65C mutation in most of the countries.

  5. Frequency of BRAF V600E Mutation in the Mexican Population of Patients With Metastatic Melanoma

    Directory of Open Access Journals (Sweden)

    Erika Ruiz-Garcia

    2017-06-01

    Full Text Available Purpose: The BRAF V600E mutation has been described in melanomas occurring in the Caucasian, European, and Asian populations. However, in the Mexican population, the status and clinical significance of BRAF mutation has not been researched on a large scale. Methods: Consecutive BRAF-tested Mexican patients with metastatic melanoma (n = 127 were analyzed for mutations in exon 15 of the BRAF gene in genomic DNA by real-time polymerase chain reaction technology for amplification and detection. The results were correlated with the clinical-pathologic features and the prognosis of the patients. Results: The frequency of somatic mutation V600E within the BRAF gene was 54.6% (43 of 127 patients. Nodular melanoma was the most prevalent subtype in our population, with BRAF mutations in 37.2% (16 of 55 patients. In contrast, superficial spread had a frequency of 18.6% BRAF mutation (eight of 24. Other clinicopathologic features were assessed to correlate with the mutation status. Conclusion: This study searched for the most prevalent BRAF V600E mutation type in melanoma in a heterogeneous population from Mexico. Nodular melanoma was found to be the most prevalent in metastatic presentation and the presence of BRAF V600E mutation, perhaps related to the mixed ancestry; in the north, ancestry is predominantly European and in the south, it is predominantly Asian. The outcomes of the mutation correlations were similar to those found in other populations.

  6. Identification of a novel mutation in WFS1 in a family affected by low-frequency hearing impairment

    Energy Technology Data Exchange (ETDEWEB)

    Kunz, Juergen; Marquez-Klaka, Ben; Uebe, Steffen; Volz-Peters, Anja; Berger, Roswitha; Rausch, Peter

    2003-04-09

    Previously we confirmed linkage of autosomal dominantly inherited low-frequency sensorineural hearing impairment (LFSNHI) in a German family to the genetic locus DFNA6/DFNA14 on chromosome 4p16.3 close to the markers D4S432 and D4S431. Analysis of data from the Human Genome Project, showed that WFS1 is located in this region. Mutations in WFS1 are known to be responsible for Wolfram syndrome (DIDMOAD, MIM no. 606201), which follows an autosomal recessive trait. Studies in low-frequency hearing loss families showed that mutations in WFS1 were responsible for the phenotype. In all affected family members analysed, we detected a missense mutation in WFS1 (K705N) and therefore confirm the finding that the majority of mutations responsible for LFSNHI are missense mutations which localise to the C-terminal domain of the protein.

  7. Identification of a novel mutation in WFS1 in a family affected by low-frequency hearing impairment

    International Nuclear Information System (INIS)

    Kunz, Juergen; Marquez-Klaka, Ben; Uebe, Steffen; Volz-Peters, Anja; Berger, Roswitha; Rausch, Peter

    2003-01-01

    Previously we confirmed linkage of autosomal dominantly inherited low-frequency sensorineural hearing impairment (LFSNHI) in a German family to the genetic locus DFNA6/DFNA14 on chromosome 4p16.3 close to the markers D4S432 and D4S431. Analysis of data from the Human Genome Project, showed that WFS1 is located in this region. Mutations in WFS1 are known to be responsible for Wolfram syndrome (DIDMOAD, MIM no. 606201), which follows an autosomal recessive trait. Studies in low-frequency hearing loss families showed that mutations in WFS1 were responsible for the phenotype. In all affected family members analysed, we detected a missense mutation in WFS1 (K705N) and therefore confirm the finding that the majority of mutations responsible for LFSNHI are missense mutations which localise to the C-terminal domain of the protein

  8. Frequency of mutations in the genes associated with hereditary sensory and autonomic neuropathy in a UK cohort.

    LENUS (Irish Health Repository)

    Davidson, G L

    2012-08-01

    The hereditary sensory and autonomic neuropathies (HSAN, also known as the hereditary sensory neuropathies) are a clinically and genetically heterogeneous group of disorders, characterised by a progressive sensory neuropathy often complicated by ulcers and amputations, with variable motor and autonomic involvement. To date, mutations in twelve genes have been identified as causing HSAN. To study the frequency of mutations in these genes and the associated phenotypes, we screened 140 index patients in our inherited neuropathy cohort with a clinical diagnosis of HSAN for mutations in the coding regions of SPTLC1, RAB7, WNK1\\/HSN2, FAM134B, NTRK1 (TRKA) and NGFB. We identified 25 index patients with mutations in six genes associated with HSAN (SPTLC1, RAB7, WNK1\\/HSN2, FAM134B, NTRK1 and NGFB); 20 of which appear to be pathogenic giving an overall mutation frequency of 14.3%. Mutations in the known genes for HSAN are rare suggesting that further HSAN genes are yet to be identified. The p.Cys133Trp mutation in SPTLC1 is the most common cause of HSAN in the UK population and should be screened first in all patients with sporadic or autosomal dominant HSAN.

  9. Frequency of mutations in the genes associated with hereditary sensory and autonomic neuropathy in a UK cohort.

    Science.gov (United States)

    Davidson, G L; Murphy, S M; Polke, J M; Laura, M; Salih, M A M; Muntoni, F; Blake, J; Brandner, S; Davies, N; Horvath, R; Price, S; Donaghy, M; Roberts, M; Foulds, N; Ramdharry, G; Soler, D; Lunn, M P; Manji, H; Davis, M B; Houlden, H; Reilly, M M

    2012-08-01

    The hereditary sensory and autonomic neuropathies (HSAN, also known as the hereditary sensory neuropathies) are a clinically and genetically heterogeneous group of disorders, characterised by a progressive sensory neuropathy often complicated by ulcers and amputations, with variable motor and autonomic involvement. To date, mutations in twelve genes have been identified as causing HSAN. To study the frequency of mutations in these genes and the associated phenotypes, we screened 140 index patients in our inherited neuropathy cohort with a clinical diagnosis of HSAN for mutations in the coding regions of SPTLC1, RAB7, WNK1/HSN2, FAM134B, NTRK1 (TRKA) and NGFB. We identified 25 index patients with mutations in six genes associated with HSAN (SPTLC1, RAB7, WNK1/HSN2, FAM134B, NTRK1 and NGFB); 20 of which appear to be pathogenic giving an overall mutation frequency of 14.3%. Mutations in the known genes for HSAN are rare suggesting that further HSAN genes are yet to be identified. The p.Cys133Trp mutation in SPTLC1 is the most common cause of HSAN in the UK population and should be screened first in all patients with sporadic or autosomal dominant HSAN.

  10. AIP mutations and gigantism.

    Science.gov (United States)

    Rostomyan, Liliya; Potorac, Iulia; Beckers, Pablo; Daly, Adrian F; Beckers, Albert

    2017-06-01

    AIP mutations are rare in sporadic acromegaly but they are seen at a higher frequency among certain specific populations of pituitary adenoma patients (pituitary gigantism cases, familial isolated pituitary adenoma (FIPA) kindreds, and patients with macroadenomas who are diagnosed ≤30 years). AIP mutations are most prevalent in patients with pituitary gigantism (29% of this group were found to have mutations in AIP gene). These data support targeted genetic screening for AIP mutations/deletions in these groups of pituitary adenoma patients. Earlier diagnosis of AIP-related acromegaly-gigantism cases enables timely clinical evaluation and treatment, thereby improving outcomes in terms of excessive linear growth and acromegaly comorbidities. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  11. Induced micro-mutations in rice - the frequency and spectrum of gamma ray induced height variations in rice variety-Jaya

    International Nuclear Information System (INIS)

    Nair, N.K.; Ninan, C.A.

    1975-01-01

    Seeds of rice variety, Jaya, treated with moderate doses of (10, 20 and 30 kR) gamma rays were subjected to study the relative magnitude of induced variability and the type of mutations induced for height of plant in M 2 and M 3 generations. Progenies of 3352 M 1 spikes, totalling to 35691 M 2 plants and their subsequent progenies in M 3 were analysed. To get wider variability, very large populations in all the generations were studied. The mean value, genetic variance and phenotypic frequency distribution with and between generations were studied. The treated population showed no significant shift in mean values from that of control. The variance was greater in the irradiated material compared to control. The variability was found to shift in both plus and minus direction from that of control with a higher frequency in the minus direction in M 2 . A high frequency of dwarf mutants was observed in 20 kR treated population in the M 2 generation. The segregation ratio was higher in M 2 compared to M 3 generation. (author)

  12. Frequency of factor V Leiden mutation

    International Nuclear Information System (INIS)

    Nasiruddin; Ali, W.; Rehman, Z.; Anwar, M.; Ayyub, M.; Ali, W.; Ahmed, S.

    2005-01-01

    Objective: To determine the frequency of factor V Leiden mutation. Design: Observational study. Patients and Methods: Two hundred subjects each of apparently healthy and unrelated Punjabi and Pathan origins were included in the study. Peripheral blood samples were collected in EDTA and DNA extracted by phenol- chloroform extraction method. DNA analysis was done by PCR for restriction fragment length polymorphism. The product was digested overnight with Mn/1 and electrophoresed on acrylamide gel to detect 67 and 153 base pair fragments of factor V Leiden against 37, 67 and 116 base pair fragments of normal factor V. Results: In the 400 subjects studied, only 5 cases of heterozygotes for factor V Leiden were detected. The overall carrier rate was 1.3% (95% CI 0.2-2.2%). The carrier rate in Punjabis and Pathans was 1 % and 1.5% respectively. Conclusion: This study confirms that the prevalence of factor V Leiden is low in Asians and Africans as compared to the European population. (author)

  13. Combination of the mutation process with the sensitization and repair processes leading to increased frequencies of mutations in algal populations

    International Nuclear Information System (INIS)

    Necas, J.

    1977-01-01

    The possibility of combining the mutation process with the induction of the repair processes was studied to increase the mutation frequencies in algal populations after UV treatment. The repair process induced by visible light was found to be much more effective than the dark repair processes in the chlorococcal algae used. In these algae, visible light possibly does not induce only those repair processes which affect their DNA, but probably also certain recovery processes which affect their damaged structures and physiological functions. A suitable combination of the sensitization of algae cells by a DNA-base analogue before UV treatment and the induction of the light repair and recovery processes resulted in a rather high increase of viable mutations in chlorococcal algae. These findings may be useful in breeding chlorococcal algae, which have no possibility of hybridization other than somatic. (author)

  14. Effect of Ku80 deficiency on mutation frequencies and spectra at a LacZ reporter locus in mouse tissues and cells.

    Directory of Open Access Journals (Sweden)

    Rita A Busuttil

    Full Text Available Non-homologous end joining (NHEJ is thought to be an important mechanism for preventing the adverse effects of DNA double strand breaks (DSBs and its absence has been associated with premature aging. To investigate the effect of inactivated NHEJ on spontaneous mutation frequencies and spectra in vivo and in cultured cells, we crossed a Ku80-deficient mouse with mice harboring a lacZ-plasmid-based mutation reporter. We analyzed various organs and tissues, as well as cultured embryonic fibroblasts, for mutations at the lacZ locus. When comparing mutant with wild-type mice, we observed a significantly higher number of genome rearrangements in liver and spleen and a significantly lower number of point mutations in liver and brain. The reduced point mutation frequency was not due to a decrease in small deletion mutations thought to be a hallmark of NHEJ, but could be a consequence of increased cellular responses to unrepaired DSBs. Indeed, we found a substantial increase in persistent 53BP1 and gammaH2AX DNA damage foci in Ku80-/- as compared to wild-type liver. Treatment of cultured Ku80-deficient or wild-type embryonic fibroblasts, either proliferating or quiescent, with hydrogen peroxide or bleomycin showed no differences in the number or type of induced genome rearrangements. However, after such treatment, Ku80-deficient cells did show an increased number of persistent DNA damage foci. These results indicate that Ku80-dependent repair of DNA damage is predominantly error-free with the effect of alternative more error-prone pathways creating genome rearrangements only detectable after extended periods of time, i.e., in young adult animals. The observed premature aging likely results from a combination of increased cellular senescence and an increased load of stable, genome rearrangements.

  15. HFE H63D mutation frequency shows an increase in Turkish women with breast cancer

    Directory of Open Access Journals (Sweden)

    Guler Emine

    2006-02-01

    Full Text Available Abstract Background The hereditary hemochromatosis gene HFE plays a pivotal role in iron homeostasis. The association between cancer and HFE hetero- or homozygosity has previously been shown including hepatocellular and nonhepatocellular malignancies. This study was performed to compare frequencies of HFE C282Y and H63D variants in Turkish women with breast cancer and healthy controls. Methods Archived DNA samples of Hacettepe University Oncology Institute were used in this study. The HFE gene was investigated by PCR-RFLP. Results All subjects studied were free from C282Y mutation. Thirty-nine patients had H63D mutation and were all heterozygous. H63D allele frequency was 22.2% (39/176 in the breast cancer patients, and 14% (28/200 in the healthy volunteers. Statistical analysis of cases with HFE H63D phenotype showed significant difference between breast cancer and healthy volunteers (P = 0.02. Conclusion Our results suggest that HFE H63D mutation frequencies were increased in the breast cancer patients in comparison to those in the general population. Also, odds ratios (odds ratio = 2.05 computed in this study suggest that H63D has a positive association with breast cancer.

  16. Normosmic congenital hypogonadotropic hypogonadism due to TAC3/TACR3 mutations: characterization of neuroendocrine phenotypes and novel mutations.

    Directory of Open Access Journals (Sweden)

    Bruno Francou

    Full Text Available CONTEXT: TAC3/TACR3 mutations have been reported in normosmic congenital hypogonadotropic hypogonadism (nCHH (OMIM #146110. In the absence of animal models, studies of human neuroendocrine phenotypes associated with neurokinin B and NK3R receptor dysfunction can help to decipher the pathophysiology of this signaling pathway. OBJECTIVE: To evaluate the prevalence of TAC3/TACR3 mutations, characterize novel TACR3 mutations and to analyze neuroendocrine profiles in nCHH caused by deleterious TAC3/TACR3 biallelic mutations. RESULTS: From a cohort of 352 CHH, we selected 173 nCHH patients and identified nine patients carrying TAC3 or TACR3 variants (5.2%. We describe here 7 of these TACR3 variants (1 frameshift and 2 nonsense deleterious mutations and 4 missense variants found in 5 subjects. Modeling and functional studies of the latter demonstrated the deleterious consequence of one missense mutation (Tyr267Asn probably caused by the misfolding of the mutated NK3R protein. We found a statistically significant (p<0.0001 higher mean FSH/LH ratio in 11 nCHH patients with TAC3/TACR3 biallelic mutations than in 47 nCHH patients with either biallelic mutations in KISS1R, GNRHR, or with no identified mutations and than in 50 Kallmann patients with mutations in KAL1, FGFR1 or PROK2/PROKR2. Three patients with TAC3/TACR3 biallelic mutations had an apulsatile LH profile but low-frequency alpha-subunit pulses. Pulsatile GnRH administration increased alpha-subunit pulsatile frequency and reduced the FSH/LH ratio. CONCLUSION: The gonadotropin axis dysfunction associated with nCHH due to TAC3/TACR3 mutations is related to a low GnRH pulsatile frequency leading to a low frequency of alpha-subunit pulses and to an elevated FSH/LH ratio. This ratio might be useful for pre-screening nCHH patients for TAC3/TACR3 mutations.

  17. [Frequency of the most common mutations of the CFTR gene in peruvian patients with cystic fibrosis using the ARMS-PCR technique].

    Science.gov (United States)

    Aquino, Ruth; Protzel, Ana; Rivera, Juan; Abarca, Hugo; Dueñas, Milagros; Nestarez, Cecilia; Purizaga, Nestor; Diringer, Benoit

    2017-01-01

    To determine the frequency of the ten most common mutations of the CFTR gene reported in Latin Americausing amplification-refractory mutation system-polymerase chain reaction (ARMS-PCR) in patients with cystic fibrosis (CF) in two referral hospitals in Peru during the year 2014. The frequency of the ten most common mutations of the CFTR gene was assessed in patients of the Hospital Nacional Edgardo Rebagliati Martins and the Instituto Nacional de Salud del Niño, both located in Lima, Peru. Blood samples were collected from 36 patients with CF, and the ARMS-PCR technique was used to determine the presence of these mutations. The study group included 73.5% of patients with a known diagnosis of CF in the country when the study was carried out. ARMS-PCR allowed three of the mutations to be identified in a combined 30.6% of the alleles from patients with CF, and 64.9% of the mutated alleles were not identified. The mutations found were p.Phe508del (22,2%), p.Gly542* (6,9%), and p.Arg1162* (1,4%). There is significant variability in both the frequency and type of mutations present in our study population and in what has been reported in other Latin American countries. It is necessary to perform studies that use complete sequencing technology for the CFTR gene to identify other mutations present in our population.

  18. The directed mutation controversy and neo-Darwinism.

    Science.gov (United States)

    Lenski, R E; Mittler, J E

    1993-01-08

    According to neo-Darwinian theory, random mutation produces genetic differences among organisms whereas natural selection tends to increase the frequency of advantageous alleles. However, several recent papers claim that certain mutations in bacteria and yeast occur at much higher rates specifically when the mutant phenotypes are advantageous. Various molecular models have been proposed that might explain these directed mutations, but the models have not been confirmed. Critics contend that studies purporting to demonstrate directed mutation lack certain controls and fail to account adequately for population dynamics. Further experiments that address these criticisms do not support the existence of directed mutations.

  19. Frequency of Somatic TP53 Mutations in Combination with Known Pathogenic Mutations in Colon Adenocarcinoma, Non–Small Cell Lung Carcinoma, and Gliomas as Identified by Next-Generation Sequencing

    Directory of Open Access Journals (Sweden)

    Zahra Shajani-Yi

    2018-03-01

    Full Text Available The tumor suppressor gene TP53 is the most frequently mutated gene in human cancer. It encodes p53, a DNA-binding transcription factor that regulates multiple genes involved in DNA repair, metabolism, cell cycle arrest, apoptosis, and senescence. TP53 is associated with human cancer by mutations that lead to a loss of wild-type p53 function as well as mutations that confer alternate oncogenic functions that enable them to promote invasion, metastasis, proliferation, and cell survival. Identifying the discrete TP53 mutations in tumor cells may help direct therapies that are more effective. In this study, we identified the frequency of individual TP53 mutations in patients with colon adenocarcinoma (48%, non–small cell lung carcinoma (NSCLC (36%, and glioma/glioblastoma (28% at our institution using next-generation sequencing. We also identified the occurrence of somatic mutations in numerous actionable genes including BRAF, EGFR, KRAS, IDH1, and PIK3CA that occurred concurrently with these TP53 mutations. Of the 480 tumors examined that contained one or more mutations in the TP53 gene, 219 were colon adenocarcinomas, 215 were NSCLCs, and 46 were gliomas/glioblastomas. Among the patients positive for TP53 mutations diagnosed with colon adenocarcinoma, 50% also showed at least one mutation in pathogenic genes of which 14% were BRAF, 33% were KRAS, and 3% were NRAS. Forty-seven percent of NSCLC patients harboring TP53 mutations also had a mutation in at least one actionable pathogenic variant with the following frequencies: BRAF: 4%, EGFR: 10%, KRAS: 28%, and PIK3CA: 4%. Fifty-two percent of patients diagnosed with glioma/glioblastoma with a positive TP53 mutation had at least one concurrent mutation in a known pathogenic gene of which 9% were CDKN2A, 41% were IDH1, and 11% were PIK3CA.

  20. Modification of UV-induced mutation frequencies in Chinese hamster- cells by dose fractionation, cycloheximide and caffeine treatments

    International Nuclear Information System (INIS)

    Chang, C.-C.; Schultz, R.; Trosko, J.E.; D'Ambrosio, S.M.; Setlow, R.B.

    1978-01-01

    Chinese hamster (V79) cells were irradiated with a fractionated regime of ultraviolet light (UV 1 +UV 2 ). The fractionation of a UV dose always increased the colony-forming ability but reduced (or it did not change) the mutation frequencies. Treatment with cycloheximide between the two UV irradiations resulted in two types of effects, depending on the protocols used. Long exposures to cycloheximide (i.e., >6h) for the entire period between UV 1 and UV 2 or partial treatment of cycloheximide (i.e., 3h) long before UV 2 always resulted in reduced colony-forming ability and enhanced or unchanged mutation frequencies. Exposure to cycloheximide for the entire period in the short fractionated regime (i.e., 4h) between UV 1 and UV 2 or partial treatment of cycloheximide just prior to UV 2 tended to give the opposite effects. Caffeine treatment before UV 2 , with or without UV 1 , significantly increased the mutation frequencies. These results suggest that an error-free postreplication repair system exists in Chinese hamster cells which is inhibitable by particular cycloheximide or caffeine treatments. (Auth.)

  1. Microsatellite frequencies vary with body mass and body temperature in mammals, suggesting correlated variation in mutation rate

    Directory of Open Access Journals (Sweden)

    William Amos

    2014-11-01

    Full Text Available Substitution rate is often found to correlate with life history traits such as body mass, a predictor of population size and longevity, and body temperature. The underlying mechanism is unclear but most models invoke either natural selection or factors such as generation length that change the number of mutation opportunities per unit time. Here we use published genome sequences from 69 mammals to ask whether life history traits impact another form of genetic mutation, the high rates of predominantly neutral slippage in microsatellites. We find that the length-frequency distributions of three common dinucleotide motifs differ greatly between even closely related species. These frequency differences correlate with body mass and body temperature and can be used to predict the phenotype of an unknown species. Importantly, different length microsatellites show complicated patterns of excess and deficit that cannot be explained by a simple model where species with short generation lengths have experienced more mutations. Instead, the patterns probably require changes in mutation rate that impact alleles of different length to different extents. Body temperature plausibly influences mutation rate by modulating the propensity for slippage. Existing hypotheses struggle to account for a link between body mass and mutation rate. However, body mass correlates inversely with population size, which in turn predicts heterozygosity. We suggest that heterozygote instability, HI, the idea that heterozygous sites show increased mutability, could provide a plausible link between body mass and mutation rate.

  2. Flow-cytometric measurements of somatic cell mutations in Thorotrast patients

    International Nuclear Information System (INIS)

    Umeki, Shigeko; Kyoizumi, Seishi; Kusunoki, Yoichiro; Nakamura, Nori; Sasaki, Masao; Mori, Takesaburo; Ishikawa, Yuichi; Cologne, J.B.; Akiyama, Mitoshi.

    1992-10-01

    Exposure to ionizing radiation is a well-recognized risk factor for cancer development. Because ionizing radiation can induce mutations, an accurate way of measuring somatic mutation frequencies could be a useful tool for evaluating cancer risk. In the present study, we have examined in vivo somatic mutation frequencies at the erythrocyte glycophorin A and T-cell receptor loci in 18 Thorotrast patients. These persons have been continuously irradiated with alpha particles emitted from the internal deposition of thorium dioxide and thus have increased risks of certain malignant tumors. When compared with controls, the Thorotrast patients showed a significantly higher frequency of mutants at the lymphocyte T-cell receptor loci but not at the erythrocyte glycophorin A loci. (author)

  3. Mutation breeding of autotetraploid Achimenes cultivars

    International Nuclear Information System (INIS)

    Broertjes, C.

    1976-01-01

    Colchicine-induced autotetraploids of three Achimenes cultivars were irradiated with X-rays or fast neutrons. The results were compared, in one cultivar, with those of the irradiated diploid form. The mutation frequency after irradiation of the autotetraploid was a 20-40 fold higher as compared to the corresponding diploid. These results may open new possibilities for mutation breeding, though they are hard to explain. Several promising mutants were selected. (author)

  4. The Frequency of c.550delA Mutation of the CANP3 Gene in the Polish LGMD2A Population.

    Science.gov (United States)

    Dorobek, Małgorzata; Ryniewicz, Barbara; Kabzińska, Dagmara; Fidziańska, Anna; Styczyńska, Maria; Hausmanowa-Petrusewicz, Irena

    2015-11-01

    Limb girdle muscular dystrophy 2A (LGMD2A) is the most frequent LGMD variant in the European population, representing about 40% of LGMD. The c.550delA mutation in the CANP3 (calcium activated neutral protease 3) gene is the most commonly reported mutation in LGMD2A. Prevalence of this mutation in the Polish population has not been previously investigated. The aim of this study was to identify and estimate the frequency of the c.550delA mutation in Polish LGMD2A patients. Polymerase chain reaction-sequencing analysis, restriction fragment length polymorphism polymerase chain reaction method. We analyzed 76 families affected with LGMD and identified 62 probands with mutations in the CANP3 gene. C.550delA was the most common mutation identified, being found in 78% of the LGMD2A families. The remaining mutations observed multiple times were as follows: c.598-612del15ntd; c.2242C>T; c.418dupC; c.1356insT, listed in terms of decreasing frequency. Two novel variants in the CANP3 gene, that is, c.700G>A Gly234Arg and c.661G>A Gly221Ser were also characterized. Overall, mutations in the LGMD2A gene were estimated to be present in 81% of patients with the LGMD phenotype who were without sarcoglycans and dysferlin deficiency on immunocytochemical analysis. The frequency of the heterozygous c.550delA mutation in the healthy Polish population was estimated at 1/124. The c.550delA is the most frequent CANP3 mutation in the Polish population, thus sequencing of exon 4 of this gene could identify the majority of LGMD2A patients in Poland.

  5. Radiation-induced mutations in sweet cherry (Prunus avium L.)

    Energy Technology Data Exchange (ETDEWEB)

    Saamin, S [Cocoa and Coconut Research Division, Malaysian Agricultural Research and Development Institute (Malaysia); Thompson, M M [Department of Horticulture, Oregon State University, Corvallis, OR (United States)

    1989-01-01

    Full text: Dormant scions of 'Bing' were exposed to 1-2.5 kR gamma radiation. The main buds were excised and the scions grafted to allow the growth of accessory buds into primary shoots. The frequency and types of mutations were described in a population of 3307 M{sub 1}V{sub 2} shoot. The overall mutation frequency was 2.7% incl. 0.15% growth-reduced mutants. The experiment was repeated using 3kR and 4kR fractionated doses in water. Differences in mutation frequency at 3kR and 4kR were not significant. Of 2765 surviving M{sub 1}V{sub 2} shoots derived from irradiation of accessory buds of both standard and V{sub 1} shoots, the overall mutation frequency was 3.3% incl. 1.7% partial leaf mutants, 1.0% leaf mutants, and 0.54% growth-reduced mutants. For maximum mutation rate with adequate survival we suggest acute irradiation of accessory buds in air at dosages approximating LD50. Mutant sectors in M{sub 1}V{sub 1} shoots derived from accessory buds are larger than those from main buds, as revealed by the higher number of mutant repeats. (author)

  6. [Mutational frequencies in usherin(USH2A gene) in 26 Colombian individuals with Usher syndrome type II].

    Science.gov (United States)

    López, Greizy; Gelvez, Nancy Yaneth; Tamayo, Martalucía

    2011-03-01

    Usher syndrome is a disorder characterized by progressive retinitis pigmentosa, prelingual sensory hearing loss and vestibular dysfunction. It is the most frequent cause of deaf-blindness in humans. Three clinical types and twelve genetic subtypes have been characterized. Type II is the most common, and among these cases, nearly 80% have mutations in the USH2A gene. The aim of the study was to establish the mutational frequencies for the short isoform of USH2A gene in Usher syndrome type II. Twenty-six Colombian individuals with Usher syndrome type II were included. SSCP analysis for 20 exons of the short isoform was performed and abnormal patterns were sequenced. Sequencing of exon 13 of the USH2A gene was performed for all the individuals because the most frequent mutation is located in this exon. The most frequent mutation was c.2299delG, identified in the 27% (n=8) of the sample. The second mutation, p.R334W, showed a frequency of 15%. A new variant identified in the 5’UTR region, g.129G>T, was present in 1 individual (4%). Four polymorphisms were identified; one of them is a new deletion in exon 20, first reported in this study. Mutations in the usherin short isoform were identified in 38% of a sample of 26 USH2 cases. Molecular diagnosis was established in 7 of the 26.

  7. Comparative effect of mutation of Aspergillus oryzae by gamma or ultraviolet irradiation

    International Nuclear Information System (INIS)

    Ito, Hitoshi; Nessa, A.

    1994-01-01

    Mutation frequency of Aspergillus oryzae IAM2630 was studied compared with gamma and ultraviolet irradiation. In this study, mutation frequency of morphological changes on survived colonies was increased up to 50% by irradiation of gamma-rays at survival fraction of 10 -3 to 10 -4 on potato-dextrose agar. On the contrary, mutation frequency of ultraviolet was obtained less than 17% at survival fraction of 10 -3 . Mutants with improvement of three-to-five hold production of α-amylase were isolated by irradiation of gamma-rays at 1.2 kGy. However, we could not isolate any mutants of higher production of α-amylase by ultraviolet irradiation. (author)

  8. Comparative effect of mutation of Aspergillus oryzae by gamma or ultraviolet irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hitoshi; Nessa, A. [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1994-08-01

    Mutation frequency of Aspergillus oryzae IAM2630 was studied compared with gamma and ultraviolet irradiation. In this study, mutation frequency of morphological changes on survived colonies was increased up to 50% by irradiation of gamma-rays at survival fraction of 10{sup -3} to 10{sup -4} on potato-dextrose agar. On the contrary, mutation frequency of ultraviolet was obtained less than 17% at survival fraction of 10{sup -3}. Mutants with improvement of three-to-five hold production of {alpha}-amylase were isolated by irradiation of gamma-rays at 1.2 kGy. However, we could not isolate any mutants of higher production of {alpha}-amylase by ultraviolet irradiation. (author).

  9. Frequency and Clinical Implication of the R450H Mutation in the Thyrotropin Receptor Gene in the Japanese Population Detected by Smart Amplification Process 2

    Science.gov (United States)

    Yanagawa, Yoshimaro; Aoki, Tomoyuki; Morimura, Tadashi; Araki, Osamu; Kimura, Takao; Ogiwara, Takayuki; Kotajima, Nobuo; Yanagawa, Masumi; Murakami, Masami

    2014-01-01

    In Japanese pediatric patients with thyrotropin (TSH) resistance, the R450H mutation in TSH receptor gene (TSHR) is occasionally observed. We studied the frequency and clinical implication of the R450H mutation in TSHR in the general population of Japanese adults using smart amplification process 2 (SmartAmp2). We designed SmartAmp2 primer sets to detect this mutation using a drop of whole blood. We analyzed thyroid function, antithyroid antibodies, and this mutation in 429 Japanese participants who had not been found to have thyroid disease. Two cases without antithyroid antibodies were heterozygous for the R450H mutation in TSHR. Thus, the prevalence of this mutation was 0.47% in the general population and 0.63% among those without antithyroid antibodies. Their serum TSH concentrations were higher than the average TSH concentration not only in subjects without antithyroid antibodies but also in those with antithyroid antibodies. The R450H mutation in TSHR is relatively common in the Japanese population and potentially affects thyroid function. The present study demonstrates that the SmartAmp2 method is useful to detect the R450H mutation in TSHR, which is one of the common causes of TSH resistance in the Japanese population. PMID:24895636

  10. Mutation frequency and genotype/phenotype correlation among phenylketonuria patients from Georgia

    Energy Technology Data Exchange (ETDEWEB)

    Woo, S.L.C.; Martinez, D.; Kuozmine, A. [Baylor College of Medicine, Houston, TX (United States)] [and others

    1994-09-01

    Phenylketonuria (PKU) is an autosomal recessive disorder caused by a deficiency of hepatic phenylalanine hydroxylase (PAH). To determine the molecular basis of PKU in the state of Georgia, thirty-five Georgian PKU patients representing sixty independent alleles were examined by a combination of DGGE and direct sequence analysis. At present, this approach has led to the identification of 55/60 or about 92% of all mutant alleles. The relatively high frequencies of mutations common to the British Isles (R408W, I65T and L348V) are compatible with 1990 census data showing that 34% of the general Georgian population claim Irish, English or Scottish ancestors. Three new mutations, E76A (1/60), R241L (2/60), and R400R (2/60), were also detected in this study. Although the nucleotide substitution in codon 400 (AGG{r_arrow}CGG) did not change the amino acid sequence, it was the only base change detected in a scan of all 13 exons of two independent alleles. Since codon 400 is split between exons 11 and 12, this change may exert some effect on splicing, as has previously been seen in the PAH gene for the silent mutation Q304Q and the nonsense mutation Y356X, each of which effect codons immediately adjacent to splicing signals. This hypothesis remains to be tested by expression analysis or studies of ectopic transcripts. The remaining 19 characterized alleles contained one of 15 previously identified mutations. Twenty-five of the thirty non-related patients examined in this study were completely genotyped, and there was a strong correlation between mutant PAH genotype, PAH activity predicted from in vitro expression studies where known, and PKU or HPA phenotype. For mutations not yet studied by expression analysis, this correlation suggests that L213P, R241L, Y277D may drastically reduce residual PAH activity while F39L and E76A may retain significant amounts of PAH activity.

  11. Relationship between mutation frequency of GPA locus and cumulative dose among medical diagnostic X-ray workers

    International Nuclear Information System (INIS)

    Wang Jixian; Yu Wenru; Li Benxiao; Fan Tiqiang; Li Zhen; Gao Zhiwei; Chen Zhenjun; Zhao Yongcheng

    2000-01-01

    Objective: To explore the feasibility of using GPA locus mutation assay as a bio-dosimeter for occupational exposure to ionizing radiation. Methods: An improved technique of GPA locus mutation assay was used in th study. The frequencies of mutant RBC in peripheral blood of 55 medical X-ray workers and 50 controls employed in different calendar-year periods were detected. The relationship between mutation frequencies (MFs) and period of entry, working years and cumulative doses were analyzed. Results: The MFs were significantly elevated among X-ray workers employed before 1970. This finding is similar to the result of cancer epidemiological study among medical X-ray workers , in which the cancer risk was significantly increased only X-ray workers employed before 1970. The MFs of GPA increased with increasing cumulative dose. The dose-effect relationship of Nφ MF with cumulative dose was closer than that of NN MF. Conclusion: There are many problems to be solved for using GPA MF assay as a bio-dosimeter such as individual variation, specificity and calibration curve of dose-effect relationship

  12. Meta-analysis of neuroblastomas reveals a skewed ALK mutation spectrum in tumors with MYCN amplification.

    Science.gov (United States)

    De Brouwer, Sara; De Preter, Katleen; Kumps, Candy; Zabrocki, Piotr; Porcu, Michaël; Westerhout, Ellen M; Lakeman, Arjan; Vandesompele, Jo; Hoebeeck, Jasmien; Van Maerken, Tom; De Paepe, Anne; Laureys, Geneviève; Schulte, Johannes H; Schramm, Alexander; Van Den Broecke, Caroline; Vermeulen, Joëlle; Van Roy, Nadine; Beiske, Klaus; Renard, Marleen; Noguera, Rosa; Delattre, Olivier; Janoueix-Lerosey, Isabelle; Kogner, Per; Martinsson, Tommy; Nakagawara, Akira; Ohira, Miki; Caron, Huib; Eggert, Angelika; Cools, Jan; Versteeg, Rogier; Speleman, Frank

    2010-09-01

    Activating mutations of the anaplastic lymphoma kinase (ALK) were recently described in neuroblastoma. We carried out a meta-analysis of 709 neuroblastoma tumors to determine their frequency and mutation spectrum in relation to genomic and clinical parameters, and studied the prognostic significance of ALK copy number and expression. The frequency and type of ALK mutations, copy number gain, and expression were analyzed in a new series of 254 neuroblastoma tumors. Data from 455 published cases were used for further in-depth analysis. ALK mutations were present in 6.9% of 709 investigated tumors, and mutations were found in similar frequencies in favorable [International Neuroblastoma Staging System (INSS) 1, 2, and 4S; 5.7%] and unfavorable (INSS 3 and 4; 7.5%) neuroblastomas (P = 0.087). Two hotspot mutations, at positions R1275 and F1174, were observed (49% and 34.7% of the mutated cases, respectively). Interestingly, the F1174 mutations occurred in a high proportion of MYCN-amplified cases (P = 0.001), and this combined occurrence was associated with a particular poor outcome, suggesting a positive cooperative effect between both aberrations. Furthermore, the F1174L mutant was characterized by a higher degree of autophosphorylation and a more potent transforming capacity as compared with the R1275Q mutant. Chromosome 2p gains, including the ALK locus (91.8%), were associated with a significantly increased ALK expression, which was also correlated with poor survival. ALK mutations occur in equal frequencies across all genomic subtypes, but F1174L mutants are observed in a higher frequency of MYCN-amplified tumors and show increased transforming capacity as compared with the R1275Q mutants.

  13. C282Y and H63D Mutation Frequencies in a Population from Central Spain

    Directory of Open Access Journals (Sweden)

    S. Alvarez

    2001-01-01

    Full Text Available Objectives: To determine the frequency of hereditary hemochromatosis gene mutations, C282Y and H63D, from 125 autochthonous blood donors originating from a Central region of Spain, to provide epidemiological data about HFE gene in the Iberian Peninsula.

  14. The influence of large deletions on the mutation frequency induced by tritiated water and X-radiation in male Drosophila melanogaster post-meiotic germ cells

    International Nuclear Information System (INIS)

    Fossett, N.G.; Byrne, B.J.; Kelley, S.J.; Tucker, A.B.; Arbour-Reily, P.; Lee, W.R.

    1994-01-01

    Tritium beta radiation ( 3 H β-radiation) in the form of tritiated water was used to induce mutations at the alcohol dehydrogenase (Adh) locus in male Drosophila melanogaster post-meiotic germ cells. All 23 Adh null mutations were large deletions (>20 kb), determined by genetic complementation and Southern blot analyses. 27 Adh null mutations have been induced by 100-kVp X-rays and have been genetically and molecularly characterized. In contrast to 3 H β-radiation, 100-kVp X-rays induced a bimodal distribution of Adh null mutations, intragenic mutations, ≤250 bp, and large deletions, >100 kb. A statistically significant difference was observed between the frequency of large deletions (23/23 or 1.0) induced by 3 H β-radiation and the frequency of large deletions (19/27 or 0.7) induced by 100-kVp X-rays. However, a statistical difference was not observed between the size distribution of the large deletions induced by 3 H β-radiation and X-rays. The relative deletion frequency (RDF) induced by 3 H β-radiation and 100-kVp X-rays was (1.0/0.7=1.4). The relative biological effectiveness (RBE) of these two radiation sources was 1.4, determined from the ratio of the regression coefficients of the respective 3 H β-radiation and X-ray sex-linked recessive lethal (SLRL) dose-response data. The large difference in size between the two classes of X-ray-induced Adh null mutations and the increase in mutation frequency and deletion frequency for 3 H β-radiation with respect to X-rays may indicate that the relative deletion frequency (RDF) is the molecular biological basis for the increase in the RBE for radiation sources with a mean LET value ≤10 keV/μm

  15. Frequency of Tabagism and N34S and P55S Mutations of Serine Peptidase Inhibitor, Kazal Type 1 (SPINK1) and R254W Mutation of Chymotrypsin C (CTRC) in Patients With Chronic Pancreatitis and Controls.

    Science.gov (United States)

    da Costa, Marianges Zadrozny Gouvêa; Pires, Júlia Glória Lucatelli; Nasser, Paulo Dominguez; Ferreira, Camila da Silva; Teixeira, Ana Cristina de Sá; Paranaguá-Vezozzo, Denise Cerqueira; Guarita, Dulce Reis; Carrilho, Flair José; Ono, Suzane Kioko

    2016-10-01

    This study aimed to investigate the association between chronic pancreatitis and smoking or genetic mutations. The study sample comprised 148 patients with chronic pancreatitis, 110 chronic alcoholic subjects without pancreatic disease, and 297 volunteer blood donors. Of the patients with chronic pancreatitis, 74% had alcoholic etiology and 26% had idiopathic pancreatitis. The frequency of smoking was 91.4% in patients with alcoholic pancreatitis, higher than 73.3% in alcoholic subjects without pancreatitis (P pancreatitis and blood donors. The N34S mutation of serine peptidase inhibitor, Kazal type 1 (SPINK1) was found in 2.7% of patients with chronic alcoholic pancreatitis, in 5.3% of patients with idiopathic pancreatitis, and in 0.4% of blood donors (P = 0.02). The P55S mutation of SPINK1 was found in 2.7% of patients with alcoholic pancreatitis and in 0.7% of blood donors (P = 0.12). The R254W mutation of chymotrypsin C was found in 0.9% of patients with alcoholic pancreatitis, in 0.9% of chronic alcoholic subjects without pancreatitis, and in 0.4% of blood donors (P = 0.75). In all cases, the mutations were heterozygous. Smoking and the N34S mutation of SPINK1 were positively correlated with chronic pancreatitis.

  16. Effects of a chromosome-3 mutator gene on radiation-induced mutability in Drosophila melanogaster females

    Energy Technology Data Exchange (ETDEWEB)

    Sankaranarayanan, K. (Rijksuniversiteit Leiden (Netherlands). Dept. of Radiation Genetics and Chemical Mutagenesis; Cohen (J.A.) Inst. voor Radiopathologie en Stralenbescherming, Leiden (Netherlands))

    1982-01-01

    A series of X-irradiation experiments was carried out using Drosophila melanogaster females homozygous for a third chromosome mutator gene and females which had a similar genetic background except that the mutator-bearing third chromosomes were substituted by normal wild-type chromosomes. In the present work, the sensitivity of the pre-meiotic germ cells of mutator and normal females to the X-ray induction (2000 R) of sex-linked recessive lethals was studied. In addition, experiments were conducted to examine the sensitivity of the immature (stage 7; prophase I of meiosis) oocytes of both kinds of females to the induction of dominant lethals, X-linked recessive lethals and X-chromosome losses. The results show that in pre-meiotic germ cells, the frequencies of radiation-induced recessive lethals are similar in both kinds of females. However, the proportion of these mutations that occur in clusters of size 3 and higher, is higher in mutator than in normal females. In stage-7 oocytes, the frequencies of radiation-induced dominant lethals and sex-linked recessive lethals were similar in both kinds of females. The X-loss frequencies however, were consistently higher in mutator females although statistical significance was obtained only at higher exposures (3000 and 3750 R) and not at lower ones (750-2250 R). Possible reasons for the discrepancy between the present results and those of Gold and Green with respect to pre-meiotic germ cells are discussed.

  17. Frequency of Epidermal Growth Factor Receptor Mutation in Smokers with Lung Cancer Without Pulmonary Emphysema.

    Science.gov (United States)

    Takeda, Kenichi; Yamasaki, Akira; Igishi, Tadashi; Kawasaki, Yuji; Ito-Nishii, Shizuka; Izumi, Hiroki; Sakamoto, Tomohiro; Touge, Hirokazu; Kodani, Masahiro; Makino, Haruhiko; Yanai, Masaaki; Tanaka, Natsumi; Matsumoto, Shingo; Araki, Kunio; Nakamura, Hiroshige; Shimizu, Eiji

    2017-02-01

    Chronic obstructive pulmonary disease is a smoking-related disease, and is categorized into the emphysema and airway dominant phenotypes. We examined the relationship between emphysematous changes and epidermal growth factor receptor (EGFR) mutation status in patients with lung adenocarcinoma. The medical records for 250 patients with lung adenocarcinoma were retrospectively reviewed. All patients were categorized into the emphysema or non-emphysema group. Wild-type EGFR was detected in 136 (54%) and mutant EGFR in 48 (19%). Emphysematous changes were observed in 87 (36%) patients. EGFR mutation was highly frequent in the non-emphysema group (p=0.0014). Multivariate logistic regression analysis showed that emphysema was an independent risk factor for reduced frequency of EGFR mutation (Odds Ratio=3.47, p=0.005). Our data showed a relationship between emphysematous changes and EGFR mutation status. There might be mutually exclusive genetic risk factors for carcinogenesis and development of emphysematous changes. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  18. Frequency of V1016I and F1534C mutations in the voltage-gated sodium channel gene in Aedes aegypti in Venezuela.

    Science.gov (United States)

    Alvarez, Leslie C; Ponce, Gustavo; Saavedra-Rodriguez, Karla; Lopez, Beatriz; Flores, Adriana E

    2015-06-01

    The V1016I and F1534C mutations in the voltage-gated sodium channel gene have been associated with resistance to pyrethroids and DDT in Aedes aegypti mosquitoes. A study was carried out to determine the frequency of I1016 and C1534 by real-time PCR in five natural populations of Ae. aegypti in Venezuela during 2008, 2010 and 2012, as well as in a strain selected with 0.14 µg of deltamethrin for 15 generations. In natural populations, frequencies of I1016 varied between 0.01 and 0.37, and frequencies of C1534 between 0.35 and 1.0. In the Pampanito strain, the frequency of I1016 increased from 0.02 in F1 up to 0.5 in F15 and from 0.35 up to fixation for C1534 after selection with deltamethrin. The results showed that C1534 frequencies are higher than I1016 frequencies in natural populations of Ae. aegypti in Venezuela, and that deltamethrin selected the C1534 more rapidly than I1016. © 2014 Society of Chemical Industry.

  19. Effect of dose-rate on the frequency of X-linked lethal mutation in the nematode Panagrellus redivivus

    International Nuclear Information System (INIS)

    Ager, D.

    1984-01-01

    A total X-ray dose of 50 Gy was applied to the nematode Panagrellus redivivus using dose-rates ranging from 0.23 Gy/min to 10.49 Gy/min, and the frequency of lethal X-chromosomes was determined. This frequency ranged from approximately 1.6% at the lower dose-rate to 4.3% at the highest dose-rate, indicating a dose-rate dependency of mutation frequency in the spermatogonia and oogonia of this organism. (orig.)

  20. Mutagenic effects of gamma rays and EMS on frequency and spectrum of chlorophyll mutations in urdbean (Vigna mungo (L.) Hepper)

    International Nuclear Information System (INIS)

    Usharani, K.S.; Ananda Kumar, C.R.

    2015-01-01

    Chlorophyll mutations act as a significant index in the judgment of induced genetic variations in mutagen treated populations. Different types of chlorophyll mutation have been observed in various crop plants. In the current study, the effect of different concentrations (40 kR, 50 kR and 60 kR) of gamma rays, Ethyl Methane Sulphonate (50 mM, 60 mM and 70 mM) in single and combination dose/concentration on the frequency and spectrum of chlorophyll mutation and the effect of VBN 4 urdbean variety to such irradiation dose was observed. Results showed induction of broad spectrum of chlorophyll mutations which included albina, xantha, chlorina and viridis. Among these chlorina type was predominant in all the mutagenic treatments. The albina type of chlorophyll mutants occurred very rarely and was found only at 60 mM of EMS treatment and at 40 kR + 50 mM, 60 kR + 70 mM of combination treatments. Based on the chlorophyll mutation frequency, gamma rays were most effective followed by EMS and combination of treatments. (author)

  1. WFS1 and non-syndromic low-frequency sensorineural hearing loss: a novel mutation in a Portuguese case.

    Science.gov (United States)

    Gonçalves, A C; Matos, T D; Simões-Teixeira, H R; Pimenta Machado, M; Simão, M; Dias, O P; Andrea, M; Fialho, G; Caria, H

    2014-04-01

    Low-frequency sensorineural hearing loss (LFSNHL) is an unusual type of HL in which frequencies at 2,000 Hz and below are predominantly affected. Most of the families with LFSNHL carry missense mutations in WFS1 gene, coding for wolframin. A Portuguese patient aged 49, reporting HL since her third decade of life, and also referring tinnitus, was shown to display bilateral moderate LFSNHL after audiological evaluation. Molecular analysis led to the identification of a novel mutation, c.511G>A (p.Asp171Asn), found in heterozygosity in the exon 5 of the WFS1 gene, and changing the aspartic acid at position 171 to an asparagine, in the extracellular N-terminus domain of the wolframin protein. This novel mutation wasn't present either in 200 control chromosomes analyzed or in the hearing proband's half-brother, and it had not been reported in 1000 Genomes, Exome Variant Server, HGMD or dbSNP databases. No mutations were found in GJB2 and GJB6 genes. Multi-alignment of 27 wolframin sequences from mammalian species, against the human wolframin sequence in ConSurf, indicated a conservation score corresponding to 7 in a 1-9 color scale where 9 is conserved and 1 is variable. In addition, the mutation p.Asp171Asn was predicted to be damaging and possibly damaging by SIFT and Polyphen-2, respectively. The auditory phenotype of this patient could thus be due to the novel mutation p.Asp171Asn. Further functional characterization might enable to elucidate in which way the change in the residue 171, as other changes introduced by LFSNHL-associated mutations previously described, leads to this type of HL. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. POLE mutations in families predisposed to cutaneous melanoma

    DEFF Research Database (Denmark)

    Aoude, Lauren G; Heitzer, Ellen; Johansson, Peter

    2015-01-01

    Germline mutations in the exonuclease domain of POLE have been shown to predispose to colorectal cancers and adenomas. POLE is an enzyme involved in DNA repair and chromosomal DNA replication. In order to assess whether such mutations might also predispose to cutaneous melanoma, we interrogated...... variants in the exonuclease domain of POLE. Although this frequency is not significantly higher than that in unselected Caucasian controls, we observed multiple cancer types in the melanoma families, suggesting that some germline POLE mutations may predispose to a broad spectrum of cancers, including...

  3. Identification of Constrained Cancer Driver Genes Based on Mutation Timing

    Science.gov (United States)

    Sakoparnig, Thomas; Fried, Patrick; Beerenwinkel, Niko

    2015-01-01

    Cancer drivers are genomic alterations that provide cells containing them with a selective advantage over their local competitors, whereas neutral passengers do not change the somatic fitness of cells. Cancer-driving mutations are usually discriminated from passenger mutations by their higher degree of recurrence in tumor samples. However, there is increasing evidence that many additional driver mutations may exist that occur at very low frequencies among tumors. This observation has prompted alternative methods for driver detection, including finding groups of mutually exclusive mutations and incorporating prior biological knowledge about gene function or network structure. Dependencies among drivers due to epistatic interactions can also result in low mutation frequencies, but this effect has been ignored in driver detection so far. Here, we present a new computational approach for identifying genomic alterations that occur at low frequencies because they depend on other events. Unlike passengers, these constrained mutations display punctuated patterns of occurrence in time. We test this driver–passenger discrimination approach based on mutation timing in extensive simulation studies, and we apply it to cross-sectional copy number alteration (CNA) data from ovarian cancer, CNA and single-nucleotide variant (SNV) data from breast tumors and SNV data from colorectal cancer. Among the top ranked predicted drivers, we find low-frequency genes that have already been shown to be involved in carcinogenesis, as well as many new candidate drivers. The mutation timing approach is orthogonal and complementary to existing driver prediction methods. It will help identifying from cancer genome data the alterations that drive tumor progression. PMID:25569148

  4. Modifying effect of 5-fluoro-2-deoxiuridine on the frequency of x-ray-induced visible mutations in wheat

    International Nuclear Information System (INIS)

    Azatyan, R.A.; Avakyan, V.A.

    1985-01-01

    A modifying effect of FUDR on the output of visible mutations induced by X-ray radiation has been studied at soft fall wheat (Tr. aestivum var. turcicum). It is shown that at X-ray radiation of dry seeds with subsequent treatment of FUDR increased is the mutant percent in M 3 which has constituted 0.61% at irradiation in dose of 100 Gy ad 1.03% at irradiation by the same dose and FUDR influence during 10 hours. In analogous variants at irradiation by 150 Gi dose the mutation frequency reached 1.47 and 2.07% respectively. It is shown that FUDR postradiation treatment promotes not only the increase of frequency but consderablly widens the spectrum of induced mutations. A supposition is made that FUDR modyfying effect is caused by DNA synthesis inhibition. A problem is discussed on a possible realization of potential DNA changes caused by irradiation, at additional influence of inhibitor

  5. The spectrum of HNF1A gene mutations in Greek patients with MODY3: relative frequency and identification of seven novel germline mutations.

    Science.gov (United States)

    Tatsi, Christina; Kanaka-Gantenbein, Christina; Vazeou-Gerassimidi, Adriani; Chrysis, Dionysios; Delis, Dimitrios; Tentolouris, Nikolaos; Dacou-Voutetakis, Catherine; Chrousos, George P; Sertedaki, Amalia

    2013-11-01

    Maturity-Onset Diabetes of the Young (MODY) is the most common type of monogenic diabetes accounting for 1-2% of the population with diabetes. The relative incidence of HNF1A-MODY (MODY3) is high in European countries; however, data are not available for the Greek population. The aims of this study were to determine the relative frequency of MODY3 in Greece, the type of the mutations observed, and their relation to the phenotype of the patients. Three hundred ninety-five patients were referred to our center because of suspected MODY during a period of 15 yr. The use of Denaturing Gradient Gel Electrophoresis of polymerase chain reaction amplified DNA revealed 72 patients carrying Glucokinase gene mutations (MODY2) and 8 patients carrying HNF1A gene mutations (MODY3). After using strict criteria, 54 patients were selected to be further evaluated by direct sequencing or by multiplex ligation probe amplification (MLPA) for the presence of HNF1A gene mutations. In 16 unrelated patients and 13 of their relatives, 15 mutations were identified in the HNF1A gene. Eight of these mutations were previously reported, whereas seven were novel. Clinical features, such as age of diabetes at diagnosis or severity of hyperglycemia, were not related to the mutation type or location. In our cohort of patients fulfilling strict clinical criteria for MODY, 12% carried an HNF1A gene mutation, suggesting that defects of this gene are responsible for a significant proportion of monogenic diabetes in the Greek population. No clear phenotype-genotype correlations were identified. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Evaluation the frequency of factor V Leiden mutation in pregnant women with preeclampsia syndrome in an Iranian population

    Directory of Open Access Journals (Sweden)

    Azadeh Azinfar

    2012-01-01

    Full Text Available Background: Role of genetic factors in etiology of preeclampsia is not confirmed yet.Objective: Gene defect frequency varies in different geographic areas as well as ethnic groups. In this study, the role of factor V Leiden mutation in the pathogenesis of preeclampsia syndrome among the pregnant population of northern shore of Persian Gulf in Iran, were considered.Materials and Methods: Between Jan. 2008 and Dec. 2009, in a nested case control study, pregnant women with preeclampsia (N=198 as cases and healthy (N=201 as controls were enrolled in the study. DNA were extracted from 10 CC peripheral blood and analyzed for presence of factor V Leiden mutation in these subjects. The maternal and neonatal outcomes of pregnancy according to the distribution of factor V Leiden were also compared among cases.Results: In total, 17(8.6% of cases and 2(1% of controls showed the factor V Leiden mutation. The incidence of factor V Leiden was typically higher in preeclamptic women than control group (OR: 9.34 %95 CI: 2.12-41.01. There was no difference in incidence rate of preterm delivery< 37 weeks (OR: 1.23 %95 CI: 0.38-4.02, very early preterm delivery<32 weeks (OR: 1.00 %95 CI: 0.12-8.46, intra uterine fetal growth restriction (IUGR (OR: 1.32 %95 CI: 0.15-11.30 ,and the rate of cesarean section (OR: 0.88 %95 CI: 0.29-2.62 among cases based on the prevalence of factor V Leiden mutation.Conclusion: The pregnant women with factor V Leiden mutation are prone for preeclampsia syndrome during pregnancy, but this risk factor was not correlated to pregnancy complications in the studied women

  7. [Research progress of mutational spectrum and pathophysiology of WFS1 gene in Wolfram syndrome and nonsyndromic low frequency sensorineural hearing loss].

    Science.gov (United States)

    Shi, S M; Han, Y H; Wang, H B

    2016-09-07

    Compound homozygous or heterozygous mutations in WFS 1 can lead to autosomal recessive Wolfram syndrome (WS), and heterozygous mutations in WFS 1 can lead to autosomal dominant non-syndromic low frequency sensorineural hearing loss (LFSNHL). In addition, mutations in the WFS region has relationship with diabetes and psychiatric diseases. In this paper, we provide an overview of genetic research with different phenotypes, including WS and LFSNHL.

  8. Frequency of p53 Gene Mutation and Protein Expression in Oral Squamous Cell Carcinoma

    International Nuclear Information System (INIS)

    Ara, N.; Atique, M.; Ahmed, S.; Bukhari, S. G. A.

    2014-01-01

    Objective: To determine the frequency of p53 gene mutation and protein expression in Oral Squamous Cell Carcinoma (OSCC) and to establish correlation between the two. Study Design: Analytical study. Place and Duration of Study: Histopathology Department and Molecular Biology Laboratory, Armed Forces Institute of Pathology (AFIP), Rawalpindi, from May 2010 to May 2011. Methodology: Thirty diagnosed cases of OSCC were selected by consecutive sampling. Seventeen were retrieved from the record files of the AFIP, and 13 fresh/frozen sections were selected from patients reporting to the Oral Surgery Department, Armed Forces Institute of Dentistry (AFID). Gene p53 mutation was analyzed in all the cases using PCRSSCP analysis. DNA was extracted from the formalin-fixed and paraffin-embedded tissue sections and fresh/frozen sections. DNA thus extracted was amplified by polymerase chain reaction. The amplified products were denatured and finally analyzed by gel electrophoresis. Gene mutation was detected as electrophoretic mobility shift. The immunohistochemical marker p53 was applied to the same 30 cases and overexpression of protein p53 was recorded. Results: Immunohistochemical expression of marker p53 was positive in 67% (95% Confidence Interval (CI) 48.7 - 80.9) of the cases. Mutations of the p53 gene were detected in 23% (95% CI 11.5 - 41.2) of the OSCC. No statistically significant correlation was found between p53 gene mutation and protein p53 expression (rs = - 0.057, p = 0.765). Conclusion: A substantial number of patients have p53 gene mutation (23%) and protein p53 expression (67%) in oral squamous cell carcinoma (OSCC). (author)

  9. Non-deletion mutations in Egyptian patients with Duchenne muscular dystrophy

    Directory of Open Access Journals (Sweden)

    Rabah M. Shawky

    2014-07-01

    Conclusion: The relative higher frequency of duplication mutations in Egyptian patients with DMD may indicate that MLPA and not PCR should be preferred for molecular testing of Egyptian patients with DMD.

  10. Differences in K-ras and mitochondrial DNA mutations and microsatellite instability between colorectal cancers of Vietnamese and Japanese patients.

    Science.gov (United States)

    Miwata, Tomohiro; Hiyama, Toru; Quach, Duc Trong; Le, Huy Minh; Hua, Ha Ngoc Thi; Oka, Shiro; Tanaka, Shinji; Arihiro, Koji; Chayama, Kazuaki

    2014-11-30

    The incidence of early-onset (under 50 years of age) colorectal cancer (CRC) in the Vietnamese has been reported to be quite higher than that in the Japanese. To clarify the differences in genetic alterations between Vietnamese and Japanese CRCs, we investigated mutations in K-ras and mitochondrial DNA (mtDNA) and high-frequency microsatellite instability (MSI-H) in the CRCs of Vietnamese and Japanese patients. We enrolled 60 Vietnamese and 233 Japanese patients with invasive CRCs. DNA was extracted from formalin-fixed, paraffin-embedded tissue sections. K-ras mutations were examined with PCR-single-strand conformation polymorphism analysis. mtDNA mutations and MSI-H were examined with microsatellite analysis using D310 and BAT-26, respectively. K-ras mutations were examined in 60 Vietnamese and 45 Japanese CRCs. The frequency of the mutations in the Vietnamese CRCs was significantly higher than that in the Japanese CRCs (8 of 24 [33%] vs 5 of 45 [11%], p =0.048). MSI-H was examined in 60 Vietnamese and 130 Japanese CRCs. The frequency of MSI-H in the Vietnamese CRCs was also significantly higher than that in the Japanese CRCs (6 of 27 [22%] vs 10 of 130 [8%], p =0.030). mtDNA mutations were examined in 60 Vietnamese and 138 Japanese CRCs. The frequency of mtDNA mutations in the Vietnamese CRCs was significantly higher than that in the Japanese CRCs (19 of 44 [43%] vs 11 of 133 [9%], p Vietnamese and Japanese patients. These results indicate that the developmental pathways of CRCs in the Vietnamese may differ from those of CRCs in the Japanese.

  11. Minisequencing mitochondrial DNA pathogenic mutations

    Directory of Open Access Journals (Sweden)

    Carracedo Ángel

    2008-04-01

    Full Text Available Abstract Background There are a number of well-known mutations responsible of common mitochondrial DNA (mtDNA diseases. In order to overcome technical problems related to the analysis of complete mtDNA genomes, a variety of different techniques have been proposed that allow the screening of coding region pathogenic mutations. Methods We here propose a minisequencing assay for the analysis of mtDNA mutations. In a single reaction, we interrogate a total of 25 pathogenic mutations distributed all around the whole mtDNA genome in a sample of patients suspected for mtDNA disease. Results We have detected 11 causal homoplasmic mutations in patients suspected for Leber disease, which were further confirmed by standard automatic sequencing. Mutations m.11778G>A and m.14484T>C occur at higher frequency than expected by change in the Galician (northwest Spain patients carrying haplogroup J lineages (Fisher's Exact test, P-value Conclusion We here developed a minisequencing genotyping method for the screening of the most common pathogenic mtDNA mutations which is simple, fast, and low-cost. The technique is robust and reproducible and can easily be implemented in standard clinical laboratories.

  12. Effect of higher frequency on the classification of steady-state visual evoked potentials

    Science.gov (United States)

    Won, Dong-Ok; Hwang, Han-Jeong; Dähne, Sven; Müller, Klaus-Robert; Lee, Seong-Whan

    2016-02-01

    Objective. Most existing brain-computer interface (BCI) designs based on steady-state visual evoked potentials (SSVEPs) primarily use low frequency visual stimuli (e.g., visual fatigue and no stimulus-related seizures. The fundamental objective of this study was to investigate the effect of stimulation frequency and duty-cycle on the usability of an SSVEP-based BCI system. Approach. We developed an SSVEP-based BCI speller using multiple LEDs flickering with low frequencies (6-14.9 Hz) with a duty-cycle of 50%, or higher frequencies (26-34.7 Hz) with duty-cycles of 50%, 60%, and 70%. The four different experimental conditions were tested with 26 subjects in order to investigate the impact of stimulation frequency and duty-cycle on performance and visual fatigue, and evaluated with a questionnaire survey. Resting state alpha powers were utilized to interpret our results from the neurophysiological point of view. Main results. The stimulation method employing higher frequencies not only showed less visual fatigue, but it also showed higher and more stable classification performance compared to that employing relatively lower frequencies. Different duty-cycles in the higher frequency stimulation conditions did not significantly affect visual fatigue, but a duty-cycle of 50% was a better choice with respect to performance. The performance of the higher frequency stimulation method was also less susceptible to resting state alpha powers, while that of the lower frequency stimulation method was negatively correlated with alpha powers. Significance. These results suggest that the use of higher frequency visual stimuli is more beneficial for performance improvement and stability as time passes when developing practical SSVEP-based BCI applications.

  13. Repair-resistant mutation in Neurospora

    International Nuclear Information System (INIS)

    Stadler, D.; Macleod, H.; Loo, M.

    1987-01-01

    Chronic UV treatment produces severalfold fewer mutations in Neurospora conidia than does the same total dose of acute UV. Experiments were designed to determine the conditions required for chronic UV mutagenesis. Measurement of the coincidence frequency for two independent mutations revealed the existence of a subset of cells which are mutable by chronic UV. Analysis of forward mutation at the mtr locus showed that the genetic alterations produced by chronic UV were virtually all point mutants, even though the assay system could detect alterations or deletions extending into neighboring genes. A significant fraction of the mutants produced by acute UV were multigenic deletions. The size of the dose-rate effect (acute UV mutation frequency divided by chronic UV mutation frequency) was compared for several different mutation assay systems. Forward mutations (recessive lethals and mtr) gave values ranging from four to nine. For events which were restricted to specific molecular sites (specific reversions and nonsense suppressor mutations), there was a wider range of dose-rate ratios. This suggests that chronic UV mutation may be restricted to certain molecular sequences or configurations

  14. Effect of low dose gamma radiation on stamen-hairs of different clones of Tradescantia presenting variability in the frequency of spontaneous mutations

    International Nuclear Information System (INIS)

    Takahashi, C.S.

    1976-01-01

    Changes in the frequency of spontaneous somatic mutations were studied for three different clones of Tradescantia heterozygotes for flower and stamen-hair color keeping them under controlled or natural conditions in order to verify the effect of different environmental conditions on the different genotypes. The effect of inflorescence age on the variation of spontaneous mutations was studied choosing young and old inflorescences of a same plant. Low dose irradiation experiments were carried out with those clones to elucidate the radiation effects on the clones presenting changes in the frequency of spontaneous mutations. The chronic-and acute irradiation effects of low dose irradiation of the stamen-hair of Tradescantia were also studied. Results are discussed. (M.A.) [pt

  15. The role of human demographic history in determining the distribution and frequency of transferase-deficient galactosaemia mutations.

    LENUS (Irish Health Repository)

    Flanagan, J M

    2010-02-01

    Classical or transferase-deficient galactosaemia is an inherited metabolic disorder caused by mutation in the human Galactose-1-phosphate uridyl transferase (GALT) gene. Of some 170 causative mutations reported, fewer than 10% are observed in more than one geographic region or ethnic group. To better understand the population history of the common GALT mutations, we have established a haplotyping system for the GALT locus incorporating eight single nucleotide polymorphisms and three short tandem repeat markers. We analysed haplotypes associated with the three most frequent GALT gene mutations, Q188R, K285N and Duarte-2 (D2), and estimated their age. Haplotype diversity, in conjunction with measures of genetic diversity and of linkage disequilibrium, indicated that Q188R and K285N are European mutations. The Q188R mutation arose in central Europe within the last 20 000 years, with its observed east-west cline of increasing relative allele frequency possibly being due to population expansion during the re-colonization of Europe by Homo sapiens in the Mesolithic age. K285N was found to be a younger mutation that originated in Eastern Europe and is probably more geographically restricted as it arose after all major European population expansions. The D2 variant was found to be an ancient mutation that originated before the expansion of Homo sapiens out of Africa.

  16. Fate of induced mutations in higher plants with special emphasis on sexually reproducing species

    International Nuclear Information System (INIS)

    Cornu, Andre

    1978-01-01

    A mutation induced in a plant somatic cell has to overcome quite many difficulties before being isolated and utilized as a marker in a mutated line. If induced in a meristem, three conditions must be fulfilled for the mutation to be transmitted to the subsequent generation: it must be compatible with normal cell multiplication, it must be located in a cell mass that will provide an inflorescence, and it must be in the sporogenetic layer (t2). Under these conditions, or if it is induced in a gamete or in a zygote, the mutation enters a first cycle of sexual reproduction. Meiosis and the subsequent haploid phase constitute severe screening steps for many chromosome aberrations. Studies on Petunia performed by means of marker genes show that male and female gametic viabilities are drastically impaired by deletions. However, a deficient chromosome can be transmitted when the losss of information is compensated for by homologous information as, for example, diploid gametes from tetraploids or disomic gametes resulting from non-disjunction. If partial or complete sterility, whether sporo- or gametophytic, is avoided, then the mutation can be transmitted to the next generation in heterozygous state. When becoming homozygous, the mutation may have effects such that its use can be most difficult. This is the case when this mutation causes rather early lethality or severe sterility. Thus, in higher plants, one faces several cases of powerful and efficient selection against mutations. On the basis of experiments carried out on Petunia, the per locus mutation rate of practical interest ranges between I and 5/10000M 1 plants. Practical conclusions are drawn about which organ should be treated, which mutagen at what dose should be used according to the scope of the research undertaken [fr

  17. Characterization of ultraviolet light-induced diphtheria toxin-resistant mutations in normal and Xeroderma pigmentosum human fibroblasts

    International Nuclear Information System (INIS)

    Glover, T.W.

    1979-01-01

    Quantitative mutagenesis studies in human cells have been severely limited by the lack of reliable genetic markers. Experiments were therefore performed to develop and characterize a better quantitative mutation assay for human cells. The uv-induction of diphtheria toxin resistant (DT/sup r/) mutations in normal and excision repair defective xeroderma pigmentosum (XP) fibroblasts has been quantitatively characterized. A concentration of diphtheria toxin to use in the selection of resistant mutants was determined whereby DT/sup r/ cells are cross-resistant to Pseudomonas aeurginosa exotoxin A, indicating mutants have altered elongation factor-2 (EF-2) which is not susceptible to ADP-ribosylation by either toxin. Results of this study indicate that XP fibroblasts have higher uv-induced mutation frequencies per unit uv-dose but similar frequencies per unit survival compared to normal cells as measured using a new genetic marker for quantitative mutagenesis. Furthermore, these results support a prediction of the mutation theory of cancer, namely, that cells from individuals with certain human syndromes that predispose the individual to cancer will have higher induced mutation frequencies than cells from non-susceptible individuals. This newly characterized genetic marker should be useful in quantitative mutagenesis studies in human cells

  18. Induced mutations in pomoid trees breeding

    International Nuclear Information System (INIS)

    Hamed, Faysal

    1986-01-01

    Induction of mutations in fruit trees by ionizing radiation complements a cross-breeding program. The objectives are: 1) the improvements of methods of induction, identification and selection of useful mutations, and 2) the initiation of useful mutations either for immediate use as improved cultivars or as a parent material for conventional cross-breeding. The induction of mutants in pomoid fruits, with special emphasis on apple, was realized by gamma-ray treatment of dormant scions subsequently propagated on a rootstoch in the nursery. The aim was to obtain compacts, presuming the feasibility of selecting compact shoots formed by the irradiated scions in the first vegetative generation and also assuming that chance of finding (e.g. fruit mutants) would be thus increased rather than lessened. Selection was carried out on one-season old shoots, formed on the same material for two or three seasons, by using a cut-back at the end of the first and second season. The procedure was highly effective. Moderate exposures, resulting in 60% survival gave high mutation frequencies. Buds 6-10 on the primary shoot gave higher frequencies of recognizable mutations than either buds 1-5 or 11-15. Preliminary results seem to indicate that, at least in some apple cultivars, there is opportunity to obtain compact growth types with good biological characteristics. 8 refs. (author)

  19. Research on mutation generation in higher plants with heavy ions at NIRS-HIMAC

    International Nuclear Information System (INIS)

    Okamura, M.; Watanabe, S.; Watanabe, M.; Toguri, T.; Furusawa, Y.

    2006-01-01

    Plants are closely related to medical treatment in medicine, foods, herbs and medical care by gardening. Ion beams have much higher linear energy transfer (LET) and relative biological effectiveness than those of gamma rays and X-rays. Ion beams are supposed to be useful as new mutagen to obtain novel mutants with superior characteristics in higher plants. In this study, the influence of heavy ions irradiation on bud growth was examined in carnation and the mutation generation was inspected in babies' breath. The growth of carnation buds began to decrease at 10 Gy and the median growth dose was estimated at 35 Gy for 290 Mev/u carbon ion beams. Mutants with petaloid leaves were observed in babies' breath by the irradiation of 290 Mev/u carbon ion beams at 20Gy. We will examine the mutation rates and spectrum for 290 MeV/u carbon, 400 MeV/u neon and 500 MeV/u argon ion beams to find optimum use of the beams in plant breeding. The efficient system to generate useful mutants using heavy ions at NIRS-HIMAC will be developed in higher plants. (author)

  20. Higher prevalence of KRAS mutations in colorectal cancer in Saudi ...

    African Journals Online (AJOL)

    We studied retrospectively tumor samples of 83 Saudi metastatic CRC patients for KRAS mutations in codon 12 and codon 13, to evaluate the relevance of KRAS mutation positive colorectal cancers with metastatic sites. KRAS mutation was observed in 42.2% (35/83) patients with CRC. The most common mutations were in ...

  1. Frequency of JAK2 V617F mutation in patients with Philadelphia positive Chronic Myeloid Leukemia in Pakistan.

    Science.gov (United States)

    Tabassum, Najia; Saboor, Mohammed; Ghani, Rubina; Moinuddin, Moinuddin

    2014-01-01

    Co-existence of myeloproliferative disorders (MPD) and Janus associated kinase 2 mutation (JAK2 V617F) is a well-established fact. Only few case reports are available showing presence of JAK2 V617F mutation in chronic myeloid leukemia (CML). Purpose of this study was to determine the frequency of JAK2 V617F mutation in Philadelphia Chromosome positive (Ph (+)) CML patients in Pakistan. The study was conducted from August 2009 to July 2010 at Civil Hospital and Baqai Institute of Hematology (BIH) Karachi. Blood samples from 25 patients with CML were collected. Multiplex reverse transcription polymerase chain reaction (RT-PCR) was performed for Breakpoint Cluster Region - Abelson (BCR-ABL) rearrangement. Conventional PCR was performed for JAK2 V617F mutation on BCR-ABL positive samples. All 25 samples showed BCR-ABL rearrangement. Out of these 11 samples (44%) had JAK2 V617F mutation; the remaining 14 (56%) cases showed JAK2 617V wild type. It is concluded that the co-existence of Ph (+)CML and JAK2 V617F mutation is possible.

  2. Mutation induction of orchids by ion beams

    International Nuclear Information System (INIS)

    Affrida Abu Hassan; Zaiton Ahmad; Sakinah Ariffin; Oono, Yutaka; Hase, Yoshihiro; Shikazono; Naoya; Narumi, Issay; Tanaka, Atsushi

    2010-01-01

    Mutation induction using ionizing radiation provides an effective alternative means for improvement of orchids. In this study, ion beams were used because they have much higher linear energy transfer (LET) than X-rays or gamma rays, and subsequently lead to higher mutation frequency and broad mutation spectrum. The proto corm-like bodies (PLBs) of three orchid species (Dendrobium crumenatum, Dendrobium mirbellianum) were irradiated at various doses with 320 MeV 12 C 6+ ions accelerated by Azimuthally Varying Field (AVF) cyclotron at JAEAs Takasaki Ion Accelerators for Advanced Radiation Application (TIARA). The optimum irradiation condition and the effect of irradiation on each species were studied, particularly on flower colour and morphology, flowering habit and insect resistance. Dose effects on plantlet regeneration for each species were also obtained. Some morphological changes were observed in flowers of Dendrobium crumenatum, whilst one insect resistant mutant was obtained in Dendrobium mirbellianum. (author)

  3. Complexity of the ultraviolet mutation frequency response curve in Escherichia coli B/r: SOS induction, one-lesion and two-lesion mutagenesis

    International Nuclear Information System (INIS)

    Doudney, C.O.

    1976-01-01

    Three distinct sections of the ultraviolet mutation frequency response (MFR) curve toward tryptophan prototrophy have been demonstrated in Escherichia coli B/r WP2 trp thy and its uvrA derivative in log-phase growth in minimal medium. The initial section, which appears fluence-squared, may reflect the necessity, if mutation is to result, for induction of two lesions, one located within the potentially mutated genetic locus and the other damaging deoxyribonucleic acid replication and resulting in induction of the error-prone SOS repair function. A second linear section is ascribed to the continued induction, after exposure above that sufficient for complete SOS expression, of isolated lesions which lead to mutation in potentially mutated loci. The third section demonstrates an increased rate of mutagenesis and suggests the induction of two lesions in proximity which result in additional mutations. Split-exposure studies support the inducible nature of the SOS function and suggest that mutation frequency decline (MFD) is due to excision resulting from or related to the prevention of SOS induction by inhibition of protein synthesis. Preirradiation tryptophan starvation of the uvr + strain for 30 min decreases MFR in the first and second sections of the curve. Reduction of MFR in the third section requires more prestarvation time and is blocked by nalidixic acid. The decreased MFR of the first and second sections is ascribed to promotion of postirradiation MFD based on excision and that of the third section to completion of the chromosome during the prestarvation period

  4. DNA mutation motifs in the genes associated with inherited diseases.

    Directory of Open Access Journals (Sweden)

    Michal Růžička

    Full Text Available Mutations in human genes can be responsible for inherited genetic disorders and cancer. Mutations can arise due to environmental factors or spontaneously. It has been shown that certain DNA sequences are more prone to mutate. These sites are termed hotspots and exhibit a higher mutation frequency than expected by chance. In contrast, DNA sequences with lower mutation frequencies than expected by chance are termed coldspots. Mutation hotspots are usually derived from a mutation spectrum, which reflects particular population where an effect of a common ancestor plays a role. To detect coldspots/hotspots unaffected by population bias, we analysed the presence of germline mutations obtained from HGMD database in the 5-nucleotide segments repeatedly occurring in genes associated with common inherited disorders, in particular, the PAH, LDLR, CFTR, F8, and F9 genes. Statistically significant sequences (mutational motifs rarely associated with mutations (coldspots and frequently associated with mutations (hotspots exhibited characteristic sequence patterns, e.g. coldspots contained purine tract while hotspots showed alternating purine-pyrimidine bases, often with the presence of CpG dinucleotide. Using molecular dynamics simulations and free energy calculations, we analysed the global bending properties of two selected coldspots and two hotspots with a G/T mismatch. We observed that the coldspots were inherently more flexible than the hotspots. We assume that this property might be critical for effective mismatch repair as DNA with a mutation recognized by MutSα protein is noticeably bent.

  5. Chloroplast mutations induced by 9-aminoacridine hydrochloride are independent of the plastome mutator in Oenothera.

    Science.gov (United States)

    GuhaMajumdar, M; Baldwin, S; Sears, B B

    2004-02-01

    Oenothera plants homozygous for the recessive plastome mutator allele ( pm) show chloroplast DNA (cpDNA) mutation frequencies that are about 1,000-fold higher than spontaneous levels. The pm-encoded gene product has been hypothesized to have a function in cpDNA replication, repair and/or mutation avoidance. Previous chemical mutagenesis experiments with the alkylating agent nitroso-methyl urea (NMU) showed a synergistic effect of NMU on the induction of mutations in the pm line, suggesting an interaction between the pm-encoded gene product and one of the repair systems that corrects alkylation damage. The goal of the experiments described here was to examine whether the pm activity extends to the repair of damage caused by non-alkylating mutagens. To this end, the intercalating mutagen, 9-aminoacridine hydrochloride (9AA) was tested for synergism with the plastome mutator. A statistical analysis of the data reported here indicates that the pm-encoded gene product is not involved in the repair of the 9AA-induced mutations. However, the recovery of chlorotic sectors in plants derived from the mutagenized seeds shows that 9AA can act as a mutagen of the chloroplast genome.

  6. Mutation rate estimation for 15 autosomal STR loci in a large population from Mainland China.

    Science.gov (United States)

    Zhao, Zhuo; Zhang, Jie; Wang, Hua; Liu, Zhi-Peng; Liu, Ming; Zhang, Yuan; Sun, Li; Zhang, Hui

    2015-09-01

    STR, short tandem repeats, are well known as a type of powerful genetic marker and widely used in studying human population genetics. Compared with the conventional genetic markers, the mutation rate of STR is higher. Additionally, the mutations of STR loci do not lead to genetic inconsistencies between the genotypes of parents and children; therefore, the analysis of STR mutation is more suited to assess the population mutation. In this study, we focused on 15 autosomal STR loci. DNA samples from a total of 42,416 unrelated healthy individuals (19,037 trios) from the population of Mainland China collected between Jan 2012 and May 2014 were successfully investigated. In our study, the allele frequencies, paternal mutation rates, maternal mutation rates and average mutation rates were detected. Furthermore, we also investigated the relationship between paternal ages, maternal ages, area, the time of pregnancy and average mutation rate. We found that the paternal mutation rate was higher than the maternal mutation rate and the paternal, maternal, and average mutation rates had a positive correlation with paternal age, maternal age and the time of pregnancy respectively. Additionally, the average mutation rate of coastal areas was higher than that of inland areas.

  7. Expanded simple tandem repeat (ESTR) mutation induction in the male germline: Lessons learned from lab mice

    Energy Technology Data Exchange (ETDEWEB)

    Somers, Christopher M. [University of Regina, Department of Biology, 3737 Wascana Parkway, Regina, SK, S4S 0A2 (Canada)]. E-mail: chris.somers@uregina.ca

    2006-06-25

    Expanded simple tandem repeat (ESTR) DNA loci that are unstable in the germline have provided the most sensitive tool ever developed for investigating low-dose heritable mutation induction in laboratory mice. Ionizing radiation exposures have shown that ESTR mutations occur mainly in pre-meiotic spermatogonia and stem cells. The average spermatogonial doubling dose is 0.62-0.69 Gy for low LET, and 0.18-0.34 Gy for high LET radiation. Chemical alkylating agents also cause significant ESTR mutation induction in pre-meiotic spermatogonia and stem cells, but are much less effective per unit dose than radiation. ESTR mutation induction efficiency is maximal at low doses of radiation or chemical mutagens, and may decrease at higher dose ranges. DNA repair deficient mice (SCID and PARP-1) with elevated levels of single and double-strand DNA breaks have spontaneously elevated ESTR mutation frequencies, and surprisingly do not show additional ESTR mutation induction following irradiation. In contrast, ESTR mutation induction in p53 knock-outs is indistinguishable from that of wild-type mice. Studies of sentinel mice exposed in situ to ambient air pollution showed elevated ESTR mutation frequencies in males exposed to high levels of particulate matter. These studies highlight the application of the ESTR assay for assessing environmental hazards under real-world conditions. All ESTR studies to date have shown untargeted mutations that occur at much higher frequencies than predicted. The mechanism of this untargeted mutation induction is unknown, and must be elucidated before we can fully understand the biological significance of ESTR mutations, or use these markers for formal risk assessment. Future studies should focus on the mechanism of ESTR mutation induction, refining dose responses, and developing ESTR markers for other animal species.

  8. Expanded simple tandem repeat (ESTR) mutation induction in the male germline: Lessons learned from lab mice

    International Nuclear Information System (INIS)

    Somers, Christopher M.

    2006-01-01

    Expanded simple tandem repeat (ESTR) DNA loci that are unstable in the germline have provided the most sensitive tool ever developed for investigating low-dose heritable mutation induction in laboratory mice. Ionizing radiation exposures have shown that ESTR mutations occur mainly in pre-meiotic spermatogonia and stem cells. The average spermatogonial doubling dose is 0.62-0.69 Gy for low LET, and 0.18-0.34 Gy for high LET radiation. Chemical alkylating agents also cause significant ESTR mutation induction in pre-meiotic spermatogonia and stem cells, but are much less effective per unit dose than radiation. ESTR mutation induction efficiency is maximal at low doses of radiation or chemical mutagens, and may decrease at higher dose ranges. DNA repair deficient mice (SCID and PARP-1) with elevated levels of single and double-strand DNA breaks have spontaneously elevated ESTR mutation frequencies, and surprisingly do not show additional ESTR mutation induction following irradiation. In contrast, ESTR mutation induction in p53 knock-outs is indistinguishable from that of wild-type mice. Studies of sentinel mice exposed in situ to ambient air pollution showed elevated ESTR mutation frequencies in males exposed to high levels of particulate matter. These studies highlight the application of the ESTR assay for assessing environmental hazards under real-world conditions. All ESTR studies to date have shown untargeted mutations that occur at much higher frequencies than predicted. The mechanism of this untargeted mutation induction is unknown, and must be elucidated before we can fully understand the biological significance of ESTR mutations, or use these markers for formal risk assessment. Future studies should focus on the mechanism of ESTR mutation induction, refining dose responses, and developing ESTR markers for other animal species

  9. Mutation spectrum produced on PBR322 by 8-Methoxypsoralen plus UV-A light

    International Nuclear Information System (INIS)

    Bauluz, C.; Vidania, R.

    1990-01-01

    The mutagenic effect of 8-MOP+UVA (PUVA treatment) on pBR322 has been analysed by determining the frequency of mutation in the tet gene and identifying the type and position of the mutations produced inside a 276 pb-fragment (Bam-H1-SalI) of the same gene. pBR322 DNA was irradiated with UVA light in the presence of increasing concentrations of 8-Methoxypsoralen (8-MOP). The number of psoralen adducts formed in pBR322 upon that treatment ranged from 0 to 10.7 adducts per plasmid molecule. Modified DNA samples were used to transform several strains of E. Coli (differing in their repair capacities), both in constitutive conditions and after sos pre-induction by 254 nm-irradiation of cells. Mutation frequencies in the tet gene showed to increase in the wild type and uvrA strains along with the number of psoralen adducts per plasmid molecule; higher mutation frequencies were found in cells that had been previously irradiated to induce the SOS expression. Mutant plasmids were isolated from ApRTcS colonies and sequenced by the method of Maxam and Gilbert. Mutations appeared to be unique in most of the cases and were always punctual, i.e. affecting only to one base pair. The relative positions of the mutations showed a high frequency of coincidence among the sequenced fragments, indicating the existence of several DNA regions with high probability to mutated ('hot spots'). (author)

  10. Frequency and clinical features of the JAK2 V617F mutation in pediatric patients with sporadic essential thrombocythemia.

    Science.gov (United States)

    Nakatani, Takuya; Imamura, Toshihiko; Ishida, Hiroyuki; Wakaizumi, Katsuji; Yamamoto, Tohru; Otabe, Osamu; Ishigami, Tsuyoshi; Adachi, Souichi; Morimoto, Akira

    2008-12-01

    Pediatric essential thrombocythemia (ET) is a rare and heterogenous disease entity. While several recent studies have focused on the role of the JAK2 V617F mutation in pediatric ET, the frequency of pediatric ET cases with this mutation and the associated clinical features remain unclear. We examined six childhood cases who had been diagnosed with ET according to WHO criteria (onset age: 0.2-14 years) for the presence of the JAK2 V617F mutation, MPLW515L mutation and JAK2 exon 12 mutations. Two sensitive PCR-based methods were used for the JAK2 V617F genotyping. We also examined the expression of polycythemia rubra vera-1 (PRV-1), which is a diagnostic marker for clonal ET. We found that three of the six cases had the JAK2 V617F mutation and that all six cases expressed PRV-1 in their peripheral granulocytes. Neither MPL W515L mutation nor JAK2 exon 12 mutations was detected in the patients without JAK2 V617F mutation. The two patients who developed thrombocythemia during infancy were JAK2 V617F-negative. These findings suggest that the JAK2 V617F mutation is not rare in childhood sporadic ET cases, and that these cases might be older and myeloproliferative features.

  11. Hot spot mutations in Finnish non-small cell lung cancers.

    Science.gov (United States)

    Mäki-Nevala, Satu; Sarhadi, Virinder Kaur; Rönty, Mikko; Kettunen, Eeva; Husgafvel-Pursiainen, Kirsti; Wolff, Henrik; Knuuttila, Aija; Knuutila, Sakari

    2016-09-01

    Non-small cell lung cancer (NSCLC) is a common cancer with a poor prognosis. The aim of this study was to screen Finnish NSCLC tumor samples for common cancer-related mutations by targeted next generation sequencing and to determine their concurrences and associations with clinical features. Sequencing libraries were prepared from DNA isolated from formalin-fixed, paraffin-embedded tumor material of 425 patients using the AmpliSeq Colon and Lung panel covering mutational hot spot regions of 22 cancer genes. Sequencing was performed with the Ion Torrent Personal Genome Machine (PGM). Data analysis of the hot spot mutations revealed mutations in 77% of the patients, with 7% having 3 or more mutations reported in the Catalogue of Somatic Mutations in Cancer (COSMIC) database. Two of the most frequently mutated genes were TP53 (46%) and KRAS (25%). KRAS codon 12 mutations were the most recurrently occurring mutations. EGFR mutations were significantly associated with adenocarcinoma, female gender and never/light-smoking history; CTNNB1 mutations with light ex-smokers, PIK3CA and TP53 mutations with squamous cell carcinoma, and KRAS with adenocarcinoma. TP53 mutations were most prevalent in current smokers and ERBB2, ERBB4, PIK3CA, NRAS, NOTCH1, FBWX7, PTEN and STK11 mutations occurred exclusively in a group of ever-smokers, however the association was not statistically significant. No mutation was found that associated with asbestos exposure. Finnish NSCLC patients have a similar mutation profile as other Western patients, however with a higher frequency of BRAF mutations but a lower frequency of STK11 and ERBB2 mutations. Moreover, TP53 mutations occurred frequently with other gene mutations, most commonly with KRAS, MET, EGFR and PIK3CA mutations. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Heart tissue of harlequin (hq)/Big Blue mice has elevated reactive oxygen species without significant impact on the frequency and nature of point mutations in nuclear DNA

    Energy Technology Data Exchange (ETDEWEB)

    Crabbe, Rory A. [Department of Biology, University of Western Ontario, London, Ontario, N6A 5B7 (Canada); Hill, Kathleen A., E-mail: khill22@uwo.ca [Department of Biology, University of Western Ontario, London, Ontario, N6A 5B7 (Canada)

    2010-09-10

    Age is a major risk factor for heart disease, and cardiac aging is characterized by elevated mitochondrial reactive oxygen species (ROS) with compromised mitochondrial and nuclear DNA integrity. To assess links between increased ROS levels and mutations, we examined in situ levels of ROS and cII mutation frequency, pattern and spectrum in the heart of harlequin (hq)/Big Blue mice. The hq mouse is a model of premature aging with mitochondrial dysfunction and increased risk of oxidative stress-induced heart disease with the means for in vivo mutation detection. The hq mutation produces a significant downregulation in the X-linked apoptosis-inducing factor gene (Aif) impairing both the antioxidant and oxidative phosphorylation functions of AIF. Brain and skin of hq disease mice have elevated frequencies of point mutations in nuclear DNA and histopathology characterized by cell loss. Reports of associated elevations in ROS in brain and skin have mixed results. Herein, heart in situ ROS levels were elevated in hq disease compared to AIF-proficient mice (p < 0.0001) yet, mutation frequency and pattern were similar in hq disease, hq carrier and AIF-proficient mice. Heart cII mutations were also assessed 15 days following an acute exposure to an exogenous ROS inducer (10 mg paraquat/kg). Acute paraquat exposure with a short mutant manifestation period was insufficient to elevate mutation frequency or alter mutation pattern in the post-mitotic heart tissue of AIF-proficient mice. Paraquat induction of ROS requires mitochondrial complex I and thus is likely compromised in hq mice. Results of this preliminary survey and the context of recent literature suggest that determining causal links between AIF deficiency and the premature aging phenotypes of specific tissues is better addressed with assay of mitochondrial ROS and large-scale changes in mitochondrial DNA in specific cell types.

  13. Heart tissue of harlequin (hq)/Big Blue mice has elevated reactive oxygen species without significant impact on the frequency and nature of point mutations in nuclear DNA

    International Nuclear Information System (INIS)

    Crabbe, Rory A.; Hill, Kathleen A.

    2010-01-01

    Age is a major risk factor for heart disease, and cardiac aging is characterized by elevated mitochondrial reactive oxygen species (ROS) with compromised mitochondrial and nuclear DNA integrity. To assess links between increased ROS levels and mutations, we examined in situ levels of ROS and cII mutation frequency, pattern and spectrum in the heart of harlequin (hq)/Big Blue mice. The hq mouse is a model of premature aging with mitochondrial dysfunction and increased risk of oxidative stress-induced heart disease with the means for in vivo mutation detection. The hq mutation produces a significant downregulation in the X-linked apoptosis-inducing factor gene (Aif) impairing both the antioxidant and oxidative phosphorylation functions of AIF. Brain and skin of hq disease mice have elevated frequencies of point mutations in nuclear DNA and histopathology characterized by cell loss. Reports of associated elevations in ROS in brain and skin have mixed results. Herein, heart in situ ROS levels were elevated in hq disease compared to AIF-proficient mice (p < 0.0001) yet, mutation frequency and pattern were similar in hq disease, hq carrier and AIF-proficient mice. Heart cII mutations were also assessed 15 days following an acute exposure to an exogenous ROS inducer (10 mg paraquat/kg). Acute paraquat exposure with a short mutant manifestation period was insufficient to elevate mutation frequency or alter mutation pattern in the post-mitotic heart tissue of AIF-proficient mice. Paraquat induction of ROS requires mitochondrial complex I and thus is likely compromised in hq mice. Results of this preliminary survey and the context of recent literature suggest that determining causal links between AIF deficiency and the premature aging phenotypes of specific tissues is better addressed with assay of mitochondrial ROS and large-scale changes in mitochondrial DNA in specific cell types.

  14. Somatic frameshift mutations in the Bloom syndrome BLM gene are frequent in sporadic gastric carcinomas with microsatellite mutator phenotype

    Directory of Open Access Journals (Sweden)

    Matei Irina

    2001-08-01

    Full Text Available Abstract Background Genomic instability has been reported at microsatellite tracts in few coding sequences. We have shown that the Bloom syndrome BLM gene may be a target of microsatelliteinstability (MSI in a short poly-adenine repeat located in its coding region. To further characterize the involvement of BLM in tumorigenesis, we have investigated mutations in nine genes containing coding microsatellites in microsatellite mutator phenotype (MMP positive and negative gastric carcinomas (GCs. Methods We analyzed 50 gastric carcinomas (GCs for mutations in the BLM poly(A tract aswell as in the coding microsatellites of the TGFβ1-RII, IGFIIR, hMSH3, hMSH6, BAX, WRN, RECQL and CBL genes. Results BLM mutations were found in 27% of MMP+ GCs (4/15 cases but not in any of the MMP negative GCs (0/35 cases. The frequency of mutations in the other eight coding regions microsatellite was the following: TGFβ1-RII (60 %, BAX (27%, hMSH6 (20%,hMSH3 (13%, CBL (13%, IGFIIR (7%, RECQL (0% and WRN (0%. Mutations in BLM appear to be more frequently associated with frameshifts in BAX and in hMSH6and/or hMSH3. Tumors with BLM alterations present a higher frequency of unstable mono- and trinucleotide repeats located in coding regions as compared with mutator phenotype tumors without BLM frameshifts. Conclusions BLM frameshifts are frequent alterations in GCs specifically associated with MMP+tumors. We suggest that BLM loss of function by MSI may increase the genetic instability of a pre-existent unstable genotype in gastric tumors.

  15. Somatic frameshift mutations in the Bloom syndrome BLM gene are frequent in sporadic gastric carcinomas with microsatellite mutator phenotype

    Science.gov (United States)

    Calin, George; Ranzani, Guglielmina N; Amadori, Dino; Herlea, Vlad; Matei, Irina; Barbanti-Brodano, Giuseppe; Negrini, Massimo

    2001-01-01

    Background Genomic instability has been reported at microsatellite tracts in few coding sequences. We have shown that the Bloom syndrome BLM gene may be a target of microsatelliteinstability (MSI) in a short poly-adenine repeat located in its coding region. To further characterize the involvement of BLM in tumorigenesis, we have investigated mutations in nine genes containing coding microsatellites in microsatellite mutator phenotype (MMP) positive and negative gastric carcinomas (GCs). Methods We analyzed 50 gastric carcinomas (GCs) for mutations in the BLM poly(A) tract aswell as in the coding microsatellites of the TGFβ1-RII, IGFIIR, hMSH3, hMSH6, BAX, WRN, RECQL and CBL genes. Results BLM mutations were found in 27% of MMP+ GCs (4/15 cases) but not in any of the MMP negative GCs (0/35 cases). The frequency of mutations in the other eight coding regions microsatellite was the following: TGFβ1-RII (60 %), BAX (27%), hMSH6 (20%),hMSH3 (13%), CBL (13%), IGFIIR (7%), RECQL (0%) and WRN (0%). Mutations in BLM appear to be more frequently associated with frameshifts in BAX and in hMSH6and/or hMSH3. Tumors with BLM alterations present a higher frequency of unstable mono- and trinucleotide repeats located in coding regions as compared with mutator phenotype tumors without BLM frameshifts. Conclusions BLM frameshifts are frequent alterations in GCs specifically associated with MMP+tumors. We suggest that BLM loss of function by MSI may increase the genetic instability of a pre-existent unstable genotype in gastric tumors. PMID:11532193

  16. Extreme assay sensitivity in molecular diagnostics further unveils intratumour heterogeneity in metastatic colorectal cancer as well as artifactual low-frequency mutations in the KRAS gene.

    Science.gov (United States)

    Mariani, Sara; Bertero, Luca; Osella-Abate, Simona; Di Bello, Cristiana; Francia di Celle, Paola; Coppola, Vittoria; Sapino, Anna; Cassoni, Paola; Marchiò, Caterina

    2017-07-25

    Gene mutations in the RAS family rule out metastatic colorectal carcinomas (mCRCs) from anti-EGFR therapies. We report a retrospective analysis by Sequenom Massarray and fast COLD-PCR followed by Sanger sequencing on 240 mCRCs. By Sequenom, KRAS and NRAS exons 2-3-4 were mutated in 52.9% (127/240) of tumours, while BRAF codon 600 mutations reached 5% (12/240). Fast COLD-PCR found extra mutations at KRAS exon 2 in 15/166 (9%) of samples, previously diagnosed by Sequenom as wild-type or mutated at RAS (exons 3-4) or BRAF genes. After UDG digestion results were reproduced in 2/12 analysable subclonally mutated samples leading to a frequency of true subclonal KRAS mutations of 1.2% (2.1% of the previous Sequenom wild-type subgroup). In 10 out of 12 samples, the subclonal KRAS mutations disappeared (9 out of 12) or turned to a different sequence variant (1 out of 12). mCRC can harbour coexisting multiple gene mutations. High sensitivity assays allow the detection of a small subset of patients harbouring true subclonal KRAS mutations. However, DNA changes with mutant allele frequencies <3% detected in formalin-fixed paraffin-embedded samples may be artifactual in a non-negligible fraction of cases. UDG pre-treatment of DNA is mandatory to identify true DNA changes in archival samples and avoid misinterpretation due to artifacts.

  17. Carrier screening of RTEL1 mutations in the Ashkenazi Jewish population.

    Science.gov (United States)

    Fedick, A M; Shi, L; Jalas, C; Treff, N R; Ekstein, J; Kornreich, R; Edelmann, L; Mehta, L; Savage, S A

    2015-08-01

    Hoyeraal-Hreidarsson syndrome (HH) is a clinically severe variant of dyskeratosis congenita (DC), characterized by cerebellar hypoplasia, microcephaly, intrauterine growth retardation, and severe immunodeficiency in addition to features of DC. Germline mutations in the RTEL1 gene have recently been identified as causative of HH. In this study, the carrier frequency for five RTEL1 mutations that occurred in individuals of Ashkenazi Jewish descent was investigated in order to advise on including them in existing clinical mutation panels for this population. Our screening showed that the carrier frequency for c.3791G>A (p.R1264H) was higher than expected, 1% in the Ashkenazi Orthodox and 0.45% in the general Ashkenazi Jewish population. Haplotype analyses suggested the presence of a common founder. We recommend that the c.3791G>A RTEL1 mutation be considered for inclusion in carrier screening panels in the Ashkenazi population. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Mutation induction in a mouse lymphoma cell mutant sensitive to 4-nitroquinoline 1-oxide and ultraviolet radiation

    International Nuclear Information System (INIS)

    Sato, K.; Hieda, N.

    1980-01-01

    The mutant mouse lymphoma cell Q31, which is sensitive to 4-nitroquinoline 1-oxide and ultraviolet radiation (UV), was compared with the parental L5178Y cell for the effect of caffeine and mutation induction after UV irradiation. Caffeine potentiated the lethal effect of UV in both cell strains to a similar extent, indicating that the defective process in Q31 cells was caffeine-insensitive. UV-induced mutation to 6-thioguanine resistance was determined in L5178Y and Q31 cells. The maximal yield of mutants was obtained 7 days post-irradiation in L5178Y cells and 14 days in Q31 cells for higher UV doses. It appears that a much longer time is required for the mutant cells than for the parental cells for full expression of the resistance phenotype even at equitoxic UV doses. A substantially higher frequency in induced mutations was observed in Q31 cells than in L5178Y cells at a given dose of UV. A plot of induced mutation frequency as a function of logarithm of surviving fraction again indicates hypermutability of Q31 cells as compared with the parental strain. In contrast, X-rays induced a similar frequency of mutations to 6-thioguanine resistance in L5178Y and Q31 cells. (orig.)

  19. Induction of mutation with gamma irradiation in camellia (Camellia Japonica L.)

    International Nuclear Information System (INIS)

    Zhou Diying; Shen Shoujiang; Wang Yanjun

    1990-01-01

    Studies on the radiosensitivity and mutagenic effects in Camellia (Camellia Japonica L.) were carried out with the shoot cuttings, one-year seedlings and three or four-year plants irradiated with 60 Co-γ rays. Results obtained showed that the radiosensitivities varied greatly in cultivars and in different parts of the plant. The suitable irradiation doses for shoot cuttings are 1-3 krad. The treatment of low doses (bellow 2 kard) resulted in higher frequency of mutation with plants of high sensitivity to γ-rays. The frequencies of mutation in flower color and type were 2.5-12.0%. The mutant with ornamental value has been obtained

  20. Somatic USP8 Gene Mutations Are a Common Cause of Pediatric Cushing Disease.

    Science.gov (United States)

    Faucz, Fabio R; Tirosh, Amit; Tatsi, Christina; Berthon, Annabel; Hernández-Ramírez, Laura C; Settas, Nikolaos; Angelousi, Anna; Correa, Ricardo; Papadakis, Georgios Z; Chittiboina, Prashant; Quezado, Martha; Pankratz, Nathan; Lane, John; Dimopoulos, Aggeliki; Mills, James L; Lodish, Maya; Stratakis, Constantine A

    2017-08-01

    Somatic mutations in the ubiquitin-specific protease 8 (USP8) gene have been recently identified as the most common genetic alteration in patients with Cushing disease (CD). However, the frequency of these mutations in the pediatric population has not been extensively assessed. We investigated the status of the USP8 gene at the somatic level in a cohort of pediatric patients with corticotroph adenomas. The USP8 gene was fully sequenced in both germline and tumor DNA samples from 42 pediatric patients with CD. Clinical, biochemical, and imaging data were compared between patients with and without somatic USP8 mutations. Five different USP8 mutations (three missense, one frameshift, and one in-frame deletion) were identified in 13 patients (31%), all of them located in exon 14 at the previously described mutational hotspot, affecting the 14-3-3 binding motif of the protein. Patients with somatic mutations were older at disease presentation [mean 5.1 ± 2.1 standard deviation (SD) vs 13.1 ± 3.6 years, P = 0.03]. Levels of urinary free cortisol, midnight serum cortisol, and adrenocorticotropic hormone, as well as tumor size and frequency of invasion of the cavernous sinus, were not significantly different between the two groups. However, patients harboring somatic USP8 mutations had a higher likelihood of recurrence compared with patients without mutations (46.2% vs 10.3%, P = 0.009). Somatic USP8 gene mutations are a common cause of pediatric CD. Patients harboring a somatic mutation had a higher likelihood of tumor recurrence, highlighting the potential importance of this molecular defect for the disease prognosis and the development of targeted therapeutic options. Copyright © 2017 Endocrine Society

  1. Frequency of janus associated kinase 2 (jak2) mutation in patients of bcr-abl negative myeloproliferative neoplasms

    International Nuclear Information System (INIS)

    Sadiq, M.A.; Ahmed, S.; Ali, N.

    2013-01-01

    To determine the frequency of Janus associated kinase 2 mutation in the patients of BCR-ABL negative classical myeloproliferative neoplasms. Study Design: Cross-sectional descriptive study Place and Duration of Study: Molecular Department of Haematology, Armed Forces Institute of Pathology (AFIP), Rawalpindi from Jul 2011 to Jul 2012. Patients and Methods: Ninety three consecutive patients of Polycythaemia vera (PV), Essential thrombocythaemia (ET) and Idiopathic myelofibrosis (IMF) diagnosed by the conventional haematological criteria were included in the study. All patients were screened for G-T point mutation (V617F) in the JAK2 gene on chromosome 9 by an allele specific PCR. Results: Out of the 93 myeloproliferative neoplasm (MPN) patients, 33(35%) had polycythaemia vera, 36(39%) had essential thrombocythaemia and 24(26%) had idiopathic myelofibrosis. JAK2 mutation was seen in 64/93 (69%) patients including 33/33(100%) in PV, 19/36(52.6%) in ET and 12/24(50%) in IMF. Conclusion: Classical myeloproliferative neoplasms are an important group of heamatological disorder in our country. JAK2 gene mutation is seen in significant proportion of these disorders (69%). JAK2 mutation analysis can be used to differentiate between polycythemia vera and secondary polycythemia in most cases with near certainty, where it was found in 100% of the cases. (author)

  2. Spectrum of EGFR gene mutations in Vietnamese patients with non-small cell lung cancer.

    Science.gov (United States)

    Vu, Hoang Anh; Xinh, Phan Thi; Ha, Hua Thi Ngoc; Hanh, Ngo Thi Tuyet; Bach, Nguyen Duc; Thao, Doan Thi Phuong; Dat, Ngo Quoc; Trung, Nguyen Sao

    2016-03-01

    Epidermal growth factor receptor (EGFR) mutational status is a crucial biomarker for prediction of response to tyrosine kinase inhibitors in patients with non-small cell lung cancer (NSCLC). Although these mutations have been well characterized in other countries, little is known about the frequency or spectrum of EGFR mutations in Vietnamese NSCLC patients. Using Sanger DNA sequencing, we investigated mutations in EGFR exons 18-21 from 332 patients diagnosed with NSCLC at University of Medicine and Pharmacy, Ho Chi Minh City, Vietnam. DNA was extracted from formalin-fixed, paraffin-embedded tissues, followed by PCR amplification and sequencing. EGFR mutations were detected in 135 samples (40.7%), of which eight samples carried double mutations. In total, 46 different types of EGFR mutations were found, including six novel mutations (p.K713E, p.K714R, p.P794S, p.R803W, p.P848S, and p.K867E). Among the four exons investigated, exon 19 was most frequently mutated (63 out of 332 patients, 19%), with the p.E746_A750del appearing in 43 samples. Exon 21 was mutated in 56 samples (16.9%), of which 47 were p.L858R. Each of exons 18 and 20 was mutated in 12 samples (3.6%). The frequency of EGFR mutations was higher in females than in males (48.9% vs 35%, P = 0.012), but not statistically different between adenocarcinomas and other histological types of NSCLC (41.3% vs 34.5%, P = 0.478). DNA sequencing detected EGFR mutations with high frequency and revealed a broad spectrum of mutation type in Vietnamese patients with NSCLC. © 2015 Wiley Publishing Asia Pty Ltd.

  3. Divergent epidermal growth factor receptor mutation patterns between smokers and non-smokers with lung adenocarcinoma.

    Science.gov (United States)

    Tseng, Jeng-Sen; Wang, Chih-Liang; Yang, Tsung-Ying; Chen, Chih-Yi; Yang, Cheng-Ta; Chen, Kun-Chieh; Hsu, Kuo-Hsuan; Tsai, Chi-Ren; Chang, Gee-Chen

    2015-12-01

    Smoking status is an important determinant of the prevalence of epidermal growth factor receptor (EGFR) mutations in lung cancer patients. However, it is unclear whether smoking status could also influence the spectrum of EGFR mutations. We enrolled patients with lung adenocarcinoma from three medical centers in Taiwan. EGFR mutations were assessed by Sanger direct sequencing. The objective of this study was to evaluate the influence of smoking status on both the frequency and patterns of EGFR mutations. From 2001 to 2013, a total of 1175 patients with lung adenocarcinoma were enrolled for EGFR mutation analysis. The overall EGFR mutation rate was 59.6%, which was significantly higher in females than males (69.1% vs. 49.8%) and in non-smokers than current/former smokers (73.8% vs. 29.8%) (both Psmokers expressed L858R mutation less frequently (35.2% vs. 50.2%, P=0.005) and exon 19 deletions more frequently (52.8% vs 38.8%, P=0.008) than non-smokers. Smokers and non-smokers also had divergent exon 19 deletions subtypes (Del E746-A750 82.5% vs. 57.6%, respectively, Psmokers were associated with a higher rate of complex mutations than non-smokers (34.2% vs. 8.4%, P<0.001). Our results suggested that smoking status could influence not only the frequency but also the spectrum of EGFR mutations. These findings provide a clue for further investigation of EGFR mutagenesis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. Prevalence of deleterious ATM germline mutations in gastric cancer patients.

    Science.gov (United States)

    Huang, Dong-Sheng; Tao, Hou-Quan; He, Xu-Jun; Long, Ming; Yu, Sheng; Xia, Ying-Jie; Wei, Zhang; Xiong, Zikai; Jones, Sian; He, Yiping; Yan, Hai; Wang, Xiaoyue

    2015-12-01

    Besides CDH1, few hereditary gastric cancer predisposition genes have been previously reported. In this study, we discovered two germline ATM mutations (p.Y1203fs and p.N1223S) in a Chinese family with a history of gastric cancer by screening 83 cancer susceptibility genes. Using a published exome sequencing dataset, we found deleterious germline mutations of ATM in 2.7% of 335 gastric cancer patients of different ethnic origins. The frequency of deleterious ATM mutations in gastric cancer patients is significantly higher than that in general population (p=0.0000435), suggesting an association of ATM mutations with gastric cancer predisposition. We also observed biallelic inactivation of ATM in tumors of two gastric cancer patients. Further evaluation of ATM mutations in hereditary gastric cancer will facilitate genetic testing and risk assessment.

  5. De novo activating epidermal growth factor mutations (EGFR) in small-cell lung cancer.

    Science.gov (United States)

    Thai, Alesha; Chia, Puey L; Russell, Prudence A; Do, Hongdo; Dobrovic, Alex; Mitchell, Paul; John, Thomas

    2017-09-01

    In Australia, mutations in epidermal growth factor mutations (EGFR) occur in 15% of patients diagnosed with non-small-cell lung cancer and are found with higher frequency in female, non-smokers of Asian ethnicity. Activating mutations in the EGFR gene are rarely described in SCLC. We present two cases of de novo EGFR mutations in patients with SCLC detected in tissue and in plasma cell free DNA, both of whom were of Asian ethnicity and never-smokers. These two cases add to the growing body of evidence suggesting that screening for EGFR mutations in SCLC should be considered in patients with specific clinical features. © 2017 Royal Australasian College of Physicians.

  6. Distinct Viral and Mutational Spectrum of Endemic Burkitt Lymphoma.

    Directory of Open Access Journals (Sweden)

    Francesco Abate

    2015-10-01

    Full Text Available Endemic Burkitt lymphoma (eBL is primarily found in children in equatorial regions and represents the first historical example of a virus-associated human malignancy. Although Epstein-Barr virus (EBV infection and MYC translocations are hallmarks of the disease, it is unclear whether other factors may contribute to its development. We performed RNA-Seq on 20 eBL cases from Uganda and showed that the mutational and viral landscape of eBL is more complex than previously reported. First, we found the presence of other herpesviridae family members in 8 cases (40%, in particular human herpesvirus 5 and human herpesvirus 8 and confirmed their presence by immunohistochemistry in the adjacent non-neoplastic tissue. Second, we identified a distinct latency program in EBV involving lytic genes in association with TCF3 activity. Third, by comparing the eBL mutational landscape with published data on sporadic Burkitt lymphoma (sBL, we detected lower frequencies of mutations in MYC, ID3, TCF3 and TP53, and a higher frequency of mutation in ARID1A in eBL samples. Recurrent mutations in two genes not previously associated with eBL were identified in 20% of tumors: RHOA and cyclin F (CCNF. We also observed that polyviral samples showed lower numbers of somatic mutations in common altered genes in comparison to sBL specimens, suggesting dual mechanisms of transformation, mutation versus virus driven in sBL and eBL respectively.

  7. Distinct Viral and Mutational Spectrum of Endemic Burkitt Lymphoma.

    Science.gov (United States)

    Abate, Francesco; Ambrosio, Maria Raffaella; Mundo, Lucia; Laginestra, Maria Antonella; Fuligni, Fabio; Rossi, Maura; Zairis, Sakellarios; Gazaneo, Sara; De Falco, Giulia; Lazzi, Stefano; Bellan, Cristiana; Rocca, Bruno Jim; Amato, Teresa; Marasco, Elena; Etebari, Maryam; Ogwang, Martin; Calbi, Valeria; Ndede, Isaac; Patel, Kirtika; Chumba, David; Piccaluga, Pier Paolo; Pileri, Stefano; Leoncini, Lorenzo; Rabadan, Raul

    2015-10-01

    Endemic Burkitt lymphoma (eBL) is primarily found in children in equatorial regions and represents the first historical example of a virus-associated human malignancy. Although Epstein-Barr virus (EBV) infection and MYC translocations are hallmarks of the disease, it is unclear whether other factors may contribute to its development. We performed RNA-Seq on 20 eBL cases from Uganda and showed that the mutational and viral landscape of eBL is more complex than previously reported. First, we found the presence of other herpesviridae family members in 8 cases (40%), in particular human herpesvirus 5 and human herpesvirus 8 and confirmed their presence by immunohistochemistry in the adjacent non-neoplastic tissue. Second, we identified a distinct latency program in EBV involving lytic genes in association with TCF3 activity. Third, by comparing the eBL mutational landscape with published data on sporadic Burkitt lymphoma (sBL), we detected lower frequencies of mutations in MYC, ID3, TCF3 and TP53, and a higher frequency of mutation in ARID1A in eBL samples. Recurrent mutations in two genes not previously associated with eBL were identified in 20% of tumors: RHOA and cyclin F (CCNF). We also observed that polyviral samples showed lower numbers of somatic mutations in common altered genes in comparison to sBL specimens, suggesting dual mechanisms of transformation, mutation versus virus driven in sBL and eBL respectively.

  8. Frequency of epidermal growth factor receptor mutations in Jordanian lung adenocarcinoma patients at diagnosis

    Directory of Open Access Journals (Sweden)

    Natheir Obeidat

    2016-01-01

    Conclusion: The present study revealed that the EGFR mutations rate in Jordanian patients with adenocarcinoma of the lung was higher than in African-American, and some white Caucasian patients, and was lower than in patients in East Asia, and other countries of South Asia.

  9. Genetic frequencies related to severe or profound sensorineural hearing loss in Inner Mongolia Autonomous Region

    Directory of Open Access Journals (Sweden)

    Yongzhi Liu

    Full Text Available Abstract The aim was to study the frequencies of common deafness-related mutations and their contribution to hearing loss in different regions of Inner Mongolia. A total of 738 deaf children were recruited from five different ethnic groups of Inner Mongolia, including Han Chinese (n=486, Mongolian (n=216, Manchurian (n=24, Hui (n=6 and Daur (n=6. Nine common mutations in four genes (GJB2, SLC26A4, GJB3 and mitochondrial MT-RNR1 gene were detected by allele-specific PCR and universal array. At least one mutated allele was detected in 282 patients. Pathogenic mutations were detected in 168 patients: 114 were homozygotes and 54 were compound heterozygotes. The 114 patients were carriers of only one mutated allele. The frequency of GJB2 variants in Han Chinese (21.0% was higher than that in Mongolians (16.7%, but not significantly different. On the other hand, the frequency of SLC26A4 variants in Han Chinese (14.8% was lower than that in Mongolians (19.4%, but also not significantly different. The frequency of patients with pathogenic mutations was different in Ulanqab (21.4%, Xilingol (40.0%, Chifeng (40.0%, Hulunbeier (30.0%, Hohhot (26.3%, and in Baotou (0%. In conclusion, the frequency of mutated alleles in deafness-related genes did not differ between Han Chinese and Mongolians. However, differences in the distribution of common deafness-related mutations were found among the investigated areas of Inner Mongolia.

  10. SPOP Mutations in Prostate Cancer across Demographically Diverse Patient Cohorts

    Directory of Open Access Journals (Sweden)

    Mirjam Blattner

    2014-01-01

    Full Text Available BACKGROUND: Recurrent mutations in the Speckle-Type POZ Protein (SPOP gene occur in up to 15% of prostate cancers. However, the frequency and features of cancers with these mutations across different populations is unknown. OBJECTIVE: To investigate SPOP mutations across diverse cohorts and validate a series of assays employing high-resolution melting (HRM analysis and Sanger sequencing for mutational analysis of formalin-fixed paraffin-embedded material. DESIGN, SETTING, AND PARTICIPANTS: 720 prostate cancer samples from six international cohorts spanning Caucasian, African American, and Asian patients, including both prostate-specific antigen-screened and unscreened populations, were screened for their SPOP mutation status. Status of SPOP was correlated to molecular features (ERG rearrangement, PTEN deletion, and CHD1 deletion as well as clinical and pathologic features. RESULTS AND LIMITATIONS: Overall frequency of SPOP mutations was 8.1% (4.6% to 14.4%, SPOP mutation was inversely associated with ERG rearrangement (P < .01, and SPOP mutant (SPOPmut cancers had higher rates of CHD1 deletions (P < .01. There were no significant differences in biochemical recurrence in SPOPmut cancers. Limitations of this study include missing mutational data due to sample quality and lack of power to identify a difference in clinical outcomes. CONCLUSION: SPOP is mutated in 4.6% to 14.4% of patients with prostate cancer across different ethnic and demographic backgrounds. There was no significant association between SPOP mutations with ethnicity, clinical, or pathologic parameters. Mutual exclusivity of SPOP mutation with ERG rearrangement as well as a high association with CHD1 deletion reinforces SPOP mutation as defining a distinct molecular subclass of prostate cancer.

  11. Frequency of ABL gene mutations in chronic myeloid leukemia patients resistant to imatinib and results of treatment switch to second-generation tyrosine kinase inhibitors.

    Science.gov (United States)

    Marcé, Silvia; Zamora, Lurdes; Cabezón, Marta; Xicoy, Blanca; Boqué, Concha; Fernández, Cristalina; Grau, Javier; Navarro, José-Tomás; Fernández de Sevilla, Alberto; Ribera, Josep-Maria; Feliu, Evarist; Millá, Fuensanta

    2013-08-04

    Tyrosine kinase inhibitors (TKI) have improved the management of patients with chronic myeloid leukemia (CML). However, a significant proportion of patients do not achieve the optimal response or are resistant to TKI. ABL kinase domain mutations have been extensively implicated in the pathogenesis of TKI resistance. Treatment with second-generation TKI has produced high rates of hematologic and cytogenetic responses in mutated ABL patients. The aim of this study was to determine the type and frequency of ABL mutations in patients who were resistant to imatinib or had lost the response, and to analyze the effect of second-generation TKI on their outcome. The presence of ABL mutations in 45 CML patients resistant to imatinib was evaluated by direct sequencing and was correlated with the results of the cytogenetic study (performed in 39 cases). The outcome of these patients after therapy with nilotinib or dasatinib was analyzed. ABL mutations were detected in 14 out of 45 resistant patients. Patients with clonal cytogenetic evolution tended to develop mutations more frequently than those without clonal evolution. Nine out of the 15 patients with ABL mutation responded to a treatment switch to nilotinib (n=4), dasatinib (n=2), interferon (n=1) or hematopoietic stem cell transplantation (n=2). The frequency of ABL mutations in CML patients resistant to imatinib is high and is more frequent among those with clonal cytogenetic evolution. The change to second-generation TKI can overcome imatinib resistance in most of the mutated patients. Copyright © 2012 Elsevier España, S.L. All rights reserved.

  12. Frequency of the hemochromatosis HFE mutations C282Y, H63D, and S65C in blood donors in the Faroe Islands

    DEFF Research Database (Denmark)

    Milman, Nils; á Steig, Torkil; Koefoed, Pernille

    2004-01-01

    on the HFE gene was assessed by genotyping using the polymerase chain reaction (PCR) technique and calculated from direct allele counting. We found no C282Y homozygous subjects; 28 (14.0%) subjects were C282Y heterozygous and four subjects were C282Y/H63D compound heterozygous (2.0%). The C282Y allele......The aim of the study was to assess the frequencies of the hereditary hemochromatosis HFE mutations C282Y, H63D, and S65C in the population in the Faroe Islands. The series comprised 200 randomly selected blood donors of Faroese heritage. The frequency of the C282Y, H63D, and S65C mutations.......6%. Screening of larger groups of the Faroese population for HFE mutations especially C282Y should be considered in order to establish the penetrance....

  13. Higher frequency network activity flow predicts lower frequency node activity in intrinsic low-frequency BOLD fluctuations.

    Science.gov (United States)

    Bajaj, Sahil; Adhikari, Bhim Mani; Dhamala, Mukesh

    2013-01-01

    The brain remains electrically and metabolically active during resting conditions. The low-frequency oscillations (LFO) of the blood oxygen level-dependent (BOLD) signal of functional magnetic resonance imaging (fMRI) coherent across distributed brain regions are known to exhibit features of this activity. However, these intrinsic oscillations may undergo dynamic changes in time scales of seconds to minutes during resting conditions. Here, using wavelet-transform based time-frequency analysis techniques, we investigated the dynamic nature of default-mode networks from intrinsic BOLD signals recorded from participants maintaining visual fixation during resting conditions. We focused on the default-mode network consisting of the posterior cingulate cortex (PCC), the medial prefrontal cortex (mPFC), left middle temporal cortex (LMTC) and left angular gyrus (LAG). The analysis of the spectral power and causal flow patterns revealed that the intrinsic LFO undergo significant dynamic changes over time. Dividing the frequency interval 0 to 0.25 Hz of LFO into four intervals slow-5 (0.01-0.027 Hz), slow-4 (0.027-0.073 Hz), slow-3 (0.073-0.198 Hz) and slow-2 (0.198-0.25 Hz), we further observed significant positive linear relationships of slow-4 in-out flow of network activity with slow-5 node activity, and slow-3 in-out flow of network activity with slow-4 node activity. The network activity associated with respiratory related frequency (slow-2) was found to have no relationship with the node activity in any of the frequency intervals. We found that the net causal flow towards a node in slow-3 band was correlated with the number of fibers, obtained from diffusion tensor imaging (DTI) data, from the other nodes connecting to that node. These findings imply that so-called resting state is not 'entirely' at rest, the higher frequency network activity flow can predict the lower frequency node activity, and the network activity flow can reflect underlying structural

  14. Epidermal growth factor receptor mutations in lung adenocarcinoma in Malaysian patients.

    Science.gov (United States)

    Liam, Chong-Kin; Wahid, Mohamed Ibrahim A; Rajadurai, Pathmanathan; Cheah, Yoke-Kqueen; Ng, Tiffany Shi-Yeen

    2013-06-01

    Despite available data from other Asian countries, the prevalence of epidermal growth factor receptor (EGFR) mutations among lung adenocarcinoma patients has not been reported in Malaysia. This study sought to determine the frequency of EGFR mutations among multiethnic Malaysian patients diagnosed with lung adenocarcinoma. Demographic and clinical information of patients whose lung adenocarcinoma biopsy specimens were submitted for EGFR mutation testing at Sime Darby Medical Center from 2009 to 2011 were analyzed. EGFR mutations at exons 18, 19, 20, and 21 were detected either through bidirectional sequencing or real-time polymerase chain reaction. Among 812 patients in the study, 49% were female, 63.7% were ethnic Chinese, 29.4% Malay, 4.8% Indian, and 2.1% other ethnic groups. Mutations were present in the tumors of 321 patients (39.5%), with mutations at exons 19 (23.5%) and 21 (14.9%) being the most common. Mutations were significantly more frequent among women than in men (52.5% versus 27.8%, p < 0.001). Although mutations were more common among Chinese (40.8%) compared with Malay (37.2%) or Indian (33.3%) patients, the difference was not statistically significant (p = 0.591). Of 211 patients with smoking history records, never-smokers had a higher mutation rate compared with ever-smokers (54.8% versus 20.7%, p < 0.001). EGFR mutations were present in 39.5% of patients. Mutations were more common in women and never-smokers with no differences in mutation frequency between different ethnicities. Because of the high mutation rates, reflex testing for EGFR mutation should be a routine practice for advanced lung adenocarcinoma patients in Malaysia.

  15. Hemochromatosis (HFE gene mutations in Brazilian chronic hemodialysis patients

    Directory of Open Access Journals (Sweden)

    F.V. Perícole

    2005-09-01

    Full Text Available Patients with chronic renal insufficiency (CRI have reduced hemoglobin levels, mostly as a result of decreased kidney production of erythropoietin, but the relation between renal insufficiency and the magnitude of hemoglobin reduction has not been well defined. Hereditary hemochromatosis is an inherited disorder of iron metabolism. The importance of the association of hemochromatosis with treatment for anemia among patients with CRI has not been well described. We analyzed the frequency of the C282Y and H63D mutations in the HFE gene in 201 Brazilian individuals with CRI undergoing hemodialysis. The analysis of the effects of HFE mutations on iron metabolism and anemia with biochemical parameters was possible in 118 patients of this study (hemoglobin, hematocrit, ferritin levels, transferrin saturation, and serum iron. A C282Y heterozygous mutation was found in 7/201 (3.4% and H63D homozygous and heterozygous mutation were found in 2/201 (1.0% and 46/201 (22.9%, respectively. The allelic frequencies of the HFE mutations (0.017 for C282Y mutation and 0.124 for H63D mutation did not differ between patients with CRI and healthy controls. Regarding the biochemical parameters, no differences were observed between HFE heterozygous and mutation-negative patients, although ferritin levels were not higher among patients with the H63D mutation (P = 0.08. From what we observed in our study, C282Y/H63D HFE gene mutations are not related to degrees of anemia or iron stores in CRI patients receiving intravenous iron supplementation (P > 0.10. Nevertheless, the present data suggest that the H63D mutation may have an important function as a modulating factor of iron overload in these patients.

  16. Hybridization alters spontaneous mutation rates in a parent-of-origin-dependent fashion in Arabidopsis.

    Science.gov (United States)

    Bashir, Tufail; Sailer, Christian; Gerber, Florian; Loganathan, Nitin; Bhoopalan, Hemadev; Eichenberger, Christof; Grossniklaus, Ueli; Baskar, Ramamurthy

    2014-05-01

    Over 70 years ago, increased spontaneous mutation rates were observed in Drosophila spp. hybrids, but the genetic basis of this phenomenon is not well understood. The model plant Arabidopsis (Arabidopsis thaliana) offers unique opportunities to study the types of mutations induced upon hybridization and the frequency of their occurrence. Understanding the mutational effects of hybridization is important, as many crop plants are grown as hybrids. Besides, hybridization is important for speciation and its effects on genome integrity could be critical, as chromosomal rearrangements can lead to reproductive isolation. We examined the rates of hybridization-induced point and frameshift mutations as well as homologous recombination events in intraspecific Arabidopsis hybrids using a set of transgenic mutation detector lines that carry mutated or truncated versions of a reporter gene. We found that hybridization alters the frequency of different kinds of mutations. In general, Columbia (Col)×Cape Verde Islands and Col×C24 hybrid progeny had decreased T→G and T→A transversion rates but an increased C→T transition rate. Significant changes in frameshift mutation rates were also observed in some hybrids. In Col×C24 hybrids, there is a trend for increased homologous recombination rates, except for the hybrids from one line, while in Col×Cape Verde Islands hybrids, this rate is decreased. The overall genetic distance of the parents had no influence on mutation rates in the progeny, as closely related accessions on occasion displayed higher mutation rates than accessions that are separated farther apart. However, reciprocal hybrids had significantly different mutation rates, suggesting parent-of-origin-dependent effects on the mutation frequency.

  17. Mutagenic treatments towards increasing the frequency of day-neutral mutations and standardization of procedures for tissue culture, in potato

    International Nuclear Information System (INIS)

    Upadhya, M.D.; Chandra, R.; Abraham, M.J.

    1976-01-01

    Various chemical mutagens and gamma radiation have been used on single dormant eyes and true seeds with a view to finding effective mutagenic treatment for the induction of day-length neutral mutants in potato using an effective screening technique for the isolation of day-length neutral mutants. Sodium meta bisulphite (SMS) was found to be an efficient mutagen in inducing mutations for this trait in true seeds although the same concentrations, when used for treating the single tuber eyes proved lethal. Pre-soaking the seeds for 24 hrs prior to treatment with 0.0025M SMS gave highest frequency of the mutants followed by 48 hrs presoaking, indicating a sensitive stage during the cell cycle in true seeds. Other mutagen treatments gave different frequencies of mutations. The highest frequency of day-length neutral mutants was observed when seeds irradiated with 40 Kr of gamma radiation were treated with 0.05M hydrazinium dichloride solution. Screening procedures have also been standardised with the development of synethetic media for the isolation of biochemical mutants at the true seed level. Initial efforts have yielded mutants resistant to LD 100 doses of ethionine. Another aspect of the study was to develop a proper potato callus culture technique. A medium has been developed to produce and maintain callus from potato leaf strips. Efforts on the regeneration of shoot and roots from callus, have so far lead to differentiation of callus to form roots. The ultimate aim of these studies is to develop plantlets from single cell which would form the units of mutation induction and isolation. (author)

  18. Patients with primary breast and primary female genital tract diffuse large B cell lymphoma have a high frequency of MYD88 and CD79B mutations.

    Science.gov (United States)

    Cao, Xin-Xin; Li, Jian; Cai, Hao; Zhang, Wei; Duan, Ming-Hui; Zhou, Dao-Bin

    2017-11-01

    This study is to retrospectively evaluate the prevalence of MYD88 and CD79B mutations and the clinicopathologic characteristics of patients with primary diffuse large B cell lymphoma (DLBCL) of the female genital tract and breast. The characteristics, treatments, and outcomes of 19 patients diagnosed with primary DLBCL of the female genital tract and breast, who had formalin-fixed and paraffin-embedded tissues obtained from diagnostic samples diagnosed between January 2004 and June 2016, were analyzed retrospectively. Nineteen female patients (7 with primary breast and 12 with primary female genital tract DLBCL) were included in this retrospective study. Eleven patients (57.9%) carried a MYD88 mutation, including 10 with MYD8 L265P and 1 with the MYD88 L265S mutation. Seven patients (36.8%) harbored a CD79B mutation, which included two cases with CD79B Y196H, two cases with CD79B Y196N, one case with CD79B Y196D, one case with CD79B Y196F, and one case with CD79B Y196X. Four cases had both MYD88 and CD79B mutations. The clinicopathologic parameters, progression-free survival (PFS), and overall survival (OS) of the MYD88 mutation-carrying group were not significantly different from those of the MYD88 wild-type group except for higher LDH levels. Six patients received cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP), while 13 patients received rituximab plus CHOP, and 13 patients received central nervous system prophylaxis. The median OS and PFS were 73 and 56 months, respectively. Patients with primary breast and primary female genital tract DLBCL have a high frequency of MYD88 and CD79B mutations. The presence of these mutations does not affect survival but may offer additional therapeutic options.

  19. Novel mutations and mutation combinations of ryanodine receptor in a chlorantraniliprole resistant population of Plutella xylostella (L.)

    Science.gov (United States)

    Guo, Lei; Liang, Pei; Zhou, Xuguo; Gao, Xiwu

    2014-01-01

    A previous study documented a glycine to glutamic acid mutation (G4946E) in ryanodine receptor (RyR) was highly correlated to diamide insecticide resistance in field populations of Plutella xylostella (Lepidoptera: Plutellidae). In this study, a field population collected in Yunnan province, China, exhibited a 2128-fold resistance to chlorantraniliprole. Sequence comparison between resistant and susceptible P. xylostella revealed three novel mutations including a glutamic acid to valine substitution (E1338D), a glutamine to leucine substitution (Q4594L) and an isoleucine to methionine substitution (I4790M) in highly conserved regions of RyR. Frequency analysis of all four mutations in this field population showed that the three new mutations showed a high frequency of 100%, while the G4946E had a frequency of 20%. Furthermore, the florescent ligand binding assay revealed that the RyR containing multiple mutations displayed a significantly lower affinity to the chlorantraniliprole. The combined results suggested that the co-existence of different combinations of the four mutations was involved in the chlorantraniliprole resistance. An allele-specific PCR based method was developed for the diagnosis of the four mutations in the field populations of P. xylostella. PMID:25377064

  20. Frequency of Fanconi anemia in Brazil and efficacy of screening for the FANCA 3788-3790del mutation

    Directory of Open Access Journals (Sweden)

    N. Magdalena

    2005-05-01

    Full Text Available Fanconi anemia (FA is an autosomal recessive genetic disease characterized by progressive bone marrow failure, susceptibility to cancer and multiple congenital anomalies. There is important clinical variability among patients and the knowledge of factors which might predict outcome would greatly help the decision making regarding the choices of treatment and the appropriate time to start it. Future studies of the possible correlation between specific mutations with specific clinical presentations will provide the answer to one of these factors. At our Center we standardized a rapid and precise screening test using a mismatch PCR assay for a specific mutation (3788-3790del in exon 38 of gene FANCA in Brazilian FA patients. We present the results obtained after screening 80 non-consanguineous FA patients referred from all regions of Brazil with a clinical diagnosis of FA supported by cellular hypersensitivity to diepoxybutane. We were able to detect the 3788-3790del allele in 24 of the 80 (30% FA patients studied. Thirteen of the 80 (16.25% were homozygotes and 11 of the 80 (13.75% were compound heterozygotes, thus confirming the high frequency of the FANCA 3788-3790del mutation in Brazilian FA patients. The identification of patients with specific mutations in the FA genes may lead to a better clinical description of this condition, also providing data for genotype-phenotype correlations, to a better understanding of the interaction of this specific mutation with other mutations in compound heterozygote patients, and ultimately to the right choices of treatment for each patient with improvement of the prognosis on future studies.

  1. Frequency of Fanconi anemia in Brazil and efficacy of screening for the FANCA 3788-3790del mutation.

    Science.gov (United States)

    Magdalena, N; Pilonetto, D V; Bitencourt, M A; Pereira, N F; Ribeiro, R C; Jeng, M; Pasquini, R

    2005-05-01

    Fanconi anemia (FA) is an autosomal recessive genetic disease characterized by progressive bone marrow failure, susceptibility to cancer and multiple congenital anomalies. There is important clinical variability among patients and the knowledge of factors which might predict outcome would greatly help the decision making regarding the choices of treatment and the appropriate time to start it. Future studies of the possible correlation between specific mutations with specific clinical presentations will provide the answer to one of these factors. At our Center we standardized a rapid and precise screening test using a mismatch PCR assay for a specific mutation (3788-3790del in exon 38 of gene FANCA) in Brazilian FA patients. We present the results obtained after screening 80 non-consanguineous FA patients referred from all regions of Brazil with a clinical diagnosis of FA supported by cellular hypersensitivity to diepoxybutane. We were able to detect the 3788-3790del allele in 24 of the 80 (30%) FA patients studied. Thirteen of the 80 (16.25%) were homozygotes and 11 of the 80 (13.75%) were compound heterozygotes, thus confirming the high frequency of the FANCA 3788-3790del mutation in Brazilian FA patients. The identification of patients with specific mutations in the FA genes may lead to a better clinical description of this condition, also providing data for genotype-phenotype correlations, to a better understanding of the interaction of this specific mutation with other mutations in compound heterozygote patients, and ultimately to the right choices of treatment for each patient with improvement of the prognosis on future studies.

  2. Ultra-deep sequencing of mouse mitochondrial DNA: mutational patterns and their origins.

    Directory of Open Access Journals (Sweden)

    Adam Ameur

    2011-03-01

    Full Text Available Somatic mutations of mtDNA are implicated in the aging process, but there is no universally accepted method for their accurate quantification. We have used ultra-deep sequencing to study genome-wide mtDNA mutation load in the liver of normally- and prematurely-aging mice. Mice that are homozygous for an allele expressing a proof-reading-deficient mtDNA polymerase (mtDNA mutator mice have 10-times-higher point mutation loads than their wildtype siblings. In addition, the mtDNA mutator mice have increased levels of a truncated linear mtDNA molecule, resulting in decreased sequence coverage in the deleted region. In contrast, circular mtDNA molecules with large deletions occur at extremely low frequencies in mtDNA mutator mice and can therefore not drive the premature aging phenotype. Sequence analysis shows that the main proportion of the mutation load in heterozygous mtDNA mutator mice and their wildtype siblings is inherited from their heterozygous mothers consistent with germline transmission. We found no increase in levels of point mutations or deletions in wildtype C57Bl/6N mice with increasing age, thus questioning the causative role of these changes in aging. In addition, there was no increased frequency of transversion mutations with time in any of the studied genotypes, arguing against oxidative damage as a major cause of mtDNA mutations. Our results from studies of mice thus indicate that most somatic mtDNA mutations occur as replication errors during development and do not result from damage accumulation in adult life.

  3. DNA synthesis time in germinating rice and pattern of diethylsulphate induced mutations in pre-soaked seeds

    International Nuclear Information System (INIS)

    Narahari, P.

    1978-01-01

    DNA synthesis pattern in germinating rice seeds, pre-soaked in water for varying periods upto 48 hr, was determined by following the pulse incorporation of 3 H-thymidine into the TCA-insoluble nucleoprotein. Synthesis of DNA commenced at 24 hr, progressively increased to a first peak at about 38 hr, thereafter showed a 1/3rd drop and subsequently increased to a 2nd and still higher peak at 46 to 48 hr of pre-soaking. Treatments of diethylsulphate (dES) at a low concentration (0.2%-2hr) administered at various progressing stages of DNA synthesis resulted in decrease in seedling height and survival, and increase in mutation frequency at 45 hr. pre-soaking, maximum mutation frequencies of 20, 10 and 2% on M 1 plants, M 1 spikes and M 2 seedling bases, respectively were observed. Higher dES concentration (0.3%-2hr) given at later periods of pre-soaking showed near lethal effects and consequently decreased mutation frequencies. Treatments of sodium fluoride given singly or in combination with dES did not show any substantially different results as compared to those of the respective controls. Mutation spectra observed after dES treatments to germinating seeds, at different pre-soaking periods, were quite dissimilar. Specific mutations of economic importance like semi-dwarf mutants were isolated from the treatment of germinating seeds pre-soaked for 37.5 hr or more when shoot apex cells were undergoing DNA synthesis. (author)

  4. Specific-locus experiments show that female mice exposed near the time of birth to low-LET ionizing radiation exhibit both a low mutational response and a dose-rate effect

    International Nuclear Information System (INIS)

    Selby, P.B.; Lee, S.S.; Kelly, E.M.; Bangham, J.W.; Raymer, G.D.; Hunsicker, P.R.

    1991-01-01

    Female mice were exposed to 300 R of 73-93 R/min X-radiation either as fetuses at 18.5d post conception (p.c.) or within 9h after birth. Combining the similar results from these 2 groups yielded a specific-locus mutation frequency of 9.4x10 -8 mutation/locus/R, which is statistically significantly higher than the historical-control mutation frequency, but much lower than the rate obtained by irradiating mature and maturing oocytes in adults. Other females, exposed at 18.5 days p.c. to 300 R of 0.79 R/min γ-radiation, yielded a mutation frequency that was statistically significantly lower than the frequency at high dose rates. The low-dose-rate group also had markedly higher fertility. It appears that the doe-rate effect for mutations induced near the time of birth may be more pronounced than that reported for mature and maturing oocytes of adults. A hypothesis sometimes advanced to explain low mutation frequencies recovered from cell populations that experience considerable radiation-induced cell killing is that there is selection against mutant cells. The reason for the relatively low mutational response following acute irradiation in the experiments is unknown; however, the finding of a dose-rate effect in these oocytes in the presence of only minor radiation-induced cell killing (as judged from fertility) makes it seem unlikely that selection was responsible for the low mutational response following acute exposure. Had selection been an important factor, the mutation frequency should have increased when oocyte killing was markedly reduced. (author). 32 refs.; 5 figs.; 5 tabs

  5. Mutation breeding newsletter. No. 33

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1989-01-01

    This issue of the newsletter reports a number of research news and research abstracts on application of radiation induced mutation techniques to increase mutagenesis and mutation frequency in plant breeding projects.

  6. Mutation breeding newsletter. No. 33

    International Nuclear Information System (INIS)

    1989-01-01

    This issue of the newsletter reports a number of research news and research abstracts on application of radiation induced mutation techniques to increase mutagenesis and mutation frequency in plant breeding projects

  7. Radiation-induced mutation frequency in marked chromosome of Macaca mulatta

    International Nuclear Information System (INIS)

    Dzhemilev, Z.A.; Machavariani, M.G.

    1976-01-01

    The symmetric and asymmetric exchange frequencies of marked (nucleolus forming) chromosomes were studied in the lymphocytes and epithelial kidney cells irradiated by X-rays at G 0 , both in vivo and in vitro. Symmetric and asymmetric exchange frequencies were found to be equal. In both the types of Macaca mulatta cells, the exchange frequency in the long arm appeared to be higher than theoretically expected. The increased exchange in the long arm is thought to be due to a greater quantity of late replicating heterochromatin in it. The short arm of marked chromosome of epithelial kidney cells enters the exchange in accordance to its length in mitosis, but exchange number in the short arm chromosome in lymphocytes is lower than in epithelial cells. This difference is caused likely by different functioning of the nucleolus forming heterochromatin. (author)

  8. An inhibitor of potentially lethal damage (PLD) repair reduces the frequency of γ-ray mutations in cultured Chinese hamster V79 cells

    International Nuclear Information System (INIS)

    Yokoiyama, A.; Kada, T.; Kuroda, Y.

    1992-01-01

    Cordycepin (3'-deoxyadenosine, 3 - dA) is an RNA antimetabolite and a radiosensitizer in cultured mammalian cells. In the present paper, the effects of 3'-dA on γ-ray-induced lethality and 6-thioguanine (6TG)-resistant mutations in cultured Chinese hamster V79 cells were examined. 3'-dA had the effect of sensitizing the lethality induced by γ-rays. The potentially lethal damage (PLD) repair produced by post-incubation cells in Hanks' solution after γ-irradiation was almost completely suppressed by 5x10 -5 M 3'-dA. When cells were irradiated with 10 Gy γ-rays and incubated with 3'-dA for 5 h, the frequency of 6TG-resistant mutations induced by γ-rays decreased to 1/6 of that of the irradiated cells incubated without 3'-dA. The decrease in the frequency of γ-ray-induced mutations was dependent on the length of incubation time with 3'-dA. It is suggested that the inhibition of PLD repair by 3'-dA may be that of error-prone repair. (author). 26 refs.; 5 figs

  9. The frequency of Tay-Sachs disease causing mutations in the Brazilian Jewish population justifies a carrier screening program.

    Science.gov (United States)

    Rozenberg, R; Pereira, L da V

    2001-07-05

    Tay-Sachs disease is an autosomal recessive disease characterized by progressive neurologic degeneration, fatal in early childhood. In the Ashkenazi Jewish population the disease incidence is about 1 in every 3,500 newborns and the carrier frequency is 1 in every 29 individuals. Carrier screening programs for Tay-Sachs disease have reduced disease incidence by 90% in high-risk populations in several countries. The Brazilian Jewish population is estimated at 90,000 individuals. Currently, there is no screening program for Tay-Sachs disease in this population. To evaluate the importance of a Tay-Sachs disease carrier screening program in the Brazilian Jewish population by determining the frequency of heterozygotes and the acceptance of the program by the community. Laboratory of Molecular Genetics--Institute of Biosciences--Universidade de São Paulo. 581 senior students from selected Jewish high schools. Molecular analysis of Tay-Sachs disease causing mutations by PCR amplification of genomic DNA, followed by restriction enzyme digestion. Among 581 students that attended educational classes, 404 (70%) elected to be tested for Tay-Sachs disease mutations. Of these, approximately 65% were of Ashkenazi Jewish origin. Eight carriers were detected corresponding to a carrier frequency of 1 in every 33 individuals in the Ashkenazi Jewish fraction of the sample. The frequency of Tay-Sachs disease carriers among the Ashkenazi Jewish population of Brazil is similar to that of other countries where carrier screening programs have led to a significant decrease in disease incidence. Therefore, it is justifiable to implement a Tay-Sachs disease carrier screening program for the Brazilian Jewish population.

  10. Measurement of optical-beat frequency in a photoconductive terahertz-wave generator using microwave higher harmonics.

    Science.gov (United States)

    Murasawa, Kengo; Sato, Koki; Hidaka, Takehiko

    2011-05-01

    A new method for measuring optical-beat frequencies in the terahertz (THz) region using microwave higher harmonics is presented. A microwave signal was applied to the antenna gap of a photoconductive (PC) device emitting a continuous electromagnetic wave at about 1 THz by the photomixing technique. The microwave higher harmonics with THz frequencies are generated in the PC device owing to the nonlinearity of the biased photoconductance, which is briefly described in this article. Thirteen nearly periodic peaks in the photocurrent were observed when the microwave was swept from 16 to 20 GHz at a power of -48 dBm. The nearly periodic peaks are generated by the homodyne detection of the optical beat with the microwave higher harmonics when the frequency of the harmonics coincides with the optical-beat frequency. Each peak frequency and its peak width were determined by fitting a Gaussian function, and the order of microwave harmonics was determined using a coarse (i.e., lower resolution) measurement of the optical-beat frequency. By applying the Kalman algorithm to the peak frequencies of the higher harmonics and their standard deviations, the optical-beat frequency near 1 THz was estimated to be 1029.81 GHz with the standard deviation of 0.82 GHz. The proposed method is applicable to a conventional THz-wave generator with a photomixer.

  11. Methylenetetrahydrofolate reductase C677T mutation and risk of retinal vein thrombosis.

    Science.gov (United States)

    Soltanpour, Mohammad Soleiman; Soheili, Zahra; Shakerizadeh, Ali; Pourfathollah, Ali Akbar; Samiei, Shahram; Meshkani, Reza; Shahjahani, Mohammad; Karimi, Abbas

    2013-06-01

    Elevated plasma homocysteine (Hcy) level has been established as a significant risk factor for venous thrombosis and cardiovascular disease. Homozygosity for the methylenetetrahydrofolate reductase (MTHFR) C677T mutation has been associated with elevated plasma Hcy concentration and may contribute to retinal vein thrombosis (RVT) development. The aim of the present study was to investigate whether the hyperhomocysteinemia and/or homozygosity for the MTHFR C677T mutation are associated with an increased risk for RVT. Our study population consisted of 73 consecutive patients (50-78 years old) with RVT and 73 control subjects (51-80 years old), matched for age and sex. Genotyping for the MTHFR C677T mutation was performed by polymerase chain reaction-restriction fragment length polymorphism technique and Hcy level was determined by an enzyme immunoassay kit. The prevalence of 677TT genotype was higher in patients than control subjects, but the difference in frequency didn't reach a significant value (P = 0.07). The frequency of the 677T allele was 26% and 21.2% in patients and controls, respectively and did not differ significantly between the two groups (odds ratio = 1.3, 95% confidence interval (0.75-2.24), P = 0.33). Fasting plasma total Hcy level was significantly higher in patients than controls (P = 0.001). Our study demonstrated that hyperhomocysteinemia, but not the MTHFR C677T mutation, is associated with RVT.

  12. Common Mediterranean Fever (MEFV Gene Mutations Associated with Ankylosing Spondylitis in Turkish Population

    Directory of Open Access Journals (Sweden)

    Serbulent Yigit

    2012-01-01

    Full Text Available Ankylosing spondylitis (AS is a common inflammatory rheumatic disease. Mediterranean fever (MEFV gene, which has already been identified as being responsible for familial Mediterranean fever (FMF, is also a suspicious gene for AS because of the clinical association of these two diseases. The aim of this study was to explore the frequency and clinical significance of MEFV gene mutations (M694V, M680I, V726A, E148Q and P369S in a cohort of Turkish patients with AS. Genomic DNAs of 103 AS patients and 120 controls were isolated and genotyped using polymerase chain reaction (PCR and restriction fragment length polymorphism (RFLP methods. There was a statistically significant difference of the MEFV gene mutation carrier rates between AS patients and healthy controls (p = 0.004, OR: 2.5, 95% CI: 1.32–4.76. This association was also observed in allele frequencies (p = 0.005, OR: 2.3, 95% CI: 1.27–4.2. A relatively higher frequency was observed for M694V mutation in AS patients than controls (10.7% versus 4.2% , p = 0.060. There were no significant differences between MEFV mutation carriers and non-carriers with respect to the clinical and demographic characteristics. The results of this study suggest that MEFV gene mutations are positively associated with a predisposition to develop AS.

  13. Detection of Ultra-Rare Mitochondrial Mutations in Breast Stem Cells by Duplex Sequencing.

    Directory of Open Access Journals (Sweden)

    Eun Hyun Ahn

    Full Text Available Long-lived adult stem cells could accumulate non-repaired DNA damage or mutations that increase the risk of tumor formation. To date, studies on mutations in stem cells have concentrated on clonal (homoplasmic mutations and have not focused on rarely occurring stochastic mutations that may accumulate during stem cell dormancy. A major challenge in investigating these rare mutations is that conventional next generation sequencing (NGS methods have high error rates. We have established a new method termed Duplex Sequencing (DS, which detects mutations with unprecedented accuracy. We present a comprehensive analysis of mitochondrial DNA mutations in human breast normal stem cells and non-stem cells using DS. The vast majority of mutations occur at low frequency and are not detectable by NGS. The most prevalent point mutation types are the C>T/G>A and A>G/T>C transitions. The mutations exhibit a strand bias with higher prevalence of G>A, T>C, and A>C mutations on the light strand of the mitochondrial genome. The overall rare mutation frequency is significantly lower in stem cells than in the corresponding non-stem cells. We have identified common and unique non-homoplasmic mutations between non-stem and stem cells that include new mutations which have not been reported previously. Four mutations found within the MT-ND5 gene (m.12684G>A, m.12705C>T, m.13095T>C, m.13105A>G are present in all groups of stem and non-stem cells. Two mutations (m.8567T>C, m.10547C>G are found only in non-stem cells. This first genome-wide analysis of mitochondrial DNA mutations may aid in characterizing human breast normal epithelial cells and serve as a reference for cancer stem cell mutation profiles.

  14. Mutation screening of the HGD gene identifies a novel alkaptonuria mutation with significant founder effect and high prevalence.

    Science.gov (United States)

    Sakthivel, Srinivasan; Zatkova, Andrea; Nemethova, Martina; Surovy, Milan; Kadasi, Ludevit; Saravanan, Madurai P

    2014-05-01

    Alkaptonuria (AKU) is an autosomal recessive disorder; caused by the mutations in the homogentisate 1, 2-dioxygenase (HGD) gene located on Chromosome 3q13.33. AKU is a rare disorder with an incidence of 1: 250,000 to 1: 1,000,000, but Slovakia and the Dominican Republic have a relatively higher incidence of 1: 19,000. Our study focused on studying the frequency of AKU and identification of HGD gene mutations in nomads. HGD gene sequencing was used to identify the mutations in alkaptonurics. For the past four years, from subjects suspected to be clinically affected, we found 16 positive cases among a randomly selected cohort of 41 Indian nomads (Narikuravar) settled in the specific area of Tamil Nadu, India. HGD gene mutation analysis showed that 11 of these patients carry the same homozygous splicing mutation c.87 + 1G > A; in five cases, this mutation was found to be heterozygous, while the second AKU-causing mutation was not identified in these patients. This result indicates that the founder effect and high degree of consanguineous marriages have contributed to AKU among nomads. Eleven positive samples were homozygous for a novel mutation c.87 + 1G > A, that abolishes an intron 2 donor splice site and most likely causes skipping of exon 2. The prevalence of AKU observed earlier seems to be highly increased in people of nomadic origin. © 2014 John Wiley & Sons Ltd/University College London.

  15. Kinetics of mutation induction by ultraviolet light in excision-deficient yeast.

    Science.gov (United States)

    Eckardt, F; Haynes, R H

    1977-02-01

    We have measured the frequency of UV-induced reversions (locus plus suppressor) for the ochre alleles ade2-1 and lys2-1 and forward mutations (ade2 adex double auxotrophs) in an excision-deficient strain of Saccharomyces cerevisiae (rad2-20). For very low UV doses, both mutational systems exhibit linear induction kinetics. However, as the dose increases, a strikingly different response is observed: in the selective reversion system a transition to higher order induction kinetics occurs near 9 ergs/mm2 (25% survival), whereas in the nonselective forward system the mutation frequency passes through a maximum near 14 ergs/mm2 (4.4% survival) and then declines. This contrast in kinetics cannot be explained in any straightforward way by current models of induced mutagenesis, which have been developed primarily on the basis of bacterial data. The bacterial models are designed to accommodate the quadratic induction kinetics that are frequently observed in these systems. We have derived a mathematical expression for mutation frequency that enables us to fit both the forward and reversion data on the assumptions that mutagenesis is basically a "single event" Poisson process, and that mutation and killing are not necessarily independent of one another. In particular, the dose-response relations are consistent with the idea that the sensitivity of the revertants is about 25% less than that of the original cell population, whereas the sensitivity of the forward mutants is about 29% greater than the population average. We argue that this relatively small differential sensitivity of mutant and nonmutant cells is associated with events that take place during mutation expression and clonal growth.

  16. Kinetics of mutation induction by ultraviolet light in excision-deficient yeast

    International Nuclear Information System (INIS)

    Eckardt, F.; Haynes, R.H.

    1977-01-01

    We have measured the frequency of uv-induced reversions (locus plus suppressor) for the ochre alleles ade 2-1 and lys 2-1 and forward mutations (ade2 adex double auxotrophs) in an excision-deficient strain of Saccharomyces cerevisiae (rad 2-20). For very low uv doses, both mutational systems exhibit linear induction kinetics. However, as the dose increases, a strikingly different response is observed: in the selective reversion system a transition to higher order induction kinetics occurs near 9 ergs/mm 2 (25 percent survival), whereas in the nonselective forward system the mutation frequency passes through a maximum near 14 ergs/mm 2 (4.4 percent survival) and then declines. This contrast in kinetics cannot be explained in any straightforward way by current models of induced mutagenesis, which have been developed primarily on the basis of bacterial data. The bacterial models are designed to accommodate the quadratic induction kinetics that are frequently observed in these systems. We have derived a mathematical expression for mutation frequency that enables us to fit both the forward and reversion data on the assumptions that mutagenesis is basically a ''single event'' Poisson process, and that mutation and killing are not necessarily independent of one another. In particular, the dose-response relations are consistent with the idea that the sensitivity of the revertants is about 25 percent less than that of the original cell population, whereas the sensitivity of the forward mutants is about 29 percent greater than the population average. We argue that this relatively small differential sensitivity of mutant and nonmutant cells is associated with events that take place during mutation expression and clonal growth

  17. Mutation breeding in rice in India

    Energy Technology Data Exchange (ETDEWEB)

    Swaminathan, M S; Siddiq, E A; Singh, C B; Pai, R A [Indian Agricultural Research Institute, New Delhi (India)

    1970-03-01

    Mutation research was continued in rice with the following aims; (a) to enhance the frequency and spectrum of mutations in indica and japonica rice varieties; (b) to change the grain quality of the japonica variety, Tainan-3, into the indica type; (c) to improve the grain quality of the indica variety, IR-8; (d) to increase the recombination frequency in japonica-indica hybrids. Both nitrosoguanidine and 5-MeV fast neutrons gave a high mutation frequency. The japonica variety was more sensitive to all mutagens than the indica types. Chemical mutagens had no particular advantage over ionizing radiations with reference to either mutation frequency or spectrum. Mutants with indica type of grain occurred readily in Tainan-3 in all treatments. Such mutants had a larger grain length/width ratio and were more resistant to alkali digestion. Fine grain types with better cooking quality occurred in the M{sub 2} populations of IR-8. These mutants are likely to render this high-yielding variety more popular. A wide range of chlorophyll and viable mutations occurred in IR-8 and Tainan-3. Some of these, like those involving dwarfing and slow senescence, are of economic interest, besides those affecting grain quality. Recombination frequency can be influenced in japonica x indica hybrids through the irradiation of F{sub 1} sporocytes. The precise influence varies with the stage at which the plant is irradiated, the dose given and the loci involved. (author)

  18. ASSOCIATION OF HFE GENE MUTATION IN THALASSEMIA MAJOR PATIENTS

    Directory of Open Access Journals (Sweden)

    Amit Kumar Tiwari

    2016-11-01

    Full Text Available BACKGROUND Thalassemia major patients are dependent on frequent blood transfusion and consequently develop iron overload. HFE gene mutations (C282Y, H63D and S65C in hereditary haemochromatosis has been shown to be associated with iron overload. The study aims at finding the association of HFE gene mutations in β-thalassemia major patients. MATERIALS AND METHODS A descriptive observational pilot study was conducted including fifty diagnosed -thalassemia major cases. DNA analysis by PCR-RFLP method for HFE gene mutations was performed. RESULTS Only H63D mutation (out of three HFE gene mutations was detected in 8 out of 50 cases. Observed frequency of H63D mutation was 16%. While frequency of C282Y and S65C were 0% each. CONCLUSION The frequency of HFE mutation in -thalassemia major is not very common.

  19. Alkylating agent (MNU)-induced mutation in space environment

    Science.gov (United States)

    Ohnishi, T.; Takahashi, A.; Ohnishi, K.; Takahashi, S.; Masukawa, M.; Sekikawa, K.; Amano, T.; Nakano, T.; Nagaoka, S.

    2001-01-01

    In recent years, some contradictory data about the effects of microgravity on radiation-induced biological responses in space experiments have been reported. We prepared a damaged template DNA produced with an alkylating agent (N-methyl-N-nitroso urea; MNU) to measure incorrect base-incorporation during DNA replication in microgravity. We examined whether mutation frequency is affected by microgravity during DNA replication for a DNA template damaged by an alkylating agent. Using an in vitro enzymatic reaction system, DNA synthesis by Taq polymerase or polymerase III was done during a US space shuttle mission (Discovery, STS-91). After the flight, DNA replication and mutation frequencies were measured. We found that there was almost no effect of microgravity on DNA replication and mutation frequency. It is suggested that microgravity might not affect at the stage of substrate incorporation in induced-mutation frequency.

  20. Mutational spectrum in a worldwide study of 29,700 families with BRCA1 or BRCA2 mutations.

    Science.gov (United States)

    Rebbeck, Timothy R; Friebel, Tara M; Friedman, Eitan; Hamann, Ute; Huo, Dezheng; Kwong, Ava; Olah, Edith; Olopade, Olufunmilayo I; Solano, Angela R; Teo, Soo-Hwang; Thomassen, Mads; Weitzel, Jeffrey N; Chan, T L; Couch, Fergus J; Goldgar, David E; Kruse, Torben A; Palmero, Edenir Inêz; Park, Sue Kyung; Torres, Diana; van Rensburg, Elizabeth J; McGuffog, Lesley; Parsons, Michael T; Leslie, Goska; Aalfs, Cora M; Abugattas, Julio; Adlard, Julian; Agata, Simona; Aittomäki, Kristiina; Andrews, Lesley; Andrulis, Irene L; Arason, Adalgeir; Arnold, Norbert; Arun, Banu K; Asseryanis, Ella; Auerbach, Leo; Azzollini, Jacopo; Balmaña, Judith; Barile, Monica; Barkardottir, Rosa B; Barrowdale, Daniel; Benitez, Javier; Berger, Andreas; Berger, Raanan; Blanco, Amie M; Blazer, Kathleen R; Blok, Marinus J; Bonadona, Valérie; Bonanni, Bernardo; Bradbury, Angela R; Brewer, Carole; Buecher, Bruno; Buys, Saundra S; Caldes, Trinidad; Caliebe, Almuth; Caligo, Maria A; Campbell, Ian; Caputo, Sandrine M; Chiquette, Jocelyne; Chung, Wendy K; Claes, Kathleen B M; Collée, J Margriet; Cook, Jackie; Davidson, Rosemarie; de la Hoya, Miguel; De Leeneer, Kim; de Pauw, Antoine; Delnatte, Capucine; Diez, Orland; Ding, Yuan Chun; Ditsch, Nina; Domchek, Susan M; Dorfling, Cecilia M; Velazquez, Carolina; Dworniczak, Bernd; Eason, Jacqueline; Easton, Douglas F; Eeles, Ros; Ehrencrona, Hans; Ejlertsen, Bent; Engel, Christoph; Engert, Stefanie; Evans, D Gareth; Faivre, Laurence; Feliubadaló, Lidia; Ferrer, Sandra Fert; Foretova, Lenka; Fowler, Jeffrey; Frost, Debra; Galvão, Henrique C R; Ganz, Patricia A; Garber, Judy; Gauthier-Villars, Marion; Gehrig, Andrea; Gerdes, Anne-Marie; Gesta, Paul; Giannini, Giuseppe; Giraud, Sophie; Glendon, Gord; Godwin, Andrew K; Greene, Mark H; Gronwald, Jacek; Gutierrez-Barrera, Angelica; Hahnen, Eric; Hauke, Jan; Henderson, Alex; Hentschel, Julia; Hogervorst, Frans B L; Honisch, Ellen; Imyanitov, Evgeny N; Isaacs, Claudine; Izatt, Louise; Izquierdo, Angel; Jakubowska, Anna; James, Paul; Janavicius, Ramunas; Jensen, Uffe Birk; John, Esther M; Vijai, Joseph; Kaczmarek, Katarzyna; Karlan, Beth Y; Kast, Karin; Investigators, KConFab; Kim, Sung-Won; Konstantopoulou, Irene; Korach, Jacob; Laitman, Yael; Lasa, Adriana; Lasset, Christine; Lázaro, Conxi; Lee, Annette; Lee, Min Hyuk; Lester, Jenny; Lesueur, Fabienne; Liljegren, Annelie; Lindor, Noralane M; Longy, Michel; Loud, Jennifer T; Lu, Karen H; Lubinski, Jan; Machackova, Eva; Manoukian, Siranoush; Mari, Véronique; Martínez-Bouzas, Cristina; Matrai, Zoltan; Mebirouk, Noura; Meijers-Heijboer, Hanne E J; Meindl, Alfons; Mensenkamp, Arjen R; Mickys, Ugnius; Miller, Austin; Montagna, Marco; Moysich, Kirsten B; Mulligan, Anna Marie; Musinsky, Jacob; Neuhausen, Susan L; Nevanlinna, Heli; Ngeow, Joanne; Nguyen, Huu Phuc; Niederacher, Dieter; Nielsen, Henriette Roed; Nielsen, Finn Cilius; Nussbaum, Robert L; Offit, Kenneth; Öfverholm, Anna; Ong, Kai-Ren; Osorio, Ana; Papi, Laura; Papp, Janos; Pasini, Barbara; Pedersen, Inge Sokilde; Peixoto, Ana; Peruga, Nina; Peterlongo, Paolo; Pohl, Esther; Pradhan, Nisha; Prajzendanc, Karolina; Prieur, Fabienne; Pujol, Pascal; Radice, Paolo; Ramus, Susan J; Rantala, Johanna; Rashid, Muhammad Usman; Rhiem, Kerstin; Robson, Mark; Rodriguez, Gustavo C; Rogers, Mark T; Rudaitis, Vilius; Schmidt, Ane Y; Schmutzler, Rita Katharina; Senter, Leigha; Shah, Payal D; Sharma, Priyanka; Side, Lucy E; Simard, Jacques; Singer, Christian F; Skytte, Anne-Bine; Slavin, Thomas P; Snape, Katie; Sobol, Hagay; Southey, Melissa; Steele, Linda; Steinemann, Doris; Sukiennicki, Grzegorz; Sutter, Christian; Szabo, Csilla I; Tan, Yen Y; Teixeira, Manuel R; Terry, Mary Beth; Teulé, Alex; Thomas, Abigail; Thull, Darcy L; Tischkowitz, Marc; Tognazzo, Silvia; Toland, Amanda Ewart; Topka, Sabine; Trainer, Alison H; Tung, Nadine; van Asperen, Christi J; van der Hout, Annemieke H; van der Kolk, Lizet E; van der Luijt, Rob B; Van Heetvelde, Mattias; Varesco, Liliana; Varon-Mateeva, Raymonda; Vega, Ana; Villarreal-Garza, Cynthia; von Wachenfeldt, Anna; Walker, Lisa; Wang-Gohrke, Shan; Wappenschmidt, Barbara; Weber, Bernhard H F; Yannoukakos, Drakoulis; Yoon, Sook-Yee; Zanzottera, Cristina; Zidan, Jamal; Zorn, Kristin K; Hutten Selkirk, Christina G; Hulick, Peter J; Chenevix-Trench, Georgia; Spurdle, Amanda B; Antoniou, Antonis C; Nathanson, Katherine L

    2018-05-01

    The prevalence and spectrum of germline mutations in BRCA1 and BRCA2 have been reported in single populations, with the majority of reports focused on White in Europe and North America. The Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) has assembled data on 18,435 families with BRCA1 mutations and 11,351 families with BRCA2 mutations ascertained from 69 centers in 49 countries on six continents. This study comprehensively describes the characteristics of the 1,650 unique BRCA1 and 1,731 unique BRCA2 deleterious (disease-associated) mutations identified in the CIMBA database. We observed substantial variation in mutation type and frequency by geographical region and race/ethnicity. In addition to known founder mutations, mutations of relatively high frequency were identified in specific racial/ethnic or geographic groups that may reflect founder mutations and which could be used in targeted (panel) first pass genotyping for specific populations. Knowledge of the population-specific mutational spectrum in BRCA1 and BRCA2 could inform efficient strategies for genetic testing and may justify a more broad-based oncogenetic testing in some populations. © 2018 Wiley Periodicals, Inc.

  1. Effects of smoke and tea on radiation-induced bone marrow cell mutation and marrow inhibition

    International Nuclear Information System (INIS)

    Gao Yong; Zhang Weiguang

    2004-01-01

    Objective: To provide scientific information for the prevention and treatment of the radiation damage by analyzing the effects of smoke and tea on radiation-induced bone marrow cell mutation and marrow inhibition. Methods: 7 group mice were exposed to smoke and/or tea and/or radiation respectively. There were also b blank control group and a cyclophosphamide positive control group. The frequencies of micronucleated polychromatic erythrocytes (MPCE), the ratio of polychromatic erythrocytes (PCE) to mature erythrocytes (RBC) in marrow, and the count of peripheral blood hemoleukocyte were observed. Results: The frequencies of MPCE in the groups irradiated with γ-rays were significantly higher than that in the blank control group (P<0.05 or 0.01). The smoke + radiation group's frequency was significantly higher than single radiation group (P<0.05). The ratios of PCE to RBC in the groups irradiated were significantly lower than that in the blank control group (P<0.01). The counts of peripheral blood hemoleukocyte in the groups irradiated were significantly lower than the blank control group (P<0.01). Conclusion: Radiation were able to cause marrow cell mutation and induce marrow inhibition. Smoke increases the effect of radiation-induced marrow cell mutation. Tea and smoke could not affect radiation-induced bone marrow inhibition

  2. Mutation and DNA replication in Escherichia coli treated with low concentrations of N-methyl-N'-nitro-N-nitrosoguanidine

    International Nuclear Information System (INIS)

    Jimenez-Sanchez, A.; Cerda-Olmedo, E.

    1975-01-01

    N-Methyl-N'-nitro-N-nitrosoguanidine (nitrosoguanidine) causes an unexpectedly high frequency of closely linked double mutants because of its specificity for chromosome regions in replication. Low nitrosoguanidine concentrations (I μg/ml) in liquid cultures allow replication at the normal rate and are mutagenic. It was expected that mutations would be spread over the chromosome as it replicated, but a high frequency of closely linked double mutants was found. If a thymine auxotroph is grown in the presence of 5-bromodeoxyuridine (BUdR) and nitrosoguanidine and then exposed to 313-nm radiation (which destroys BUdR-substituted DNA), the mutation frequency is much higher among survivors than among non-irradiated cells. It is concluded that nitrosoguanidine inhibits DNA replication in a small fraction of the population and that mutations are induced in that same fraction. Nitrosoguanidine treatment leads to a high frequency of closely linked double mutants under all known conditions

  3. Reduction of spontaneous somatic mutation frequency by a low-dose X irradiation of Drosophila larvae and possible involvement of DNA single-strand damage repair.

    Science.gov (United States)

    Koana, Takao; Takahashi, Takashi; Tsujimura, Hidenobu

    2012-03-01

    The third instar larvae of Drosophila were irradiated with X rays, and the somatic mutation frequency in their wings was measured after their eclosion. In the flies with normal DNA repair and apoptosis functions, 0.2 Gy irradiation at 0.05 Gy/min reduced the frequency of the so-called small spot (mutant cell clone with reduced reproductive activity) compared with that in the sham-irradiated flies. When apoptosis was suppressed using the baculovirus p35 gene, the small spot frequency increased four times in the sham-irradiated control group, but the reduction by the 0.2-Gy irradiation was still evident. In a non-homologous end joining-deficient mutant, the small spot frequency was also reduced by 0.2 Gy radiation. In a mutant deficient in single-strand break repair, no reduction in the small spot frequency by 0.2 Gy radiation was observed, and the small spot frequency increased with the radiation dose. Large spot (mutant cell clone with normal reproductive activity) frequency was not affected by suppression of apoptosis and increased monotonically with radiation dose in wild-type larvae and in mutants for single- or double-strand break repair. It is hypothesized that some of the small spots resulted from single-strand damage and, in wild-type larvae, 0.2 Gy radiation activated the normal single-strand break repair gene, which reduced the background somatic mutation frequency.

  4. Mutation Spectrum and Phenotypic Features in Noonan Syndrome with PTPN11 Mutations: Definition of Two Novel Mutations.

    Science.gov (United States)

    Atik, Tahir; Aykut, Ayca; Hazan, Filiz; Onay, Huseyin; Goksen, Damla; Darcan, Sukran; Tukun, Ajlan; Ozkinay, Ferda

    2016-06-01

    To evaluate the spectrum of PTPN11 gene mutations in Noonan syndrome patients and to study the genotype-phenotype associations. In this study, twenty Noonan syndrome patients with PTPN11 mutations were included. The patients underwent a detailed clinical and physical evaluation. To identify inherited cases, parents of all mutation positive patients were analyzed. Thirteen different PTPN11 mutations, two of them being novel, were detected in the study group. These mutations included eleven missense mutations: p.G60A, p.D61N, p.Y62D, p.Y63C, p.E69Q, p.Q79R, p.Y279C,p.N308D, p.N308S, p.M504V, p.Q510R and two novel missense mutations: p.I56V and p.I282M. The frequency of cardiac abnormalities and short stature were found to be 80 % and 80 %, respectively. Mental retardation was not observed in patients having exon 8 mutations. No significant correlations were detected between other phenotypic features and genotypes. By identifying genotype-phenotype correlations, this study provides information on phenotypes observed in NS patients with different PTPN11 mutations.

  5. Analysis of mutation/rearrangement frequencies and methylation patterns at a given DNA locus using restriction fragment length polymorphism.

    Science.gov (United States)

    Boyko, Alex; Kovalchuk, Igor

    2010-01-01

    Restriction fragment length polymorphism (RFLP) is a difference in DNA sequences of organisms belonging to the same species. RFLPs are typically detected as DNA fragments of different lengths after digestion with various restriction endonucleases. The comparison of RFLPs allows investigators to analyze the frequency of occurrence of mutations, such as point mutations, deletions, insertions, and gross chromosomal rearrangements, in the progeny of stressed plants. The assay involves restriction enzyme digestion of DNA followed by hybridization of digested DNA using a radioactively or enzymatically labeled probe. Since DNA can be digested with methylation sensitive enzymes, the assay can also be used to analyze a methylation pattern of a particular locus. Here, we describe RFLP analysis using methylation-insensitive and methylation-sensitive enzymes.

  6. Calreticulin Mutations in Bulgarian MPN Patients.

    Science.gov (United States)

    Pavlov, Ivan; Hadjiev, Evgueniy; Alaikov, Tzvetan; Spassova, Sylva; Stoimenov, Angel; Naumova, Elissaveta; Shivarov, Velizar; Ivanova, Milena

    2018-01-01

    Somatic mutations in JAK2, MPL and CALR are recurrently identified in most of the cases with Philadelphia chromosome negative myeloproliferative neoplasms (MPNs). We applied four molecular genetic methods for identification of CALR exon 9 mutations, including high resolution melt (HRM) analysis, Sanger sequencing, semiconductor target genes sequencing and whole exome sequencing. A total of 78 patients with myeloid malignancies were included in the study. We identified 14 CALR exon 9 mutated cases out of 78 studied patients with myeloid malignancies. All mutated patients were diagnosed with MPN being either PMF (n = 7) or ET (n = 7). Nine cases had type 1 mutations and 5 cases had type 2 mutations. CALR exon 9, MPL exon 10 and JAK2 p. V617F were mutually exclusive. There were no statistically significant differences in the hematological parameters between the cases with CALR and JAK2 or MPL mutations. Notably, all four techniques were fully concordant in the detection of CALR mutations. This is one of the few reports on the CALR mutations frequency in South-eastern populations. Our study shows that the frequency and patterns of these mutations is identical to those in the patients' cohorts from Western countries. Besides we demonstrated the utility of four different methods for their detection.

  7. TOX3 mutations in breast cancer.

    Directory of Open Access Journals (Sweden)

    James Owain Jones

    Full Text Available TOX3 maps to 16q12, a region commonly lost in breast cancers and recently implicated in the risk of developing breast cancer. However, not much is known of the role of TOX3 itself in breast cancer biology. This is the first study to determine the importance of TOX3 mutations in breast cancers. We screened TOX3 for mutations in 133 breast tumours and identified four mutations (three missense, one in-frame deletion of 30 base pairs in six primary tumours, corresponding to an overall mutation frequency of 4.5%. One potentially deleterious missense mutation in exon 3 (Leu129Phe was identified in one tumour (genomic DNA and cDNA. Whilst copy number changes of 16q12 are common in breast cancer, our data show that mutations of TOX3 are present at low frequency in tumours. Our results support that TOX3 should be further investigated to elucidate its role in breast cancer biology.

  8. Geographical distribution of β-globin gene mutations in Syria.

    Science.gov (United States)

    Murad, Hossam; Moasses, Faten; Dabboul, Amir; Mukhalalaty, Yasser; Bakoor, Ahmad Omar; Al-Achkar, Walid; Jarjour, Rami A

    2018-04-11

    Objectives β-Thalassemia disease is caused by mutations in the β-globin gene. This is considered as one of the common genetic disorders in Syria. The aim of this study was to identify the geographical distribution of the β-thalassemia mutations in Syria. Methods β-Globin gene mutations were characterized in 636 affected patients and 94 unrelated carriers using the amplification refractory mutations system-polymerase chain reaction technique and DNA sequencing. Results The study has revealed the presence of 38 β-globin gene mutations responsible for β-thalassemia in Syria. Important differences in regional distribution were observed. IVS-I.110 [G > A] (22.2%), IVS-I.1 [G > A] (17.8%), Cd 39 [C > T] (8.2%), IVS-II.1 [G > A] (7.6%), IVS-I.6 [T > C] (7.1%), Cd 8 [-AA] (6%), Cd 5 [-CT] (5.6%) and IVS-I.5 [G > C] (4.1%) were the eight predominant mutations found in our study. The coastal region had higher relative frequencies (37.9 and 22%) than other regions. A clear drift in the distribution of the third common Cd 39 [C > T] mutation in the northeast region (34.8%) to the northwest region (2.5%) was noted, while the IVS-I.5 [G > C] mutation has the highest prevalence in north regions. The IVS-I.6 [T > C] mutation had a distinct frequency in the middle region. Ten mutations -86 [C > G], -31 [A > G], -29 [A > G], 5'UTR; +22 [G > A], CAP + 1 [A > C], Codon 5/6 [-TG], IVS-I (-3) or codon 29 [C > T], IVS-I.2 [T > A], IVS-I.128 [T > G] and IVS-II.705 [T > G] were found in Syria for the first time. Conclusions These data will significantly facilitate the population screening, genetic counseling and prenatal diagnosis in Syrian population.

  9. The frequency of Tay-Sachs disease causing mutations in the Brazilian Jewish population justifies a carrier screening program

    Directory of Open Access Journals (Sweden)

    Roberto Rozenberg

    Full Text Available CONTEXT: Tay-Sachs disease is an autosomal recessive disease characterized by progressive neurologic degeneration, fatal in early childhood. In the Ashkenazi Jewish population the disease incidence is about 1 in every 3,500 newborns and the carrier frequency is 1 in every 29 individuals. Carrier screening programs for Tay-Sachs disease have reduced disease incidence by 90% in high-risk populations in several countries. The Brazilian Jewish population is estimated at 90,000 individuals. Currently, there is no screening program for Tay-Sachs disease in this population. OBJECTIVE: To evaluate the importance of a Tay-Sachs disease carrier screening program in the Brazilian Jewish population by determining the frequency of heterozygotes and the acceptance of the program by the community. SETTING: Laboratory of Molecular Genetics - Institute of Biosciences - Universidade de São Paulo. PARTICIPANTS: 581 senior students from selected Jewish high schools. PROCEDURE: Molecular analysis of Tay-Sachs disease causing mutations by PCR amplification of genomic DNA, followed by restriction enzyme digestion. RESULTS: Among 581 students that attended educational classes, 404 (70% elected to be tested for Tay-Sachs disease mutations. Of these, approximately 65% were of Ashkenazi Jewish origin. Eight carriers were detected corresponding to a carrier frequency of 1 in every 33 individuals in the Ashkenazi Jewish fraction of the sample. CONCLUSION: The frequency of Tay-Sachs disease carriers among the Ashkenazi Jewish population of Brazil is similar to that of other countries where carrier screening programs have led to a significant decrease in disease incidence. Therefore, it is justifiable to implement a Tay-Sachs disease carrier screening program for the Brazilian Jewish population.

  10. Characterization of a mutant of Escherichia coli B/R defective in mutation frequency decline

    International Nuclear Information System (INIS)

    George, D.L.

    1974-01-01

    A mutant of Escherichia coli B/r designated mfd is very deficient in the ability to exhibit mutation frequency decline (MFD), the characteristic loss of potential suppressor mutations which occurs when protein synthesis is briefly inhibited after irradiation with ultraviolet light (uv). This mutant is known to excise pyrimidine dimers very slowly, although it is as uv-resistant as its mfd + B/r parent strain. We have found that the mfd mutant performs the initial incision step of excision repair normally, but repairs the resulting single-strand breaks much more slowly than the mfd + strain. In spite of the slow dimer excision in the mfd mutant, single-strand DNA breaks do not accumulate during postirradiation incubation, implying that incision and excision are well corrdinated. the prolonged postirradiation lag in cell division and DNA synthesis which accompany slow excision in the mfd strain indicates that resumption of these processes of optimal rates is linked to the timing of excision repair. The normal uv-resistance of the mfd mutant also suggests such coordination and shows that the rate of excision repair is independent of its ultimate efficiency in the removal of potentially lethal uv-induced damage. (U.S.)

  11. Studies on mutation techniques in rice breeding

    International Nuclear Information System (INIS)

    Wang Cailian; Chen Qiufang; Jin Wei

    2001-01-01

    Synthetical techniques for improving rice mutation breeding efficiency were studied. The techniques consist of corresponding relationship between radiosensitivity and mutation frequency, choosing appropriate materials, combination of physical and chemical mutagens, mutagenic effects of the new mutagenic agents as proton, ions, synchronous irradiation and space mutation. These techniques and methods for inducing mutations are very valuable to increase inducing mutation efficiency and breeding level

  12. Petroleum pollution and mutation in mangroves

    International Nuclear Information System (INIS)

    Klekowski, E.J. Jr.; Corredor, J.E.; Morell, J.M.; Del Castillo, C.A.

    1994-01-01

    Chlorophyll-deficiency has often been used as a sensitive genetic end-point in plant mutation research. The frequency of trees heterozygous for nuclear chlorophyll-deficient mutations was determined for mangrove populations growing along the southwest coast of Puerto Rico. The frequency of heterozygotes was strongly correlated with the concentration of polycyclic aromatic hydrocarbons in the underlying sediment and with both acute and chronic petroleum pollution. Although epidemiological studies can seldom prove causation, a strong correlation is certainly compatible with a cause-effect relationship. Our results suggest that the biota of oil-polluted habitats may be experiencing increased mutation. (Author)

  13. The NOD2 3020insC Mutation in Women with Breast Cancer from the Bydgoszcz Region in Poland. First Results

    Directory of Open Access Journals (Sweden)

    Janiszewska Hanna

    2006-01-01

    Full Text Available Abstract The frameshift NOD2 gene mutation 3020insC is predominantly associated with Crohn's disease, but predisposes to many types of common cancers as well. We studied the frequency of this mutant NOD2 allele in 148 breast cancer women from the Bydgoszcz region in Poland. The NOD2 mutation was present in 8.8% of the patients. The mean age at breast cancer diagnosis of the mutation carriers was 43 years. We did not find any mutation in patients diagnosed with breast cancer after the age of 50 years. There was no association of the NOD2 mutation with a strong family history of breast cancer. On the contrary, the mutation frequency (11.4% was two times higher in women from families with a single case of breast cancer and with aggregation of other common types of cancer, especially digestive tract cancers. Low risk of breast cancer in the mutation carriers seems to be confirmed by finding the 3020insC mutation in three healthy parents of probands aged 73, 74 and 83 years, from three separate families.

  14. Reducing Undue Conservatism in "Higher Frequency" Structural Design Loads in Aerospace Components

    Science.gov (United States)

    Knight, J. Brent

    2012-01-01

    This study is intended to investigate the frequency dependency of significant strain due to vibratory loads in aerospace vehicle components. The notion that "higher frequency" dynamic loads applied as static loads is inherently conservative is perceived as widely accepted. This effort is focused on demonstrating that principle and attempting to evolve methods to capitalize on it to mitigate undue conservatism. It has been suggested that observations of higher frequency modes that resulted in very low corresponding strain did so due to those modes not being significant. Two avionics boxes, one with its first significant mode at 341 Hz and the other at 857 Hz, were attached to a flat panel installed on a curved orthogrid panel which was driven acoustically in tests performed at NASA/MSFC. Strain and acceleration were measured at select locations on each of the boxes. When possible, strain gage rosettes and accelerometers were installed on either side of a given structural member so that measured strain and acceleration data would directly correspond to one another. Ultimately, a frequency above which vibratory loads can be disregarded for purposes of static structural analyses and sizing of typical robust aerospace components is sought.

  15. Methylenetetrahydrofolate reductase C677T mutation and risk of retinal vein thrombosis

    Directory of Open Access Journals (Sweden)

    Mohammad Soleiman Soltanpour

    2013-01-01

    Full Text Available Background: Elevated plasma homocysteine (Hcy level has been established as a significant risk factor for venous thrombosis and cardiovascular disease. Homozygosity for the methylenetetrahydrofolate reductase (MTHFR C677T mutation has been associated with elevated plasma Hcy concentration and may contribute to retinal vein thrombosis (RVT development. The aim of the present study was to investigate whether the hyperhomocysteinemia and/or homozygosity for the MTHFR C677T mutation are associated with an increased risk for RVT. Materials and Methods: Our study population consisted of 73 consecutive patients (50-78 years old with RVT and 73 control subjects (51-80 years old, matched for age and sex. Genotyping for the MTHFR C677T mutation was performed by polymerase chain reaction-restriction fragment length polymorphism technique and Hcy level was determined by an enzyme immunoassay kit. Results: The prevalence of 677TT genotype was higher in patients than control subjects, but the difference in frequency didn′t reach a significant value (P = 0.07. The frequency of the 677T allele was 26% and 21.2% in patients and controls, respectively and did not differ significantly between the two groups (odds ratio = 1.3, 95% confidence interval (0.75-2.24, P = 0.33. Fasting plasma total Hcy level was significantly higher in patients than controls (P = 0.001. Conclusion: Our study demonstrated that hyperhomocysteinemia, but not the MTHFR C677T mutation, is associated with RVT.

  16. Frequency and phenotype of patients carrying TPM2 and TPM3 gene mutations in a cohort of 94 patients with congenital myopathy

    DEFF Research Database (Denmark)

    Citirak, Gülsenay; Witting, Nanna; Duno, Morten

    2014-01-01

    , two related female patients and two sporadic, male patients were found to carry mutations in the tropomyosin 2 (TPM2) and tropomyosin 3 (TPM3) genes, respectively. This indicates a low (4.3%) frequency of TPM2 and TPM3 mutations as a cause of congenital myopathy. Compared to previously described...... patients carrying the same mutations as found in our study (c.503G>A, and c.502C>T in TPM3, and c.415_417delGAG in TPM2), clinical presentation and muscle morphological findings differed in our patients. Differences included variation in distribution of muscle weakness, presence of scoliosis and ptosis...... had nemaline myopathy and fiber size disproportion, while three patients had congenital fiber type disproportion (CFTD) on muscle biopsies. TPM2-related CFTD has only been described in two cases, indicating that mutations in TPM2 are rare causes of CFTD....

  17. Experimental mutations in soybean and their selection value

    International Nuclear Information System (INIS)

    Sichkar', V.I.

    1979-01-01

    Efficiency of widely used chemical mutagens and gamma irradiation in inducing chlorophyll changes in some soya varieties has been compared in order to further specify the relationship between this type of mutations and other morphological changes. The most active mutations found were NMU, NEU, EI and gamma radiation. The frequency of chrolophyll changes depended on the mutagen concentration and soya variety and varied from 1.58% to 19.04%. EO, NDMM and DMS produced 4-5 times lower yield of chlorophyll mutations. The following mutagen concentrations for the varieties studied were found optimum (in per cent): NMU - 0.0125, NEU - 0.025, EI - 0.03, EO - 0.05, NDMM - 0.0O625, DMS - 0.02. No relationship between the dose of gamma radiation and the mutation frequency was found. Varieties of VNIIMK 9186 and Lanka were the most mutable, 89-10 hybrid showed very low mutability. Mutagens that induced high frequency of mutations also gave the broadest spectrum of changes. Most frequent changes were xantha, lutescens and xanthaterminalis. Very few mutations from green color to white one were isolated

  18. Radio frequency plasma nitriding of aluminium at higher power levels

    International Nuclear Information System (INIS)

    Gredelj, Sabina; Kumar, Sunil; Gerson, Andrea R.; Cavallaro, Giuseppe P.

    2006-01-01

    Nitriding of aluminium 2011 using a radio frequency plasma at higher power levels (500 and 700 W) and lower substrate temperature (500 deg. C) resulted in higher AlN/Al 2 O 3 ratios than obtained at 100 W and 575 deg. C. AlN/Al 2 O 3 ratios derived from X-ray photoelectron spectroscopic analysis (and corroborated by heavy ion elastic recoil time of flight spectrometry) for treatments preformed at 100 (575 deg. C), 500 (500 deg. C) and 700 W (500 deg. C) were 1.0, 1.5 and 3.3, respectively. Scanning electron microscopy revealed that plasma nitrided surfaces obtained at higher power levels exhibited much finer nodular morphology than obtained at 100 W

  19. Major contribution from recurrent alterations and MSH6 mutations in the Danish Lynch syndrome population

    DEFF Research Database (Denmark)

    Nilbert, Mef; Wikman, Friedrik P; Hansen, Thomas V O

    2009-01-01

    mutations in 164 families are considered pathogenic and an additional 50 variants from 76 families are considered to represent variants of unknown pathogenicity. The different MMR genes contribute to 40% (MSH2), 29% (MLH1), and 22% (MSH6) of the mutations and the Danish population thus shows a considerably...... higher frequency of MSH6 mutations than previously described. Although 69/88 (78%) pathogenic mutations were present in a single family, previously recognized recurrent/founder mutations were causative in 75/137 (55%) MLH1/MSH2 mutant families. In addition, the Danish MLH1 founder mutation c.1667......+2_1667_+8TAAATCAdelinsATTT was identified in 14/58 (24%) MLH1 mutant families. The Danish Lynch syndrome population thus demonstrates that MSH6 mutations and recurrent/founder mutations have a larger contribution than previously recognized, which implies that the MSH6 gene should be included in routine diagnostics...

  20. Increased frequency of co-existing JAK2 exon-12 or MPL exon-10 mutations in patients with low JAK2(V617F) allelic burden.

    Science.gov (United States)

    Nussenzveig, Roberto H; Pham, Ha T; Perkins, Sherrie L; Prchal, Josef T; Agarwal, Archana M; Salama, Mohamed E

    2016-01-01

    The frequency of co-existing JAK2(V617F)/MPL and JAK2(V617F)/JAK2 exon-12 mutations has not been previously investigated in MPNs. Poor survival was reported in primary myelofibrosis with low JAK2(V617F) allelic burden. However, mutational status of JAK2 exon-12 or MPL were not reported in these patients. This study developed a cost-effective multiplex high resolution melt assay that screens for mutations in JAK2 gene exons-12 and -14 ((V617F)) and MPL gene exon-10. Co-existing mutations with JAK2(V617F) were detected in 2.9% (6/208; two JAK2 exon-12 and four MPL exon-10) patient specimens with known JAK2(V617F) (allelic-burden range: 0.1-96.8%). Co-existing mutations were detected in specimens with MPL exon-10 mutation should be pursued.

  1. Germline APC mutations in hepatoblastoma.

    Science.gov (United States)

    Yang, Adeline; Sisson, Rebecca; Gupta, Anita; Tiao, Greg; Geller, James I

    2018-04-01

    Conflicting reports on the frequency of germline adenomatous polyposis coli (APC) gene mutations in patients with hepatoblastoma (HB) have called into question the clinical value of APC mutation testing on apparently sporadic HB. An Institutional Review Board approved retrospective review of clinical data collected from patients with HB who received APC testing at our institution was conducted. All HB patients seen at Cincinnati Children's Hospital Medical Center were eligible for testing. Potential genotype/phenotype correlations were assessed. As of July 2015, 29 patients with HB had received constitutional APC testing. Four (14%) were found to have APC pathogenic truncations of the APC protein and in addition two (7%) had APC missense variants of unknown clinical significance. Two patients (7%) had family histories indicative of familial adenomatous polyposis (FAP). Response to chemotherapy tracked differently in APC pathogenic cases, with a slower imaging response despite an equivalent or slightly faster α-fetoprotein (AFP) response. The prevalence of pathogenic APC variants in apparently sporadic HB may be higher than previously detected. Differences in time to imaging response, despite similar AFP response, may impact surgical planning. All patients with HB warrant germline APC mutation testing for underlying FAP. © 2017 Wiley Periodicals, Inc.

  2. Mutation analysis for DJ-1 in sporadic and familial parkinsonism: screening strategy in parkinsonism.

    Science.gov (United States)

    Tomiyama, Hiroyuki; Li, Yuanzhe; Yoshino, Hiroyo; Mizuno, Yoshikuni; Kubo, Shin-Ichiro; Toda, Tatsushi; Hattori, Nobutaka

    2009-05-22

    DJ-1 mutations cause autosomal recessive parkinsonism (ARP). Although some reports of DJ-1 mutations have been published, there is lack of information on the prevalence of these mutations in large-scale studies of both familial and sporadic parkinsonism. In this genetic screening study, we analyzed the distribution and frequency of DJ-1 mutations by direct nucleotide sequencing of coding exons and exon-intron boundaries of DJ-1, in 386 parkin-negative parkinsonism patients (371 index cases: 67 probands of autosomal recessive parkinsonism families, 90 probands of autosomal dominant parkinsonism families, 201 patients with sporadic parkinsonism, and 13 with unknown family histories) from 12 countries (Japan 283, China 27, Taiwan 22, Korea 22, Israel 16, Turkey 5, Philippines 2, Bulgaria 2, Greece 2, Tunisia 1, USA 2, Ukraine 1, unknown 1). None had causative mutation in DJ-1, suggesting DJ-1 mutation is very rare among patients with familial and sporadic parkinsonism from Asian countries and those with other ethnic background. This is in contrast to the higher frequencies and worldwide distribution of parkin- and PINK1-related parkinsonism in ARP and sporadic parkinsonism. Thus, after obtaining clinical information, screening for mutations in (1) parkin, (2) PINK1, (3) DJ-1, (4) ATP13A2 should be conducted in that order, in ARP and sporadic parkinsonism, based on their reported frequencies. In addition, haplotype analysis should be employed to check for homozygosity of 1p36, which harbors a cluster of causative genes for ARP such as DJ-1, PINK1 and ATP13A2 in ARP and sporadic parkinsonism, especially in parkinsonism with consanguinity.

  3. Genome-wide analysis of mutations in mutant lineages selected following fast-neutron irradiation mutagenesis of Arabidopsis thaliana

    KAUST Repository

    Belfield, E.J.; Gan, X.; Mithani, A.; Brown, C.; Jiang, C.; Franklin, K.; Alvey, E.; Wibowo, A.; Jung, M.; Bailey, K.; Kalwani, S.; Ragoussis, J.; Mott, R.; Harberd, N.P.

    2012-01-01

    Ionizing radiation has long been known to induce heritable mutagenic change in DNA sequence. However, the genome-wide effect of radiation is not well understood. Here we report the molecular properties and frequency of mutations in phenotypically selected mutant lines isolated following exposure of the genetic model flowering plant Arabidopsis thaliana to fast neutrons (FNs). Previous studies suggested that FNs predominantly induce deletions longer than a kilobase in A. thaliana. However, we found a higher frequency of single base substitution than deletion mutations. While the overall frequency and molecular spectrum of fast-neutron (FN)-induced single base substitutions differed substantially from those of "background" mutations arising spontaneously in laboratory-grown plants, G:C>A:T transitions were favored in both. We found that FN-induced G:C>A:T transitions were concentrated at pyrimidine dinucleotide sites, suggesting that FNs promote the formation of mutational covalent linkages between adjacent pyrimidine residues. In addition, we found that FNs induced more single base than large deletions, and that these single base deletions were possibly caused by replication slippage. Our observations provide an initial picture of the genome-wide molecular profile of mutations induced in A. thaliana by FN irradiation and are particularly informative of the nature and extent of genome-wide mutation in lines selected on the basis of mutant phenotypes from FN-mutagenized A. thaliana populations.

  4. Genome-wide analysis of mutations in mutant lineages selected following fast-neutron irradiation mutagenesis of Arabidopsis thaliana

    KAUST Repository

    Belfield, E.J.

    2012-04-12

    Ionizing radiation has long been known to induce heritable mutagenic change in DNA sequence. However, the genome-wide effect of radiation is not well understood. Here we report the molecular properties and frequency of mutations in phenotypically selected mutant lines isolated following exposure of the genetic model flowering plant Arabidopsis thaliana to fast neutrons (FNs). Previous studies suggested that FNs predominantly induce deletions longer than a kilobase in A. thaliana. However, we found a higher frequency of single base substitution than deletion mutations. While the overall frequency and molecular spectrum of fast-neutron (FN)-induced single base substitutions differed substantially from those of "background" mutations arising spontaneously in laboratory-grown plants, G:C>A:T transitions were favored in both. We found that FN-induced G:C>A:T transitions were concentrated at pyrimidine dinucleotide sites, suggesting that FNs promote the formation of mutational covalent linkages between adjacent pyrimidine residues. In addition, we found that FNs induced more single base than large deletions, and that these single base deletions were possibly caused by replication slippage. Our observations provide an initial picture of the genome-wide molecular profile of mutations induced in A. thaliana by FN irradiation and are particularly informative of the nature and extent of genome-wide mutation in lines selected on the basis of mutant phenotypes from FN-mutagenized A. thaliana populations.

  5. Lineage dynamics and mutation-selection balance in non-adapting asexual populations

    Science.gov (United States)

    Pénisson, Sophie; Sniegowski, Paul D.; Colato, Alexandre; Gerrish, Philip J.

    2013-02-01

    In classical population genetics, mutation-selection balance refers to the equilibrium frequency of a deleterious allele established and maintained under two opposing forces: recurrent mutation, which tends to increase the frequency of the allele; and selection, which tends to decrease its frequency. In a haploid population, if μ denotes the per capita rate of production of the deleterious allele by mutation and s denotes the selective disadvantage of carrying the allele, then the classical mutation-selection balance frequency of the allele is approximated by μ/s. This calculation assumes that lineages carrying the mutant allele in question—the ‘focal allele’—do not accumulate deleterious mutations linked to the focal allele. In principle, indirect selection against the focal allele caused by such additional mutations can decrease the frequency of the focal allele below the classical mutation-selection balance. This effect of indirect selection will be strongest in an asexual population, in which the entire genome is in linkage. Here, we use an approach based on a multitype branching process to investigate this effect, analyzing lineage dynamics under mutation, direct selection, and indirect selection in a non-adapting asexual population. We find that the equilibrium balance between recurrent mutation to the focal allele and the forces of direct and indirect selection against the focal allele is closely approximated by γμ/(s + U) (s = 0 if the focal allele is neutral), where γ ≈ eθθ-(ω+θ)(ω + θ)(Γ(ω + θ) - Γ(ω + θ,θ)), \\theta =U/\\tilde {s}, and \\omega =s/\\tilde {s}; U denotes the genomic deleterious mutation rate and \\tilde {s} denotes the geometric mean selective disadvantage of deleterious mutations elsewhere on the genome. This mutation-selection balance for asexual populations can remain surprisingly invariant over wide ranges of the mutation rate.

  6. Nicotinamide starvation and inhibition of poly(ADP-Ribose) synthesis enhance the induced mutation in Chinese hamster V79 cells

    International Nuclear Information System (INIS)

    Okada, Gensaku; Kaneko, Ichiro; Mitsui, Hideki.

    1987-01-01

    The effects of nicotinamide (NA) deficiency and added NA and 3-aminobenzamide (3AB) on the cytotoxicity and the induction of mutations in Chinese hamster V79-14 cells were investigated. In NA deficiency the addition of NA (up to 4 mM) and 3AB (up to 7.5 mM) was not cytotoxic. The presence of NA prior to exposure to mitomycin C (MMC) or γ-rays produced a dose-dependent increase in the relative cloning ability of DNA-damaged cells. The lethality of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was significantly potentiated by pre-treatment with 5 mM 3AB, but no potentiation by 3AB was observed for MMC, ultraviolet (UV)-B light, or γ-rays. Among cells pre-cultured in NA-free medium there were increased frequencies of mutations at both the hypoxanthineguanine phosphoribosyltransferase (HGPRT) and the adenine phosphoribosyltransferase (APRT) loci following DNA damage. The enhancing effect by NA deficiency was time-dependent. Incubation with NA prior to DNA damage produced a significant reduction in the frequency of mutations. The addition of 3AB to the nicotinamide adenine dinucleotide (NAD + )-depleted cell cultures before or after the DNA damage also strongly increased the frequency of induced mutations, with increasing concentrations of 3AB up to 5 mM, but the frequency was reduced at higher concentrations. The interaction between NA deficiency and the addition of 3AB appears to act synergistically on mutation induction. A correlation was observed between the potential of inhibiting poly (ADP-ribose) polymerase and the enhancement of mutation frequency. (author)

  7. A novel mutation in the WFS1 gene identified in a Taiwanese family with low-frequency hearing impairment

    Directory of Open Access Journals (Sweden)

    Chung Shing-Fang

    2007-05-01

    Full Text Available Abstract Background Wolfram syndrome gene 1 (WFS1 accounts for most of the familial nonsyndromic low-frequency sensorineural hearing loss (LFSNHL which is characterized by sensorineural hearing losses equal to and below 2000 Hz. The current study aimed to contribute to our understanding of the molecular basis of LFSNHL in an affected Taiwanese family. Methods The Taiwanese family with LFSNHL was phenotypically characterized using audiologic examination and pedigree analysis. Genetic characterization was performed by direct sequencing of WFS1 and mutation analysis. Results Pure tone audiometry confirmed that the family members affected with LFSNHL had a bilateral sensorineural hearing loss equal to or below 2000 Hz. The hearing loss threshold of the affected members showed no progression, a characteristic that was consistent with a mutation in the WFS1 gene located in the DFNA6/14/38 locus. Pedigree analysis showed a hereditarily autosomal dominant pattern characterized by a full penetrance. Among several polymorphisms, a missense mutation Y669H (2005T>C in exon 8 of WFS1 was identified in members of a Taiwanese family diagnosed with LFSNHL but not in any of the control subjects. Conclusion We discovered a novel heterozygous missense mutation in exon 8 of WFS1 (i.e., Y669H which is likely responsible for the LFSNHL phenotype in this particular Taiwanese family.

  8. Emergent HIV-1 Drug Resistance Mutations Were Not Present at Low-Frequency at Baseline in Non-Nucleoside Reverse Transcriptase Inhibitor-Treated Subjects in the STaR Study.

    Science.gov (United States)

    Porter, Danielle P; Daeumer, Martin; Thielen, Alexander; Chang, Silvia; Martin, Ross; Cohen, Cal; Miller, Michael D; White, Kirsten L

    2015-12-07

    At Week 96 of the Single-Tablet Regimen (STaR) study, more treatment-naïve subjects that received rilpivirine/emtricitabine/tenofovir DF (RPV/FTC/TDF) developed resistance mutations compared to those treated with efavirenz (EFV)/FTC/TDF by population sequencing. Furthermore, more RPV/FTC/TDF-treated subjects with baseline HIV-1 RNA >100,000 copies/mL developed resistance compared to subjects with baseline HIV-1 RNA ≤100,000 copies/mL. Here, deep sequencing was utilized to assess the presence of pre-existing low-frequency variants in subjects with and without resistance development in the STaR study. Deep sequencing (Illumina MiSeq) was performed on baseline and virologic failure samples for all subjects analyzed for resistance by population sequencing during the clinical study (n = 33), as well as baseline samples from control subjects with virologic response (n = 118). Primary NRTI or NNRTI drug resistance mutations present at low frequency (≥2% to 20%) were detected in 6.6% of baseline samples by deep sequencing, all of which occurred in control subjects. Deep sequencing results were generally consistent with population sequencing but detected additional primary NNRTI and NRTI resistance mutations at virologic failure in seven samples. HIV-1 drug resistance mutations emerging while on RPV/FTC/TDF or EFV/FTC/TDF treatment were not present at low frequency at baseline in the STaR study.

  9. Emergent HIV-1 Drug Resistance Mutations Were Not Present at Low-Frequency at Baseline in Non-Nucleoside Reverse Transcriptase Inhibitor-Treated Subjects in the STaR Study

    Directory of Open Access Journals (Sweden)

    Danielle P. Porter

    2015-12-01

    Full Text Available At Week 96 of the Single-Tablet Regimen (STaR study, more treatment-naïve subjects that received rilpivirine/emtricitabine/tenofovir DF (RPV/FTC/TDF developed resistance mutations compared to those treated with efavirenz (EFV/FTC/TDF by population sequencing. Furthermore, more RPV/FTC/TDF-treated subjects with baseline HIV-1 RNA >100,000 copies/mL developed resistance compared to subjects with baseline HIV-1 RNA ≤100,000 copies/mL. Here, deep sequencing was utilized to assess the presence of pre-existing low-frequency variants in subjects with and without resistance development in the STaR study. Deep sequencing (Illumina MiSeq was performed on baseline and virologic failure samples for all subjects analyzed for resistance by population sequencing during the clinical study (n = 33, as well as baseline samples from control subjects with virologic response (n = 118. Primary NRTI or NNRTI drug resistance mutations present at low frequency (≥2% to 20% were detected in 6.6% of baseline samples by deep sequencing, all of which occurred in control subjects. Deep sequencing results were generally consistent with population sequencing but detected additional primary NNRTI and NRTI resistance mutations at virologic failure in seven samples. HIV-1 drug resistance mutations emerging while on RPV/FTC/TDF or EFV/FTC/TDF treatment were not present at low frequency at baseline in the STaR study.

  10. Mitochondrial mutations drive prostate cancer aggression

    DEFF Research Database (Denmark)

    Hopkins, Julia F.; Sabelnykova, Veronica Y.; Weischenfeldt, Joachim

    2017-01-01

    Nuclear mutations are well known to drive tumor incidence, aggression and response to therapy. By contrast, the frequency and roles of mutations in the maternally inherited mitochondrial genome are poorly understood. Here we sequence the mitochondrial genomes of 384 localized prostate cancer...... in prostate cancer, and suggest interplay between nuclear and mitochondrial mutational profiles in prostate cancer....

  11. Radiation induced chlorophyll mutations in rice

    International Nuclear Information System (INIS)

    Bari, G.; Mustafa, G.; Soomro, A.M.; Baloch, A.W.

    1985-01-01

    Air dried grains of four local varieties of rice were treated with gamma-rays and fast neutrons for determining their mutagenic effectiveness through the occurence of chlorophyll mutations. Fast neutrons were more effective in inducing chlorophyll mutations and the rice variety Basmati 370 produced maximum number of mutations followed by varieties Sonahri Sugdasi, Jajai 77 and Sada Gulab. The highest frequency of chlorophyll mutations was that of albina types followed by striata types. The xantha, viridis and tigrina types of mutations were less frequent. (authors)

  12. Frequency of Hereditary Hemochromatosis (HFE) Gene Mutations in Egyptian Beta Thalassemia Patients and its Relation to Iron Overload.

    Science.gov (United States)

    Enein, Azza Aboul; El Dessouky, Nermine A; Mohamed, Khalda S; Botros, Shahira K A; Abd El Gawad, Mona F; Hamdy, Mona; Dyaa, Nehal

    2016-06-15

    This study aimed to detect the most common HFE gene mutations (C282Y, H63D, and S56C) in Egyptian beta thalassemia major patients and its relation to their iron status. The study included 50 beta thalassemia major patients and 30 age and sex matched healthy persons as a control group. Serum ferritin, serum iron and TIBC level were measured. Detection of the three HFE gene mutations (C282Y, H63D and S65C) was done by PCR-RFLP analysis. Confirmation of positive cases for the mutations was done by sequencing. Neither homozygote nor carrier status for the C282Y or S65C alleles was found. The H63D heterozygous state was detected in 5/50 (10%) thalassemic patients and in 1/30 (3.3%) controls with no statistically significant difference between patients and control groups (p = 0.22). Significantly higher levels of the serum ferritin and serum iron in patients with this mutation (p = 001). Our results suggest that there is an association between H63D mutation and the severity of iron overload in thalassemic patients.

  13. Temporal frequency of knockdown resistance mutations, F1534C and V1016G, in Aedes aegypti in Chiang Mai city, Thailand and the impact of the mutations on the efficiency of thermal fogging spray with pyrethroids.

    Science.gov (United States)

    Plernsub, Suriya; Saingamsook, Jassada; Yanola, Jintana; Lumjuan, Nongkran; Tippawangkosol, Pongsri; Walton, Catherine; Somboon, Pradya

    2016-10-01

    In Thailand, control of dengue outbreaks is currently attained by the use of space sprays, particularly thermal fogging using pyrethroids, with the aim of killing infected Aedes mosquito vectors in epidemic areas. However, the principal dengue vector, Aedes aegypti, is resistant to pyrethroids conferred mainly by mutations in the voltage-gated sodium channel gene, F1534C and V1016G, termed knockdown resistance (kdr). The objectives of this study were to determine the temporal frequencies of F1534C and V1016G in Ae. aegypti populations in relation to pyrethroid resistance in Chiang Mai city, and to evaluate the impact of the mutations on the efficacy of thermal fogging with the pyrethroid deltamethrin. Larvae and pupae were collected from several areas around Chiang Mai city during 2011-2015 and reared to adulthood for bioassays for deltamethrin susceptibility. These revealed no trend of increasing deltamethrin resistance during the study period (mortality 58.0-69.5%, average 62.8%). This corresponded to no overall change in the frequencies of the C1534 allele (0.55-0.66, average 0.62) and G1016 allele (0.34-0.45, average 0.38), determined using allele specific amplification. Only three genotypes of kdr mutations were detected: C1534 homozygous (VV/CC); G1016/C1534 double heterozygous (VG/FC); and G1016 homozygous (GG/FF) indicating that the F1534C and V1016G mutations occurred on separate haplotypic backgrounds and a lack of recombination between them to date. The F1 progeny females were used to evaluate the efficacy of thermal fogging spray with Damthrin-SP(®) (deltamethrin+S-bioallethrin+piperonyl butoxide) using a caged mosquito bioassay. The thermal fogging spray killed 100% and 61.3% of caged mosquito bioassay placed indoors and outdoors, respectively. The outdoor spray had greater killing effect on C1534 homozygous and had partially effect on double heterozygous mosquitoes, but did not kill any G1016 homozygous mutants living outdoors. As this selection

  14. Radiation-induced dominant skeletal mutations in mice: mutation rate, characteristics, and usefulness in estimating genetic hazard to humans from radiation

    International Nuclear Information System (INIS)

    Selby, P.B.

    1979-01-01

    The work discussed in this paper represents a major advance in the difficult task of trying to estimate the effects that an increase in mutation frequency would have on human health. Male mice were bred to three females prior to being killed and skeleton studies made. Guidelines were instituted for checking progeny mutations. Surprising results showed a mutation frequency of 1.4% per gamete where none would have been expected. It is now clear that mice can be greatly deformed without showing external effects

  15. GBM-associated mutations and altered protein expression are more common in young patients.

    Science.gov (United States)

    Ferguson, Sherise D; Xiu, Joanne; Weathers, Shiao-Pei; Zhou, Shouhao; Kesari, Santosh; Weiss, Stephanie E; Verhaak, Roeland G; Hohl, Raymond J; Barger, Geoffrey R; Reddy, Sandeep K; Heimberger, Amy B

    2016-10-25

    Geriatric glioblastoma (GBM) patients have a poorer prognosis than younger patients, but IDH1/2 mutations (more common in younger patients) confer a favorable prognosis. We compared key GBM molecular alterations between an elderly (age ≥ 70) and younger (18 GBM cohort compared to the older cohort (P GBM cohort, younger patients had significantly more mutations in PDGFRA, PTPN11, SMARCA4, BRAF and TP53. GBMs from 178 elderly patients and 197 young patients were analyzed using DNA sequencing, immunohistochemistry, in situ hybridization, and MGMT-methylation assay to ascertain mutational and amplification/expressional status. Significant molecular differences occurred in GBMs from elderly and young patients. Except for the older cohort's more frequent PTEN mutation and MGMT methylation, younger patients had a higher frequency of potential therapeutic targets.

  16. Analysis of point mutations in an ultraviolet-irradiated shuttle vector plasmid propagated in cells from Japanese xeroderma pigmentosum patients in complementation groups A and F

    International Nuclear Information System (INIS)

    Yagi, T.; Tatsumi-Miyajima, J.; Sato, M.; Kraemer, K.H.; Takebe, H.

    1991-01-01

    To assess the contribution to mutagenesis by human DNA repair defects, a UV-treated shuttle vector plasmid, pZ189, was passed through fibroblasts derived from Japanese xeroderma pigmentosum (XP) patients in two different DNA repair complementation groups (A and F). Patients with XP have clinical and cellular UV hypersensitivity, increased frequency of skin cancer, and defects in DNA repair. The XP DNA repair defects represented by complementation groups A (XP-A) and F (XP-F) are more common in Japan than in Europe or the United States. In comparison to results with DNA repair-proficient human cells (W138-VA13), UV-treated pZ189 passed through the XP-A [XP2OS(SV)] or XP-F [XP2YO(SV)] cells showed fewer surviving plasmids (XP-A less than XP-F) and a higher frequency of mutated plasmids (XP-A greater than XP-F). Base sequence analysis of more than 200 mutated plasmids showed the major type of base substitution mutation to be the G:C----A:T transition with all three cell lines. The XP-A and XP-F cells revealed a higher frequency of G:C----A:T transitions and a lower frequency of transversions among plasmids with single or tandem mutations and a lower frequency of plasmids with multiple point mutations compared to the normal line. The spectrum of mutations in pZ189 with the XP-A cells was similar to that with the XP-F cells. Seventy-six to 91% of the single base substitution mutations occurred at G:C base pairs in which the 5'-neighboring base of the cytosine was thymine or cytosine. These studies indicate that the DNA repair defects in Japanese XP patients in complementation groups A and F result in different frequencies of plasmid survival and mutagenesis but in similar types of mutagenic abnormalities despite marked differences in clinical features

  17. Estimation of the frequency of occult mutations for an autosomal recessive disease in the presence of genetic heterogeneity: application to genetic hearing loss disorders.

    Science.gov (United States)

    Kimberling, William J

    2005-11-01

    The routine testing for pathologic mutation(s) in a patient's DNA has become the foundation of modern molecular genetic diagnosis. It is especially valuable when the phenotype shows genetic heterogeneity, and its importance will grow as treatments become genotype specific. However, the technology of mutation detection is imperfect and mutations are often missed. This can be especially troublesome when dealing with a recessive disorder where the combination of genetic heterogeneity and missed mutation creates an imprecision in the genotypic assessment of individuals who do not appear to have the expected complement of two pathologic mutations. This article describes a statistical approach to the estimation of the likelihood of a genetic diagnosis under these conditions. In addition to providing a means of testing for missed mutations, it also provides a method of estimating and testing for the presence of genetic heterogeneity in the absence of linkage data. Gene frequencies as well as estimates of sensitivity and specificity can be obtained as well. The test is applied to GJB2 recessive nonsyndromic deafness, Usher syndrome types Ib and IIa, and Pendred-enlarged vestibular aqueduct syndrome. Copyright 2005 Wiley-Liss, Inc.

  18. Use of nfsB, encoding nitroreductase, as a reporter gene to determine the mutational spectrum of spontaneous mutations in Neisseria gonorrhoeae

    Directory of Open Access Journals (Sweden)

    Dunham Stephen

    2009-11-01

    Full Text Available Abstract Background Organisms that are sensitive to nitrofurantoin express a nitroreductase. Since bacterial resistance to this compound results primarily from mutations in the gene encoding nitroreductase, the resulting loss of function of nitroreductase results in a selectable phenotype; resistance to nitrofurantoin. We exploited this direct selection for mutation to study the frequency at which spontaneous mutations arise (transitions and transversions, insertions and deletions. Results A nitroreductase- encoding gene was identified in the N. gonorrhoeae FA1090 genome by using a bioinformatic search with the deduced amino acid sequence derived from the Escherichia coli nitroreductase gene, nfsB. Cell extracts from N. gonorrhoeae were shown to possess nitroreductase activity, and activity was shown to be the result of NfsB. Spontaneous nitrofurantoin-resistant mutants arose at a frequency of ~3 × 10-6 - 8 × 10-8 among the various strains tested. The nfsB sequence was amplified from various nitrofurantoin-resistant mutants, and the nature of the mutations determined. Transition, transversion, insertion and deletion mutations were all readily detectable with this reporter gene. Conclusion We found that nfsB is a useful reporter gene for measuring spontaneous mutation frequencies. Furthermore, we found that mutations were more likely to arise in homopolymeric runs rather than as base substitutions.

  19. JAK2, MPL, and CALR mutations in Chinese Han patients with essential thrombocythemia.

    Science.gov (United States)

    Wang, Jing; Zhang, Biao; Chen, Bing; Zhou, Rong-Fu; Zhang, Qi-Guo; Li, Juan; Yang, Yong-Gong; Zhou, Min; Shao, Xiao-Yan; Xu, Yong; Xu, Xi-Hui; Ouyang, Jian; Xu, Jingyan; Ye, Qing

    2017-04-01

    Mutations in Janus kinase 2 (JAK2), myeloproliferative leukemia (MPL), and CALR are highly relevant to Philadelphia chromosome (Ph)-negative myeloproliferative neoplasms. Assessing the prevalence of molecular mutations in Chinese Han patients with essential thrombocythemia (ET), and correlating their mutational profile with disease characteristics/phenotype. Of the 110 subjects studied, 62 carried the JAK2 V617F mutation, 21 had CALR mutations, one carried an MPL (W515) mutation, and 28 had non-mutated JAK2, CALR, and MPL (so-called triple-negative ET). Mutations in JAK2 exon 12 were not detected in any patient. Two ET patients had both CALR and JAK2 V617F mutations. Comparing the hematological parameters of the patients with JAK2 mutations with those of the patients with CALR mutations showed that the ET patients with CALR mutations were younger (p = 0.045) and had higher platelet counts (p = 0.043). Genotyping for CALR could be a useful diagnostic tool for JAK2/MPL-negative ET, since the data suggest that CALR is much more prevalent than MPL, therefore testing for CALR should be considered in patients who are JAK2 negative as its frequency is almost 20 times that of MPL mutation.

  20. Effects of near-ultraviolet light on mutations, intragenic and intergenic recombinations in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Machida, Isamu; Saeki, Tetsuya; Nakai, Sayaka

    1986-01-01

    The effects of far and near ultraviolet light on mutations, intragenic and intergenic recombinations were compared in diploid strains of Saccharomyces cerevisiae. At equivalent survival levels there was not much difference in the induction of nonsense and missense mutations between far- and near-UV radiations. However, frameshift mutations were induced more frequently by near-UV than by far-UV radiation. Near-UV radiation induced intragenic recombination as efficiently as far-UV radiation. A strikingly higher frequency was observed for the intergenic recombination induced by near-UV radiation than by far-UV radiation when compared at equivalent survival levels. Photoreactivation reduced the frequency only slightly in far-UV induced intergenic recombination and not at all in near-UV induction. These results indicate that near-UV damage involves strand breakage in addition to pyrimidine dimers and other lesions induced, whereas far-UV damage consists largely of photoreactivable lesions, pyrimidine dimers, and near-UV induced damage is more efficient for the induction of crossing-over. (Auth.)

  1. Somatic Mutations and Clonal Hematopoiesis in Aplastic Anemia.

    Science.gov (United States)

    Yoshizato, Tetsuichi; Dumitriu, Bogdan; Hosokawa, Kohei; Makishima, Hideki; Yoshida, Kenichi; Townsley, Danielle; Sato-Otsubo, Aiko; Sato, Yusuke; Liu, Delong; Suzuki, Hiromichi; Wu, Colin O; Shiraishi, Yuichi; Clemente, Michael J; Kataoka, Keisuke; Shiozawa, Yusuke; Okuno, Yusuke; Chiba, Kenichi; Tanaka, Hiroko; Nagata, Yasunobu; Katagiri, Takamasa; Kon, Ayana; Sanada, Masashi; Scheinberg, Phillip; Miyano, Satoru; Maciejewski, Jaroslaw P; Nakao, Shinji; Young, Neal S; Ogawa, Seishi

    2015-07-02

    In patients with acquired aplastic anemia, destruction of hematopoietic cells by the immune system leads to pancytopenia. Patients have a response to immunosuppressive therapy, but myelodysplastic syndromes and acute myeloid leukemia develop in about 15% of the patients, usually many months to years after the diagnosis of aplastic anemia. We performed next-generation sequencing and array-based karyotyping using 668 blood samples obtained from 439 patients with aplastic anemia. We analyzed serial samples obtained from 82 patients. Somatic mutations in myeloid cancer candidate genes were present in one third of the patients, in a limited number of genes and at low initial variant allele frequency. Clonal hematopoiesis was detected in 47% of the patients, most frequently as acquired mutations. The prevalence of the mutations increased with age, and mutations had an age-related signature. DNMT3A-mutated and ASXL1-mutated clones tended to increase in size over time; the size of BCOR- and BCORL1-mutated and PIGA-mutated clones decreased or remained stable. Mutations in PIGA and BCOR and BCORL1 correlated with a better response to immunosuppressive therapy and longer and a higher rate of overall and progression-free survival; mutations in a subgroup of genes that included DNMT3A and ASXL1 were associated with worse outcomes. However, clonal dynamics were highly variable and might not necessarily have predicted the response to therapy and long-term survival among individual patients. Clonal hematopoiesis was prevalent in aplastic anemia. Some mutations were related to clinical outcomes. A highly biased set of mutations is evidence of Darwinian selection in the failed bone marrow environment. The pattern of somatic clones in individual patients over time was variable and frequently unpredictable. (Funded by Grant-in-Aid for Scientific Research and others.).

  2. A current drive by using the fast wave in frequency range higher than two timeslower hybrid resonance frequency on tokamaks

    Directory of Open Access Journals (Sweden)

    Kim Sun Ho

    2017-01-01

    Full Text Available An efficient current drive scheme in central or off-axis region is required for the steady state operation of tokamak fusion reactors. The current drive by using the fast wave in frequency range higher than two times lower hybrid resonance (w>2wlh could be such a scheme in high density, high temperature reactor-grade tokamak plasmas. First, it has relatively higher parallel electric field to the magnetic field favorable to the current generation, compared to fast waves in other frequency range. Second, it can deeply penetrate into high density plasmas compared to the slow wave in the same frequency range. Third, parasitic coupling to the slow wave can contribute also to the current drive avoiding parametric instability, thermal mode conversion and ion heating occured in the frequency range w<2wlh. In this study, the propagation boundary, accessibility, and the energy flow of the fast wave are given via cold dispersion relation and group velocity. The power absorption and current drive efficiency are discussed qualitatively through the hot dispersion relation and the polarization. Finally, those characteristics are confirmed with ray tracing code GENRAY for the KSTAR plasmas.

  3. Spectrum of K ras mutations in Pakistani colorectal cancer patients

    International Nuclear Information System (INIS)

    Murtaza, B.N.; Bibi, A.; Rashid, M.U.; Khan, Y.I.; Chaudri, M.S.; Shakoori, A.R.

    2013-01-01

    The incidence of colorectal cancer (CRC) is increasing daily worldwide. Although different aspects of CRC have been studied in other parts of the world, relatively little or almost no information is available in Pakistan about different aspects of this disease at the molecular level. The present study was aimed at determining the frequency and prevalence of K ras gene mutations in Pakistani CRC patients. Tissue and blood samples of 150 CRC patients (64% male and 36% female) were used for PCR amplification of K ras and detection of mutations by denaturing gradient gel electrophoresis, restriction fragment length polymorphism analysis, and nucleotide sequencing. The K ras mutation frequency was found to be 13%, and the most prevalent mutations were found at codons 12 and 13. A novel mutation was also found at codon 31. The dominant mutation observed was a G to A transition. Female patients were more susceptible to K ras mutations, and these mutations were predominant in patients with a nonmetastatic stage of CRC. No significant differences in the prevalence of K ras mutations were observed for patient age, gender, or tumor type. It can be inferred from this study that Pakistani CRC patients have a lower frequency of K ras mutations compared to those observed in other parts of the world, and that K ras mutations seemed to be significantly associated with female patients

  4. Spectrum of K ras mutations in Pakistani colorectal cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Murtaza, B.N.; Bibi, A. [School of Biological Sciences, University of the Punjab, Quaid-i-Azam Campus, Lahore (Pakistan); Rashid, M.U.; Khan, Y.I. [Shaukat Khanum Memorial Cancer Hospital and Research Centre, Johar Town, Lahore (Pakistan); Chaudri, M.S. [Services Institute of Medical Sciences, Lahore (Pakistan); Shakoori, A.R. [School of Biological Sciences, University of the Punjab, Quaid-i-Azam Campus, Lahore (Pakistan)

    2013-11-29

    The incidence of colorectal cancer (CRC) is increasing daily worldwide. Although different aspects of CRC have been studied in other parts of the world, relatively little or almost no information is available in Pakistan about different aspects of this disease at the molecular level. The present study was aimed at determining the frequency and prevalence of K ras gene mutations in Pakistani CRC patients. Tissue and blood samples of 150 CRC patients (64% male and 36% female) were used for PCR amplification of K ras and detection of mutations by denaturing gradient gel electrophoresis, restriction fragment length polymorphism analysis, and nucleotide sequencing. The K ras mutation frequency was found to be 13%, and the most prevalent mutations were found at codons 12 and 13. A novel mutation was also found at codon 31. The dominant mutation observed was a G to A transition. Female patients were more susceptible to K ras mutations, and these mutations were predominant in patients with a nonmetastatic stage of CRC. No significant differences in the prevalence of K ras mutations were observed for patient age, gender, or tumor type. It can be inferred from this study that Pakistani CRC patients have a lower frequency of K ras mutations compared to those observed in other parts of the world, and that K ras mutations seemed to be significantly associated with female patients.

  5. IDH mutation is paradoxically associated with higher {sup 18}F-FDOPA PET uptake in diffuse grade II and grade III gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Verger, A. [APHM, La Timone Hospital, Department of Nuclear Medicine, Marseille (France); Lorraine University, Department of Nuclear Medicine and Nancyclotep Imaging Platform, CHRU Nancy, Nancy (France); Lorraine University, IADI, INSERM, UMR 947, Nancy (France); Metellus, P. [Centre Hospitalier Prive Clairval, Department of Neurosurgery, Marseille (France); Aix-Marseille University, INSERM, UMR 911, Marseille (France); Sala, Q. [APHM, La Timone Hospital, Department of Nuclear Medicine, Marseille (France); Colin, C. [Aix-Marseille University, INSERM, UMR 911, Marseille (France); Bialecki, E. [Centre Hospitalier Prive Clairval, Department of Neurosurgery, Marseille (France); Taieb, D. [APHM, La Timone Hospital, Department of Nuclear Medicine, Marseille (France); Aix-Marseille University, CERIMED, Marseille (France); Chinot, O. [Aix-Marseille University, INSERM, UMR 911, Marseille (France); APHM, La Timone Hospital, Department of Neuro-Oncology, Marseille (France); Figarella-Branger, D. [Aix-Marseille University, INSERM, UMR 911, Marseille (France); APHM, La Timone Hospital, Department of Anatomopathology, Marseille (France); Guedj, E. [APHM, La Timone Hospital, Department of Nuclear Medicine, Marseille (France); Aix-Marseille University, CERIMED, Marseille (France); Aix-Marseille University, Institut de Neurosciences de la Timone, CNRS, UMR 7289, Marseille (France); Hopital de la Timone, Service Central de Biophysique et Medecine Nucleaire, Marseille (France)

    2017-08-15

    The World Health Organization Classification of Tumors of the Central Nervous System has recently been updated by the integration of diagnostic and prognostic molecular parameters, giving pivotal attention to IDH mutation as a favourable factor. Amino acid PET is increasingly used in the management of gliomas, but its prognostic value is a matter of debate. The aim of this study was to assess the relationship between IDH mutation and {sup 18}F-FDOPA uptake on PET in newly diagnosed gliomas. A total of 43 patients, presenting with diffuse astrocytic and oligodendroglial grade II and III gliomas, reclassified according to the 2016 WHO classification of tumours of the CNS, were retrospectively included. They had all undergone {sup 18}F-FDOPA PET at an initial stage before surgery and histological diagnosis. {sup 18}F-FDOPA uptake values were compared between patients with and without IDH mutation in terms of maximum standardized uptake value (SUVmax) ratios between tumour and normal contralateral brain (T/N), and between tumour and striatum (T/S). Patients with IDH mutation showed higher {sup 18}F-FDOPA T/N SUVmax ratios (1.6 vs. 1.2) and T/S SUVmax ratios (0.9 vs. 0.6) than patients without IDH mutation (p < 0.05). This study showed paradoxically higher {sup 18}F-FDOPA uptake in diffuse grade II and III gliomas with IDH mutation. Despite evident interest in the management of gliomas, and especially in relation to posttherapy evaluation, our findings raise the question of the prognostic value of {sup 18}F-FDOPA uptake on PET uptake in this group of patients. This may be related to differences in amino acid integration, metabolism, or cell differentiation. (orig.)

  6. Is Increased Low-dose somatic Radiosensitivity Associated with Increased Transgenerational Germline Mutation

    International Nuclear Information System (INIS)

    Brenner, David J.

    2008-01-01

    Using single-molecule polymerase chain reaction, the frequency of spontaneous and radiation-induced mutation at an expanded simple tandem repeat (ESTR) locus was studied in DNA samples extracted from sperm and bone marrow of Atm knockout (Atm+/-) heterozygous male mice. The frequency of spontaneous mutation in sperm and bone marrow in Atm+/- males did not significantly differ from that in wild-type BALB/c mice. Acute gamma-ray exposure did not affect ESTR mutation frequency in bone marrow and resulted in similar increases in sperm samples taken from Atm+/- and BALB/c males. Taken together, these results suggest that the Atm haploinsufficiency analyzed in our study does not affect spontaneous and radiation-induced ESTR mutation frequency in mice

  7. INVESTIGATION OF RANGES AND FREQUENCY OF MUTATIONS IN THE embB GENE IN MYCOBACTERIUMTUBERCULOSIS ASSOCIATED WITH RESISTANCE TO ETHAMBUTOL USING REAL-TIME POLYMERASE CHAINREACTION

    Directory of Open Access Journals (Sweden)

    Yu. S. Аlyapkinа

    2017-01-01

    Full Text Available Based on real-time allele-specific polymerase chain reaction, the ranges of potential mutations in codons of 306 and 405 of the embBgene in Mycobacterium tuberculosis associated with resistance to ethambutol were investigated. 5 different mutations were detected in codon 306 and 3 mutations were found in codon 406 of the embB gene. The detected mutations were confirmed by sequencing and mass spectrometry. By analyzing the frequency of detected mutations of , the set of reagents was developed for rapid testing of susceptibility tuberculous mycobacteria to ethambutol by multi-competitive allele-specific real-time PCR. Out of 107 tested specimens of clinical isolates, mutations of the embB gene of M. tuberculosis were detected in 49 (45.8% specimens, and no mutations were found in 58 (52.2% specimens. 39 (36.4% specimens had mutations in codon 306 of the embB gene, and 9 (8.4% specimens had a mutation in codon 406, and 1 (0.9% specimen had mutations in both codons 306 and 406. The high level of agreement in the results of molecular genetic and bacteriological tests (84% proved the significance of mutations in codons 306 and 406 of the embB gene in M. tuberculosis and the need for their identification in order to detect ethambutol resistant strains of M. tuberculosis. When using molecular genetic tests, the sensitivity level made 75.8%, while the specificity of standard culture-based methods makes 95.6%.

  8. Uncommon EGFR mutations in cytological specimens of 1,874 newly diagnosed Indonesian lung cancer patients

    Science.gov (United States)

    Syahruddin, Elisna; Wulandari, Laksmi; Sri Muktiati, Nunuk; Rima, Ana; Soeroso, Noni; Ermayanti, Sabrina; Levi, Michael; Hidajat, Heriawaty; Widjajahakim, Grace; Utomo, Ahmad Rusdan Handoyo

    2018-01-01

    Purpose We aimed to evaluate the distribution of individual epidermal growth factor receptor (EGFR) mutation subtypes found in routine cytological specimens. Patients and methods A retrospective audit was performed on EGFR testing results of 1,874 consecutive cytological samples of newly diagnosed or treatment-naïve Indonesian lung cancer patients (years 2015–2016). Testing was performed by ISO15189 accredited central laboratory. Results Overall test failure rate was 5.1%, with the highest failure (7.1%) observed in pleural effusion and lowest (1.6%) in needle aspiration samples. EGFR mutation frequency was 44.4%. Tyrosine kinase inhibitor (TKI)-sensitive common EGFR mutations (ins/dels exon 19, L858R) and uncommon mutations (G719X, T790M, L861Q) contributed 57.1% and 29%, respectively. Approximately 13.9% of mutation-positive patients carried a mixture of common and uncommon mutations. Women had higher EGFR mutation rate (52.9%) vs men (39.1%; pcytological techniques yielded similar success rate to detect EGFR mutations. Uncommon EGFR mutations were frequent events in Indonesian lung cancer patients. PMID:29615847

  9. Fitness loss and germline mutations in barn swallows breeding in Chernobyl

    Energy Technology Data Exchange (ETDEWEB)

    Ellegren, Hans; Lindgren, Gabriella; Primmer, C.R. [Swedish Univ. of Agricultural Sciences, Animal Breeding and Genetics Dept., Uppsala (Sweden); Moeller, A.P. [Universite Pierre et Marie Curie. Lab. d`Ecologie, Paris, 75 (France)

    1997-10-09

    The severe nuclear accident at Chernobyl in 1986 resulted in the worst reported accidental exposure of radioactive material to free-living organisms. Short-term effects on human populations inhabiting polluted areas include increased incidence of thyroid cancer, infant leukaemia, and congenital malformations in newborns. Two recent studies have reported, although with some controversy, that germline mutation rates were increased in humans and voles living close to Chernobyl, but little is known about the viability of the organisms affected. Here we report an increased frequency of partial albinism, a morphological aberration associated with a loss of fitness, among barn swallows, Hirundo rustica, breeding close to Chernobyl. Heretability estimates indicate that mutations causing albinism were at least partly of germline origin. Furthermore, evidence for an increased germline mutation rate was obtained from segregation analysis at two hypervariable microsatellite loci, indicating that mutation events in barn swallows from Chernobyl were two- to tenfold higher than in birds from control areas in Ukraine and Italy. (author).

  10. Fitness loss and germline mutations in barn swallows breeding in Chernobyl

    International Nuclear Information System (INIS)

    Ellegren, Hans; Lindgren, Gabriella; Primmer, C.R.; Moeller, A.P.

    1997-01-01

    The severe nuclear accident at Chernobyl in 1986 resulted in the worst reported accidental exposure of radioactive material to free-living organisms. Short-term effects on human populations inhabiting polluted areas include increased incidence of thyroid cancer, infant leukaemia, and congenital malformations in newborns. Two recent studies have reported, although with some controversy, that germline mutation rates were increased in humans and voles living close to Chernobyl, but little is known about the viability of the organisms affected. Here we report an increased frequency of partial albinism, a morphological aberration associated with a loss of fitness, among barn swallows, Hirundo rustica, breeding close to Chernobyl. Heretability estimates indicate that mutations causing albinism were at least partly of germline origin. Furthermore, evidence for an increased germline mutation rate was obtained from segregation analysis at two hypervariable microsatellite loci, indicating that mutation events in barn swallows from Chernobyl were two- to tenfold higher than in birds from control areas in Ukraine and Italy. (author)

  11. Studies of human mutation rates: Progress report

    International Nuclear Information System (INIS)

    Neel, J.V.

    1988-01-01

    Progress was recorded between January 1 and July 1, 1987 on a project entitled ''Studies of Human Mutation Rates''. Studies underway include methodology for studying mutation at the DNA level, algorithms for automated analyses of two-dimensional polyacrylamide DNA gels, theoretical and applied population genetics, and studies of mutation frequency in A-bomb survivors

  12. Effects of diurnal temperature difference and gamma radiation on the frequency of somatic cell mutations in the stamen hairs

    International Nuclear Information System (INIS)

    Kim, Jin Kyu; Kim, Won Rok; Kim, Jae Sung; Shin, Hae Shick; Lee, Jeong Joo

    1998-01-01

    This study deals with the effects of diurnal temperature difference (DTD) on somatic cell mutation frequencies in Tradescantia stamen hairs irradiated with radiation. Potted plants of Tradescantia 4430 were irradiated with 0.3, 0.5, 1.0 and 2.0 Gy of gamma radiation. The irradiated plants were maintained under two different experimental conditions; at constant temperature of 20 degree C (DTD0) and at 28 degree C for 14-h day and 8 degree C for 10-h night (DTD20). The somatic cell mutation rate in 0.5 Gy irradiated group showed a big increase on the 6th day and reached a maximum value on the 10th day after irradiation while the rate in the experimental group under the condition of DTD20 started to increase on the 8th day and got to a maximal value on the 14th day postirradiation. In both of the two experiments, the dose-response relationships were clearly linear. The slope of the DTD20 dose-response curve was much steeper than that of the DTD0 one. In conclusion, a great DTD, as one of environmental stresses, enhanced the effectiveness of radiation in the induction of somatic cell mutations and caused a shift of the peak interval of radiation-induced mutations in Tradescantia stamen hairs

  13. The Frequency of MEFV Gene Mutations and Genotypes in Sanliurfa Province, South-Eastern Region of Turkey, after the Syrian Civil War by Using Next Generation Sequencing and Report of a Novel Exon 4 Mutation (I423T).

    Science.gov (United States)

    Gumus, Evren

    2018-05-07

    Familial Mediterranean Fever (FMF) is a genetic disorder characterized by recurrent episodes of fever and abdominal pain. Mutations in the Mediterranean fever (MEFV) gene are localized on the p arm of chromosome 16. Over 333 MEFV sequence variants have been identified so far in FMF patients, which occur mostly in the 2nd and 10th exons of the gene. In this study, 296 unrelated patients with clinical suspicion of FMF, which were admitted during January⁻December 2017, were retrospectively reviewed to identify the frequency of MEFV gene mutations by using next generation sequencing. Eighteen different mutations, 45 different genotypes and a novel exon 4 (I423T) mutation were identified in this study. This mutation is the fourth mutation identified in exon 4.The most frequent mutation was R202Q, followed by M694V, E148Q, M680I, R761H, V726A and R354W. One of the most important aims of this study is to investigate the MEFV mutation type and genotype of migrants coming to Sanliurfa after the civil war of Syria. This study also examines the effect of the condition on the region’s gene pool and the distribution of different types of mutations. Our results indicated that MEFV mutations are highly heterogeneous in our patient population, which is consistent with the findings of other studies in our region. Previously used methods, such as Restriction Fragment Length Polymorphism (RFLP), do not define uncommon or especially novel mutations. Therefore, Next Generation Sequencing (NGS) analysis of the MEFV gene could be useful for finding novel mutations, except for those located on exon 2 and 10.

  14. Polymorphism of the cytochrome P450 CYP2D6 gene in a European population: characterization of 48 mutations and 53 alleles, their frequencies and evolution.

    Science.gov (United States)

    Marez, D; Legrand, M; Sabbagh, N; Lo Guidice, J M; Spire, C; Lafitte, J J; Meyer, U A; Broly, F

    1997-06-01

    The polymorphic cytochrome P450 CYP2D6 is involved in the metabolism of various drugs of wide therapeutic use and is a presumed susceptibility factor for certain environmentally-induced diseases. Our aim was to define the mutations and alleles of the CYP2D6 gene and to evaluate their frequencies in the European population. Using polymerase chain reaction-single strand conformation polymorphism analysis, 672 unrelated subjects were screened for mutations in the 9 exons of the gene and their exon-intron boundaries. A total of 48 point mutations were identified, of which 29 were novel. Mutations 1749 G-->C, 2938 C-->T and 4268 G-->C represented 52.6%, 34.3% and 52.9% of the mutations in the total population, respectively. Of the eight detrimental mutations detected, the 1934 G-->A, the 1795 Tdel and the 2637 Adel accounted for 65.8%, 6.2% and 4.8% respectively, within the poor metabolizer subgroup. Fifty-three different alleles were characterized from the mutation pattern and by allele-specific sequencing. They are derived from three major alleles, namely the wild-type CYP2D6*1A, the functional CYP2D6*2 and the null CYP2D6*4A. Five allelic variants (CYP2D6*1A, *2, *2B, *4A and *5) account for about 87% of all alleles, while the remaining alleles occur with a frequency of 0.1%-2.7%. These data provide a solid basis for future epidemiological, clinical as well as interethnic studies of the CYP2D6 polymorphism and highlight that the described single strand conformation polymorphism method can be successfully used in designing such studies.

  15. Tumor-specific mutations in low-frequency genes affect their functional properties

    NARCIS (Netherlands)

    L. Erdem-Eraslan (Lale); D. Heijsman (Daphne); M. De Wit (Maurice); A.E. Kremer (Andreas); A. Sacchetti (Andrea); P.J. van der Spek (Peter); P.A.E. Sillevis Smitt (Peter); P.J. French (Pim)

    2015-01-01

    textabstractCausal genetic changes in oligodendrogliomas (OD) with 1p/19q co-deletion include mutations in IDH1, IDH2, CIC, FUBP1, TERT promoter and NOTCH1. However, it is generally assumed that more somatic mutations are required for tumorigenesis. This study aimed to establish whether genes

  16. Distribution of the PKU mutation 165T in Spain and Latin America

    Energy Technology Data Exchange (ETDEWEB)

    Perez, B.; deLucca, M.; Desviat, L.R. [UAM-CSIC, Madrid (Spain)] [and others

    1994-09-01

    The 165T mutation is the second most common mutation in the Spanish PKU patients. In order to provide some additional data about the origin of this mutation, we have analyzed 452 PKU alleles from all regions of Spain. The mutation was found in 9% of alleles. We have found a South-North gradient with a highest frequency in the South and the lowest in the North. In the North-West regions (which has the greatest Celtic influence in Spain) the frequency was 7%. The chromosomes bearing this mutation contained the 8 repeat VNTR allele, as has been described in other populations. In view of these results, we suggest an origin other than Celtic for this mutation. On the other hand, we have analyzed 406 PKU alleles from five Latin American countries, 158 from Brazil, 170 from Chile, 56 from Argentina, 14 from Mexico and 8 from Venezuela. Unlike the results of the IVS10 mutation, 165T is present in Latin America with a low frequency. The results show that this mutation is rare in Chile (1%) and is absent in the chromosomes analyzed from Argentina, Mexico and Venezuela. Only in Brazil has this mutation been found in 5% of the alleles. Up to now, Spain is the only Mediterranean country where this mutation is present with a relatively high frequency. This mutation has been detected in the Portuguese patients and would also have migrated to Brazil.

  17. Welding characteristics of 27, 40 and 67 kHz ultrasonic plastic welding systems using fundamental- and higher-resonance frequencies.

    Science.gov (United States)

    Tsujino, Jiromaru; Hongoh, Misugi; Yoshikuni, Masafumi; Hashii, Hidekazu; Ueoka, Tetsugi

    2004-04-01

    The welding characteristics of 27, 40 and 67 kHz ultrasonic plastic welding systems that are driven at only the fundamental-resonance frequency vibration were compared, and also those of the welding systems that were driven at the fundamental and several higher resonance frequencies simultaneously were studied. At high frequency, welding characteristics can be improved due to the larger vibration loss of plastic materials. For welding of rather thin or small specimens, as the fundamental frequency of these welding systems is higher and the numbers of driven higher frequencies are driven simultaneously, larger welded area and weld strength were obtained.

  18. In utero DNA damage from environmental pollution is associated with somatic gene mutation in newborns

    Energy Technology Data Exchange (ETDEWEB)

    Perera, F.; Hemminki, K.; Jedrychowski, W.; Whyatt, R.; Campbell, U.; Hsu, Y.Z.; Santella, R.; Albertini, R.; O' Neill, J.P. [Columbia University, New York, NY (United States). School of Public Health

    2002-10-01

    Transplacental exposure to carcinogenic air pollutants from the combustion of fossil fuels is a growing health concern, given evidence of the heightened susceptibility of the fetus. These mutagenic/carcinogenic pollutants include aromatic compounds such as polycyclic aromatic hydrocarbons that bind to DNA, forming chemical-DNA adducts. The genotoxic effects of transplacental exposure in humans has been investigated by analyzing aromatic-DNA adducts and the frequency of gene mutations at the hypoxanthine-guanine phosphoribosyltransferase (HPRT) locus in umbilical cord and maternal blood samples. Here the authors show, in a cross-sectional study of 67 mothers and 64 newborns from the Krakow Region of Poland, that aromatic-DNA adducts measured by P-32-postlabeling are positively associated with HPRT mutant frequency in the newborns (beta = 0.56, P = 0.03) after controlling for exposure to tobacco smoke, diet, and socioeconomic status. In contrast to the fetus, HPRT mutations and DNA adducts do not reflect similar exposure periods in the mother, and the maternal biomarkers were not correlated. Adducts were higher in the newborn than the mother, indicating differential susceptibility of the fetus to DNA damage; but HPRT mutation frequency was 4-fold lower, consistent with the long lifetime of the biomarker. These results provide the first demonstration of a molecular link between somatic mutation in the newborn and transplacental exposure to common air pollutants, a finding that is relevant to cancer risk assessment.

  19. Lethal mutagenesis: targeting the mutator phenotype in cancer.

    Science.gov (United States)

    Fox, Edward J; Loeb, Lawrence A

    2010-10-01

    The evolution of cancer and RNA viruses share many similarities. Both exploit high levels of genotypic diversity to enable extensive phenotypic plasticity and thereby facilitate rapid adaptation. In order to accumulate large numbers of mutations, we have proposed that cancers express a mutator phenotype. Similar to cancer cells, many viral populations, by replicating their genomes with low fidelity, carry a substantial mutational load. As high levels of mutation are potentially deleterious, the viral mutation frequency is thresholded at a level below which viral populations equilibrate in a traditional mutation-selection balance, and above which the population is no longer viable, i.e., the population undergoes an error catastrophe. Because their mutation frequencies are fine-tuned just below this error threshold, viral populations are susceptible to further increases in mutational load and, recently this phenomenon has been exploited therapeutically by a concept that has been termed lethal mutagenesis. Here we review the application of lethal mutagenesis to the treatment of HIV and discuss how lethal mutagenesis may represent a novel therapeutic approach for the treatment of solid cancers. Copyright © 2010 Elsevier Ltd. All rights reserved.

  20. The Frequency of MEFV Gene Mutations and Genotypes in Sanliurfa Province, South-Eastern Region of Turkey, after the Syrian Civil War by Using Next Generation Sequencing and Report of a Novel Exon 4 Mutation (I423T

    Directory of Open Access Journals (Sweden)

    Evren Gumus

    2018-05-01

    Full Text Available Background: Familial Mediterranean Fever (FMF is a genetic disorder characterized by recurrent episodes of fever and abdominal pain. Mutations in the Mediterranean fever (MEFV gene are localized on the p arm of chromosome 16. Over 333 MEFV sequence variants have been identified so far in FMF patients, which occur mostly in the 2nd and 10th exons of the gene. Methods: In this study, 296 unrelated patients with clinical suspicion of FMF, which were admitted during January–December 2017, were retrospectively reviewed to identify the frequency of MEFV gene mutations by using next generation sequencing. Results: Eighteen different mutations, 45 different genotypes and a novel exon 4 (I423T mutation were identified in this study. This mutation is the fourth mutation identified in exon 4.The most frequent mutation was R202Q, followed by M694V, E148Q, M680I, R761H, V726A and R354W. Conclusions: One of the most important aims of this study is to investigate the MEFV mutation type and genotype of migrants coming to Sanliurfa after the civil war of Syria. This study also examines the effect of the condition on the region’s gene pool and the distribution of different types of mutations. Our results indicated that MEFV mutations are highly heterogeneous in our patient population, which is consistent with the findings of other studies in our region. Previously used methods, such as Restriction Fragment Length Polymorphism (RFLP, do not define uncommon or especially novel mutations. Therefore, Next Generation Sequencing (NGS analysis of the MEFV gene could be useful for finding novel mutations, except for those located on exon 2 and 10.

  1. Frequencies of CCR5-D32, CCR2-64I and SDF1-3’A mutations in Human Immunodeficiency Virus (HIV seropositive subjects and seronegative individuals from the state of Pará in Brazilian Amazonia

    Directory of Open Access Journals (Sweden)

    Fernanda Andreza de Pinho Lott Carvalhaes

    2005-12-01

    Full Text Available The distribution of genetic polymorphisms of chemokine receptors CCR5-delta32, CCR2-64I and chemokine (SDF1-3’A mutations were studied in 110 Human Immunodeficiency Virus type 1 (HIV-1 seropositive individuals (seropositive group and 139 seronegative individuals (seronegative group from the population of the northern Brazilian city of Belém which is the capital of the state of Pará in the Brazilian Amazon. The CCR5-delta32 mutation was found in the two groups at similar frequencies, i.e. 2.2% for the seronegative group and 2.7% for the seropositive group. The frequencies of the SDF1-3’A mutation were 21.0% for the seronegative group and 15.4% for the seropositive group, and the CCR2-64I allele was found at frequencies of 12.5% for the seronegative group and 5.4% for the seropositive group. Genotype distributions were consistent with Hardy-Weinberg expectations in both groups, suggesting that none of the three mutations has a detectable selective effect. Difference in the allelic and genotypic frequencies was statistically significant for the CCR2 locus, the frequency in the seronegative group being twice that found in the seropositive group. This finding may indicate a protective effect of the CCR2-64I mutation in relation to HIV transmission. However, considering that the CCR2-64I mutation has been more strongly associated with a decreased risk for progression for AIDS than to the resistance to the HIV infection, this could reflect an aspect of population structure or a Type I error.

  2. Resistance to DDT and pyrethroids and increased kdr mutation frequency in An. gambiae after the implementation of permethrin-treated nets in Senegal.

    Directory of Open Access Journals (Sweden)

    Mamadou O Ndiath

    Full Text Available The aim of this study was to evaluate the susceptibility to insecticides of An. gambiae mosquitoes sampled in Dielmo (Senegal, in 2010, 2 years after the implementation of Long Lasting Insecticide-treated Nets (LLINs and to report the evolution of kdr mutation frequency from 2006 to 2010.WHO bioassay susceptibility tests to 6 insecticides were performed on adults F0, issuing from immature stages of An. gambiae s.l., sampled in August 2010. Species and molecular forms as well as the presence of L1014F and L1014S kdr mutations were assessed by PCR. Longitudinal study of kdr mutations was performed on adult mosquitoes sampled monthly by night landing catches from 2006 to 2010.No specimen studied presented the L1014S mutation. During the longitudinal study, L1014F allelic frequency rose from 2.4% in year before the implementation of LLINs to 4.6% 0-12 months after and 18.7% 13-30 months after. In 2010, An. gambiae were resistant to DDT, Lambda-cyhalothrin, Deltamethrin and Permethrin (mortality rates ranging from 46 to 63% but highly susceptible to Fenitrothion and Bendiocarb (100% mortality. There was significantly more RR genotype among An. gambiae surviving exposure to DDT or Pyrethroids. An. arabiensis represented 3.7% of the sampled mosquitoes (11/300 with no kdr resistance allele detected. An. gambiae molecular form M represented 29.7% of the mosquitoes with, among them, kdr genotypes SR (18% and SS (82%. An. gambiae molecular form S represented 66% of the population with, among them, kdr genotype SS (33.3%, SR (55.6% and RR (11.1%. Only 2 MS hybrid mosquitoes were sampled and presented SS kdr genotype.Biological evidence of resistance to DDT and pyrethroids was detected among An. gambiae mosquitoes in Dielmo (Senegal within 24 months of community use of LLINs. Molecular identification of L1014F mutation indicated that target site resistance increased after the implementation of LLINs.

  3. Association of mutations in the hemochromatosis gene with shorter life expectancy

    DEFF Research Database (Denmark)

    Bathum, L; Christiansen, L; Nybo, H

    2001-01-01

    BACKGROUND: To investigate whether the frequency of carriers of mutations in the HFE gene associated with hereditary hemochromatosis diminishes with age as an indication that HFE mutations are associated with increased mortality. It is of value in the debate concerning screening for hereditary...... hemochromatosis to determine the significance of heterozygosity. METHODS: Genotyping for mutations in exons 2 and 4 of the HFE gene using denaturing gradient gel electrophoresis in 1784 participants aged 45 to 100 years from 4 population-based studies: all 183 centenarians from the Danish Centenarian Study, 601...... in the distribution of mutations in exon 2 in the different age groups. CONCLUSIONS: In a high-carrier frequency population like Denmark, mutations in HFE show an age-related reduction in the frequency of heterozygotes for C282Y, which suggests that carrier status is associated with shorter life expectancy....

  4. Sucrose and IQ induced mutations in rat colon by independent

    DEFF Research Database (Denmark)

    Hansen, Max; Hald, M. T.; Autrup, H.

    2004-01-01

    Sucrose-rich diets have repeatedly been observed to have co-carcinogenic actions in colon and liver of rats and to increase the number of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) induced aberrant crypt foci in rat colon. To investigate a possible interaction between sucrose and IQ...... on the genotoxicity in rat liver and colon, we gave Big Blue rats(TM) a diet containing sucrose (0%, 3.45% or 13.4% w/w) and/or IQ (70 ppm) for a period of 3 weeks. Sucrose and IQ increased the mutation frequency in the colon. The effect of combined treatments with IQ and sucrose on the mutation frequencies...... was additive indicating that sucrose and IQ act independently. This was supported by the mutation spectra where sucrose expands the background mutations in the colon, whereas IQ, in other studies, more specifically has induced G:C --> T:A transversions. In the liver IQ increased the mutation frequency, whereas...

  5. Mutational screening of the USH2A gene in Spanish USH patients reveals 23 novel pathogenic mutations

    Directory of Open Access Journals (Sweden)

    Diaz-Llopis Manuel

    2011-10-01

    Full Text Available Abstract Background Usher Syndrome type II (USH2 is an autosomal recessive disorder, characterized by moderate to severe hearing impairment and retinitis pigmentosa (RP. Among the three genes implicated, mutations in the USH2A gene account for 74-90% of the USH2 cases. Methods To identify the genetic cause of the disease and determine the frequency of USH2A mutations in a cohort of 88 unrelated USH Spanish patients, we carried out a mutation screening of the 72 coding exons of this gene by direct sequencing. Moreover, we performed functional minigene studies for those changes that were predicted to affect splicing. Results As a result, a total of 144 DNA sequence variants were identified. Based upon previous studies, allele frequencies, segregation analysis, bioinformatics' predictions and in vitro experiments, 37 variants (23 of them novel were classified as pathogenic mutations. Conclusions This report provide a wide spectrum of USH2A mutations and clinical features, including atypical Usher syndrome phenotypes resembling Usher syndrome type I. Considering only the patients clearly diagnosed with Usher syndrome type II, and results obtained in this and previous studies, we can state that mutations in USH2A are responsible for 76.1% of USH2 disease in patients of Spanish origin.

  6. Parkinson's disease-related LRRK2 G2019S mutation results from independent mutational events in humans.

    Science.gov (United States)

    Lesage, Suzanne; Patin, Etienne; Condroyer, Christel; Leutenegger, Anne-Louise; Lohmann, Ebba; Giladi, Nir; Bar-Shira, Anat; Belarbi, Soraya; Hecham, Nassima; Pollak, Pierre; Ouvrard-Hernandez, Anne-Marie; Bardien, Soraya; Carr, Jonathan; Benhassine, Traki; Tomiyama, Hiroyuki; Pirkevi, Caroline; Hamadouche, Tarik; Cazeneuve, Cécile; Basak, A Nazli; Hattori, Nobutaka; Dürr, Alexandra; Tazir, Meriem; Orr-Urtreger, Avi; Quintana-Murci, Lluis; Brice, Alexis

    2010-05-15

    Mutations in the leucine-rich-repeat kinase 2 (LRRK2) gene have been identified in families with autosomal dominant Parkinson's disease (PD) and in sporadic cases; the G2019S mutation is the single most frequent. Intriguingly, the frequency of this mutation in PD patients varies greatly among ethnic groups and geographic origins: it is present at <0.1% in East Asia, approximately 2% in European-descent patients and can reach frequencies of up to 15-40% in PD Ashkenazi Jews and North African Arabs. To ascertain the evolutionary dynamics of the G2019S mutation in different populations, we genotyped 74 markers spanning a 16 Mb genomic region around G2019S, in 191 individuals carrying the mutation from 126 families of different origins. Sixty-seven families were of North-African Arab origin, 18 were of North/Western European descent, 37 were of Jewish origin, mostly from Eastern Europe, one was from Japan, one from Turkey and two were of mixed origins. We found the G2019S mutation on three different haplotypes. Network analyses of the three carrier haplotypes showed that G2019S arose independently at least twice in humans. In addition, the population distribution of the intra-allelic diversity of the most widespread carrier haplotype, together with estimations of the age of G2019S determined by two different methods, suggests that one of the founding G2019S mutational events occurred in the Near East at least 4000 years ago.

  7. The allele-frequency spectrum in a decoupled Moran model with mutation, drift, and directional selection, assuming small mutation rates.

    Science.gov (United States)

    Vogl, Claus; Clemente, Florian

    2012-05-01

    We analyze a decoupled Moran model with haploid population size N, a biallelic locus under mutation and drift with scaled forward and backward mutation rates θ(1)=μ(1)N and θ(0)=μ(0)N, and directional selection with scaled strength γ=sN. With small scaled mutation rates θ(0) and θ(1), which is appropriate for single nucleotide polymorphism data in highly recombining regions, we derive a simple approximate equilibrium distribution for polymorphic alleles with a constant of proportionality. We also put forth an even simpler model, where all mutations originate from monomorphic states. Using this model we derive the sojourn times, conditional on the ancestral and fixed allele, and under equilibrium the distributions of fixed and polymorphic alleles and fixation rates. Furthermore, we also derive the distribution of small samples in the diffusion limit and provide convenient recurrence relations for calculating this distribution. This enables us to give formulas analogous to the Ewens-Watterson estimator of θ for biased mutation rates and selection. We apply this theory to a polymorphism dataset of fourfold degenerate sites in Drosophila melanogaster. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Mutations in the glucocerebrosidase gene are common in patients with Parkinson's disease from Eastern Canada.

    Science.gov (United States)

    Han, Fabin; Grimes, David A; Li, Fang; Wang, Ting; Yu, Zhe; Song, Na; Wu, Shichao; Racacho, Lemuel; Bulman, Dennis E

    2016-01-01

    Mutations in the β-glucocerebrosidase gene (GBA) have been implicated as a risk factor for Parkinson's disease (PD). However, GBA mutations in PD patients of different ethnic origins were reported to be inconsistent. We sequenced all exons of the GBA gene in 225 PD patients and 110 control individuals from Eastern Canada. Two novel GBA variants of c.-119 A/G and S(-35)N, five known GBA mutations of R120W, N370S, L444P, RecNciI and RecTL mutation (del55/D409H/RecNciI) as well as two non-pathological variants of E326K and T369M were identified from PD patients while only one mutation of S13L and two non-pathological variants of E326K and T369M were found in the control individuals. The frequency of GBA mutations within PD patients (4.4%) is 4.8 times higher than the 0.91% observed in control individuals (X(2) = 2.91, p = 0.088; odds ratio = 4.835; 95% confidence interval = 2.524-9.123). The most common mutations of N370S and L444P accounted for 36.0% (9/25) of all the GBA mutations in this Eastern Canadian PD cohort. The frequency (6.67%) of E326K and T369M in PD patients is comparable to 7.27% in control individuals (X(2) = 0.042, p = 0.8376), further supporting that these two variants have no pathological effects on PD. Phenotype analysis showed that no significant difference in family history, age at onset and cognitive impairment was identified between the GBA mutation carriers and non-GBA mutation carriers. GBA mutations were found to be a common genetic risk factor for PD in Eastern Canadian patients.

  9. A challenge to mutation theory of radiation carcinogenesis

    International Nuclear Information System (INIS)

    Watanabe, Masami

    2006-01-01

    This paper presents an objection against the commonly accepted mutation theory in radiation carcinogenesis. First, author's studies of X-ray irradiated syrian hamster embryo (SHE) cells on malignant morphological changes and mutational change of HGPRT gene showed that the changing patterns were quite different, and as well, other studies in mice gave the essentially similar results. Thus radiation-induced carcinogenesis in cells does not simply occur by an accumulation of radiation-induced mutation. Second, as cultured cells usually used for oncogenesis studies already have the infinitively proliferative ability, the author used the primary cell culture obtained from the rodent embryo. Even those cells became immortal to be cancerous after repeated culture passage with the higher frequency of 10 3 -10 4 relative to somatic cell mutation. Cells thus seem to be easily changeable to cancerous ones. Bystander effect can cause transformation in non-irradiated cells and genetic instability by radiation can form the potentially unstable chromatin region, which induces telomere instability. The author has found that, while short-lived radicals yielded by X-ray irradiation attack DNA to induce cell death and chromosome aberration, long-lived radicals in biomolecules do not, but can cause mutation and carcinogenesis, which are reduced by vitamine C supplementation. The author concludes that the primary target in the radiation carcinogenesis in cells and even in the whole individuals is conceivably protein and not DNA. (T.I.)

  10. High Frequency of Alkaptonuria in Slovakia: Evidence for the Appearance of Multiple Mutations in HGO Involving Different Mutational Hot Spots

    Science.gov (United States)

    Zatková, Andrea; de Bernabé, Daniel Beltrán Valero; Poláková, Helena; Zvarík, Marek; Feráková, Eva; Bošák, Vladimir; Ferák, Vladimír; Kádasi, L'udovít; de Córdoba , Santiago Rodríguez

    2000-01-01

    Alkaptonuria (AKU) is an autosomal recessive disorder caused by the deficiency of homogentisate 1,2 dioxygenase (HGO) activity. AKU shows a very low prevalence (1:100,000–250,000) in most ethnic groups. One notable exception is in Slovakia, where the incidence of AKU rises to 1:19,000. This high incidence is difficult to explain by a classical founder effect, because as many as 10 different AKU mutations have been identified in this relatively small country. We have determined the allelic associations of 11 HGO intragenic polymorphisms for 44 AKU chromosomes from 20 Slovak pedigrees. These data were compared to the HGO haplotype data available in our laboratory for >80 AKU chromosomes from different European and non-European countries. The results show that common European AKU chromosomes have had only a marginal contribution to the Slovak AKU gene pool. Six of the ten Slovak AKU mutations, including the prevalent G152fs, G161R, G270R, and P370fs mutations, most likely originated in Slovakia. Data available for 17 Slovak AKU pedigrees indicate that most of the AKU chromosomes have their origins in a single very small region in the Carpathian mountains, in the northwestern part of the country. Since all six Slovak AKU mutations are associated with HGO mutational hot spots, we suggest that an increased mutation rate at the HGO gene is responsible for the clustering of AKU mutations in such a small geographical region. PMID:11017803

  11. Founder Mutations in Xeroderma Pigmentosum

    Science.gov (United States)

    Tamura, Deborah; DiGiovanna, John J.; Kraemer, Kenneth H.

    2012-01-01

    In this issue, Soufir et al. report a founder mutation in the XPC DNA repair gene in 74% of families with xeroderma pigmentosum (XP) in the Maghreb region (Algeria, Morocco, and Tunisia) of northern Africa. These patients have a high frequency of skin cancer. The presence of this founder mutation provides an opportunity for genetic counseling and early diagnosis of XP. PMID:20463673

  12. HFE gene mutations and iron status of Brazilian blood donors.

    Science.gov (United States)

    Santos, P C J L; Cançado, R D; Terada, C T; Rostelato, S; Gonzales, I; Hirata, R D C; Hirata, M H; Chiattone, C S; Guerra-Shinohara, E M

    2010-01-01

    Mutations of the HFE and TFR2 genes have been associated with iron overload. HFE and TFR2 mutations were assessed in blood donors, and the relationship with iron status was evaluated. Subjects (N = 542) were recruited at the Hemocentro da Santa Casa de São Paulo, São Paulo, Brazil. Iron status was not influenced by HFE mutations in women and was independent of blood donation frequency. In contrast, men carrying the HFE 282CY genotype had lower total iron-binding capacity (TIBC) than HFE 282CC genotype carriers. Men who donated blood for the first time and were carriers of the HFE 282CY genotype had higher transferrin saturation values and lower TIBC concentrations than those with the homozygous wild genotype for the HFE C282Y mutation. Moreover, in this group of blood donors, carriers of HFE 63DD plus 63HD genotypes had higher serum ferritin values than those with the homozygous wild genotype for HFE H63D mutation. Multiple linear regression analysis showed that HFE 282CY leads to a 17.21% increase (P = 0.018) and a 83.65% decrease (P = 0.007) in transferrin saturation and TIBC, respectively. In addition, serum ferritin is influenced by age (3.91%, P = 0.001) and the HFE 63HD plus DD genotype (55.84%, P = 0.021). In conclusion, the HFE 282Y and 65C alleles were rare, while the HFE 63D allele was frequent in Brazilian blood donors. The HFE C282Y and H63D mutations were associated with alterations in iron status in blood donors in a gender-dependent manner.

  13. HFE gene mutations and iron status of Brazilian blood donors

    Directory of Open Access Journals (Sweden)

    P.C.J.L. Santos

    2010-01-01

    Full Text Available Mutations of the HFE and TFR2 genes have been associated with iron overload. HFE and TFR2 mutations were assessed in blood donors, and the relationship with iron status was evaluated. Subjects (N = 542 were recruited at the Hemocentro da Santa Casa de São Paulo, São Paulo, Brazil. Iron status was not influenced by HFE mutations in women and was independent of blood donation frequency. In contrast, men carrying the HFE 282CY genotype had lower total iron-binding capacity (TIBC than HFE 282CC genotype carriers. Men who donated blood for the first time and were carriers of the HFE 282CY genotype had higher transferrin saturation values and lower TIBC concentrations than those with the homozygous wild genotype for the HFE C282Y mutation. Moreover, in this group of blood donors, carriers of HFE 63DD plus 63HD genotypes had higher serum ferritin values than those with the homozygous wild genotype for HFE H63D mutation. Multiple linear regression analysis showed that HFE 282CY leads to a 17.21% increase (P = 0.018 and a 83.65% decrease (P = 0.007 in transferrin saturation and TIBC, respectively. In addition, serum ferritin is influenced by age (3.91%, P = 0.001 and the HFE 63HD plus DD genotype (55.84%, P = 0.021. In conclusion, the HFE 282Y and 65C alleles were rare, while the HFE 63D allele was frequent in Brazilian blood donors. The HFE C282Y and H63D mutations were associated with alterations in iron status in blood donors in a gender-dependent manner.

  14. Mutational analysis of Greek patients with suspected hereditary neuropathy with liability to pressure palsies (HNPP): a 15-year experience.

    Science.gov (United States)

    Karadima, Georgia; Koutsis, Georgios; Raftopoulou, Maria; Karletidi, Karolina-Maria; Zambelis, Thomas; Karandreas, Nikolaos; Panas, Marios

    2015-06-01

    There has been limited information from population studies regarding the overall frequency of the common 1.5-Mb 17p11.2 deletion and even scarcer data regarding the overall frequency of PMP22 micromutations in patients with a clinical suspicion of hereditary neuropathy with liability to pressure palsies (HNPP). We have analysed 100 consecutive Greek patients referred for HNPP genetic testing over a 15-year period to our Neurogenetics Unit in Athens, a reference centre for all regions of Greece. All patients were screened for the 1.5-Mb deletion and a selected subgroup of deletion-negative patients for PMP22 micromutations. Mutation-positive and mutation-negative patients were compared for various clinical parameters. In total, 54 mutation-positive patients were identified. In index cases, the deletion frequency was 47.8%, and the PMP22 micromutation frequency was 2.2%. Within mutation-positive patients, the common deletion represented 95.7% and PMP22 micromutations 4.3% of cases. Two previously reported PMP22 micromutations (c.364_365delCC and c.79-2A>G) were detected. HNPP index cases had a 2.8-1 male-to-female ratio, similar to mutation-negative patients. A typical phenotype (recurrent or isolated palsies) was present in 82.4% of symptomatic HNPP cases, significantly higher than mutation-negative patients. Sensitivity of proposed electrophysiological diagnostic criteria for HNPP was calculated at 95.7% and specificity at 80.5%. In conclusion, the common HNPP deletion accounts for ∼50% and PMP22 micromutations for ∼2% of cases in a large consecutive cohort of patients with suspected HNPP. The mutational and phenotypic spectrum of HNPP is similar in the Greek population compared with other populations. Proposed electrophysiological diagnostic criteria perform satisfactorily in everyday clinical practice. © 2015 Peripheral Nerve Society.

  15. Specific-locus mutation frequencies in mouse stem-cell spermatogonia at very low radiation dose rates, and their use in the estimation of genetic hazards of radiation in man

    International Nuclear Information System (INIS)

    Russell, W.L.; Kelly, E.M.

    1982-01-01

    Experiments were undertaken to augment the information on the lowest radiation dose rates feasible for scoring transmitted induced mutations detected by the specific-locus method in the mouse. This is the type of information most suitable for estimating genetic hazards of radiation in man. The results also aid in resolving conflicting possibilities about the relationship between mutation frequency and radiation dose at low dose rates

  16. Frequency of Antiretroviral Resistance Mutations among Infants Exposed to Single-Dose Nevirapine and Short Course Maternal Antiretroviral Regimens: ACTG A5207.

    Science.gov (United States)

    Hitti, Jane; Halvas, Elias K; Zheng, Lu; Panousis, Constantinos G; Kabanda, Joseph; Taulo, Frank; Kumarasamy, Nagalingeswaran; Pape, Jean William; Lalloo, Umesh; Sprenger, Heather; Klingman, Karin L; Chan, Ellen S; McMahon, Deborah; Mellors, John W

    2014-11-01

    Intrapartum single-dose nevirapine (sdNVP) reduces HIV-1 perinatal transmission but selects NVP resistance among mothers and infants. We evaluated the frequency of antiretroviral resistance among infants with intrauterine HIV-1 infection exposed to sdNVP and maternal antenatal or breastfeeding antiretroviral therapy. This analysis included 429 infants from sub-Saharan Africa, India and Haiti whose 422 mothers received sdNVP plus maternal study treatment. At entry mothers had CD4>250/μL and were ART-naïve except for antenatal ZDV per local standard of care. Maternal study treatment started intrapartum and included ZDV/3TC, TDF/FTC or LPV/r for 7 or 21 days in a randomized factorial design. Infants received sdNVP study treatment and ZDV if local standard of care. Infant HIV RNA or DNA PCR and samples for genotype were obtained at birth and weeks 2, 4 and 12; infants who ever breast-fed were also tested at weeks 16, 24, 48 and 96. Samples from HIV-1-infected infants were tested for drug resistance by population genotype (ViroSeq). NVP or NRTI resistance mutations were assessed using the IAS-USA mutation list. Perinatal HIV-1 transmission occurred in 17 (4.0%) infants including 12 intrauterine infections. Resistance mutations were detected among 5 (42%) intrauterine-infected infants; of these, 3 had mutations conferring resistance to NVP alone, 1 had resistance to NRTI alone, and 1 had dual-class resistance mutations. Among the 2 infants with NRTI mutations, one (K70R) was likely maternally transmitted and one (K65R) occurred in the context of breastfeeding exposure to maternal antiretroviral therapy. Infants with intrauterine HIV infection are at risk of acquiring resistance mutations from exposure to maternal antiretroviral medications intrapartum and/or during breastfeeding. New approaches are needed to lower the risk of antiretroviral resistance in these infants.

  17. Spectrum and Frequency of Mutations Induced by Gamma Radiations in Three Varieties of Nigerian Sesame (Sesamum indicum L.

    Directory of Open Access Journals (Sweden)

    Muhammad Liman MUHAMMAD

    2018-03-01

    Full Text Available Insufficient genetic variability is one of the major problems of plant breeding programmes, especially in sesame. Gamma radiation has been reported to be very effective in creating genetic variability in plants. Three varieties of Nigerian sesame were assessed for spectrum and frequency of mutation induced by Gamma radiations in M1 and M2 generations. The varieties (NCRIBEN-04E, NCRIBEN-01M and NCRIBEN-03L were treated with four different doses of gamma rays (250, 350, 450 and 550 Gy. The treated and untreated seeds (control were sown in planting bags (under field condition to raise M1 plants. Four treatments: V1D5, V2D3, V3D2 and V3D4 (from M1 plants were selected and bulked to obtain M2 populations. The results of M1 revealed four mutant fruit traits: multicarpellate capsule, multiple capsule per leaf axil, indehiscent capsule and terminal capsules. The highest frequencies of the traits in M1 generation were 2.50×10-2, 9.17×10-2, 1.67×10-2and3.33×10-2 respectively. The highest branching (7 was from NCRIBEN-01M, while the least (2 was from NCRIBEN-04E. The M2 plants were grouped into eight M2 lines. The dose range (250-550 Gy was proved to be effective in inducing viable mutations in sesame.

  18. Carrier frequency of GJB2 gene mutations c.35delG, c.235delC and c.167delT among the populations of Eurasia.

    Science.gov (United States)

    Dzhemileva, Lilya U; Barashkov, Nikolay A; Posukh, Olga L; Khusainova, Rita I; Akhmetova, Vita L; Kutuev, Ildus A; Gilyazova, Irina R; Tadinova, Vera N; Fedorova, Sardana A; Khidiyatova, Irina M; Lobov, Simeon L; Khusnutdinova, Elza K

    2010-11-01

    Hearing impairment is one of the most common disorders of sensorineural function and the incidence of profound prelingual deafness is about 1 per 1000 at birth. GJB2 gene mutations make the largest contribution to hereditary hearing impairment. The spectrum and prevalence of some GJB2 mutations are known to be dependent on the ethnic origin of the population. This study presents data on the carrier frequencies of major GJB2 mutations, c.35delG, c.167delT and c.235delC, among 2308 healthy persons from 18 various populations of Eurasia: Russians, Bashkirs, Tatars, Chuvashes, Udmurts, Komi-Permyaks and Mordvins (Volga-Ural region of Russia); Belarusians and Ukrainians (East Europe); Abkhazians, Avars, Cherkessians and Ingushes (Caucasus); Kazakhs, Uighurs and Uzbeks (Central Asia); and Yakuts and Altaians (Siberia). The data on c.35delG and c.235delC mutation prevalence in the studied ethnic groups can be used to investigate the prospective founder effect in the origin and prevalence of these mutations in Eurasia and consequently in populations around the world.

  19. Mutational influences of low-dose and high let ionizing radiation in drosophila melanogaster

    Science.gov (United States)

    Lei, Huang; Fanjun, Kong; Sun, Yeqing

    For cosmic environment consists of a varying kinds of radiation particles including high Z and energy ions which was charactered with low-dose and high RBE, it is important to determine the possible biofuctions of high LET radiation on human beings. To analyse the possible effectes of mutational influences of low-dose and high-LET ionizing radiation, wild fruit flies drosophila melanogaster were irradiated by 12C6+ ions in two LET levels (63.3 and 30 keV/µum) with different low doses from 2mGy to 2000mGy (2, 20, 200, 2000mGy) in HIRFL (Heavy ion radiation facility laboratory, lanzhou, China).In the same LET value group, the average polymorphic frequency was elevated along with adding doses of irradation, the frequency in 2000 mGy dose samples was significantly higher than other samples (p<0.01).These results suggest that genomic DNA sequence could be effected by low-dose and high-LET ionizing radiation, the irradiation dose is an important element in genomic mutation frequency origination.

  20. Genomic mutation study for long-term cells induced by carbon ions

    International Nuclear Information System (INIS)

    Wang, X.; Furusawa, Y.; Suzuki, M.; Hirayama, R.; Matsumoto, Y.; Qin, Y.

    2007-01-01

    Complete text of publication follows. Objective: Densely ionizing (high LET) radiation can increase the relative biological effectiveness of cell and tissue. Astronauts in the space exploration have the potential exposure of chronic low-dose radiations in the field of low-flux galactic cosmic rays (GCR) and the subsequent biological effects have become one of the major concerns of space science. Furthermore, Heavy ions also are used new radiation therapy owing increased lethal effectiveness of high LET radiation. During radiation therapy, normal tissues also are exposed to ionizing radiation. Radiation can induce genomic mutation and instability in descendants of irradiated cells. Induction of genomic instability can represent one of the initiating steps leading to malignant transformation. Higher frequencies of mutation can be expected to provide higher rates of carcinogenicity with human exposure. Therefore, the study of radiation induced genomic mutation and instability is relevant to the estimates of the risk of secondary malignancies associated with radiation therapy and the carcinogenic effects of space environmental radiation. The hypoxanthine-guanine phosphoribosyltransferase (hprt) locus has been the most commonly used as a target gene for mutation detection studies. In this study, we investigated the generation expression dependence of mutation induction on HPRT locus in CHO cells irradiated with carbon ions. Methods: Chinese hamster ovary (CHO) cells were irradiated with graded doses of carbon ions (290MeV/u, LET:13kev/um) accelerated with Heavy Ion Medical Accelerator in Chiba (HIMAC) at National Institute of Radiological Sciences(NIRS). The survival effect of cells plated immediately after irradiation was measured with cell colony formation assay. After irradiation, cells were continues reseeding and cultures for lone-term proliferation. Cell samples were collected at 6, 12, 18, 24, 30, 37 and 44 days post irradiation. Mutation induction of cell

  1. Determination of EGFR and KRAS mutational status in Greek non-small-cell lung cancer patients.

    Science.gov (United States)

    Papadopoulou, Eirini; Tsoulos, Nikolaos; Tsirigoti, Angeliki; Apessos, Angela; Agiannitopoulos, Konstantinos; Metaxa-Mariatou, Vasiliki; Zarogoulidis, Konstantinos; Zarogoulidis, Pavlos; Kasarakis, Dimitrios; Kakolyris, Stylianos; Dahabreh, Jubrail; Vlastos, Fotis; Zoublios, Charalampos; Rapti, Aggeliki; Papageorgiou, Niki Georgatou; Veldekis, Dimitrios; Gaga, Mina; Aravantinos, Gerasimos; Karavasilis, Vasileios; Karagiannidis, Napoleon; Nasioulas, George

    2015-10-01

    It has been reported that certain patients with non-small-cell lung cancer (NSCLC) that harbor activating somatic mutations within the tyrosine kinase domain of the epidermal growth factor receptor ( EGFR ) gene may be effectively treated using targeted therapy. The use of EGFR inhibitors in patient therapy has been demonstrated to improve response and survival rates; therefore, it was suggested that clinical screening for EGFR mutations should be performed for all patients. Numerous clinicopathological factors have been associated with EGFR and Kirsten-rat sarcoma oncogene homolog (KRAS) mutational status including gender, smoking history and histology. In addition, it was reported that EGFR mutation frequency in NSCLC patients was ethnicity-dependent, with an incidence rate of ~30% in Asian populations and ~15% in Caucasian populations. However, limited data has been reported on intra-ethnic differences throughout Europe. The present study aimed to investigate the frequency and spectrum of EGFR mutations in 1,472 Greek NSCLC patients. In addition, KRAS mutation analysis was performed in patients with known smoking history in order to determine the correlation of type and mutation frequency with smoking. High-resolution melting curve (HRM) analysis followed by Sanger sequencing was used to identify mutations in exons 18-21 of the EGFR gene and in exon 2 of the KRAS gene. A sensitive next-generation sequencing (NGS) technology was also employed to classify samples with equivocal results. The use of sensitive mutation detection techniques in a large study population of Greek NSCLC patients in routine diagnostic practice revealed an overall EGFR mutation frequency of 15.83%. This mutation frequency was comparable to that previously reported in other European populations. Of note, there was a 99.8% concordance between the HRM method and Sanger sequencing. NGS was found to be the most sensitive method. In addition, female non-smokers demonstrated a high prevalence of

  2. New approaches for effective mutation induction in gamma field

    Energy Technology Data Exchange (ETDEWEB)

    Nagatomi, Shigeki [National Institute of Agrobiological Resources, Institute of Radiation Breeding, Omiya, Ibaraki (Japan)

    2001-03-01

    The purpose of the report is to clarify the effects of chronic irradiation using in vitro culture on inducing the mutation of two model plants. Culture technique combined with irradiation can overcome the problem of chimera formation and provided 10 times greater mutation efficiency than conventional method. Proper mutagenic treatment using cultured materials is indispensable to effective mutation induction. The chronic culture method showed the widest color spectrum in chrysanthemum and extended toward not only the negative but positive direction. However, the acute culture methods indicated a relatively low mutation rate and a very limited flower color spectrum. Flower color mutation of the regenerations could be induced more from petals and buds than from leaves. These facts is supposed that the gene loci fully expressed on floral organs may be unstable for mutation by mutagenesis or culture. It may be likely to control a direction of desired mutation. One possible reason why the chronic culture methods showed higher frequencies is that most of the cells composing the tissue and organs continually irradiated into a cell division which was highly sensitive and more mutable to irradiation. Under these conditions, many mutated sectors may accumulate in the cells of the growing organs. Regenerated mutant lines show remarkable decrease of chromosome numbers by irradiation. It is a proper indicator to monitor radiation damage. In this study, the six flower color mutant varieties registered were derived from chronic irradiation. The combined method of chronic irradiation with floral organ cultures proved to be of particularly great practical use in mutation breeding for not only flower species but any other species. (author)

  3. New approaches for effective mutation induction in gamma field

    International Nuclear Information System (INIS)

    Nagatomi, Shigeki

    2001-01-01

    The purpose of the report is to clarify the effects of chronic irradiation using in vitro culture on inducing the mutation of two model plants. Culture technique combined with irradiation can overcome the problem of chimera formation and provided 10 times greater mutation efficiency than conventional method. Proper mutagenic treatment using cultured materials is indispensable to effective mutation induction. The chronic culture method showed the widest color spectrum in chrysanthemum and extended toward not only the negative but positive direction. However, the acute culture methods indicated a relatively low mutation rate and a very limited flower color spectrum. Flower color mutation of the regenerations could be induced more from petals and buds than from leaves. These facts is supposed that the gene loci fully expressed on floral organs may be unstable for mutation by mutagenesis or culture. It may be likely to control a direction of desired mutation. One possible reason why the chronic culture methods showed higher frequencies is that most of the cells composing the tissue and organs continually irradiated into a cell division which was highly sensitive and more mutable to irradiation. Under these conditions, many mutated sectors may accumulate in the cells of the growing organs. Regenerated mutant lines show remarkable decrease of chromosome numbers by irradiation. It is a proper indicator to monitor radiation damage. In this study, the six flower color mutant varieties registered were derived from chronic irradiation. The combined method of chronic irradiation with floral organ cultures proved to be of particularly great practical use in mutation breeding for not only flower species but any other species. (author)

  4. Higher risk of death among MEN1 patients with mutations in the JunD interacting domain: a Groupe d'etude des Tumeurs Endocrines (GTE) cohort study.

    Science.gov (United States)

    Thevenon, Julien; Bourredjem, Abderrahmane; Faivre, Laurence; Cardot-Bauters, Catherine; Calender, Alain; Murat, Arnaud; Giraud, Sophie; Niccoli, Patricia; Odou, Marie-Françoise; Borson-Chazot, Françoise; Barlier, Anne; Lombard-Bohas, Catherine; Clauser, Eric; Tabarin, Antoine; Parfait, Béatrice; Chabre, Olivier; Castermans, Emilie; Beckers, Albert; Ruszniewski, Philippe; Le Bras, Morgane; Delemer, Brigitte; Bouchard, Philippe; Guilhem, Isabelle; Rohmer, Vincent; Goichot, Bernard; Caron, Philippe; Baudin, Eric; Chanson, Philippe; Groussin, Lionel; Du Boullay, Hélène; Weryha, Georges; Lecomte, Pierre; Penfornis, Alfred; Bihan, Hélène; Archambeaud, Françoise; Kerlan, Véronique; Duron, Françoise; Kuhn, Jean-Marc; Vergès, Bruno; Rodier, Michel; Renard, Michel; Sadoul, Jean-Louis; Binquet, Christine; Goudet, Pierre

    2013-05-15

    Multiple endocrine neoplasia syndrome type 1 (MEN1), which is secondary to mutation of the MEN1 gene, is a rare autosomal-dominant disease that predisposes mutation carriers to endocrine tumors. Although genotype-phenotype studies have so far failed to identify any statistical correlations, some families harbor recurrent tumor patterns. The function of MENIN is unclear, but has been described through the discovery of its interacting partners. Mutations in the interacting domains of MENIN functional partners have been shown to directly alter its regulation abilities. We report on a cohort of MEN1 patients from the Groupe d'étude des Tumeurs Endocrines. Patients with a molecular diagnosis and a clinical follow-up, totaling 262 families and 806 patients, were included. Associations between mutation type, location or interacting factors of the MENIN protein and death as well as the occurrence of MEN1-related tumors were tested using a frailty Cox model to adjust for potential heterogeneity across families. Accounting for the heterogeneity across families, the overall risk of death was significantly higher when mutations affected the JunD interacting domain (adjusted HR = 1.88: 95%-CI = 1.15-3.07). Patients had a higher risk of death from cancers of the MEN1 spectrum (HR = 2.34; 95%-CI = 1.23-4.43). This genotype-phenotype correlation study confirmed the lack of direct genotype-phenotype correlations. However, patients with mutations affecting the JunD interacting domain had a higher risk of death secondary to a MEN1 tumor and should thus be considered for surgical indications, genetic counseling and follow-up.

  5. HIGHER MODE FREQUENCY EFFECTS ON RESONANCE IN MACHINERY, STRUCTURES, AND PIPE SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Leishear, R.

    2010-05-02

    The complexities of resonance in multi-degree of freedom systems (multi-DOF) may be clarified using graphic presentations. Multi-DOF systems represent actual systems, such as beams or springs, where multiple, higher order, natural frequencies occur. Resonance occurs when a cyclic load is applied to a structure, and the frequency of the applied load equals one of the natural frequencies. Both equations and graphic presentations are available in the literature for single degree of freedom (SDOF) systems, which describe the response of spring-mass-damper systems to harmonically applied, or cyclic, loads. Loads may be forces, moments, or forced displacements applied to one end of a structure. Multi-DOF systems are typically described only by equations in the literature, and while equations certainly permit a case by case analysis for specific conditions, graphs provide an overall comprehension not gleaned from single equations. In fact, this collection of graphed equations provides novel results, which describe the interactions between multiple natural frequencies, as well as a comprehensive description of increased vibrations near resonance.

  6. CALR, JAK2 and MPL mutation status in Argentinean patients with BCR-ABL1- negative myeloproliferative neoplasms.

    Science.gov (United States)

    Ojeda, Mara Jorgelina; Bragós, Irma Margarita; Calvo, Karina Lucrecia; Williams, Gladis Marcela; Carbonell, María Magdalena; Pratti, Arianna Flavia

    2018-05-01

    To establish the frequency of JAK2, MPL and CALR mutations in Argentinean patients with BCR-ABL1-negative  myeloproliferative neoplasms (MPN) and to compare their clinical and haematological features. Mutations of JAK2V617F, JAK2 exon 12, MPL W515L/K and CALR were analysed in 439 Argentinean patients with BCR-ABL1-negative MPN, including 176 polycythemia vera (PV), 214 essential thrombocythemia (ET) and 49 primary myelofibrosis (PMF). In 94.9% of PV, 85.5% ET and 85.2% PMF, we found mutations in JAK2, MPL or CALR. 74.9% carried JAK2V617F, 12.3% CALR mutations, 2.1% MPL mutations and 10.7% were triple negative. In ET, nine types of CALR mutations were identified, four of which were novel. PMF patients were limited to types 1 and 2, type 2 being more frequent. In ET, patients with CALR mutation were younger and had higher platelet counts than those with JAK2V617F and triple negative. In addition, JAK2V617F patients had high leucocyte and haemoglobin values compared with CALR-mutated and triple-negative patients. In PMF, patients with mutant CALR were associated with higher platelet counts. Our study underscores the importance of JAK2, MPL and CALR genotyping for accurate diagnosis of patients with BCR-ABL1-negative MPN.

  7. High frequency of the recurrent c.1310_1313delAAGA BRCA2 mutation in the North-East of Morocco and implication for hereditary breast-ovarian cancer prevention and control.

    Science.gov (United States)

    Laarabi, Fatima-Zahra; Ratbi, Ilham; Elalaoui, Siham Chafai; Mezzouar, Loubna; Doubaj, Yassamine; Bouguenouch, Laila; Ouldim, Karim; Benjaafar, Noureddine; Sefiani, Abdelaziz

    2017-06-02

    To date, a limited number of BRCA1/2 germline mutations have been reported in hereditary breast and/or ovarian cancer in the Moroccan population. Less than 20 different mutations of these two genes have been identified in Moroccan patients, and recently we reported a further BRCA2 mutation (c.1310_1313delAAGA; p.Lys437IlefsX22) in three unrelated patients, all from the North-East of the country. We aimed in this study to evaluate the frequency and geographic distribution of this BRCA2 frameshift mutation, in order to access its use as the first-line BRCA genetic testing strategy for Moroccan patients. We enrolled in this study 122 patients from different regions of Morocco, with suggestive inherited predisposition to breast and ovarian cancers. All subjects gave written informed consent to BRCA1/2 genetic testing. According to available resources of our lab and enrolled families, 51 patients were analyzed by the conventional individual exon-by-exon Sanger sequencing, 23 patients were able to benefit from a BRCA next generation sequencing and a target screening for exon 10 of BRCA2 gene was performed in 48 patients. Overall, and among the 122 patients analyzed for at least the exon 10 of the BRCA2 gene, the c.1310_1313delAAGA frameshift mutation was found in 14 patients. Genealogic investigation revealed that all carriers of this mutation shared the same geographic origin and were descendants of the North-East of Morocco. In this study, we highlighted that c.1310_1313delAAGA mutation of BRCA2 gene is recurrent with high frequency in patients from the North-East region of Morocco. Therefore, we propose to use, in public health strategies, the detection of this mutation as the first-line screening tests in patients with breast and ovarian cancer originated from this region.

  8. A second mutation associated with apparent [beta]-hexosaminidase A pseudodeficiency: Identification and frequency estimation

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Z.; Chabot, T.; Triggs-Raine, B.L. (Univ. of Manitoba, Winnepeg (Canada)); Natowicz, M.R.; Prence, E.M. (Shriver Center for Mental Retardation, Waltham, MA (United States) Harvard Medical School, Boston, MA (United States)); Kaback, M.M.; Lim-Steele, S.T.; Brown, D. (Children' s Hospital, San Diego, CA (United States) Univ. of California, San Diego, CA (United States))

    1993-12-01

    Deficient activity of [beta]-hexosaminidase A (Hex A), resulting from mutations in the HEXA gene, typically causes Tay-Sachs disease. However, healthy individuals lacking Hex A activity against synthetic substrates (i.e., individuals who are pseudodeficient) have been described. Recently, an apparently benign C[sub 739]-to-T (Arg247Trp) mutation was found among individuals with Hex A levels indistinguishable from those of carriers of Tay-Sachs disease. This allele, when in compound heterozygosity with a second [open quotes]disease-causing[close quotes] allele, results in Hex A pseudodeficiency. The authors examined the HEXA gene of a healthy 42-year-old who was Hex A deficient but did not have the C[sub 739]-to-T mutation. The HEXA exons were PCR amplified, and the products were analyzed for mutations by using restriction-enzyme digestion or single-strand gel electrophoresis. A G[sub 805]-to-A (Gly269Ser) mutation associated with adult-onset G[sub m2] gangliosidosis was found on one chromosome. A new mutation, C[sub 745]-to-T (Arg 249Trp), was identified on the second chromosome. This mutation was detected in an additional 4/63 (6%) non-Jewish and 0/218 Ashkenazi Jewish enzyme-defined carriers. Although the Arg249Trp change may result in a late-onset form of G[sub M2] gangliosidosis, any phenotype must be very mild. This new mutation and the benign C[sub 739]-to-T mutation together account for [approximately]38% of non-Jewish enzyme-defined carriers. Because carriers of the C[sub 739]-to-T and C[sub 745]-to-T mutations cannot be differentiated from carriers of disease-causing alleles by using the classical biochemical screening approaches, DNA-based analyses for these mutations should be offered for non-Jewish enzyme-defined heterozygotes, before definitive counseling is provided. 46 refs., 5 figs., 2 tabs.

  9. Frequency of c.35delG Mutation in GJB2 Gene (Connexin 26 in Syrian Patients with Nonsyndromic Hearing Impairment

    Directory of Open Access Journals (Sweden)

    Hazem Kaheel

    2017-01-01

    Full Text Available Background. Hearing impairments (HI are the most common birth defect worldwide. Very large numbers of genes have been identified but the most profound is GJB2. The clinical interest regarding this gene is very pronounced due to its high carrier frequency (0.5–5.4% across different ethnic groups. This study aimed to determine the prevalence of common GJB2 mutations in Syrian patients with profound sensorineural HI. Methods. We carried out PCR, restriction enzyme based screening, and sequencing of 132 Syrian patients diagnosed clinically with hereditary deafness for different GJB2 mutations. Results. The result revealed that, in GJB2 gene, c.35delG is the most prevalent among affected studied subjects (13.64%, followed by c.457G>A (2.4%. Conclusion. The benefit of this study on the one hand is its first report of prelingual deafness causative gene mutations identified by sequencing technology in the Syrian families. It is obvious from the results that the deployment in biomedical research is highly effective and has a great impact on the ability to uncover the cause of genetic variation in different genetic diseases.

  10. Multi-center analysis of glucocerebrosidase mutations in Parkinson disease

    Science.gov (United States)

    Sidransky, Ellen; Nalls, Michael A.; Aasly, Jan O.; Aharon-Peretz, Judith; Annesi, Grazia; Barbosa, Egberto Reis; Bar-Shira, Anat; Berg, Daniela; Bras, Jose; Brice, Alexis; Chen, Chiung-Mei; Clark, Lorraine N.; Condroyer, Christel; De Marco, Elvira Valeria; Dürr, Alexandra; Eblan, Michael J.; Fahn, Stanley; Farrer, Matthew; Fung, Hon-Chung; Gan-Or, Ziv; Gasser, Thomas; Gershoni-Baruch, Ruth; Giladi, Nir; Griffith, Alida; Gurevich, Tanya; Januario, Cristina; Kropp, Peter; Lang, Anthony E.; Lee-Chen, Guey-Jen; Lesage, Suzanne; Marder, Karen; Mata, Ignacio F.; Mirelman, Anat; Mitsui, Jun; Mizuta, Ikuko; Nicoletti, Giuseppe; Oliveira, Catarina; Ottman, Ruth; Orr-Urtreger, Avi; Pereira, Lygia V.; Quattrone, Aldo; Rogaeva, Ekaterina; Rolfs, Arndt; Rosenbaum, Hanna; Rozenberg, Roberto; Samii, Ali; Samaddar, Ted; Schulte, Claudia; Sharma, Manu; Singleton, Andrew; Spitz, Mariana; Tan, Eng-King; Tayebi, Nahid; Toda, Tatsushi; Troiano, André; Tsuji, Shoji; Wittstock, Matthias; Wolfsberg, Tyra G.; Wu, Yih-Ru; Zabetian, Cyrus P.; Zhao, Yi; Ziegler, Shira G.

    2010-01-01

    Background Recent studies indicate an increased frequency of mutations in the gene for Gaucher disease, glucocerebrosidase (GBA), among patients with Parkinson disease. An international collaborative study was conducted to ascertain the frequency of GBA mutations in ethnically diverse patients with Parkinson disease. Methods Sixteen centers participated, including five from the Americas, six from Europe, two from Israel and three from Asia. Each received a standard DNA panel to compare genotyping results. Genotypes and phenotypic data from patients and controls were analyzed using multivariate logistic regression models and the Mantel Haenszel procedure to estimate odds ratios (ORs) across studies. The sample included 5691 patients (780 Ashkenazi Jews) and 4898 controls (387 Ashkenazi Jews). Results All 16 centers could detect GBA mutations, L444P and N370S, and the two were found in 15.3% of Ashkenazi patients with Parkinson disease (ORs = 4.95 for L444P and 5.62 for N370S), and in 3.2% of non-Ashkenazi patients (ORs = 9.68 for L444P and 3.30 for N370S). GBA was sequenced in 1642 non-Ashkenazi subjects, yielding a frequency of 6.9% for all mutations, demonstrate that limited mutation screens miss half the mutant alleles. The presence of any GBA mutation was associated with an OR of 5.43 across studies. Clinically, although phenotypes varied, subjects with a GBA mutation presented earlier, and were more likely to have affected relatives and atypical manifestations. Conclusion Data collected from sixteen centers demonstrate that there is a strong association between GBA mutations and Parkinson disease. PMID:19846850

  11. The effect of electric field maximum on the Rabi flopping and generated higher frequency spectra

    International Nuclear Information System (INIS)

    Niu Yueping; Cui Ni; Xiang Yang; Li Ruxin; Gong Shangqing; Xu Zhizhan

    2008-01-01

    We investigate the effect of the electric field maximum on the Rabi flopping and the generated higher frequency spectra properties by solving Maxwell-Bloch equations without invoking any standard approximations. It is found that the maximum of the electric field will lead to carrier-wave Rabi flopping (CWRF) through reversion dynamics which will be more evident when the applied field enters the sub-one-cycle regime. Therefore, under the interaction of sub-one-cycle pulses, the Rabi flopping follows the transient electric field tightly through the oscillation and reversion dynamics, which is in contrast to the conventional envelope Rabi flopping. Complete or incomplete population inversion can be realized through the control of the carrier-envelope phase (CEP). Furthermore, the generated higher frequency spectra will be changed from distinct to continuous or irregular with the variation of the CEP. Our results demonstrate that due to the evident maximum behavior of the electric field, pulses with different CEP give rise to different CWRFs, and then different degree of interferences lead to different higher frequency spectral features.

  12. Clinical significance of FLG gene mutations in children with atopic dermatitis

    Directory of Open Access Journals (Sweden)

    E. E. Varlamov

    2015-01-01

    Full Text Available Skin barrier dysfunction due to deficiency of the skin protein filaggrin is one of the factors involved in the pathogenesis of atopic dermatitis. Objective: to determine the clinical significance of 2282 del CAGT, R501X, R2447X, and S3247X mutations in the FLG gene in children with atopic dermatitis. The investigation included 58 children with atopic dermatitis. A molecular genetic analysis of the four mutations in the FLG gene was done in all the children. In the patients with FLG gene mutations, there was a tendency towards a higher frequency of sensitization to house dust allergens, significantly more often sensitization to cat epidermal allergen, and significantly higher levels of specific IgE to the cat epidermis. Conclusion. Mutations in the FLG gene encoding the protein filaggrin raise the risk for sensitization to domestic and epidermal allergens and, in case of already existing sensitization to the cat epidermis, the patients are found with a high degree of probability to have the high concentration of specific IgE to this allergen. The above fact justifies the need to place special emphasis on measures to eliminate house dust allergens, and cat epidermis allergen in particular, and to personalize approaches to therapy and prevention of atopic dermatitis in children. 

  13. Mutation profiles of phenylketonuria in Quebec populations: Evidence of stratification and novel mutations

    Energy Technology Data Exchange (ETDEWEB)

    Rozen, R.; Mascisch, A.; Scriver, C.R. (McGill Univ., Montreal (Canada)); Lambert, M. (Hopital Ste-Justine, Montreal (Canada)); Laframboise, R. (Centre Hospitalier Universite Laval, Quebec (Canada))

    1994-08-01

    Independent phenylketonuria (PKU) chromosomes (n=109) representing 80% of a proband cohort in Quebec province carry 18 different identified mutations in 20 different mutation/haplotype combinations. The study reported here, the third in a series on Quebec populations, was done in the Montreal region and predominantly on French Canadians. It has identified three novel mutations (A309D, D338Y, and 1054/1055delG [352fs]) and one unusual mutation/RFLP haplotype combination (E280K on Hp 2). The relative frequencies and distribution of PKU mutations were then compared in three regions and population subsets (eastern Quebec, French Canadian; western Quebec, French Canadian; and Montreal, non-French Canadian). The distributions of the prevalent and rare mutations are nonrandom and provide evidence for genetic stratification. The latter and the presence of eight unusual mutation/haplotype combinations in Quebec families with European ancestries (the aforementioned four and M1V, 165T, S349P, and R408W on Hp 1) corroborate demographic and anthropologic evidence, from elsewhere, for different origins of French Canadians in eastern and western Quebec. 29 refs., 1 fig., 1 tab.

  14. Study of hepatitis B virus gene mutations with enzymatic colorimetry-based DNA microarray.

    Science.gov (United States)

    Mao, Hailei; Wang, Huimin; Zhang, Donglei; Mao, Hongju; Zhao, Jianlong; Shi, Jian; Cui, Zhichu

    2006-01-01

    To establish a modified microarray method for detecting HBV gene mutations in the clinic. Site-specific oligonucleotide probes were immobilized to microarray slides and hybridized to biotin-labeled HBV gene fragments amplified from two-step PCR. Hybridized targets were transferred to nitrocellulose membranes, followed by intensity measurement using BCIP/NBT colorimetry. HBV genes from 99 Hepatitis B patients and 40 healthy blood donors were analyzed. Mutation frequencies of HBV pre-core/core and basic core promoter (BCP) regions were found to be significantly higher in the patient group (42%, 40% versus 2.5%, 5%, P colorimetry method exhibited the same level of sensitivity and reproducibility. An enzymatic colorimetry-based DNA microarray assay was successfully established to monitor HBV mutations. Pre-core/core and BCP mutations of HBV genes could be major causes of HBV infection in HBeAg-negative patients and could also be relevant to chronicity and aggravation of hepatitis B.

  15. TP53 mutation spectrum in smokers and never smoking lung cancer patients

    Directory of Open Access Journals (Sweden)

    Ann Rita Halvorsen

    2016-05-01

    Full Text Available AbstractBackground: TP53 mutations are among the most common mutations found in lung cancers, identified as an independent prognostic factor in many types of cancers. The purpose of this study was to investigate the frequency and prognostic impact of TP53 mutations in never-smokers and in different histological subtypes of lung cancer.Methods: We analysed tumour tissue from 394 non-small cell carcinomas including adenocarcinomas (n=229, squamous cell carcinomas (n=112, large cell carcinomas (n=30 and others (n=23 for mutations in TP53 by the use of Sanger sequencing (n=394 and next generation sequencing (n=100. Results: TP53 mutations were identified in 47.2% of the samples, with the highest frequency (65% of mutations among squamous cell carcinomas. Among never-smokers, 36% carried a TP53 mutation, identified as a significant independent negative prognostic factor in this subgroup. For large cell carcinomas, a significantly prolonged progression free survival was found for those carrying a TP53 mutation. In addition, the frequency of frameshift mutations was doubled in squamous cell carcinomas (20.3% compared to adenocarcinomas (9.1%.Conclusion: TP53 mutation patterns differ between the histological subgroups of lung cancers, as also influenced by smoking history. This indicates that the histological subtypes in lung cancer are genetically different, and that smoking-induced TP53 mutations may have a different biological impact than TP53 mutations occurring in never-smokers.

  16. Compound heterozygous ASPM mutations in Pakistani MCPH families

    DEFF Research Database (Denmark)

    Muhammad, Farooq; Mahmood Baig, Shahid; Hansen, Lars

    2009-01-01

    Autosomal recessive primary microcephaly (MCPH) is characterized by reduced head circumference (50% of all reported families. In spite of the high frequency of MCPH in Pakistan only one case of compound heterozygosity for mutations in ASPM has been reported yet. In this large MCPH study we...... confirmed compound heterozygosity in two and homozygous mutations in 20 families, respectively, showing that up to 10% of families with MCPH caused by ASPM are compound heterozygous. In total we identified 16 different nonsense or frameshift mutations of which 12 were novel thereby increasing the number...... of mutations in ASPM significantly from 35 to 47. We found no correlation between the severity of the condition and the site of truncation. We suggest that the high frequency of compound heterozygosity observed in this study is taken into consideration as part of future genetic testing and counseling...

  17. Frequency of CCR5 Delta-32 Mutation in Human Immunodeficiency Virus (HIV-seropositive and HIV-exposed Seronegative Individuals and in General Population of Medellin, Colombia

    Directory of Open Access Journals (Sweden)

    Francisco J Díaz

    2000-04-01

    Full Text Available Repeated exposure to human immunodeficiency virus (HIV does not always result in seroconversion. Modifications in coreceptors for HIV entrance to target cells are one of the factors that block the infection. We studied the frequency of Delta-32 mutation in ccr5 gene in Medellin, Colombia. Two hundred and eighteen individuals distributed in three different groups were analyzed for Delta-32 mutation in ccr5 gene by polymerase chain reaction (PCR: 29 HIV seropositive (SP, 39 exposed seronegative (ESN and 150 individuals as a general population sample (GPS. The frequency of the Delta-32 mutant allele was 3.8% for ESN, 2.7% for GPS and 1.7% for SP. Only one homozygous mutant genotype (Delta-32/Delta-32 was found among the ESN (2.6%. The heterozygous genotype (ccr5/Delta-32 was found in eight GPS (5.3%, in one SP (3.4% and in one ESN (2.6%. The differences in the allelic and genotypic frequencies among the three groups were not statistically significant. A comparison between the expected and the observed genotypic frequencies showed that these frequencies were significantly different for the ESN group, which indirectly suggests a protective effect of the mutant genotype (Delta-32/Delta-32. Since this mutant genotype explained the resistance of infection in only one of our ESN persons, different mechanisms of protection must be playing a more important role in this population.

  18. Parameters affecting frequency of CRISPR/Cas9 mediated targeted mutagenesis in rice.

    Science.gov (United States)

    Mikami, Masafumi; Toki, Seiichi; Endo, Masaki

    2015-10-01

    Frequency of CRISPR/Cas9-mediated targeted mutagenesis varies depending on Cas9 expression level and culture period of rice callus. Recent reports have demonstrated that the CRISPR/Cas9 system can function as a sequence-specific nuclease in various plant species. Induction of mutation in proliferating tissue during embryogenesis or in germline cells is a practical means of generating heritable mutations. In the case of plant species in which cultured cells are used for transformation, non-chimeric plants can be obtained when regeneration occurs from mutated cells. Since plantlets are regenerated from both mutated and non-mutated cells in a random manner, any increment in the proportion of mutated cells in Cas9- and guide RNA (gRNA)-expressing cells will help increase the number of plants containing heritable mutations. In this study, we examined factors affecting mutation frequency in rice calli. Following sequential transformation of rice calli with Cas9- and gRNA- expression constructs, the mutation frequency in independent Cas9 transgenic lines was analyzed. A positive correlation between Cas9 expression level and mutation frequency was found. This positive relationship was observed regardless of whether the transgene or an endogenous gene was used as the target for CRISPR/Cas9-mediated mutagenesis. Furthermore, we found that extending the culture period increased the proportion of mutated cells as well as the variety of mutations obtained. Because mutated and non-mutated cells might proliferate equally, these results suggest that a prolonged tissue culture period increases the chance of inducing de novo mutations in non-mutated cells. This fundamental knowledge will help improve systems for obtaining non-chimeric regenerated plants in many plant species.

  19. X-ray-induced specific-locus mutations in the ad-3 region of two-component heterokaryons of Neurospora crassa

    International Nuclear Information System (INIS)

    Serres, F.J. de

    1989-01-01

    More extensive genetic tests have been preformed on a series of 832 X-ray-induced specific-locus mutations in the ad-3 region of a 2-component heterokaryon of Neurospora crassa, reported earlier. Using new tester strains and techniques for performing large-scale genetic tests to characterize ad-3 mutants induced in 2-component heterokaryons, new data have been obtained on this sample of X-ray-induced mutants. These new data show that unexpectedly high frequencies of both single-locus mutations and multilocus deletions in the ad-3 region have addition, but separate, sites of recessive lethal damage in the imeediately adjacent genetic regions. The frequencies of these X-ray-induced multiple-locus mutants in the ad-3 region are orders of magnitude higher than expected on the basis of target theory and classical models of chromosome structure during interphase. Current models of interphase chromosome structure in higher eukaryotes as revealed by chromosome 'painting' offer a possible explanation of the Neurospora data. (author). 25 refs.; 5 figs

  20. TERT promoter hot spot mutations are frequent in Indian cervical and oral squamous cell carcinomas.

    Science.gov (United States)

    Vinothkumar, Vilvanathan; Arunkumar, Ganesan; Revathidevi, Sundaramoorthy; Arun, Kanagaraj; Manikandan, Mayakannan; Rao, Arunagiri Kuha Deva Magendhra; Rajkumar, Kottayasamy Seenivasagam; Ajay, Chandrasekar; Rajaraman, Ramamurthy; Ramani, Rajendren; Murugan, Avaniyapuram Kannan; Munirajan, Arasambattu Kannan

    2016-06-01

    Squamous cell carcinoma (SCC) of the uterine cervix and oral cavity are most common cancers in India. Telomerase reverse transcriptase (TERT) overexpression is one of the hallmarks for cancer, and activation through promoter mutation C228T and C250T has been reported in variety of tumors and often shown to be associated with aggressive tumors. In the present study, we analyzed these two hot spot mutations in 181 primary tumors of the uterine cervix and oral cavity by direct DNA sequencing and correlated with patient's clinicopathological characteristics. We found relatively high frequency of TERT hot spot mutations in both cervical [21.4 % (30/140)] and oral [31.7 % (13/41)] squamous cell carcinomas. In cervical cancer, TERT promoter mutations were more prevalent (25 %) in human papilloma virus (HPV)-negative cases compared to HPV-positive cases (20.6 %), and both TERT promoter mutation and HPV infection were more commonly observed in advanced stage tumors (77 %). Similarly, the poor and moderately differentiated tumors of the uterine cervix had both the TERT hot spot mutations and HPV (16 and 18) at higher frequency (95.7 %). Interestingly, we observed eight homozygous mutations (six 228TT and two 250TT) only in cervical tumors, and all of them were found to be positive for high-risk HPV. To the best of our knowledge, this is the first study from India reporting high prevalence of TERT promoter mutations in primary tumors of the uterine cervix and oral cavity. Our results suggest that TERT reactivation through promoter mutation either alone or in association with the HPV oncogenes (E6 and E7) could play an important role in the carcinogenesis of cervical and oral cancers.

  1. Multiple Hotspot Mutations Scanning by Single Droplet Digital PCR.

    Science.gov (United States)

    Decraene, Charles; Silveira, Amanda B; Bidard, François-Clément; Vallée, Audrey; Michel, Marc; Melaabi, Samia; Vincent-Salomon, Anne; Saliou, Adrien; Houy, Alexandre; Milder, Maud; Lantz, Olivier; Ychou, Marc; Denis, Marc G; Pierga, Jean-Yves; Stern, Marc-Henri; Proudhon, Charlotte

    2018-02-01

    Progress in the liquid biopsy field, combined with the development of droplet digital PCR (ddPCR), has enabled noninvasive monitoring of mutations with high detection accuracy. However, current assays detect a restricted number of mutations per reaction. ddPCR is a recognized method for detecting alterations previously characterized in tumor tissues, but its use as a discovery tool when the mutation is unknown a priori remains limited. We established 2 ddPCR assays detecting all genomic alterations within KRAS exon 2 and EGFR exon 19 mutation hotspots, which are of clinical importance in colorectal and lung cancer, with use of a unique pair of TaqMan ® oligoprobes. The KRAS assay scanned for the 7 most common mutations in codons 12/13 but also all other mutations found in that region. The EGFR assay screened for all in-frame deletions of exon 19, which are frequent EGFR-activating events. The KRAS and EGFR assays were highly specific and both reached a limit of detection of <0.1% in mutant allele frequency. We further validated their performance on multiple plasma and formalin-fixed and paraffin-embedded tumor samples harboring a panel of different KRAS or EGFR mutations. This method presents the advantage of detecting a higher number of mutations with single-reaction ddPCRs while consuming a minimum of patient sample. This is particularly useful in the context of liquid biopsy because the amount of circulating tumor DNA is often low. This method should be useful as a discovery tool when the tumor tissue is unavailable or to monitor disease during therapy. © 2017 American Association for Clinical Chemistry.

  2. Influence of radiation exposure rate on somatic mutation frequency and loss of reproductive integrity in tradescantia stamen hairs

    International Nuclear Information System (INIS)

    Ichikawa, S.; Nauman, C.H.; Sparrow, A.H.; Takahashi, C.S.

    1978-01-01

    Inflorescences of Tradescantia clone 02 (2n=12), hetero- or hemi-zygous for flower color, were exposed to a series of γ-ray exposures at two different exposure rates, 29.3 R/min and 0.026-0.52 R/min. Pink mutation-response curves, and survival curves based on reproductive integrity, were constructed for each of the exposure rates. Loss of reproductive integrity was also assessed at high (256 R/min) and low (0.52-4.17 R/min) γ-ray exposure rates in T. blossfeldiana (2n=72). All observations were made on stamen hairs. The higher exposure rate was 1.3-1.7 times more effective in inducing pink mutations in clone 02. A greater efficiency of the higher exposure rate was also found for both taxa at the loss of reproductive integrity endpoint. The D 0 values obtained at the higher exposure rates, 154 R for clone 02 and 720 R for T. blossfeldiana, were significantly lower than the corresponding values of 270 R and 1880 R obtained at the lower exposure rates. These D 0 's differ by factors of 1.75 and 2.61 for clone 02 and T. blossfeldiana, respectively. D 0 's for the two taxa were found to be inversely correlated with their interphase chromosome volumes. (Auth.)

  3. BRCA Mutation Frequency and Patterns of Treatment Response in BRCA Mutation–Positive Women With Ovarian Cancer: A Report From the Australian Ovarian Cancer Study Group

    Science.gov (United States)

    Alsop, Kathryn; Fereday, Sian; Meldrum, Cliff; deFazio, Anna; Emmanuel, Catherine; George, Joshy; Dobrovic, Alexander; Birrer, Michael J.; Webb, Penelope M.; Stewart, Colin; Friedlander, Michael; Fox, Stephen; Bowtell, David; Mitchell, Gillian

    2012-01-01

    Purpose The frequency of BRCA1 and BRCA2 germ-line mutations in women with ovarian cancer is unclear; reports vary from 3% to 27%. The impact of germ-line mutation on response requires further investigation to understand its impact on treatment planning and clinical trial design. Patients and Methods Women with nonmucinous ovarian carcinoma (n = 1,001) enrolled onto a population-based, case-control study were screened for point mutations and large deletions in both genes. Survival outcomes and responses to multiple lines of chemotherapy were assessed. Results Germ-line mutations were found in 14.1% of patients overall, including 16.6% of serous cancer patients (high-grade serous, 22.6%); 44% had no reported family history of breast or ovarian cancer. Patients carrying germ-line mutations had improved rates of progression-free and overall survival. In the relapse setting, patients carrying mutations more frequently responded to both platin- and nonplatin-based regimens than mutation-negative patients, even in patients with early relapse after primary treatment. Mutation-negative patients who responded to multiple cycles of platin-based treatment were more likely to carry somatic BRCA1/2 mutations. Conclusion BRCA mutation status has a major influence on survival in ovarian cancer patients and should be an additional stratification factor in clinical trials. Treatment outcomes in BRCA1/2 carriers challenge conventional definitions of platin resistance, and mutation status may be able to contribute to decision making and systemic therapy selection in the relapse setting. Our data, together with the advent of poly(ADP-ribose) polymerase inhibitor trials, supports the recommendation that germ-line BRCA1/2 testing should be offered to all women diagnosed with nonmucinous, ovarian carcinoma, regardless of family history. PMID:22711857

  4. Mutational effects of γ-rays and carbon ion beams on Arabidopsis seedlings

    International Nuclear Information System (INIS)

    Yoshihara, Ryohei; Nozawa, Shigeki; Hase, Yoshihiro; Sakamoto, Ayako N.; Narumi, Issay; Hidema, Jun

    2013-01-01

    To assess the mutational effects of radiation on vigorously proliferating plant tissue, the mutation spectrum was analyzed with Arabidopsis seedlings using the plasmid-rescue method. Transgenic plants containing the Escherichia coli rpsL gene were irradiated with γ-rays and carbon ion beams (320-MeV 12 C 6+ ), and mutations in the rpsL gene were analyzed. Mutant frequency increased significantly following irradiation by γ-rays, but not by 320-MeV 12 C 6+ . Mutation spectra showed that both radiations increased the frequency of frameshifts and other mutations, including deletions and insertions, but only γ-rays increased the frequency of total base substitutions. These results suggest that the type of DNA lesions which cause base substitutions were less often induced by 320-MeV 12 C 6+ than by γ-rays in Arabidopsis seedlings. Furthermore, γ-rays never increased the frequencies of G:C to T:A or A:T to C:G transversions, which are caused by oxidized guanine; 320-MeV 12 C 6+ , however, produced a slight increase in both transversions. Instead, γ-rays produced a significant increase in the frequency of G:C to A:T transitions. These results suggest that 8-oxoguanine has little effect on mutagenesis in Arabidopsis cells. (author)

  5. Iron overload and HFE gene mutations in Polish patients with liver cirrhosis.

    Science.gov (United States)

    Sikorska, Katarzyna; Romanowski, Tomasz; Stalke, Piotr; Iżycka-Świeszewska, Ewa; Bielawski, Krzysztof Piotr

    2011-06-01

    Increased liver iron stores may contribute to the progression of liver injury and fibrosis, and are associated with a higher risk of hepatocellular carcinoma development. Pre-transplant symptoms of iron overload in patients with liver cirrhosis are associated with higher risk of infectious and malignant complications in liver transplant recipients. HFE gene mutations may be involved in the pathogenesis of liver iron overload and influence the progression of chronic liver diseases of different origins. This study was designed to determine the prevalence of iron overload in relation to HFE gene mutations among Polish patients with liver cirrhosis. Sixty-one patients with liver cirrhosis included in the study were compared with a control group of 42 consecutive patients subjected to liver biopsy because of chronic liver diseases. Liver function tests and serum iron markers were assessed in both groups. All patients were screened for HFE mutations (C282Y, H63D, S65C). Thirty-six of 61 patients from the study group and all controls had liver biopsy performed with semiquantitative assessment of iron deposits in hepatocytes. The biochemical markers of iron overload and iron deposits in the liver were detected with a higher frequency (70% and 47% respectively) in patients with liver cirrhosis. There were no differences in the prevalence of all HFE mutations in both groups. In patients with a diagnosis of hepatocellular carcinoma, no significant associations with iron disorders and HFE gene mutations were found. Iron disorders were detected in patients with liver cirrhosis frequently but without significant association with HFE gene mutations. Only the homozygous C282Y mutation seems to occur more frequently in the selected population of patients with liver cirrhosis. As elevated biochemical iron indices accompanied liver iron deposits more frequently in liver cirrhosis compared to controls with chronic liver disease, there is a need for more extensive studies searching for

  6. HFE gene mutations in coronary atherothrombotic disease

    Directory of Open Access Journals (Sweden)

    Calado R.T.

    2000-01-01

    Full Text Available Although iron can catalyze the production of free radicals involved in LDL lipid peroxidation, the contribution of iron overload to atherosclerosis remains controversial. The description of two mutations in the HFE gene (Cys282Tyr and His63Asp related to hereditary hemochromatosis provides an opportunity to address the question of the association between iron overload and atherosclerosis. We investigated the prevalence of HFE mutations in 160 survivors of myocardial infarction with angiographically demonstrated severe coronary atherosclerotic disease, and in 160 age-, gender- and race-matched healthy control subjects. PCR amplification of genomic DNA followed by RsaI and BclI restriction enzyme digestion was used to determine the genotypes. The frequency of the mutant Cys282Tyr allele was identical among patients and controls (0.022; carrier frequency, 4.4%, whereas the mutant His63Asp allele had a frequency of 0.143 (carrier frequency, 27.5% in controls and of 0.134 (carrier frequency, 24.5% in patients. Compound heterozygotes were found in 2 of 160 (1.2% controls and in 1 of 160 (0.6% patients. The finding of a similar prevalence of Cys282Tyr and His63Asp mutations in the HFE gene among controls and patients with coronary atherothrombotic disease, indirectly questions the possibility of an association between hereditary hemochromatosis and atherosclerosis.

  7. Irradiation-induced mutation experiments with eiploid and tetraploid tomato plants

    International Nuclear Information System (INIS)

    Boda, J.

    1979-01-01

    Tomato mutation experiments are described. The tomatoes used in the experiment were the diploid Reziszta and its autotetraploid variety. The experimental plants were exposed to an irradiation of 5000 rsd for 1-2 days, and after transplantation into the gamma field, to chronic irradiation during the whole growing season. The chronic treatment heavily reduced fertility in the generations of tetraploid tomato plants. Recurrent treatment of tetraploid led to further deterioration in fertility. Several berries were formed with few seeds or with no seeds at all. After three irradiations, the chlorophyll mutation frequency increased in the diploid and tetraploid tomato plants. For diploids, treatment applied at the seedling stage gave a lower chlorophyll mutation frequency. With tetraploids the same treatment induced similar chlorophyll mutation frequency. As regards to phenotypic variability of quantitative characteristics in diploid and tetraploid tomatoes, the single and repeated chronic irradiation induced no increase in the variability of properties like flowering time, weight, height etc. (author)

  8. Mutation Pattern of Paired Immunoglobulin Heavy and Light Variable Domains in Chronic Lymphocytic Leukemia B Cells

    Science.gov (United States)

    Ghiotto, Fabio; Marcatili, Paolo; Tenca, Claudya; Calevo, Maria Grazia; Yan, Xiao-Jie; Albesiano, Emilia; Bagnara, Davide; Colombo, Monica; Cutrona, Giovanna; Chu, Charles C; Morabito, Fortunato; Bruno, Silvia; Ferrarini, Manlio; Tramontano, Anna; Fais, Franco; Chiorazzi, Nicholas

    2011-01-01

    B-cell chronic lymphocytic leukemia (CLL) patients display leukemic clones bearing either germline or somatically mutated immunoglobulin heavy variable (IGHV ) genes. Most information on CLL immunoglobulins (Igs), such as the definition of stereotyped B-cell receptors (BCRs), was derived from germline unmutated Igs. In particular, detailed studies on the distribution and nature of mutations in paired heavy- and light-chain domains of CLL clones bearing mutated Igs are lacking. To address the somatic hyper-mutation dynamics of CLL Igs, we analyzed the mutation pattern of paired IGHV–diversity-joining (IGHV-D-J ) and immunoglobulin kappa/lambda variable-joining (IGK/LV-J ) rearrangements of 193 leukemic clones that displayed ≥2% mutations in at least one of the two immunoglobulin variable (IGV ) genes (IGHV and/or IGK/LV ). The relationship between the mutation frequency in IGHV and IGK/LV complementarity determining regions (CDRs) and framework regions (FRs) was evaluated by correlation analysis. Replacement (R) mutation frequency within IGK/LV chain CDRs correlated significantly with mutation frequency of paired IGHV CDRs in λ but not κ isotype CLL clones. CDRs of IGKV-J rearrangements displayed a lower percentage of R mutations than IGHVs. The frequency/pattern of mutations in kappa CLL Igs differed also from that in κ-expressing normal B cells described in the literature. Instead, the mutation frequency within the FRs of IGHV and either IGKV or IGLV was correlated. Notably, the amount of diversity introduced by replaced amino acids was comparable between IGHVs and IGKVs. The data indicate a different mutation pattern between κ and λ isotype CLL clones and suggest an antigenic selection that, in κ samples, operates against CDR variation. PMID:21785810

  9. Mutation Pattern of Paired Immunoglobulin Heavy and Light Variable Domains in Chronic Lymphocytic Leukemia B Cells

    KAUST Repository

    Ghiotto, Fabio; Marcatili, Paolo

    2011-01-01

    B-cell chronic lymphocytic leukemia (CLL) patients display leukemic clones bearing either germline or somatically mutated immunoglobulin heavy variable (IGHV ) genes. Most information on CLL immunoglobulins (Igs), such as the definition of stereotyped B-cell receptors (BCRs), was derived from germline unmutated Igs. In particular, detailed studies on the distribution and nature of mutations in paired heavy- and light-chain domains of CLL clones bearing mutated Igs are lacking. To address the somatic hyper-mutation dynamics of CLL Igs, we analyzed the mutation pattern of paired IGHV-diversity-joining (IGHV-D-J ) and immunoglobulin kappa/lambda variable-joining (IGK/LV-J ) rearrangements of 193 leukemic clones that displayed ≥ 2% mutations in at least one of the two immunoglobulin variable (IGV ) genes (IGHV and/or IGK/LV ). The relationship between the mutation frequency in IGHV and IGK/LV complementarity determining regions (CDRs) and framework regions (FRs) was evaluated by correlation analysis. Replacement (R) mutation frequency within IGK/LV chain CDRs correlated significantly with mutation frequency of paired IGHV CDRs in λ but not κ isotype CLL clones. CDRs of IGKV-J rearrangements displayed a lower percentage of R mutations than IGHVs. The frequency/pattern of mutations in kappa CLL Igs differed also from that in κ-expressing normal B cells described in the literature. Instead, the mutation frequency within the FRs of IGHV and either IGKV or IGLV was correlated. Notably, the amount of diversity introduced by replaced amino acids was comparable between IGHVs and IGKVs. The data indicate a different mutation pattern between κ and λ isotype CLL clones and suggest an antigenic selection that, in κ samples, operates against CDR variation.

  10. Species With Greater Aerial Maneuverability Have Higher Frequency of Collisions With Aircraft: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Esteban Fernández-Juricic

    2018-03-01

    Full Text Available Antipredator responses may appear unsuccessful when animals are exposed to approaching vehicles, often resulting in mortality. Recent studies have addressed whether certain biological traits are associated with variation in collision risk with cars, but not with higher speed-vehicles like aircraft. Our goal was to establish the association between different species traits (i.e., body mass, eye size, brain size, wing loading, wing aspect ratio and the frequency of bird collisions with aircraft (hereafter, bird strikes using a comparative approach controlling for the effects of shared ancestry. We proposed directional predictions as to how each of the species traits would affect the frequency of bird strikes. Considering 39 bird species with all traits represented, the model containing wing loading had the best fit to account for the variance in bird strikes across species. In another model with 54 species exploring the fit to different polynomial models but considering only wing loading, we found that wing loading was negatively and linearly associated with the frequency of bird strikes. Counterintuitively, species with lower wing loading (hence, greater maneuverability had a higher frequency of bird strikes. We discuss potential non-mutually exclusive explanations (e.g., high wing loading species fly faster, thus gaining some extra time to avoid the aircraft flight path; high wing loading species are hazed more intensively at airports, which could lower collisions, etc.. Ultimately, our findings uncovered that species with low wing loading get struck at a higher rate at airports, which reduces the safety risk for humans because these species tend not to cause damaging strikes, but the ecological consequences of their potentially higher local mortality are unknown.

  11. Cancer risk and clinicopathological characteristics of thyroid nodules harboring thyroid-stimulating hormone receptor gene mutations.

    Science.gov (United States)

    Mon, Sann Y; Riedlinger, Gregory; Abbott, Collette E; Seethala, Raja; Ohori, N Paul; Nikiforova, Marina N; Nikiforov, Yuri E; Hodak, Steven P

    2018-05-01

    Thyroid-stimulating hormone receptor (TSHR) gene mutations play a critical role in thyroid cell proliferation and function. They are found in 20%-82% of hyperfunctioning nodules, hyperfunctioning follicular thyroid cancers (FTC), and papillary thyroid cancers (PTC). The diagnostic importance of TSHR mutation testing in fine needle aspiration (FNA) specimens remains unstudied. To examine the association of TSHR mutations with the functional status and surgical outcomes of thyroid nodules, we evaluated 703 consecutive thyroid FNA samples with indeterminate cytology for TSHR mutations using next-generation sequencing. Testing for EZH1 mutations was performed in selected cases. The molecular diagnostic testing was done as part of standard of care treatment, and did not require informed consent. TSHR mutations were detected in 31 (4.4%) nodules and were located in exons 281-640, with codon 486 being the most common. Allelic frequency ranged from 3% to 45%. Of 16 cases (12 benign, 3 FTC, 1 PTC) with surgical correlation, 15 had solitary TSHR mutations and 1 PTC had comutation with BRAF V600E. Hyperthyroidism was confirmed in all 3 FTC (2 overt, 1 subclinical). Of 5 nodules with solitary TSHR mutations detected at high allelic frequency, 3 (60%) were FTC. Those at low allelic frequency (3%-22%) were benign. EZH1 mutations were detected in 2 of 4 TSHR-mutant malignant nodules and neither of 2 benign nodules. We report that TSHR mutations occur in ∼5% thyroid nodules in a large consecutive series with indeterminate cytology. TSHR mutations may be associated with an increased cancer risk when present at high allelic frequency, even when the nodule is hyperfunctioning. Benign nodules were however most strongly correlated with TSHR mutations at low allelic frequency. © 2018 Wiley Periodicals, Inc.

  12. Thalassemia mutations in Gaziantep, Turkey

    African Journals Online (AJOL)

    STORAGESEVER

    2010-02-22

    Feb 22, 2010 ... Table 3. Frequency of β-thalassemia mutations in the Eastern Mediterranean. Mutation. This study Turkey Cyprus Greece Syria Palestine Bulgaria Azerbaijan Iran Iraq. IVS 1.110 (G>A). 29.1. 39.3. 79.7. 42.1. 24.1. 17.6. 24.2. 20.2. 4.8 1.9. IVS 2.1 (G>A). 12.3. 4.7. -. 3.3. 4.2. 2.9. -. -. 33.9 18.3. IVS 1.1 (G>A).

  13. The mutual dependence of M1 fertility and M2 mutations in rice

    International Nuclear Information System (INIS)

    Gopinathan Nair, V.

    1982-01-01

    The mutual dependence of M 1 fertility and M 2 mutations in rice was studied after treatment with gamma rays and EMS. The frequency of chlorophyll mutations increased with decrease in seed fertility when M 1 ears were selected at random. However, at the lowest fertility class the mutation frequency was low. This reduction is attributed to the elimination of mutants in the high sterility class. The mutation yield can therefore be significantly enhanced by selecting M 1 ears of low fertility. The segregation ratio of mutants increased as fertility decreased. Mutation spectrum was however not influenced by M 1 fertility. This makes selection for fertility quite ineffective in altering the mutation spectrum. (author)

  14. Mutation breeding in ornamental plants

    International Nuclear Information System (INIS)

    Datta, S.K.

    1990-01-01

    Full text: Mutation induction produced a large number of new promising varieties in ornamental species. 37 new mutants of Chrysanthemum and 14 of rose have been developed by mutations and released for commercialisation. The mutations in flower colour/shape were detected as chimeras in M 1 V 1 , M 1 V 2 , M 1 V 3 generations. The mutation frequency varied with the cultivar and exposure to gamma rays. Comparative analysis of original cultivars and their respective induced mutants on cytomorphological, anatomical and biochemical characters are being carried out for better understanding of the mechanism involved in the origin and evolution of somatic flower colour/shape mutations. Cytological analysis with reference to chromosomal aberrations, chromosome number, ICV, INV and DNA content gave no differences between the original and mutant cultivars. Analysis of florets/petal pigments by TLC and spectrophotometric methods indicated both qualitative and quantitative changes. (author)

  15. BRCA1 and BRCA2 Gene Mutations Screening In Sporadic Breast Cancer Patients In Kazakhstan.

    Directory of Open Access Journals (Sweden)

    Ainur R. Akilzhanova

    2013-05-01

    Full Text Available Background: A large number of distinct mutations in the BRCA1 and BRCA2 genes have been reported worldwide, but little is known regarding the role of these inherited susceptibility genes in breast cancer risk among Kazakhstan women. Aim: To evaluate the role of BRCA1/2 mutations in Kazakhstan women presenting with sporadic breast cancer. Methods: We investigated the distribution and nature of polymorphisms in BRCA1 and BRCA2 entire coding regions in 156 Kazakhstan sporadic breast cancer cases and 112 age-matched controls using automatic direct sequencing. Results: We identified 22 distinct variants, including 16 missense mutations and 6 polymorphisms in BRCA1/2 genes. In BRCA1, 9 missense mutations and 3 synonymous polymorphisms were observed. In BRCA2, 7 missense mutations and 3 polymorphisms were detected. There was a higher prevalence of observed mutations in Caucasian breast cancer cases compared to Asian cases (p<0.05; higher frequencies of sequence variants were observed in Asian controls. No recurrent or founder mutations were observed in BRCA1/2 genes. There were no statistically significant differences in age at diagnosis, tumor histology, size of tumor, and lymph node involvement between women with breast cancer with or without the BRCA sequence alterations. Conclusions: Considering the majority of breast cancer cases are sporadic, the present study will be helpful in the evaluation of the need for the genetic screening of BRCA1/2 mutations and reliable genetic counseling for Kazakhstan sporadic breast cancer patients. Evaluation of common polymorphisms and mutations and breast cancer risk in families with genetic predisposition to breast cancer is ongoing in another current investigation. 

  16. Smoking status and self-reported race affect the frequency of clinically relevant oncogenic alterations in non-small-cell lung cancers at a United States-based academic medical practice.

    Science.gov (United States)

    Yamaguchi, Norihiro; Vanderlaan, Paul A; Folch, Erik; Boucher, David H; Canepa, Hannah M; Kent, Michael S; Gangadharan, Sidharta P; Majid, Adnan; Kocher, Olivier N; Goldstein, Michael A; Huberman, Mark S; Costa, Daniel B

    2013-10-01

    The identification of somatic genomic aberrations in non-small-cell lung cancer (NSCLC) is part of evidence-based practice guidelines for care of patients with NSCLC. We sought to establish the frequency and correlates with these changes in routine patient-tumor sample pairs. Clinicopathologic data and tumor genotype were retrospectively compiled and analyzed from an overall cohort of 381 patient-tumor samples. Of these patients, 75.9% self-reported White race, 13.1% Asian, 6.5% Black, 27.8% were never-smokers, 54.9% former-smokers and 17.3% current-smokers. The frequency of EGFR mutations was 23.9% (86/359), KRAS mutations 34.2% (71/207) and ALK FISH positivity 9.1% (23/252) in tumor samples, and almost all had mutually exclusive results for these oncogenes. In tumors from White, Black and Asian patients, the frequencies of EGFR mutations were 18.4%, 18.2% and 62%, respectively; of ALK FISH positivity 7.81%, 0% and 14.8%, respectively; and of KRAS mutations 41.6%, 20% and 0%. These patterns changed significant with increasing pack-year history of smoking. In White patients, the frequencies of EGFR mutations and ALK FISH positivity decreased with increasing pack-year cohorts; while the frequencies of KRAS mutations increased. Interestingly, in Asian patients the frequencies of EGFR mutations were similar in never smokers and in the cohorts with less than 45pack-year histories of smoking and only decreased in the 45pack-year plus cohort. The frequencies of somatic EGFR, KRAS, and ALK gene abnormalities using routine lung cancer tissue samples from our United States-based academic medical practice reflect the diverse ethnicity (with a higher frequency of EGFR mutations in Asian patients) and smoking patterns (with an inverse correlation between EGFR mutation and ALK rearrangement) of our tested population. These results may help other medical practices appreciate the expected results from introduction of routine tumor genotyping techniques into their day-to-day care

  17. MLH1-Silenced and Non-Silenced Subgroups of Hypermutated Colorectal Carcinomas Have Distinct Mutational Landscapes

    Science.gov (United States)

    Donehower, Lawrence A.; Creighton, Chad J.; Schultz, Nikolaus; Shinbrot, Eve; Chang, Kyle; Gunaratne, Preethi H.; Muzny, Donna; Sander, Chris; Hamilton, Stanley R.; Gibbs, Richard A.; Wheeler, David

    2014-01-01

    Approximately 15% of colorectal carcinomas (CRC) exhibit a hypermutated genotype accompanied by high levels of microsatellite instability (MSI-H) and defects in DNA mismatch repair. These tumors, unlike the majority of colorectal carcinomas, are often diploid, exhibit frequent epigenetic silencing of the MLH1 DNA mismatch repair gene, and have a better clinical prognosis. As an adjunct study to The Cancer Genome Atlas consortium that recently analyzed 224 colorectal cancers by whole exome sequencing, we compared the 35 CRC (15.6%) with a hypermutated genotype to those with a non-hypermutated genotype. We found that 22 (63%) of hypermutated CRC exhibited transcriptional silencing of the MLH1 gene, a high frequency of BRAF V600E gene mutations and infrequent APC and KRAS mutations, a mutational pattern significantly different from their non-hypermutated counterparts. However, the remaining 13 (37%) hypermutated CRC lacked MLH1 silencing, contained tumors with the highest mutation rates (“ultramutated” CRC), and exhibited higher incidences of APC and KRAS mutations, but infrequent BRAF mutations. These patterns were confirmed in an independent validation set of 250 exome-sequenced CRC. Analysis of mRNA and microRNA expression signatures revealed that hypermutated CRC with MLH1 silencing had greatly reduced levels of WNT signaling and increased BRAF signaling relative non-hypermutated CRC. Our findings suggest that hypermutated CRC include one subgroup with fundamentally different pathways to malignancy than the majority of CRC. Examination of MLH1 expression status and frequencies of APC, KRAS, and BRAF mutation in CRC may provide a useful diagnostic tool that could supplement the standard microsatellite instability assays and influence therapeutic decisions. PMID:22899370

  18. Detection of low frequency FGFR3 mutations in the urine of bladder cancer patients using next-generation deep sequencing

    Directory of Open Access Journals (Sweden)

    Millholl

    2012-06-01

    Full Text Available John M Millholland, Shuqiang Li, Cecilia A Fernandez, Anthony P ShuberPredictive Biosciences Inc, Lexington, MA, USAAbstract: Biological fluid-based noninvasive biomarker assays for monitoring and diagnosing disease are clinically powerful. A major technical hurdle for developing these assays is the requirement of high analytical sensitivity so that biomarkers present at very low levels can be consistently detected. In the case of biological fluid-based cancer diagnostic assays, sensitivities similar to those of tissue-based assays are difficult to achieve with DNA markers due to the high abundance of normal DNA background present in the sample. Here we describe a new urine-based assay that uses ultradeep sequencing technology to detect single mutant molecules of fibroblast growth factor receptor 3 (FGFR3 DNA that are indicative of bladder cancer. Detection of FGFR3 mutations in urine would provide clinicians with a noninvasive means of diagnosing early-stage bladder cancer. The single-molecule assay detects FGFR3 mutant DNA when present at as low as 0.02% of total urine DNA and results in 91% concordance with the frequency that FGFR3 mutations are detected in bladder cancer tumors, significantly improving diagnostic performance. To our knowledge, this is the first practical application of next-generation sequencing technology for noninvasive cancer diagnostics.Keywords: FGFR3, mutation, urine, single molecule, sequencing, bladder cancer

  19. Comprehensive analysis of gene mutation and phenotype of tuberous sclerosis complex in China

    Directory of Open Access Journals (Sweden)

    Guo-qiang HUANG

    2015-04-01

    Full Text Available Objective To summarize the clinical features of tuberous sclerosis complex (TSC, the distribution and description of TSC gene, and to probe into the correlation of genotype with phenotype.  Methods According to the 1998 International Tuberous Sclerosis Complex Diagnostic Criteria, a total of 163 TSC patients with pathogenic mutation in TSC gene (3 cases were detected in our hospital, and the other 160 cases were collected from other institutions in China were enrolled, and their gene detection results and clinical data were analyzed.  Results Among 163 cases, TSC1 mutation (31 cases accounted for 19.02% [32.26% (10/31 in exon 15, 16.13% (5/31 in exon 21, 12.90% (4/31 in exon 18], and TSC2 mutation (132 cases accounted for 80.98% [9.85% (13/132 in exon 37, 7.58% (10/132 in exon 40, 6.82%(9/132 in exon 33]. The proportion of base replacement in TSC1 was 41.94% (13/31, and 52.27% (69/132 in TSC2. Male patients exhibited significantly more subependymal nodules or calcifications than thefemale patients (χ2 = 8.016, P = 0.005. Sporadic patients exhibited significantly more cortical tubers than familial patients (χ2 = 6.273, P = 0.012. Patients with TSC2 mutations had significantly higher frequencies of hypomelanotic macules than patients with TSC1 mutations (χ2 = 6.756, P = 0.009. Patients with missense mutations were more likely to have facial angiofibromas compared with patients with other mutations (χ2 = 4.438, P = 0.035.  Conclusions Exon 15, 21 and 18 of TSC1 and exon 37, 40 and 33 of TSC2 accounted for higher percentage of mutations. Correlating genotypes with phenotypes should facilitate the individualized treatment and prognostic assessment of tuberous sclerosis complex. DOI: 10.3969/j.issn.1672-6731.2015.04.013

  20. Understanding the role of p53 in adaptive response to radiation-induced germline mutations

    International Nuclear Information System (INIS)

    Langlois, N.L.; Quinn, J.S.; Somers, C.M.; Boreham, D.R.; Mitchel, R.E.J.

    2003-01-01

    Full text: Radiation-induced adaptive response is now a widely studied area of radiation biology. Studies have demonstrated reduced levels of radiation-induced biological damage when an 'adaptive dose' is given before a higher 'challenge dose' compared to when the challenge dose is given alone. It has been shown in some systems to be a result of inducible cellular repair systems. The adaptive response has been clearly demonstrated in many model systems, however its impact on heritable effects in the mammalian germline has never been studied. Expanded Simple Tandem Repeat (ESTR) loci have been used as markers demonstrating that induced heritable mutations in mice follow a dose-response relationship. Recent data in our laboratory show preliminary evidence of radiation-induced adaptive response suppressing germline mutations at ESTR loci in wild type mice. The frequency of heritable mutations was significantly reduced when a priming dose of 0.1 Gy was given 24 hours prior to a 1 Gy acute challenging dose. We are now conducting a follow-up study to attempt to understand the mechanism of this adaptive response. P53 is known to play a significant role in governing apoptosis, DNA repair and cancer induction. In order to determine what function p53 has in the adaptive response for heritable mutations, we have mated radiation treated Trp53+/- male mice (C57Bl) to untreated, normal females (C57Bl). Using DNA fingerprinting, we are investigating the rate of inherited radiation-induced mutations on pre- and post-meiotic radiation-treated gametocytes by examining mutation frequencies in offspring DNA. If p53 is integral in the mechanism of adaptive response, we should not see an adaptive response in radiation-induced heritable mutations in these mice. This research is significant in that it will provide insight to understanding the mechanism behind radiation-induced adaptive response in the mammalian germline

  1. Recurrent APC gene mutations in Polish FAP families

    Directory of Open Access Journals (Sweden)

    Pławski Andrzej

    2007-12-01

    Full Text Available Abstract The molecular diagnostics of genetically conditioned disorders is based on the identification of the mutations in the predisposing genes. Hereditary cancer disorders of the gastrointestinal tracts are caused by mutations of the tumour suppressor genes or the DNA repair genes. Occurrence of recurrent mutation allows improvement of molecular diagnostics. The mutation spectrum in the genes causing hereditary forms of colorectal cancers in the Polish population was previously described. In the present work an estimation of the frequency of the recurrent mutations of the APC gene was performed. Eight types of mutations occurred in 19.4% of our FAP families and these constitute 43% of all Polish diagnosed families.

  2. Prevalent mutations in fatty acid oxidation disorders

    DEFF Research Database (Denmark)

    Gregersen, N; Andresen, B S; Bross, P

    2000-01-01

    UNLABELLED: The mutational spectrum in a given disease-associated gene is often comprised of a large number of different mutations, of which a single or a few are present in a large proportion of diseased individuals. Such prevalent mutations are known in four genes of the fatty acid oxidation...... of the disease in question and determination of the carrier frequency in the general population may help in elucidating the penetrance of the genotype. This is exemplified in disorders of mitochondrial fatty acid oxidation....

  3. HFE gene mutation and iron overload in Egyptian pediatric acute lymphoblastic leukemia survivors: a single-center study.

    Science.gov (United States)

    El-Rashedi, Farida H; El-Hawy, Mahmoud A; El-Hefnawy, Sally M; Mohammed, Mona M

    2017-08-01

    Hereditary hemochromatosis gene (HFE) mutations have a role in iron overload in pediatric acute lymphoblastic leukemia (ALL) survivors. We aimed to evaluate the genotype frequency and allelic distribution of the two HFE gene mutations (C282Y and H63D) in a sample of Egyptian pediatric ALL survivors and to detect the impact of these two mutations on their iron profile. This study was performed on 35 ALL survivors during their follow-up visits to the Hematology and Oncology Unit, Pediatric Department, Menoufia University Hospitals. Thirty-five healthy children of matched age and sex were chosen as controls. After completing treatment course, ALL survivors were screened for the prevalence of these two mutations by polymerase chain reaction-restriction fragment length polymorphism. Serum ferritin levels were measured by an enzyme-linked immunosorbent assay technique (ELISA). C282Y mutation cannot be detected in any of the 35 survivors or the 35 controls. The H63D heterozygous state (CG) was detected in 28.6% of the survivors group and in 20% of controls, while the H63D homozygous (GG) state was detected in 17.1% of survivors. No compound heterozygosity (C282Y/H63D) was detected at both groups with high G allele frequency (31.4%) in survivors more than controls (10%). There were significant higher levels of iron parameters in homozygote survivors than heterozygotes and the controls. H63D mutation aggravates the iron overload status in pediatric ALL survivors.

  4. Object Categorization in Finer Levels Relies More on Higher Spatial Frequencies and Takes Longer.

    Science.gov (United States)

    Ashtiani, Matin N; Kheradpisheh, Saeed R; Masquelier, Timothée; Ganjtabesh, Mohammad

    2017-01-01

    advantage of the superordinate (resp. basic) level to basic (resp. subordinate) level is mainly due to the computational constraints (the visual system processes higher spatial frequencies more slowly, and categorization in finer levels depends more on these higher spatial frequencies).

  5. Targeted cancer exome sequencing reveals recurrent mutations in myeloproliferative neoplasms

    Science.gov (United States)

    Tenedini, E; Bernardis, I; Artusi, V; Artuso, L; Roncaglia, E; Guglielmelli, P; Pieri, L; Bogani, C; Biamonte, F; Rotunno, G; Mannarelli, C; Bianchi, E; Pancrazzi, A; Fanelli, T; Malagoli Tagliazucchi, G; Ferrari, S; Manfredini, R; Vannucchi, A M; Tagliafico, E

    2014-01-01

    With the intent of dissecting the molecular complexity of Philadelphia-negative myeloproliferative neoplasms (MPN), we designed a target enrichment panel to explore, using next-generation sequencing (NGS), the mutational status of an extensive list of 2000 cancer-associated genes and microRNAs. The genomic DNA of granulocytes and in vitro-expanded CD3+T-lymphocytes, as a germline control, was target-enriched and sequenced in a learning cohort of 20 MPN patients using Roche 454 technology. We identified 141 genuine somatic mutations, most of which were not previously described. To test the frequency of the identified variants, a larger validation cohort of 189 MPN patients was additionally screened for these mutations using Ion Torrent AmpliSeq NGS. Excluding the genes already described in MPN, for 8 genes (SCRIB, MIR662, BARD1, TCF12, FAT4, DAP3, POLG and NRAS), we demonstrated a mutation frequency between 3 and 8%. We also found that mutations at codon 12 of NRAS (NRASG12V and NRASG12D) were significantly associated, for primary myelofibrosis (PMF), with highest dynamic international prognostic scoring system (DIPSS)-plus score categories. This association was then confirmed in 66 additional PMF patients composing a final dataset of 168 PMF showing a NRAS mutation frequency of 4.7%, which was associated with a worse outcome, as defined by the DIPSS plus score. PMID:24150215

  6. TET2 mutations in B cells of patients affected by angioimmunoblastic T-cell lymphoma.

    Science.gov (United States)

    Schwartz, Friederike H; Cai, Qian; Fellmann, Eva; Hartmann, Sylvia; Mäyränpää, Mikko I; Karjalainen-Lindsberg, Marja-Liisa; Sundström, Christer; Scholtysik, René; Hansmann, Martin-Leo; Küppers, Ralf

    2017-06-01

    Angioimmunoblastic T-cell lymphomas (AITLs) frequently carry mutations in the TET2 and IDH2 genes. TET2 mutations represent early genetic lesions as they had already been detected in haematopoietic precursor cells of AITL patients. We show by analysis of whole-tissue sections and microdissected PD1 + cells that the frequency of TET2-mutated AITL is presumably even higher than reported (12/13 cases in our collection; 92%). In two-thirds of informative AITLs (6/9), a fraction of B cells was also TET2-mutated. Investigation of four AITLs by TET2 and IGHV gene sequencing of single microdissected B cells showed that between 10% and 60% of polyclonal B cells in AITL lymph nodes harboured the identical TET2 mutations of the respective T-cell lymphoma clone. Thus, TET2-mutated haematopoietic precursor cells in AITL patients not only give rise to the T-cell lymphoma but also generate a large population of mutated mature B cells. Future studies will show whether this is a reason why AITL patients frequently also develop B-cell lymphomas. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  7. Common Β- Thalassaemia Mutations in

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    P Azarfam

    2005-01-01

    Full Text Available Introduction: β –Thalassaemia was first explained by Thomas Cooly as Cooly’s anaemia in 1925. The β- thalassaemias are hereditary autosomal disorders with decreased or absent β-globin chain synthesis. The most common genetic defects in β-thalassaemias are caused by point mutations, micro deletions or insertions within the β-globin gene. Material and Methods: In this research , 142 blood samples (64 from childrens hospital of Tabriz , 15 samples from Shahid Gazi hospital of Tabriz , 18 from Urumia and 45 samples from Aliasghar hospital of Ardebil were taken from thalassaemic patients (who were previously diagnosed .Then 117 non-familial samples were selected . The DNA of the lymphocytes of blood samples was extracted by boiling and Proteinase K- SDS procedure, and mutations were detected by ARMS-PCR methods. Results: From the results obtained, eleven most common mutations,most of which were Mediterranean mutations were detected as follows; IVS-I-110(G-A, IVS-I-1(G-A ،IVS-I-5(G-C ,Frameshift Codon 44 (-C,( codon5(-CT,IVS-1-6(T-C, IVS-I-25(-25bp del ,Frameshift 8.9 (+G ,IVS-II-1(G-A ,Codon 39(C-T, Codon 30(G-C the mutations of the samples were defined. The results showed that Frameshift 8.9 (+G, IVS-I-110 (G-A ,IVS-II-I(G-A, IVS-I-5(G-C, IVS-I-1(G-A , Frameshift Codon 44(-C , codon5(-CT , IVS-1-6(T-C , IVS-I-25(-25bp del with a frequency of 29.9%, 25.47%,17.83%, 7.00%, 6.36% , 6.63% , 3.8% , 2.5% , 0.63% represented the most common mutations in North - west Iran. No mutations in Codon 39(C-T and Codon 30(G-C were detected. Cunclusion: The frequency of the same mutations in patients from North - West of Iran seems to be different as compared to other regions like Turkey, Pakistan, Lebanon and Fars province of Iran. The pattern of mutations in this region is more or less the same as in the Mediterranean region, but different from South west Asia and East Asia.

  8. Mutation effect of ion implantation on tomato breeding

    International Nuclear Information System (INIS)

    Wu Baoshan; Ling Haiqiu; Mao Peihong; Jin Xiang; Zeng Xianxian

    2003-01-01

    The mutation effects of N + ion implantation on cultivated tomato, Catchup type and Eatable type were studied. The result show that the mutation ranges of single-fruit weight and fruit number per plant were increased and their mutation frequencies were high, however the effect of ion implantation on germination rate of seed and quality of fruit was very weak. Using doses of 4 x 10 16 and 6 x 10 16 N + /cm 2 , the yield was greatly improved. The optimum mutation dosage was slightly different for seed of 2 tomato lines

  9. Frequency of CHEK2 mutations in a population based, case–control study of breast cancer in young women

    International Nuclear Information System (INIS)

    Friedrichsen, Danielle M; Malone, Kathleen E; Doody, David R; Daling, Janet R; Ostrander, Elaine A

    2004-01-01

    The cell-cycle checkpoint kinase (CHEK)2 protein truncating mutation 1100delC has been associated with increased risk for breast or prostate cancer. Multiple studies have found an elevated frequency of the 1100delC variant in specific stratifications of breast cancer patients with a family history of the disease, including BRCA1/BRCA2 negative families and families with a history of bilateral disease or male breast cancer. However, the 1100delC mutation has only been investigated in a few population-based studies and none from North America. We report here on the frequency of three CHEK2 variants that alter protein function – 1100delC, R145W, and I175T – in 506 cases and 459 controls from a population based, case–control study of breast cancer conducted in young women from western Washington. There was a suggestive enrichment in the 1100delC variant in the cases (1.2%) as compared with the controls (0.4%), but this was based on small numbers of carriers and the differences were not statistically significant. The 1100delC variant was more frequent in cases with a first-degree family history of breast cancer (4.3%; P = 0.02) and slightly enriched in cases with a family history of ovarian cancer (4.4%; P = 0.09). The CHEK2 variants are rare in the western Washington population and, based on accumulated evidence across studies, are unlikely to be major breast cancer susceptibility genes. Thus, screening for the 1100delC variant may have limited usefulness in breast cancer prevention programs in the USA

  10. Mutational pattern of the nurse shark antigen receptor gene (NAR) is similar to that of mammalian Ig genes and to spontaneous mutations in evolution: the translesion synthesis model of somatic hypermutation.

    Science.gov (United States)

    Diaz, M; Velez, J; Singh, M; Cerny, J; Flajnik, M F

    1999-05-01

    The pattern of somatic mutations of shark and frog Ig is distinct from somatic hypermutation of Ig in mammals in that there is a bias to mutate GC base pairs and a low frequency of mutations. Previous analysis of the new antigen receptor gene in nurse sharks (NAR), however, revealed no bias to mutate GC base pairs and the frequency of mutation was comparable to that of mammalian IgG. Here, we analyzed 1023 mutations in NAR and found no targeting of the mechanism to any particular nucleotide but did obtain strong evidence for a transition bias and for strand polarity. As seen for all species studied to date, the serine codon AGC/T in NAR was a mutational hotspot. The NAR mutational pattern is most similar to that of mammalian IgG and furthermore both are strikingly akin to mutations acquired during the neutral evolution of nuclear pseudogenes, suggesting that a similar mechanism is at work for both processes. In yeast, most spontaneous mutations are introduced by the translesion synthesis DNA polymerase zeta (REV3) and in various DNA repair-deficient backgrounds transitions were more often REV3-dependent than were transversions. Therefore, we propose a model of somatic hypermutation where DNA polymerase zeta is recruited to the Ig locus. An excess of DNA glycosylases in germinal center reactions may further enhance the mutation frequency by a REV3-dependent mutagenic process known as imbalanced base excision repair.

  11. Effect of uvs1, uvs2 and xrs mutations on the radiosensitivity and the induced mitotic recombination frequency in diploid yeast cells

    International Nuclear Information System (INIS)

    Suslova, N.G.; Fedorova, I.V.; Zheleznyakova, N.Yu.

    1975-01-01

    The influence of the loci of radiosensitivity uvs1, uvs2, and xrs in the homozygous state at the diploid level on the sensitivity to UV and ionizing radiation and induced mitotic recombination was studied in the yeast Sacch. cerevisiae. Hypersensitivity to UV irradiation was detected in the diploids uvs2 uvs2 xrs xrs in comparision with the corresponding control. The diploid uvs1 uvs1 uvs2 uvs2 does not differ in UV sensitivity from the diploid uvs1 uvs1 UVS2 UVS2. These facts demonstrate that the uvs1 and uvs2 mutations, on the one hand, and the xrs mutations, on the other, normally control different pathways of elimination of UV-induced damages. It was shown that the diploid uvs2 uvs2 xrs3 xrs3 is far more sensitive to the lethal action of x rays than the control diploid UVS2 UVS2 xrs3 xrs3. Consequently, the mutations uvs2 and xrs3 block different modes of repair of damages induced by ionizing radiation. In all the double-mutant diploids, the frequency of mitotic recombination induced by UV rays increases sharply in comparison with that of the radioresistant diploids UVS UVS XRS XRS and the UV-sensitive diploids uvs2 uvs2 XRS XRS. Possible causes of the observed phenomenon are discussed. It was established that in a diploid homozygous for the loci uvs2 xrs5, the frequency of mitotic recombination induced by x rays increases extremely sharply. This fact confirms the hypothesis that the gene product of the locus uvs2 participates in the repair of DNA after the action of ionizing radiation. (author)

  12. The influence of calf thymus DNA and deoxyribonucleosides on the induction of different mutation types in Drosophila

    International Nuclear Information System (INIS)

    Ondrej, M.

    1975-01-01

    The influence of an exogenous DNA on the induction of mutations by X rays was compared with the influence of an equimolar mixture of four deoxyribonucleosides. Pre-treatment and post-treatment with the calf thymus DNA did not influence mutation frequency in the specific loci dp, b, cn and bw as well as Minute mutations induced in the Drosophila sperm by X radiation. Pre-treatment with the equimolar mixture of four deoxyribonucleosides increased the frequency of the Minutes but did not affect mutation frequency in the loci dp, b, cn, bw. The equimolar mixture of nucleosides alone induced a low frequency of Minute mutations in the Drosophila sperm. DNA alone induced a low frequency of recessive lethals. These lethals arose as mosaics of small sectors of the gonads of the F 1 females and were revealed as late as in the F 3 generation. (author)

  13. Mutations in Splicing Factor Genes Are a Major Cause of Autosomal Dominant Retinitis Pigmentosa in Belgian Families

    Science.gov (United States)

    Coppieters, Frauke; Roels, Dimitri; De Jaegere, Sarah; Flipts, Helena; De Zaeytijd, Julie; Walraedt, Sophie; Claes, Charlotte; Fransen, Erik; Van Camp, Guy; Depasse, Fanny; Casteels, Ingele; de Ravel, Thomy

    2017-01-01

    Purpose Autosomal dominant retinitis pigmentosa (adRP) is characterized by an extensive genetic heterogeneity, implicating 27 genes, which account for 50 to 70% of cases. Here 86 Belgian probands with possible adRP underwent genetic testing to unravel the molecular basis and to assess the contribution of the genes underlying their condition. Methods Mutation detection methods evolved over the past ten years, including mutation specific methods (APEX chip analysis), linkage analysis, gene panel analysis (Sanger sequencing, targeted next-generation sequencing or whole exome sequencing), high-resolution copy number screening (customized microarray-based comparative genomic hybridization). Identified variants were classified following American College of Medical Genetics and Genomics (ACMG) recommendations. Results Molecular genetic screening revealed mutations in 48/86 cases (56%). In total, 17 novel pathogenic mutations were identified: four missense mutations in RHO, five frameshift mutations in RP1, six mutations in genes encoding spliceosome components (SNRNP200, PRPF8, and PRPF31), one frameshift mutation in PRPH2, and one frameshift mutation in TOPORS. The proportion of RHO mutations in our cohort (14%) is higher than reported in a French adRP population (10.3%), but lower than reported elsewhere (16.5–30%). The prevalence of RP1 mutations (10.5%) is comparable to other populations (3.5%-10%). The mutation frequency in genes encoding splicing factors is unexpectedly high (altogether 19.8%), with PRPF31 the second most prevalent mutated gene (10.5%). PRPH2 mutations were found in 4.7% of the Belgian cohort. Two families (2.3%) have the recurrent NR2E3 mutation p.(Gly56Arg). The prevalence of the recurrent PROM1 mutation p.(Arg373Cys) was higher than anticipated (3.5%). Conclusions Overall, we identified mutations in 48 of 86 Belgian adRP cases (56%), with the highest prevalence in RHO (14%), RP1 (10.5%) and PRPF31 (10.5%). Finally, we expanded the molecular

  14. Mitochondrial mutations in subjects with psychiatric disorders.

    Directory of Open Access Journals (Sweden)

    Adolfo Sequeira

    Full Text Available A considerable body of evidence supports the role of mitochondrial dysfunction in psychiatric disorders and mitochondrial DNA (mtDNA mutations are known to alter brain energy metabolism, neurotransmission, and cause neurodegenerative disorders. Genetic studies focusing on common nuclear genome variants associated with these disorders have produced genome wide significant results but those studies have not directly studied mtDNA variants. The purpose of this study is to investigate, using next generation sequencing, the involvement of mtDNA variation in bipolar disorder, schizophrenia, major depressive disorder, and methamphetamine use. MtDNA extracted from multiple brain regions and blood were sequenced (121 mtDNA samples with an average of 8,800x coverage and compared to an electronic database containing 26,850 mtDNA genomes. We confirmed novel and rare variants, and confirmed next generation sequencing error hotspots by traditional sequencing and genotyping methods. We observed a significant increase of non-synonymous mutations found in individuals with schizophrenia. Novel and rare non-synonymous mutations were found in psychiatric cases in mtDNA genes: ND6, ATP6, CYTB, and ND2. We also observed mtDNA heteroplasmy in brain at a locus previously associated with schizophrenia (T16519C. Large differences in heteroplasmy levels across brain regions within subjects suggest that somatic mutations accumulate differentially in brain regions. Finally, multiplasmy, a heteroplasmic measure of repeat length, was observed in brain from selective cases at a higher frequency than controls. These results offer support for increased rates of mtDNA substitutions in schizophrenia shown in our prior results. The variable levels of heteroplasmic/multiplasmic somatic mutations that occur in brain may be indicators of genetic instability in mtDNA.

  15. Mutation spectrum produced on PBR322 by 8-Methoxypsoralen plus UV-A light. Localizacion puntual de mutaciones producidas en PBR322 por tratamiento con 8-metoxipsoraleno mas luz ultravioleta-A

    Energy Technology Data Exchange (ETDEWEB)

    Bauluz, C.; Vidania, R.

    1990-01-01

    The mutagenic effect of 8-MOP+UVA (PUVA treatment) on pBR322 has been analysed by determining the frequency of mutation in the tet gene and identifying the type and position of the mutations produced inside a 276 pb-fragment (Bam-H1-SalI) of the same gene. pBR322 DNA was irradiated with UVA light in the presence of increasing concentrations of 8-Methoxypsoralen (8-MOP). The number of psoralen adducts formed in pBR322 upon that treatment ranged from 0 to 10.7 adducts per plasmid molecule. Modified DNA samples were used to transform several strains of E. Coli (differing in their repair capacities), both in constitutive conditions and after sos pre-induction by 254 nm-irradiation of cells. Mutation frequencies in the tet gene showed to increase in the wild type and uvrA strains along with the number of psoralen adduts per plasmid molecule; higher mutation frequencies were found in cells that had been previously irradiated to induce the SOS expression. Mutant plasmids were isolated from ApRTcS colonies and sequenced by the method of Maxam and Gilbert. Mutations appeared to be unique in most of the cases and were always punctual, i.e. affecting only to one base pair. The relative positions of the mutations showed a high frequency of coincidence among the sequenced fragments, indicating the existence of several DNA regions with high probability to mutated ([sup h]ot spots[sup )]. (author)

  16. Mutation spectrum produced on PBR322 by 8-Methoxypsoralen plus UV-A light; Localizacion puntual de mutaciones producidas en PBR322 por tratamiento con 8-metoxipsoraleno mas luz ultravioleta-A

    Energy Technology Data Exchange (ETDEWEB)

    Bauluz, C.; Vidania, R.

    1990-12-31

    The mutagenic effect of 8-MOP+UVA (PUVA treatment) on pBR322 has been analysed by determining the frequency of mutation in the tet gene and identifying the type and position of the mutations produced inside a 276 pb-fragment (Bam-H1-SalI) of the same gene. pBR322 DNA was irradiated with UVA light in the presence of increasing concentrations of 8-Methoxypsoralen (8-MOP). The number of psoralen adducts formed in pBR322 upon that treatment ranged from 0 to 10.7 adducts per plasmid molecule. Modified DNA samples were used to transform several strains of E. Coli (differing in their repair capacities), both in constitutive conditions and after sos pre-induction by 254 nm-irradiation of cells. Mutation frequencies in the tet gene showed to increase in the wild type and uvrA strains along with the number of psoralen adduts per plasmid molecule; higher mutation frequencies were found in cells that had been previously irradiated to induce the SOS expression. Mutant plasmids were isolated from ApRTcS colonies and sequenced by the method of Maxam and Gilbert. Mutations appeared to be unique in most of the cases and were always punctual, i.e. affecting only to one base pair. The relative positions of the mutations showed a high frequency of coincidence among the sequenced fragments, indicating the existence of several DNA regions with high probability to mutated ({sup h}ot spots{sup )}. (author)

  17. Mutation, somatic mutation and diseases of man

    International Nuclear Information System (INIS)

    Burnet, F.M.

    1976-01-01

    The relevance of the intrinsic mutagenesis for the evolution process, genetic diseases and the process of aging is exemplified. The fundamental reaction is the function of the DNA and the DNA-enzymes like the DNA-polymerases in replication, repair, and transcription. These defects are responsible for the mutation frequency and the genetic drift in the evolution process. They cause genetic diseases like Xeroderma pigmentosum which is described here in detail. The accumulation of structural and functional mistakes leads to diseases of old age, for example to autoimmune diseases and immune suppression. There is a proportionality between the duration of life and the frequency of mistakes in the enzymatic repair system. No possibility of prophylaxis or therapy is seen. Methods for prognosis could be developed. (AJ) [de

  18. Mutation breeding in soybean

    International Nuclear Information System (INIS)

    Baradjanegara, A.A.

    1983-01-01

    In Indonesia, soybean is one of the important crop after rice. It is generally cultivated in the lowlands and rarely in the highlands. Seeds of soybean variety ORBA were treated with various doses of fast neutrons, gamma rays, EMS and NaN 3 with the aims of studying the mutagen effects in M-1 and M-2 generations and also to select mutants adapted to highland conditions. D-50 doses for gamma rays, fast neutrons and EMS were around 23 krad, 2,300 rad, 0.3%, respectively. Much higher chlorophyll mutation frequency was observed in EMS treatment of 0.3%. Seven mutants were shorter and four early mutants matured from 4 to 20 days earlier than the control plants. Two early mutants were quite adaptable in both the low and highlands and produced better yields than the parental material. (author)

  19. Extended Opacity Tables with Higher Temperature-Density-Frequency Resolution

    Science.gov (United States)

    Schillaci, Mark; Orban, Chris; Delahaye, Franck; Pinsonneault, Marc; Nahar, Sultana; Pradhan, Anil

    2015-05-01

    Theoretical models for plasma opacities underpin our understanding of radiation transport in many different astrophysical objects. These opacity models are also relevant to HEDP experiments such as ignition scale experiments on NIF. We present a significantly expanded set of opacity data from the widely utilized Opacity Project, and make these higher resolution data publicly available through OSU's portal with dropbox.com. This expanded data set is used to assess how accurate the interpolation of opacity data in temperature-density-frequency dimensions must be in order to adequately model the properties of most stellar types. These efforts are the beginning of a larger project to improve the theoretical opacity models in light of experimental results at the Sandia Z-pinch showing that the measured opacity of Iron disagrees strongly with all current models.

  20. FAMILY ANAMNESIS OF CHILDREN WITH MUTATION OF THE INHERITED HEMOCHROMATOSIS

    Directory of Open Access Journals (Sweden)

    S.I. Polyakova

    2010-01-01

    Full Text Available The inherited burdened is studied on diseases, associated with an overload iron in 41 children with frequent mutations of the inherited hemochromatosis (IG of a 1 type (C282y, H63d, S65c. Control group was made by 27 children with undiscovered frequent mutations of NG. Frequencies of iron-associated diseases are compared for 560 members of families which have children with mutations of IG and 390 members of families which have children without IG mutations. Some features of medical-genealogical anamnesis, which can be conditioned of siderosis, are exposed, and indirectly specify in the presence of mutations in the gene of HFE. So, the high frequency of oncologic diseases, diabetes mellitus, hepatocirrhosis and deaths of relatives under the age of 50 years are the foundation for research of exchange of iron and holding of molecular-genetic research of the inherited hemochromatosis. Key words: inherited hemochromatosis, heredity, children. (Pediatric Pharmacology. – 2010; 7(3:52-56

  1. Studies on mutation breeding in mulberry (Morus spp.)

    International Nuclear Information System (INIS)

    Fujita, H.; Wada, M.

    1982-01-01

    Re-irradiation of induced mulberry mutants with gamma rays has proved to give higher mutation frequencies and a wider mutation spectrum than when the original cultivars were irradiated. A comparison between chronic and acute re-irradiation was made, using a special cutting-back technique. Mutation frequencies of the shoots that developed from the sub-lateral shoot in chronic irradiation were lower than in acute irradiation. The five-lobed cultivar Ichinose raised an entire-leaved mutant, IRB240-1, by gamma rays, which showed reversion in leaf shape, from entire to lobed, by re-treatment of the mutant with gamma rays. The mutant and original cultivar were crossed with an entire-leaved cultivar Shiromekeiso. As a result of these crosses, the three mutants are supposed to be not of genic origin concerning leaf shape. A drop of conidia suspension was placed on a scratched surface of the irradiated shoots to select resistant mutants to die-back disease. Two resistant strains were selected by means of inoculation of conidia. It is considered that inoculation of solution using a vaccination apparatus was most efficient and reliable for selecting resistant mutants. Thirteen mutants and three strains were tested for the rooting ability of semi-softwood cuttings. Some mutant strains did not show any disability of rooting initiation of the shoot. Useful mutants which show high rooting ability can be selected by gamma irradiation. To detect the change in fine structure of mulberry a scanning electron microscope was used. The mutants not only varied in visible character from the original, but also in invisible changes, such as trichome, idioblast, etc

  2. The association of JAK2V617F mutation and leukocytosis with thrombotic events in essential thrombocythemia.

    Science.gov (United States)

    Hsiao, Hui-Hua; Yang, Ming-Yu; Liu, Yi-Chang; Lee, Ching-Ping; Yang, Wen-Chi; Liu, Ta-Chih; Chang, Chao-Sung; Lin, Sheng-Fung

    2007-11-01

    The Janus kinase 2 mutation, JAK2 (V617F), and megakaryocytic mutations, MPL (W515L/K), have been identified and correlated with a subtype of essential thrombocythemia (ET) patients. We investigated the frequency of mutations in ET patients and analyzed the relationship with their clinical features. Fifty-three ET patients were enrolled in the study. The amplification refractory mutation system was applied for the mutation survey of the JAK2V617F, while the polymerase chain reaction with sequencing was used for the mutation survey of MPLW515L/K. Thirty-five (66%) patients harboring the JAK2 (V617F) mutation, including 3 homozygous and 32 heterozygous changes, but no MPLW515L/K mutation, were found. During follow-up, 17 (32.1%) patients suffered from documented thrombotic events, with 15 having JAK2V617F mutations. Statistical analysis showed that patients with the JAK2 mutation had significantly higher leukocytes, hemoglobin level, and thrombotic event (p = 0.043, p = 0.001, and p = 0.029, respectively). Thrombotic events were also significantly correlated with leukocytosis and older age. The JAK2V617F mutation was noted in a certain population of ET patients and correlated with leukocytosis, high hemoglobin level, and thrombosis. Therefore, detection of the JAK2V617F mutation can affect not only the diagnosis, but also the management of ET patients.

  3. Radiation in relation to mutation rate, mutational damage and human ill-health

    International Nuclear Information System (INIS)

    Roberts, P.B.

    1976-09-01

    The effect of radiation in increasing the frequency of gene mutations is now reasonably understood. We discuss first how an increase in the mutation rate is reflected in the mutational damage expressed in populations. It is shown that the mutational damage, assessed by the loss of fitness in a population or the number of eventual gene extinctions, is equal to the number of new mutations arising per generation or the mutation rate. In a population of stable size, a dose of 1 rem given to 10 6 people leads to roughly 600 gene extinctions when summed over all ensuing generations if the dose is applied to only one generation; this number of extinctions will occur in each succeeding generation if the dose is given to every generation. However, the concept of genetic extinction, although quantifiable, is of limited value in assessing radiation risks since its impact on human ill-health is very speculative. In particular, no estimate can be made of the total cost of effects which are minor in each individual in which they arise, but which, because they are so minor, persist in the population for many generations. The best current estimate is for 14-140 obvious defects in the first few generations following exposure of 10 6 people to a dose of 1 rem. (auth.)

  4. Effects of chronic low level radiation in the population residing in the high level natural radiation area in Kerala, India: employing heritable DNA mutation studies.

    Science.gov (United States)

    Ahmad, Shazia; Koya, P K M; Seshadri, M

    2013-03-18

    To study the effect of chronic low level radiation, 4040 meiosis were screened at eight microsatellite and five minisatellite (2485 and 1555 meiosis respectively) marker loci in people residing in high and normal level natural radiation areas of Kerala. Variants in the repeat length of allele were considered as mutants. Mutation rates (expressed as the number of mutations observed in the total number of meiosis) were 6.4×10(-3) (16/2485) and 2.6×10(-3) (4/1555) at microsatellite and minisatellite respectively. The germline microsatellite mutation frequency of father was 1.78 times higher at 7.52×10(-3) (8/1064) compared to 4.22×10(-3) (6/1421) of mother (P=0.292, Fisher's Exact two-sided test). The paternal and maternal mutation rates at minisatellite loci were more or less similar at 2.78×10(-3) (2/719) and 2.39×10(-3) (2/836), respectively (P=1.0, Fisher's Exact two-sided test). Higher but statistically non-significant microsatellite mutation frequency was observed in HLNRA compared to NLNRA (7.25×10(-3) vs 3.64×10(-3); P=0.547). The apparent increase in the mutation rate of microsatellite loci with the increase in radiation dose was also not statistically significant. All the four minisatellite mutation observed were from HLNRA (1198 meiosis) and no mutation was observed among 357 meiosis screened from NLNRA families. All the markers used in the present study were in the non-coding region and hence mutations in these regions may not cause adverse health effects, but the study is important in understanding the effect of chronic low level radiation. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. P53, K-RAS, β-CATENIN, C-KIT and BAK mutations in the lung cancer of Chinese and Japanese patients

    International Nuclear Information System (INIS)

    Shuo Xing; Nobotoshi Nawa; Kazuhiro Tanabe; Tadashi Hongyo; Li- Ya Li; Jing-Tian Tang; Mitsunori Ohta

    2005-01-01

    Seventeen Chinese (Beijing) and 24 Japanese (Osaka) lung cancer cases were analyzed for mutations of p53, K-ras, β-catenin, c-kit and bak genes by PCR-SSCP analysis followed by direct sequencing. Significantly higher mutation frequency of p53 gene, one of key genes for radiation sensitivity, was found in Chinese cases (11/17; 64.7 %) than Japanese cases (8/24; 33.3 %) (p< O.O5). Fourteen of the 16 mutations found in the Chinese cases were transitions at exon 4,5 and intron 4. In the Japanese cases, of the total of 11 mutations, 5 were transitions and 5 were transversions and one was deletion. Six β-catenin mutations were found in 6 Chinese cases (35.3 % ) at codon 53 and 58, and 4 were found in 3 Japanese cases (12.5 %). C-kit mutations were detected in 5 Chinese cases (29.4 %), while no mutations were found in Japanese cases (p< O.O5). No K-ras mutation was found in both Chinese and Japanese cases. For the first time, we report on bak mutation in human lung cancer in Chinese (2/17; 11.8% ) and Japanese cases (2/24; 8.3% ). C-kit and bak genes are also definitive factors to radiosensitivity. These data thus suggest that there were apparent differences in frequency and/or mutational types of p53, β-catenin and c-kit? genes between Chinese and Japanese cases. The differences can be attributed to factors such as lifestyles including smoking and racial and/or environmental factors, and also to the prediction of the response to radiotherapy. (author)

  6. Prevalence of common MEFV mutations and carrier frequencies in a ...

    Indian Academy of Sciences (India)

    Christian Oberkanins, oberkanins@viennalab.com. 1967; Pras et al. ... affected populations with spreading very diverse mutational patterns, especially ..... Arabs, mainly living in Syria, Lebanon, Palestine, Jordan and Iraq, and North .... Mediterranean fever suspected patients and gender correlation: a retrospective study.

  7. High frequency of potentially pathogenic SORL1 mutations in autosomal dominant early-onset Alzheimer disease.

    Science.gov (United States)

    Pottier, C; Hannequin, D; Coutant, S; Rovelet-Lecrux, A; Wallon, D; Rousseau, S; Legallic, S; Paquet, C; Bombois, S; Pariente, J; Thomas-Anterion, C; Michon, A; Croisile, B; Etcharry-Bouyx, F; Berr, C; Dartigues, J-F; Amouyel, P; Dauchel, H; Boutoleau-Bretonnière, C; Thauvin, C; Frebourg, T; Lambert, J-C; Campion, D

    2012-09-01

    Performing exome sequencing in 14 autosomal dominant early-onset Alzheimer disease (ADEOAD) index cases without mutation on known genes (amyloid precursor protein (APP), presenilin1 (PSEN1) and presenilin2 (PSEN2)), we found that in five patients, the SORL1 gene harbored unknown nonsense (n=1) or missense (n=4) mutations. These mutations were not retrieved in 1500 controls of same ethnic origin. In a replication sample, including 15 ADEOAD cases, 2 unknown non-synonymous mutations (1 missense, 1 nonsense) were retrieved, thus yielding to a total of 7/29 unknown mutations in the combined sample. Using in silico predictions, we conclude that these seven private mutations are likely to have a pathogenic effect. SORL1 encodes the Sortilin-related receptor LR11/SorLA, a protein involved in the control of amyloid beta peptide production. Our results suggest that besides the involvement of the APP and PSEN genes, further genetic heterogeneity, involving another gene of the same pathway is present in ADEOAD.

  8. Bulk Genotyping of Biopsies Can Create Spurious Evidence for Hetereogeneity in Mutation Content.

    Directory of Open Access Journals (Sweden)

    Rumen Kostadinov

    2016-04-01

    Full Text Available When multiple samples are taken from the neoplastic tissues of a single patient, it is natural to compare their mutation content. This is often done by bulk genotyping of whole biopsies, but the chance that a mutation will be detected in bulk genotyping depends on its local frequency in the sample. When the underlying mutation count per cell is equal, homogenous biopsies will have more high-frequency mutations, and thus more detectable mutations, than heterogeneous ones. Using simulations, we show that bulk genotyping of data simulated under a neutral model of somatic evolution generates strong spurious evidence for non-neutrality, because the pattern of tissue growth systematically generates differences in biopsy heterogeneity. Any experiment which compares mutation content across bulk-genotyped biopsies may therefore suggest mutation rate or selection intensity variation even when these forces are absent. We discuss computational and experimental approaches for resolving this problem.

  9. Bulk Genotyping of Biopsies Can Create Spurious Evidence for Hetereogeneity in Mutation Content.

    Science.gov (United States)

    Kostadinov, Rumen; Maley, Carlo C; Kuhner, Mary K

    2016-04-01

    When multiple samples are taken from the neoplastic tissues of a single patient, it is natural to compare their mutation content. This is often done by bulk genotyping of whole biopsies, but the chance that a mutation will be detected in bulk genotyping depends on its local frequency in the sample. When the underlying mutation count per cell is equal, homogenous biopsies will have more high-frequency mutations, and thus more detectable mutations, than heterogeneous ones. Using simulations, we show that bulk genotyping of data simulated under a neutral model of somatic evolution generates strong spurious evidence for non-neutrality, because the pattern of tissue growth systematically generates differences in biopsy heterogeneity. Any experiment which compares mutation content across bulk-genotyped biopsies may therefore suggest mutation rate or selection intensity variation even when these forces are absent. We discuss computational and experimental approaches for resolving this problem.

  10. Contribution of TARDBP mutations to sporadic amyotrophic lateral sclerosis.

    Science.gov (United States)

    Daoud, H; Valdmanis, P N; Kabashi, E; Dion, P; Dupré, N; Camu, W; Meininger, V; Rouleau, G A

    2009-02-01

    Mutations in the TARDBP gene, which encodes the TAR DNA binding protein (TDP-43), have been described in individuals with familial and sporadic amyotrophic lateral sclerosis (ALS). We screened the TARDBP gene in 285 French sporadic ALS patients to assess the frequency of TARDBP mutations in ALS. Six individuals had potentially deleterious mutations of which three were novel including a Y374X truncating mutation and P363A and A382P missense mutations. This suggests that TARDBP mutations may predispose to ALS in approximately 2% of the individuals followed in this study. Our findings, combined with those from other collections, brings the total number of mutations in unrelated ALS patients to 17, further suggesting that mutations in the TARDBP gene have an important role in the pathogenesis of ALS.

  11. The mutation frequency of 8-oxo-7,8 dihydroguanine (8-oxoG) situated in a multiply damaged site: comparison of a single and two closely opposed 8-oxodG in Escherichia coli

    International Nuclear Information System (INIS)

    Malyarchuk, S.G.; Youngblood, R.C.; Landry, A.M.; Quillin, E.; Harrison, L.

    2003-01-01

    Full text: A multiply damaged site (MDS) is defined as >= two lesions within a distance of 10-15 base pairs (bp). MDS generated by ionizing radiation contains oxidative base damage, and in vitro studies have indicated that if the base damage is less than 3 bp apart, repair of one lesion is inhibited until repair of the lesion in the opposite strand is completed. Inhibition of repair could result in an increase in the mutation frequency of the base damage. We have designed an assay to determine whether a closely opposed lesion causes an increase in adenine insertion opposite an 8-oxodG in bacteria. The double-stranded oligonucleotides (with no damage, each single 8-oxodG or the MDS) were ligated into the firefly luciferase coding region of a reporter vector and transformed into wild type or MutY-deficient bacteria. The MDS contained an 8-oxodG in the transcribed strand (T) and a second 8-oxodG immediately 5' to this lesion in the non-transcribed strand (NT). During two rounds of replication, insertion of adenine opposite the 8-oxodG in the T or NT strand results in a translation termination codon at position 444 or 445, respectively. In wild-type bacteria, we detected a translation stop at a frequency of 0.15% (codon 444) and 0.09% (codon 445) with a single 8-oxodG in the T or NT strand, respectively. This was enhanced ∼3 fold when single lesions were replicated in MutY-deficient bacteria. Positioning an 8-oxodG in the T strand within the MDS enhanced the mutation frequency by ∼2 fold in wild-type bacteria and 8 fold in Mut Y-deficient bacteria, while the mutation frequency of the 8-oxodG in the NT strand increased by 6 fold in Mut Y-deficient bacteria. This enhancement of mutation frequency supports the in vitro MDS studies, which demonstrated the inability of base excision repair to completely repair closely opposed lesions

  12. Population carrier rates of pathogenic ARSA gene mutations: is metachromatic leukodystrophy underdiagnosed?

    Directory of Open Access Journals (Sweden)

    Agnieszka Ługowska

    Full Text Available BACKGROUND: Metachromatic leukodystrophy (MLD is a severe neurometabolic disease caused mainly by deficiency of arylsulfatase A encoded by the ARSA gene. Based on epidemiological surveys the incidence of MLD per 100,000 live births varied from 0.6 to 2.5. Our purpose was to estimate the birth prevalence of MLD in Poland by determining population frequency of the common pathogenic ARSA gene mutations and to compare this estimate with epidemiological data. METHODOLOGY: We studied two independently ascertained cohorts from the Polish background population (N∼3000 each and determined carrier rates of common ARSA gene mutations: c.459+1G>A, p.P426L, p.I179S (cohort 1 and c.459+1G>A, p.I179S (cohort 2. PRINCIPAL FINDINGS: Taking into account ARSA gene mutation distribution among 60 Polish patients, the expected MLD birth prevalence in the general population (assuming no selection against homozygous fetuses was estimated as 4.0/100,000 and 4.1/100,000, respectively for the 1(st and the 2(nd cohort with a pooled estimate of 4.1/100,000 (CI: 1.8-9.4 which was higher than the estimate of 0.38 per 100,000 live births based on diagnosed cases. The p.I179S mutation was relatively more prevalent among controls than patients (OR = 3.6, P = 0.0082, for a comparison of p.I179S frequency relative to c.459+1G>A between controls vs. patients. CONCLUSIONS/SIGNIFICANCE: The observed discrepancy between the measured incidence of metachromatic leukodystrophy and the predicted carriage rates suggests that MLD is substantially underdiagnosed in the Polish population. The underdiagnosis rate may be particularly high among patients with p.I179S mutation whose disease is characterized mainly by psychotic symptoms.

  13. Age and sex effects on human mutation rates. An old problem with new complexities

    International Nuclear Information System (INIS)

    Crow, James F.

    2006-01-01

    Base substitution mutations are far more common in human males than in females, and the frequency increases with paternal age. Both can be accounted for by the greater number of pre-meiotic cell divisions in males, especially old ones. In contrast, small deletions do not show any important age effect and occur with approximately equal frequency in the two sexes. Mutations in most genes include both types, and the sex and paternal age effect depends on the proportion of the two types. A few traits, of which Apert Syndrome is best understood, are mutation hot spots with all the mutations occurring in one or two codons, usually at one nucleotide. They occur with very high frequency almost exclusively in males and the frequency increases rapidly with paternal age. It has been suggested that the mutant cells have a selective advantage in the male germ-line prior to meiosis. Evidence for this surprising, but important, hypothesis is discussed. A possible mechanism is the conversion of asymmetrical stem-cell divisions into symmetric ones. Some traits with complex etiology show a slight paternal age effect. There is also a short discussion of the high deleterious mutation rate and the role of sexual reproduction in reducing the consequent mutation load. (author)

  14. Lack of mutational hot spots during decitabine-mediated HIV-1 mutagenesis.

    Science.gov (United States)

    Rawson, Jonathan M O; Landman, Sean R; Reilly, Cavan S; Bonnac, Laurent; Patterson, Steven E; Mansky, Louis M

    2015-11-01

    Decitabine has previously been shown to induce lethal mutagenesis of human immunodeficiency virus type 1 (HIV-1). However, the factors that determine the susceptibilities of individual sequence positions in HIV-1 to decitabine have not yet been defined. To investigate this, we performed Illumina high-throughput sequencing of multiple amplicons prepared from proviral DNA that was recovered from decitabine-treated cells infected with HIV-1. We found that decitabine induced an ≈4.1-fold increase in the total mutation frequency of HIV-1, primarily due to a striking ≈155-fold increase in the G-to-C transversion frequency. Intriguingly, decitabine also led to an ≈29-fold increase in the C-to-G transversion frequency. G-to-C frequencies varied substantially (up to ≈80-fold) depending upon sequence position, but surprisingly, mutational hot spots (defined as upper outliers within the mutation frequency distribution) were not observed. We further found that every single guanine position examined was significantly susceptible to the mutagenic effects of decitabine. Taken together, these observations demonstrate for the first time that decitabine-mediated HIV-1 mutagenesis is promiscuous and occurs in the absence of a clear bias for mutational hot spots. These data imply that decitabine-mediated G-to-C mutagenesis is a highly effective antiviral mechanism for extinguishing HIV-1 infectivity. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  15. Genetic and molecular analyses of UV radiation-induced mutations in the fem-3 gene of Caenorhabditis elegans

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, P S; De Wilde, D; Dwarakanath, V N [Texas Christian Univ., Fort Worth, TX (United States). Dept. of Biology

    1995-06-01

    The utility of a new target gene (fem-3) is described for investigating the molecular nature of mutagenesis in the nematode Caenorhabditis elegans. As a principal attribute, this system allows for the selection, maintenance and molecular analysis of any type of mutation that disrupts the gene, including deletions. In this study, 86 mutant strains were isolated, of which 79 proved to have mutations in fem-3. Twenty of these originally tested as homozygous inviable. Homozygous inviability was expected, as Stewart and coworkers had previously observed that, unlike in other organisms, most UV radiation-induced mutations in C. elegans are chromosomal rearrangements of deficiencies (Mutat. Res 249, 37-54, 1991). However, additional data, including Southern blot analyses on 49 of the strains, indicated that most of the UV radiation-induced fem-3 mutations were not deficiencies, as originally inferred from their homozygous inviability. Instead, the lethals were most likely ``coincident mutations`` in linked, essential genes that were concomitantly induced. As such, they were lost owing to genetic recombination during stock maintenance. As in mammalian cells, yeast and bacteria, the frequency of coincident mutations was much higher than would be predicted by chance. (Author).

  16. New parkin mutations and atypical phenotypes in families with autosomal recessive parkinsonism.

    NARCIS (Netherlands)

    Rawal, N.; Periquet, M.; Lohmann, E.; Lucking, C.B.; Teive, H.; Ambrosio, G.; Raskin, S.; Lincoln, S.; Hattori, N.; Guimaraes, J.; Horstink, M.W.I.M.; Santos Bele, W. Dos; Brousolle, E.; Destee, A.; Mizuno, Y.; Farrer, M.; Deleuze, J.F.; Michele, G. de; Agid, Y.; Durr, A.; Brice, A.

    2003-01-01

    The frequency of parkin mutations was evaluated in 30 families of highly diverse geographic origin with early-onset autosomal recessive parkinsonism. Twelve different mutations, six of which were new, were found in 10 families from Europe and Brazil. Patients with parkin mutations had significantly

  17. Effect of hsm mutations enhancing spontaneous mutability on induced mutagenesis and mitotic recombination in Saccharomyces cerevisiae yeast

    International Nuclear Information System (INIS)

    Fedorova, I.V.; Koval'tsova, S.V.; Ivanov, E.L.

    1993-01-01

    The authors have studied the effect of five nonallelic hms1-hms5 mutations on the incidence of direct mutations in loci ADE1 and ADE2, induced by UV-radiation, 6-hydroxyl-aminopurine, and nitrosomethylurea. All hms mutants were found to be insensitive to the lethal action of these mutagens. The frequency of UV-induced mutations to adenine dependence was increased in mutants hsm2-1, hsm3-1, hsm5-1, and particularly in hsm1-1, but remained unchanged in hsm4-1 compared to HSM. Mutagenesis induced by 6-hydroxylaminopurine was increased in all mutants studied, particularly in mutant hsm3-1. The authors did not detect any appreciable effect of hsm mutations on mutagenesis induced by nitrosomethylurea. The frequency of spontaneous mitotic conversion to prototrophy was studied in diploids heteroallelic to gene ADE2 and homo- and heterozygous for hsm mutations. Mutation hsm5-1 considerably increased the frequency of conversion for all heteroalleles studied, mutations hsm1-1 and hsm3-1 also considerably increased the conversion frequency, while mutations hsm1-1 and hsm4-1 had little effect on this process. The study of the properties of hsm mutations revealed joint genetic control of spontaneous and induced mutagenesis and recombination in yeast. The possibility that hsm mutations belong to the class of mutations impairing correction of unpaired DNA bases is discussed. 25 refs., 3 figs., 3 tabs

  18. Mutational effects of space flight on Zea mays seeds

    Science.gov (United States)

    Mei, M.; Qiu, Y.; He, Y.; Bucker, H.; Yang, C. H.

    1994-01-01

    The growth and development of more than 500 Zea mays seeds flown on Long Duration Exposure Facility (LDEF) were studied. Somatic mutations, including white-yellow stripes on leaves, dwarfing, change of leaf sheath color or seedling color were observed in plants developed from these seeds. When the frequency of white-yellow formation was used as the endpoint and compared with data from ground based studies, the dose to which maize seeds might be exposed during the flight was estimated to be equivalent to 635 cGy of gamma rays. Seeds from one particular holder gave a high mutation frequency and a wide mutation spectrum. White-yellow stripes on leaves were also found in some of the inbred progenies from plants displayed somatic mutation. Electron microscopy studies showed that the damage of chloroplast development in the white-yellow stripe on leaves was similar between seeds flown on LDEF and that irradiated by accelerated heavy ions on ground.

  19. Mutation induction by gamma irradiation in a triploid banana Pisang Berangan

    International Nuclear Information System (INIS)

    Mak, C.; Liew, K.W.

    1995-01-01

    Shoot-tip meristems of triploid banana Pisang Berangan (Intan cultivar) were irradiated at 0, 25, 35, 45 and 60 Gy in gamma cell with a Co-60 source. The explants were in-vitro multiplied to produce M sub 1 V sub 4 plants. Increasing gamma doses caused a reduction of survival rates as well as the average number of buds or shoots produced per explant. On the basis of linear estimate of bud/shoot proliferation to gamma doses, the radiation dose that reduced the growth to 50% of the control treatment, i.e. LD sub 50 was about 38 Gy. Many phenotypic variants in growth, leaf deformation and changes in pigmentation and texture were observed in nursery plants. In addition, field-grown plants also produced various forms of bunch and fruit abnormality. Generally, mutagenic treatments resulted in a 4 to 6 fold increase in the frequency of variant plants. For number of weeks to harvest and plant height, the mean values of irradiated plants did not differ significantly from the control plants. However, mutation induction tended not only to increase the variability of these two quantitative traits but also showed a much higher frequency for plants having early fruiting or shorter plant stature. As in-vitro mutation induction could create genetic variability as well as many undesirable variants, it is highly desirable to integrate in-vitro mutation with a selection system that can screen for large mutagen treated populations

  20. Highly sensitive detection of ESR1 mutations in cell-free DNA from patients with metastatic breast cancer using molecular barcode sequencing.

    Science.gov (United States)

    Masunaga, Nanae; Kagara, Naofumi; Motooka, Daisuke; Nakamura, Shota; Miyake, Tomohiro; Tanei, Tomonori; Naoi, Yasuto; Shimoda, Masafumi; Shimazu, Kenzo; Kim, Seung Jin; Noguchi, Shinzaburo

    2018-01-01

    We aimed to develop a highly sensitive method to detect ESR1 mutations in cell-free DNA (cfDNA) using next-generation sequencing with molecular barcode (MB-NGS) targeting the hotspot segment (c.1600-1713). The sensitivity of MB-NGS was tested using serially diluted ESR1 mutant DNA and then cfDNA samples from 34 patients with metastatic breast cancer were analyzed with MB-NGS. The results of MB-NGS were validated in comparison with conventional NGS and droplet digital PCR (ddPCR). MB-NGS showed a higher sensitivity (0.1%) than NGS without barcode (1%) by reducing background errors. Of the cfDNA samples from 34 patients with metastatic breast cancer, NGS without barcode revealed seven mutations in six patients (17.6%) and MB-NGS revealed six additional mutations including three mutations not reported in the COSMIC database of breast cancer, resulting in total 13 ESR1 mutations in ten patients (29.4%). Regarding the three hotspot mutations, all the patients with mutations detected by MB-NGS had identical mutations detected by droplet digital PCR (ddPCR), and mutant allele frequency correlated very well between both (r = 0.850, p < 0.01). Moreover, all the patients without these mutations by MB-NGS were found to have no mutations by ddPCR. In conclusion, MB-NGS could successfully detect ESR1 mutations in cfDNA with a higher sensitivity of 0.1% than conventional NGS and was considered as clinically useful as ddPCR.

  1. Enhancement of hypermutation frequency in the chicken B cell line DT40 for efficient diversification of the antibody repertoire

    Energy Technology Data Exchange (ETDEWEB)

    Magari, Masaki; Kanehiro, Yuichi; Todo, Kagefumi; Ikeda, Mika; Kanayama, Naoki, E-mail: nkanayama@cc.okayama-u.ac.jp; Ohmori, Hitoshi

    2010-05-28

    Chicken B cell line DT40 continuously accumulates mutations in the immunoglobulin variable region (IgV) gene by gene conversion and point mutation, both of which are mediated by activation-induced cytidine deaminase (AID), thereby producing an antibody (Ab) library that is useful for screening monoclonal Abs (mAbs) in vitro. We previously generated an engineered DT40 line named DT40-SW, whose AID expression can be reversibly switched on or off, and developed an in vitro Ab generation system using DT40-SW cells. To efficiently create an Ab library with sufficient diversity, higher hypermutation frequency is advantageous. To this end, we generated a novel cell line DT40-SW{Delta}C, which conditionally expresses a C-terminus-truncated AID mutant lacking the nuclear export signal. The transcription level of the mutant AID gene in DT40-SW{Delta}C cells was similar to that of the wild-type gene in DT40-SW cells. However, the protein level of the truncated AID mutant was less than that of the wild type. The mutant protein was enriched in the nuclei of DT40-SW{Delta}C cells, although the protein might be highly susceptible to degradation. In DT40-SW{Delta}C cells, both gene conversion and point mutation occurred in the IgV gene with over threefold higher frequency than in DT40-SW cells, suggesting that a lower level of the mutant AID protein was sufficient to increase mutation frequency. Thus, DT40-SW{Delta}C cells may be useful for constructing Ab libraries for efficient screening of mAbs in vitro.

  2. HPRT gene locus mutation in peripheral blood lymphocytes induced by internal exposure to radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Jingyong, Zhao; Yongzhong, Xu; Tao, Zhao; Fengmei, Cui; Liuyi, Wang; Qinhua, Lao [Suzhou Univ., Suzhou (China). Radiation Medicine Department

    2001-07-01

    HPRT gene locus mutation in peripheral blood lymphocytes induced by internal exposure to radionuclides was performed and the relationships between mutation frequency and dose were studied. Rats were injected intravenously with radionuclides, the blood was sampled at different time after injection; HPRT gene locus mutation frequency (GMF) were examined by methods of multi-nucleus cell and Brdurd assay, working out the Dose-response function. GMF rose with the increase of dose and dose-rates and were clearly interrelated. The HPRT gene locus mutation is very sensitive to radiation and may be used as a biological dosimeter.

  3. Photoreactivation of conversion and de novo suppressor mutation in Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Bockrath, R C; Plamer, J E [Indiana Univ., Indianapolis (USA). Dept. of Microbiology

    1977-04-01

    Studies of mutagenesis and photoreactivation in various E.coli strains have shown that conversion mutation of a mutant containing an amber suppressor to one containing an ochre suppressor is sensitive to photoreactivation. Direct photoreactivation by photoreactivating light (PRL) after uv mutagenesis reduced mutation frequencies by a factor of about 2 for each minute of exposure during the first 5 to 8 min of exposure for cells with normal repair capacity. Conversion and potential de novo suppressor mutations were about equally sensitive. For conversion, the sensitivities to PRL were identical in the repair-normal and excisions-repair-deficient strains. For de novo suppressor mutation, the rate of mutation frequency reduction by PRL in the repair-deficient strain was about one-half that in the other strains. The results suggest that ultraviolet radiation produces both de novo suppressor mutation and conversion at the sup(E,B) locus by photoreversible pyrimidine dimers in the DNA. The causative dimers could be Thy()Cyt dimers in the transcribed strand or the non-transcribed strand, respectively.

  4. Mutation accumulation may be a minor force in shaping life history traits

    DEFF Research Database (Denmark)

    Dańko, Maciej Jan; Kozłowski, Jan; Vaupel, James Walton

    2012-01-01

    -strings to capture different age-specific mutational patterns. Each pattern represents a genotype and for each genotype we find the life history strategy that maximizes fitness. Genotypes compete with each other and are subject to selection and to new mutations over generations until equilibrium in gene......-frequencies is reached. The mutation-selection equilibrium provides information about mutational load and the differential effects of mutations on a life history trait--the optimal age at maturity. We find that mutations accumulate only at ages with negligible impact on fitness and that mutation accumulation has very...

  5. The spectrum of mutation produced by low dose radiation

    International Nuclear Information System (INIS)

    Morley, Alexander A.; Turner, David R.

    2004-01-01

    Inherited mutations are the basis of evolution and acquired mutations in humans are important in ageing, cancer and possibly various forms of tissue degeneration. Mutations are responsible for many of the long-term effects of radiation. However, sensitive direct detection of mutations in humans has been difficult. The aims of the project were to develop methods for the sensitive enumeration of mutations in DNA, to measure mutation frequencies in a wide variety of tissue types and to quantify the mutational effect of direct oxidative damage produced by radiation, at both high and low doses. The project was successful in developing a sensitive method which could detect mutations directly in the genetic material, DNA at a sensitivity of 1 mutated molecule in 1000000000 unmutated molecules. However a number of methodological problems had to be overcome and lack of ongoing funding made it impossible to fulfill all of the aims of the project

  6. [Observation and analysis on mutation of routine STR locus].

    Science.gov (United States)

    Li, Qiu-yang; Feng, Wei-jun; Yang, Qin-gen

    2005-05-01

    To observe and analyze the characteristic of mutation at STR locus. 27 mutant genes observed in 1211 paternity testing cases were checked by PAGE-silver stained and PowerPlex 16 System Kit and validated by sequencing. Mutant genes locate on 15 loci. The pattern of mutation was accord with stepwise mutation model. The mutation ratio of male-to-female was 8:1 and correlated to the age of father. Mutation rate is correlated to the geometric mean of the number of homogeneous repeats of locus. The higher the mean, the higher the mutation rate. These loci are not so appropriate for use in paternity testing.

  7. [Frequency of chromosome aberrations in residents of the Semipalatinsk Oblast].

    Science.gov (United States)

    Gubitskaia, E G; Akhmatullina, N B; Vsevolodov, E B; Bishnevskaia, S S; Sharipov, I K; Cherednichenko, O G

    1999-06-01

    Cytogenetic analysis of the population of the Beskaragai district of the Semipalatinsk oblast adjacent to the territory of the nuclear test site was conducted by means of an ecological genetic questionnaire and cytogenetic examination of metaphase chromosomes. An increase in the total mutation level in the region was observed. The frequency of chromosome aberrations among the population of the Beskaragai district (3.2%) was statistically significantly (about 1.5 times) higher than the background levels in the clear regions (from 1 to 2%). Furthermore, the frequency of aberrations in adolescents was comparable with that in the adults. The spectrum of chromosome aberrations pointed to a significant contribution of radiation component to the mutagenesis.

  8. BRCA2 Mutations in 154 Finnish Male Breast Cancer Patients

    Directory of Open Access Journals (Sweden)

    Kirsi Syrjäkoski

    2004-09-01

    Full Text Available The etiology and pathogenesis of male breast cancer (MBC are poorly known. This is due to the fact that the disease is rare, and large-scale genetic epidemiologic studies have been difficult to carry out. Here, we studied the frequency of eight recurrent Finnish BRCA2 founder mutations in a large cohort of 154 MBC patients (65% diagnosed in Finland from 1967 to 1996. Founder mutations were detected in 10 patients (6.5%, eight of whom carried the 9346(-2 A>G mutation. Two novel mutations (4075 delGT and 5808 del5 were discovered in a screening of the entire BRCA2 coding region in 34 samples. However, these mutations were not found in the rest of the 120 patients studied. Patients with positive family history of breast and/or ovarian cancer were often BRCA2 mutation carriers (44%, whereas those with no family history showed a low frequency of involvement (3.6%; P < .0001. Finally, we found only one Finnish MBC patient with 999 dell, the most common founder mutation in Finnish female breast cancer (FBC patients, and one that explains most of the hereditary FBC and MBC cases in Iceland. The variation in BRCA2 mutation spectrum between Finnish MBC patients and FBC patients in Finland and breast cancer patients in Iceland suggests that modifying genetic and environmental factors may significantly influence the penetrance of MBC and FBC in individuals carrying germline BRCA2 mutations in some populations.

  9. Mutation induction by ion beams in arabidopsis

    International Nuclear Information System (INIS)

    Tanaka, Atsushi

    1999-01-01

    An investigation was made on characteristics of ion beams for the biological effects and the induction of mutation using Arabidopsis plant as a model plant for the molecular genetics. Here, the characteristics of mutation at the molecular level as well as new mutants induced by ion beams were described. The ast and sep1 were obtained from the offspring of 1488 carbon ion-irradiated seeds respectively. The uvi1-uvi4 mutants were also induced from 1280 M 1 lines. Thus, ion beams can induce not only known mutants such as tt, gl and hy but also novel mutants with high frequency. Even in the tt phenotype, two new mutant loci other than known loci were found. In chrysanthemum, several kinds of single, complex or stripped flower-color mutants that have been never induced by γirradiation, indicating that ion beams could produce a variety of mutants with the same phenotype. In conclusion, ion beams for the mutation induction are characterized by 1) to induce mutants with high frequency, 2) to show broad mutation spectrum and 3) to produce novel mutants. For these reasons, chemical mutagens such as EMS and low LET ionizing radiation such as X-rays and γ-rays will predominantly induce many but small modifications or DNA damages on the DNA strands. As the result, several point mutations will be produced on the genome. On the contrary, ion beams as a high LET ionizing radiation will not cause so many but large and irreparable DNA damage locally, resulting in production of limited number of null mutation. (M.N.)

  10. Mutation induction by ion beams in arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Atsushi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1999-07-01

    An investigation was made on characteristics of ion beams for the biological effects and the induction of mutation using Arabidopsis plant as a model plant for the molecular genetics. Here, the characteristics of mutation at the molecular level as well as new mutants induced by ion beams were described. The ast and sep1 were obtained from the offspring of 1488 carbon ion-irradiated seeds respectively. The uvi1-uvi4 mutants were also induced from 1280 M{sub 1} lines. Thus, ion beams can induce not only known mutants such as tt, gl and hy but also novel mutants with high frequency. Even in the tt phenotype, two new mutant loci other than known loci were found. In chrysanthemum, several kinds of single, complex or stripped flower-color mutants that have been never induced by {gamma}irradiation, indicating that ion beams could produce a variety of mutants with the same phenotype. In conclusion, ion beams for the mutation induction are characterized by 1) to induce mutants with high frequency, 2) to show broad mutation spectrum and 3) to produce novel mutants. For these reasons, chemical mutagens such as EMS and low LET ionizing radiation such as X-rays and {gamma}-rays will predominantly induce many but small modifications or DNA damages on the DNA strands. As the result, several point mutations will be produced on the genome. On the contrary, ion beams as a high LET ionizing radiation will not cause so many but large and irreparable DNA damage locally, resulting in production of limited number of null mutation. (M.N.)

  11. Prevalence and evolution of low frequency HIV drug resistance mutations detected by ultra deep sequencing in patients experiencing first line antiretroviral therapy failure.

    Science.gov (United States)

    Vandenhende, Marie-Anne; Bellecave, Pantxika; Recordon-Pinson, Patricia; Reigadas, Sandrine; Bidet, Yannick; Bruyand, Mathias; Bonnet, Fabrice; Lazaro, Estibaliz; Neau, Didier; Fleury, Hervé; Dabis, François; Morlat, Philippe; Masquelier, Bernard

    2014-01-01

    Clinical relevance of low-frequency HIV-1 variants carrying drug resistance associated mutations (DRMs) is still unclear. We aimed to study the prevalence of low-frequency DRMs, detected by Ultra-Deep Sequencing (UDS) before antiretroviral therapy (ART) and at virological failure (VF), in HIV-1 infected patients experiencing VF on first-line ART. Twenty-nine ART-naive patients followed up in the ANRS-CO3 Aquitaine Cohort, having initiated ART between 2000 and 2009 and experiencing VF (2 plasma viral loads (VL) >500 copies/ml or one VL >1000 copies/ml) were included. Reverse transcriptase and protease DRMs were identified using Sanger sequencing (SS) and UDS at baseline (before ART initiation) and VF. Additional low-frequency variants with PI-, NNRTI- and NRTI-DRMs were found by UDS at baseline and VF, significantly increasing the number of detected DRMs by 1.35 fold (plow-frequency DRMs modified ARV susceptibility predictions to the prescribed treatment for 1 patient at baseline, in whom low-frequency DRM was found at high frequency at VF, and 6 patients at VF. DRMs found at VF were rarely detected as low-frequency DRMs prior to treatment. The rare low-frequency NNRTI- and NRTI-DRMs detected at baseline that correlated with the prescribed treatment were most often found at high-frequency at VF. Low frequency DRMs detected before ART initiation and at VF in patients experiencing VF on first-line ART can increase the overall burden of resistance to PI, NRTI and NNRTI.

  12. Mutagenic and epigenetic influence of caffeine on the frequencies of UV-induced ouabain-resistant Chinese hamster cells

    International Nuclear Information System (INIS)

    Chang, Chia-Cheng; Philipps, C.; Trosko, J.E.; Hart, R.W.

    1977-01-01

    Caffeine, given as a post-treatment to UV-irradiated Chinese hamster cells in vitro, modified the frequency of induced mutations at the ouabain resistance locus. Mutation frequencies were increased when caffeine was added only for the DNA repair and mutation fixation period. When caffeine was added after the DNA repair and mutation fixation period, or immediately after DNA damage and for the entire repair and selection period, mutation frequencies were reduced. A hypothesis, given to explain both results, is that caffeine, by blocking a constitutive 'error-free' postreplication repair process, allows an 'error-prone' DNA repair process to produce many mutations. Moreover, caffeine, possibly by modifying C-AMP metabolism, causes a repression of induced mutations which, in effect, explains its anti-mutagenic and anti-carcinogenic properties

  13. Delayed manifestation and transmission bias of de novo chromosome mutations. Their relevance for radiation health effect

    International Nuclear Information System (INIS)

    Sasaki, Masao S.

    2006-01-01

    The origin and transmission of de novo chromosome mutations were reviewed on the basis of our chromosome studies in retinoblastoma patients and male infertility. In a series of 264 sporadic retinoblastoma families, gross chromosome rearrangements involving the RB1 locus were identified in 23 cases (8.7%), of which 16 were non-mosaic and 7 were mosaic mutations. The newly formed chromosome mutations, whether they were non-mosaic or mosaic, had a strong bias towards paternally derived chromosome, indicating that they shared a common mechanism where a pre-mutational event or instability is carried over to zygote by sperm and manifested as gross chromosome mutation at the early stages of development. The de novo chromosome mutations are preferentially transmitted through female carriers. This transmission bias is consistent with the finding of higher frequencies of translocation carriers in infertile men (7.69% versus 0.27% in general populations) in whom meiotic progression is severely suppressed, possibly through activation of meiotic checkpoints. Such a meiotic surveillance mechanism may minimize the spreading of newly-arisen chromosome mutations in populations. A quantitative model of meiotic surveillance mechanism is proposed and successfully applied to the published data on ''humped'' dose-response curves for radiation-induced spermatogonial reciprocal translocations in several mammalian species. (author)

  14. Spectrum of rhodopsin mutations in Korean patients with retinitis pigmentosa

    Science.gov (United States)

    Kim, Kwang Joong; Kim, Cinoo; Bok, Jeong; Kim, Kyung-Seon; Lee, Eun-Ju; Park, Sung Pyo; Chung, Hum; Han, Bok-Ghee; Kim, Hyung-Lae; Kimm, Kuchan; Yu, Hyeong Gon

    2011-01-01

    Purpose To determine the spectrum and frequency of rhodopsin gene (RHO) mutations in Korean patients with retinitis pigmentosa (RP) and to characterize genotype–phenotype correlations in patients with mutations. Methods The RHO mutations were screened by direct sequencing, and mutation prevalence was measured in patients and controls. The impact of missense mutations to RP was predicted by segregation analysis, peptide sequence alignment, and in silico analysis. The severity of disease in patients with the missense mutations was compared by visual acuity, electroretinography, optical coherence tomography, and kinetic visual field testing. Results Five heterozygous mutations were identified in six of 302 probands with RP, including a novel mutation (c.893C>A, p.A298D) and four known mutations (c.50C>T, p.T17M; c.533A>G, p.Y178C; c.888G>T, p.K296N; and c.1040C>T, p.P347L). The allele frequency of missense mutations was measured in 114 ethnically matched controls. p.A298D, newly identified in a sporadic patient, had never been found in controls and was predicted to be pathogenic. Among the patients with the missense mutations, we observed the most severe phenotype in patients with p.P347L, less severe phenotypes in patients with p.Y178C or p.A298D, and a relatively moderate phenotype in a patient with p.T17M. Conclusions The results reveal the spectrum of RHO mutations in Korean RP patients and clinical features that vary according to mutations. Our findings will be useful for understanding these genetic spectra and the genotype–phenotype correlations and will therefore help with predicting disease prognosis and facilitating the development of gene therapy. PMID:21677794

  15. A population genetic analysis of the potential for a crude oil spill to induce heritable mutations and impact natural populations

    Energy Technology Data Exchange (ETDEWEB)

    Cronin, M.A. [LGL Alaska Research Associates Inc., Anchorage, AK (United States); Bickham, J.W. [Texas A and M University, College Station, TX (United States). Dept. of Wildlife and Fisheries Sciences; LGL Ecological Genetics Inc., Bryan, TX (United States)

    1998-07-01

    The primary environmental impact following an oil spill typically is acute toxicity to fish and wildlife. However, multigenerational effects through toxicant-induced heritable mutations might also occur. Some polycyclic aromatic hydrocarbon (PAH) components of crude oil are potentially mutagenic, although specific components and doses that induce mutations are poorly known. We applied population genetics concepts to assess the extent of mortality and the persistence of deleterious heritable mutations resulting from exposure to potential mutagens, such as crude oil. If lethal mutations are induced, the population will experience some mortality, but the mutations are quickly removed or reduced to low frequency by natural selection. This occurs within one or a few generations when mutations are dominant or partially recessive. Totally recessive alleles persist in low frequency for many generations, but result in relatively little impact on the population, depending on the number of mutated loci. We also applied population genetics concepts to assess the potential for heritable mutations induced by the Exxon Valdez oil spill in Prince William Sound, Alaska, to affect pink salmon populations. We stress that breeding units (e.g., streams with distinct spawning populations of salmon) must be considered individually to assess heritable genetic effects. For several streams impacted by the oil spill, there is inconsistency between observed egg mortality and that expected if lethal heritable mutations had been induced by exposure to crude oil. Observed mortality was either higher or lower than expected depending on the spawning population, year, and cohort considered. Any potential subtle effect of lethal mutations induced by the Exxon Valdez oil spill is overridden by natural environmental variation among spawning areas. We discuss the need to focus on population-level effects in toxicological assessments because fish and wildlife management focuses on populations, not

  16. Analysis of chlorophyll mutations induced by γ-rays in barley (hordeum vulgare)

    International Nuclear Information System (INIS)

    Wang Cailian; Shen Mei; Xu Gang; Zhao Kongnan; Chen Qiufang

    1991-06-01

    Thirty varieties of dormant barley seeds were irradiated with 137 Cs γ-rays. Dose-effect relations of chlorophyll mutation frequency in M 2 seedling and differences resulting from cultured types or radiosensitive types were investigated. Experimental results show that the relations between chlorophyll mutation frequency and doses can be fitted by a linear regression equation Y = A + BX. According to analysis of covariance, there is no considerable difference in various cultured types, but the difference of five different radiosensitive types is remarkable. The sensitive and intermediate types need much lower doses than other types to induce maximum chlorophyll mutation

  17. Coevolution of the Ile1,016 and Cys1,534 Mutations in the Voltage Gated Sodium Channel Gene of Aedes aegypti in Mexico.

    Directory of Open Access Journals (Sweden)

    Farah Z Vera-Maloof

    2015-12-01

    Full Text Available Worldwide the mosquito Aedes aegypti (L. is the principal urban vector of dengue viruses. Currently 2.5 billion people are at risk for infection and reduction of Ae. aegypti populations is the most effective means to reduce the risk of transmission. Pyrethroids are used extensively for adult mosquito control, especially during dengue outbreaks. Pyrethroids promote activation and prolong the activation of the voltage gated sodium channel protein (VGSC by interacting with two distinct pyrethroid receptor sites [1], formed by the interfaces of the transmembrane helix subunit 6 (S6 of domains II and III. Mutations of S6 in domains II and III synergize so that double mutants have higher pyrethroid resistance than mutants in either domain alone. Computer models predict an allosteric interaction between mutations in the two domains. In Ae. aegypti, a Ile1,016 mutation in the S6 of domain II was discovered in 2006 and found to be associated with pyrethroid resistance in field populations in Mexico. In 2010 a second mutation, Cys1,534 in the S6 of domain III was discovered and also found to be associated with pyrethroid resistance and correlated with the frequency of Ile1,016.A linkage disequilibrium analysis was performed on Ile1,016 and Cys1,534 in Ae. aegypti collected in Mexico from 2000-2012 to test for statistical associations between S6 in domains II and III in natural populations. We estimated the frequency of the four dilocus haplotypes in 1,016 and 1,534: Val1,016/Phe1,534 (susceptible, Val1,016/Cys1,534, Ile1,016/Phe1,534, and Ile1,016/Cys1,534 (resistant. The susceptible Val1,016/Phe1,534 haplotype went from near fixation to extinction and the resistant Ile1,016/Cys1,534 haplotype increased in all collections from a frequency close to zero to frequencies ranging from 0.5-0.9. The Val1,016/Cys1,534 haplotype increased in all collections until 2008 after which it began to decline as Ile1,016/Cys1,534 increased. However, the Ile1,016/Phe1

  18. Monitoring mutations in people: an in vivo study of people accidentally or occupationally exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Glickman, B.W.

    1996-01-01

    Recent developments in molecular biology and medicine now permit the monitoring of mutation in humans 'in vivo'. The most commonly used approach, and the main one reported in this paper, is the study of mutations at the hypoxanthine phosphoribosyl transferase (hprt) locus in peripheral T-lymphocytes. This paper deals with evidence from the radiological accident in Goiania, Brazil (where several hundred people were accidentally exposed to cesium-137), from a study of Soviet cosmonauts, and from monozygotic twins. The conclusions from Brazil are: mutation at hprt increases with age and is higher in smokers; in adults a linear dose response was found; no radiation-induced mutational fingerprint was found; children are particularly sensitive; the level of mutation dropped over several years (probably reflecting natural T-cell turnover). The conclusions from cosmonauts are: each cosmonaut had a significantly above-average level of mutation, but this may not be due to radiation at all; no 'fingerprint' was found, and there was no apparent dependence on dose. The study of twins showed a very strong correlation of mutant frequencies between one twin and the other, but this correlation decreased with age, presumably due to environmental effects. 1 tab., 2 figs

  19. Tyrosine kinase domain mutations of EGFR gene in head and neck squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Vatte C

    2017-03-01

    Full Text Available Chittibabu Vatte,1 Ali M Al Amri,2 Cyril Cyrus,1 Shahanas Chathoth,1 Sadananda Acharya,3 Tariq Mohammad Hashim,4 Zhara Al Ali,2 Saleh Tawfeeq Alshreadah,2 Ahmed Alsayyah,4 Amein K Al-Ali5 1Department of Genetic Research, Institute for Research and Medical Consultation, University of Dammam, Dammam, 2Department of Internal Medicine, King Fahd Hospital of the University, University of Dammam, Al-Khobar, 3Department of Stemcell Research, Institute for Research and Medical Consultation, 4Department of Pathology, King Fahd Hospital of the University, University of Dammam, Al-Khobar, 5Department of Biochemistry, College of Medicine, University of Dammam, Dammam, Kingdom of Saudi Arabia Background: Epidermal growth factor receptor (EGFR is a commonly altered gene that is identified in various cancers, including head and neck squamous cell carcinoma (HNSCC. Therefore, EGFR is a promising molecular marker targeted by monoclonal antibodies and small molecule inhibitors targeting the tyrosine kinase (TK domain. Objective: The objective of this study was to investigate the spectrum of mutations in exons 18, 19, 20, and 21 of the EGFR gene in HNSCC patients. Materials and methods: This retrospective study included 47 confirmed HNSCC cases. Mutations in the TK domain, exons 18, 19, 20, and 21 of the EGFR gene, were detected by Scorpion® chemistry and ARMS® technologies on Rotor-Gene Q real-time polymerase chain reaction.Results: The tumors exhibited EGFR-TK domain mutations in 57% of cases. Four cases of T790M mutations were reported for the first time among HNSCC patients. Out of the total mutations, L861Q (exon 21, exon 20 insertions and deletions of exon 19 accounted for the majority of mutations (21%, 19%, and 17%, respectively. EGFR mutation status was correlated with the higher grade (P=0.026 and advanced stage (P=0.034 of HNSCC tumors.Conclusion: Higher frequency of EGFR-TK domain mutations together with the presence of the T790M mutation suggests

  20. Higher moments method for generalized Pareto distribution in flood frequency analysis

    Science.gov (United States)

    Zhou, C. R.; Chen, Y. F.; Huang, Q.; Gu, S. H.

    2017-08-01

    The generalized Pareto distribution (GPD) has proven to be the ideal distribution in fitting with the peak over threshold series in flood frequency analysis. Several moments-based estimators are applied to estimating the parameters of GPD. Higher linear moments (LH moments) and higher probability weighted moments (HPWM) are the linear combinations of Probability Weighted Moments (PWM). In this study, the relationship between them will be explored. A series of statistical experiments and a case study are used to compare their performances. The results show that if the same PWM are used in LH moments and HPWM methods, the parameter estimated by these two methods is unbiased. Particularly, when the same PWM are used, the PWM method (or the HPWM method when the order equals 0) shows identical results in parameter estimation with the linear Moments (L-Moments) method. Additionally, this phenomenon is significant when r ≥ 1 that the same order PWM are used in HPWM and LH moments method.

  1. Phenylalanine hydroxylase gene mutations in the United States: Report from the maternal PKU collaborative study

    Energy Technology Data Exchange (ETDEWEB)

    Guldberg, P.; Henriksen, K.F.; Guettler, F. [John F. Kennedy Inst., Glostrup (Denmark)] [and others

    1996-07-01

    The major cause of hyperphenylalaninemia is mutations in the gene encoding phenylalanine hydroxylase (PAH). The known mutations have been identified primarily in European patients. The purpose of this study was to determine the spectrum of mutations responsible for PAH deficiency in the United States. One hundred forty-nine patients enrolled in the Maternal PKU Collaborative Study were subjects for clinical and molecular investigations. PAH gene mutations associated with phenylketonuria (PKU) or mild hyperphenylalaninemia (MHP) were identified on 279 of 294 independent mutant chromosomes, a diagnostic efficiency of 95%. The spectrum is composed of 71 different mutations, including 47 missense mutations, 11 splice mutations, 5 nonsense mutations, and 8 microdeletions. Sixteen previously unreported mutations were identified. Among the novel mutations, five were found in patients with MHP, and the remainder were found in patients with PKU. The most common mutations were R408W, IVS12nt1g{r_arrow}a, and Y414C, accounting for 18.7%, 7.8% and 5.4% of the mutant chromosomes, respectively. Thirteen mutations had relative frequencies of 1%-5%, and 55 mutations each had frequencies {le}1%. The mutational spectrum corresponded to that observed for the European ancestry of the U.S. population. To evaluate the extent of allelic variation at the PAH locus within the United States in comparison with other populations, we used allele frequencies to calculate the homozygosity for 11 populations where >90% ascertainment has been obtained. The United States was shown to contain one of the most heterogeneous populations, with homozygosity values similar to Sicily and ethnically mixed sample populations in Europe. The extent of allelic heterogeneity must be a major determining factor in the choice of mutation-detection methodology for molecular diagnosis in PAH deficiency. 47 refs., 1 fig., 5 tabs.

  2. Oncogenic mutations in melanomas and benign melanocytic nevi of the female genital tract.

    Science.gov (United States)

    Tseng, Diane; Kim, Julie; Warrick, Andrea; Nelson, Dylan; Pukay, Marina; Beadling, Carol; Heinrich, Michael; Selim, Maria Angelica; Corless, Christopher L; Nelson, Kelly

    2014-08-01

    The genetic heterogeneity of melanomas and melanocytic nevi of the female genital tract is poorly understood. We aim to characterize the frequency of mutations of the following genes: BRAF, NRAS, KIT, GNA11, and GNAQ in female genital tract melanomas. We also characterize the frequency of BRAF mutations in female genital tract melanomas compared with melanocytic nevi. Mutational screening was performed on the following female genital tract melanocytic neoplasms: 25 melanomas, 7 benign melanocytic nevi, and 4 atypical melanocytic nevi. Of the 25 female genital tract melanoma specimens queried, KIT mutations were detected in 4 (16.0%), NRAS mutations in 4 (16.0%), and BRAF mutations in 2 (8.0%) samples. Two of the tumors with KIT mutations harbored double mutations in the same exon. No GNAQ or GNA11 mutations were identified among 11 melanomas screened. BRAF V600E mutations were detected in 7 of 7 benign melanocytic genital nevi (100%) and 3 of 4 atypical genital nevi (75%). Our study is limited by the small sample size of this rare subset of melanomas. KIT, NRAS, and BRAF mutations are found in a subset of female genital tract melanomas. Screening for oncogenic mutations is important for developing and applying clinical therapies for melanomas of the female genital tract. Copyright © 2014 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

  3. RADIA: RNA and DNA integrated analysis for somatic mutation detection.

    Directory of Open Access Journals (Sweden)

    Amie J Radenbaugh

    Full Text Available The detection of somatic single nucleotide variants is a crucial component to the characterization of the cancer genome. Mutation calling algorithms thus far have focused on comparing the normal and tumor genomes from the same individual. In recent years, it has become routine for projects like The Cancer Genome Atlas (TCGA to also sequence the tumor RNA. Here we present RADIA (RNA and DNA Integrated Analysis, a novel computational method combining the patient-matched normal and tumor DNA with the tumor RNA to detect somatic mutations. The inclusion of the RNA increases the power to detect somatic mutations, especially at low DNA allelic frequencies. By integrating an individual's DNA and RNA, we are able to detect mutations that would otherwise be missed by traditional algorithms that examine only the DNA. We demonstrate high sensitivity (84% and very high precision (98% and 99% for RADIA in patient data from endometrial carcinoma and lung adenocarcinoma from TCGA. Mutations with both high DNA and RNA read support have the highest validation rate of over 99%. We also introduce a simulation package that spikes in artificial mutations to patient data, rather than simulating sequencing data from a reference genome. We evaluate sensitivity on the simulation data and demonstrate our ability to rescue back mutations at low DNA allelic frequencies by including the RNA. Finally, we highlight mutations in important cancer genes that were rescued due to the incorporation of the RNA.

  4. Rhodosporidium toruloides BANNO: Dose-response relationship, mutagenic efficiency and spectrum of mutants of auxotrophy-producing mutations induced by ultraviolet light and N-methyl-N'-nitro-N-nitrosoguanidine

    International Nuclear Information System (INIS)

    Boettcher, F.; Samsonova, I.A.

    1978-01-01

    The kinetics, efficiency, and specificity of induction of forward mutations to auxotrophy by ultraviolet light (UV) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was examined in stationary phase cells of Rhodosporidium (Rhodotorula) wild strain Rg1. In comparison to the spontaneous level the frequency of auxotrophic mutants was increased more than 1000 times by both mutagens, however, the mutagenic efficiency of MNNG was higher than that of UV. We found that the forward mutation rate is a linear function of the applicated UV and MNNG doses in the range to 600 J m -2 or 25 mM x min, respectively. The 35 studied biosynthetic pathways to amino acids, purines, pyrimidines, and vitamins are genetically blocked at different frequencies, but there is not any significant difference between UV and MNNG induced frequencies of mutants with a specific requirement. However, in difference to the approximately equal distribution of the MNNG-induced nic mutants among the genetic blocks of the tryptophan-nicotinamide pathway, UV-induced nic mutants occurred with a higher frequency in the genes of the tryptophan pyrrolase and the 3-hydroxykynureninase than in the genes of the other enzymes of the pathway. (author)

  5. Mutations in rpoB and katG genes of multidrug resistant ...

    African Journals Online (AJOL)

    Introduction: Tuberculosis remains the leading causes of death worldwide with frequencies of mutations in rifampicin and isoniazid resistant Mycobacterium tuberculosis isolates varying according to geographical location. There is limited information in Zimbabwe on specific antibiotic resistance gene mutation patterns in ...

  6. Analysis of Higher Order Modes in Large Superconducting Radio Frequency Accelerating Structures

    CERN Document Server

    Galek, Tomasz; Brackebusch, Korinna; Van Rienen, Ursula

    2015-01-01

    Superconducting radio frequency cavities used for accelerating charged particle beams are commonly used in accelerator facilities around the world. The design and optimization of modern superconducting RF cavities requires intensive numerical simulations. Vast number of operational parameters must be calculated to ensure appropriate functioning of the accelerating structures. In this study, we primarily focus on estimation and behavior of higher order modes in superconducting RF cavities connected in chains. To calculate large RF models the state-space concatenation scheme, an efficient hybrid method, is employed.

  7. X-ray-induced bystander response reduce spontaneous mutations in V79 cells

    International Nuclear Information System (INIS)

    Maeda, Munetoshi; Kobayashi, Katsumi; Matsumoto, Hideki; Usami, Noriko; Tomiya, Masanori

    2013-01-01

    The potential for carcinogenic risks is increased by radiation-induced bystander responses; these responses are the biological effects in unirradiated cells that receive signals from the neighboring irradiated cells. Bystander responses have attracted attention in modern radiobiology because they are characterized by non-linear responses to low-dose radiation. We used a synchrotron X-ray microbeam irradiation system developed at the Photon Factory, High Energy Accelerator Research Organization, KEK, and showed that nitric oxide (NO)-mediated bystander cell death increased biphasically in a dose-dependent manner. Here, we irradiated five cell nuclei using 10 × 10 µm 2 5.35 keV X-ray beams and then measured the mutation frequency at the hypoxanthine-guanosine phosphoribosyl transferase (HPRT) locus in bystander cells. The mutation frequency with the null radiation dose was 2.6 × 10 -5 (background level), and the frequency decreased to 5.3 × 10 -6 with a dose of approximately 1 Gy (absorbed dose in the nucleus of irradiated cells). At high doses, the mutation frequency returned to the background level. A similar biphasic dose-response effect was observed for bystander cell death. Furthermore, we found that incubation with 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO), a specific scavenger of NO, suppressed not only the biphasic increase in bystander cell death but also the biphasic reduction in mutation frequency of bystander cells. These results indicate that the increase in bystander cell death involves mechanisms that suppress mutagenesis. This study has thus shown that radiation-induced bystander responses could affect processes that protect the cell against naturally occurring alterations such as mutations. (author)

  8. The Influence of Higher Protein Intake and Greater Eating Frequency on Appetite Control in Overweight and Obese Men

    Science.gov (United States)

    Leidy, Heather J.; Armstrong, Cheryl L.H.; Tang, Minghua; Mattes, Richard D.; Campbell, Wayne W.

    2014-01-01

    The purpose of this study was to determine the effects of dietary protein intake and eating frequency on perceived appetite, satiety, and hormonal responses in overweight/obese men. Thirteen men (age 51 ± 4 years; BMI 31.3 ± 0.8 kg/m2) consumed eucaloric diets containing normal protein (79 ± 2 g protein/day; 14% of energy intake as protein) or higher protein (138 ± 3 g protein/day; 25% of energy intake as protein) equally divided among three eating occasions (3-EO; every 4 h) or six eating occasions (6-EO; every 2 h) on four separate days in randomized order. Hunger, fullness, plasma glucose, and hormonal responses were assessed throughout 11 h. No protein × eating frequency interactions were observed for any of the outcomes. Independent of eating frequency, higher protein led to greater daily fullness (P < 0.05) and peptide YY (PYY) concentrations (P < 0.05). In contrast, higher protein led to greater daily ghrelin concentrations (P < 0.05) vs. normal protein. Protein quantity did not influence daily hunger, glucose, or insulin concentrations. Independent of dietary protein, 6-EO led to lower daily fullness (P < 0.05) and PYY concentrations (P < 0.05). The 6-EO also led to lower glucose (P < 0.05) and insulin concentrations (P < 0.05) vs. 3-EO. Although the hunger-related perceived sensations and hormonal responses were conflicting, the fullness-related responses were consistently greater with higher protein intake but lower with increased eating frequency. Collectively, these data suggest that higher protein intake promotes satiety and challenge the concept that increasing the number of eating occasions enhances satiety in overweight and obese men. PMID:20339363

  9. Highly prevalent LIPH founder mutations causing autosomal recessive woolly hair/hypotrichosis in Japan and the genotype/phenotype correlations.

    Directory of Open Access Journals (Sweden)

    Kana Tanahashi

    Full Text Available Mutations in LIPH cause of autosomal recessive woolly hair/hypotrichosis (ARWH, and the 2 missense mutations c.736T>A (p.Cys246Ser and c.742C>A (p.His248Asn are considered prevalent founder mutations for ARWH in the Japanese population. To reveal genotype/phenotype correlations in ARWH cases in Japan and the haplotypes in 14 Japanese patients from 14 unrelated Japanese families. 13 patients had woolly hair, and 1 patient had complete baldness since birth. An LIPH mutation search revealed homozygous c.736T>A mutations in 10 of the patients. Compound heterozygous c.736T>A and c.742C>A mutations were found in 3 of the patients, and homozygous c.742C>A mutation in 1 patient. The phenotype of mild hypotrichosis with woolly hair was restricted to the patients with the homozygous c.736T>A mutation. The severe phenotype of complete baldness was seen in only 1 patient with homozygous c.742C>A. Haplotype analysis revealed that the alleles containing the LIPH c.736T>A mutation had a haplotype identical to that reported previously, although 4 alleles out of 5 chromosomes containing the LIPH c.742C>A mutation had a different haplotype from the previously reported founder allele. These alleles with c.742C>A are thought to be the third founder LIPH mutation causing ARWH. To accurately determine the prevalence of the founder mutations, we investigated allele frequencies of those mutations in 819 Japanese controls. Heterozygous c.736T>A mutations were found in 13 controls (allele frequency: 0.0079; carrier rate: 0.016, and heterozygous c.742C>A mutations were found in 2 controls (allele frequency: 0.0012; carrier rate: 0.0024. In conclusion, this study confirms the more accurate allele frequencies of the pathogenic founder mutations of LIPH and shows that there is a third founder mutation in Japan. In addition, the present findings suggest that the mutation patterns of LIPH might be associated with hypotrichosis severity in ARWH.

  10. CFTR mutations spectrum and the efficiency of molecular diagnostics in Polish cystic fibrosis patients.

    Directory of Open Access Journals (Sweden)

    Ewa Ziętkiewicz

    Full Text Available Cystic fibrosis (CF is caused by mutations in the cystic fibrosis transmembrane regulator gene (CFTR. In light of the strong allelic heterogeneity and regional specificity of the mutation spectrum, the strategy of molecular diagnostics and counseling in CF requires genetic tests to reflect the frequency profile characteristic for a given population. The goal of the study was to provide an updated comprehensive estimation of the distribution of CFTR mutations in Polish CF patients and to assess the effectiveness of INNOLiPA_CFTR tests in Polish population. The analyzed cohort consisted of 738 patients with the clinically confirmed CF diagnosis, prescreened for molecular defects using INNOLiPA_CFTR panels from Innogenetics. A combined efficiency of INNOLiPA CFTR_19 and CFTR_17_TnUpdate tests was 75.5%; both mutations were detected in 68.2%, and one mutation in 14.8% of the affected individuals. The group composed of all the patients with only one or with no mutation detected (109 and 126 individuals, respectively was analyzed further using a mutation screening approach, i.e. SSCP/HD (single strand conformational polymorphism/heteroduplex analysis of PCR products followed by sequencing of the coding sequence. As a result, 53 more mutations were found in 97 patients. The overall efficiency of the CF allele detection was 82.5% (7.0% increase compared to INNOLiPA tests alone. The distribution of the most frequent mutations in Poland was assessed. Most of the mutations repetitively found in Polish patients had been previously described in other European populations. The most frequent mutated allele, F508del, represented 54.5% of Polish CF chromosomes. Another eight mutations had frequencies over 1%, 24 had frequencies between 1 and 0.1%; c.2052-2053insA and c.3468+2_3468+3insT were the most frequent non-INNOLiPA mutations. Mutation distribution described herein is also relevant to the Polish diaspora. Our study also demonstrates that the reported

  11. AIP mutations in Brazilian patients with sporadic pituitary adenomas: a single-center evaluation

    Science.gov (United States)

    Kasuki, Leandro; de Azeredo Lima, Carlos Henrique; Ogino, Liana; Camacho, Aline H S; Chimelli, Leila; Korbonits, Márta

    2017-01-01

    Aryl hydrocarbon receptor-interacting protein (AIP) gene mutations (AIPmut) are the most frequent germline mutations found in apparently sporadic pituitary adenomas (SPA). Our aim was to evaluate the frequency of AIPmut among young Brazilian patients with SPA. We performed an observational cohort study between 2013 and 2016 in a single referral center. AIPmut screening was carried out in 132 SPA patients with macroadenomas diagnosed up to 40 years or in adenomas of any size diagnosed until 18 years of age. Twelve tumor samples were also analyzed. Leukocyte DNA and tumor tissue DNA were sequenced for the entire AIP-coding region for evaluation of mutations. Eleven (8.3%) of the 132 patients had AIPmut, comprising 9/74 (12%) somatotropinomas, 1/38 (2.6%) prolactinoma, 1/10 (10%) corticotropinoma and no non-functioning adenomas. In pediatric patients (≤18 years), AIPmut frequency was 13.3% (2/15). Out of the 5 patients with gigantism, two had AIPmut, both truncating mutations. The Y268* mutation was described in Brazilian patients and the K273Rfs*30 mutation is a novel mutation in our patient. No somatic AIP mutations were found in the 12 tumor samples. A tumor sample from an acromegaly patient harboring the A299V AIPmut showed loss of heterozygosity. In conclusion, AIPmut frequency in SPA Brazilian patients is similar to other populations. Our study identified two mutations exclusively found in Brazilians and also shows, for the first time, loss of heterozygosity in tumor DNA from an acromegaly patient harboring the A299V AIPmut. Our findings corroborate previous observations that AIPmut screening should be performed in young patients with SPA. PMID:29074612

  12. BRAF, KIT, NRAS, GNAQ and GNA11 mutation analysis in cutaneous melanomas in Turkish population

    Directory of Open Access Journals (Sweden)

    Ismail Yilmaz

    2015-01-01

    Full Text Available Background: KIT and mitogen-activated protein kinase cascade are important for melanomagenesis. In the present study, we analyzed the frequency of BRAF, NRAS, KIT, GNAQ and GNA11 gene mutations and investigated their association with clinicopathological features of melanomas in Turkish population. Materials and Methods: Forty-seven primary cutaneous melanomas were included in our study. Sanger sequencing method was used for mutation analysis in all cases. Results: Mean age was 62.1 (29-101 years. Female:male ratio was 17:30. Among 47 melanomas, 14 (29.8% BRAF, 10 (21.3% NRAS, 4 (8.5% KIT and 1(2.1% GNAQ gene mutations were detected. Two of the KIT mutations were found in acral lentiginous melanoma (ALM. In the head and neck region, mutation frequency was significantly lower than in other locations (P = 0.035. The only GNAQ gene mutation (p.Q209L was detected in a melanoma arising from blue nevus located on the scalp. None of the melanomas harbored NRAS exon 2, KIT exon 13/17/18, GNAQ exon 4 and GNA11 exon 4/5 mutations. Overall mutation frequency did not show significant difference between metastatic (8/14, 57.1% and nonmetastatic (18/33, 54.5% patients. We did not observe any significant association between mutation status and gender or age of various patients. Conclusions: Our results support that BRAF and NRAS gene mutations are common in cutaneous melanomas. The activating mutations of KIT gene are rare and especially seen in ALM. GNAQ and GNA11 mutations are infrequent in cutaneous melanomas and may be associated only with melanomas arising from blue nevus.

  13. Mutation frequencies in female mice and the estimation of genetic hazards of radiation in women

    International Nuclear Information System (INIS)

    Russell, W.L.

    1977-01-01

    The female germ cell stage of primary importance in radiation genetic hazards is the immature, arrested oocyte. In the mouse, this stage has a near zero or zero sensitivity to mutation induction by radiation. However, the application of these mouse results to women has been questioned on the ground that the mouse arrested oocytes are highly sensitive to killing by radiation, while the human cells are not; and, furthermore, that the mature and maturing oocytes in the mouse, which are resistant to killing, are sensitive to mutation induction. The present results have a 2-fold bearing on this problem. First, a more detailed analysis of oocyte-stage sensitivity to killing and mutation induction shows that there is no consistent correlation, either negative or positive, between the two. This indicates that the sensitivity to cell killing of the mouse immature oocyte may not be sufficient reason to prevent its use in predicting the mutational response of the human immature oocyte. Second, if the much more cautious assumption is made that the human arrested oocyte might be as mutationally sensitive as the most sensitive of all oocyte stages in the mouse, namely the maturing and mature ones, then the present data on the duration of these stages permit more accurate estimates than were heretofore possible on the mutational response of these stages to chronic irradiation

  14. Experimental evolution and the dynamics of genomic mutation rate modifiers.

    Science.gov (United States)

    Raynes, Y; Sniegowski, P D

    2014-11-01

    Because genes that affect mutation rates are themselves subject to mutation, mutation rates can be influenced by natural selection and other evolutionary forces. The population genetics of mutation rate modifier alleles has been a subject of theoretical interest for many decades. Here, we review experimental contributions to our understanding of mutation rate modifier dynamics. Numerous evolution experiments have shown that mutator alleles (modifiers that elevate the genomic mutation rate) can readily rise to high frequencies via genetic hitchhiking in non-recombining microbial populations. Whereas these results certainly provide an explanatory framework for observations of sporadically high mutation rates in pathogenic microbes and in cancer lineages, it is nonetheless true that most natural populations have very low mutation rates. This raises the interesting question of how mutator hitchhiking is suppressed or its phenotypic effect reversed in natural populations. Very little experimental work has addressed this question; with this in mind, we identify some promising areas for future experimental investigation.

  15. Study on space mutation breeding of rice

    International Nuclear Information System (INIS)

    Xu Jianlong; Lin Yizi; Xi Yongan; Jiang Xingcun; Li Jinguo

    1997-01-01

    Air-dried seeds of rice variety ZR9 were carried by high altitude balloon (HAB) and recoverable satellite (RS) for space mutation. Mutagentic effects of high altitude environment (HAE) of 30∼38 km and outer space environment (OSE) of 218∼326 km above sea level on rice plant were studied. The results indicated that the germination percentage (GP) of seeds was obviously lower than that of the controls. the mutation in plant height (PH) and growth period duration (GPD) of SP 1 carried by HAB were induced. However, the GP of seeds and characters of SP 1 carried by RS had no evident change. More stronger segregation of major characters such as PH, GPD and length of panicle, appeared in the two SP 2 generations resulting from HAB and RS. And their mutation frequency were 4.31% and 4.10% respectively. Mutation lines selected from the two mutation progenies improved significantly in PH, GPD, disease resistance and yield. Therefore, space mutation could be considered as a new breeding method

  16. Mutations induced by ultraviolet light

    International Nuclear Information System (INIS)

    Pfeifer, Gerd P.; You, Young-Hyun; Besaratinia, Ahmad

    2005-01-01

    The different ultraviolet (UV) wavelength components, UVA (320-400 nm), UVB (280-320 nm), and UVC (200-280 nm), have distinct mutagenic properties. A hallmark of UVC and UVB mutagenesis is the high frequency of transition mutations at dipyrimidine sequences containing cytosine. In human skin cancers, about 35% of all mutations in the p53 gene are transitions at dipyrimidines within the sequence 5'-TCG and 5'-CCG, and these are localized at several mutational hotspots. Since 5'-CG sequences are methylated along the p53 coding sequence in human cells, these mutations may be derived from sunlight-induced pyrimidine dimers forming at sequences that contain 5-methylcytosine. Cyclobutane pyrimidine dimers (CPDs) form preferentially at dipyrimidines containing 5-methylcytosine when cells are irradiated with UVB or sunlight. In order to define the contribution of 5-methylcytosine to sunlight-induced mutations, the lacI and cII transgenes in mouse fibroblasts were used as mutational targets. After 254 nm UVC irradiation, only 6-9% of the base substitutions were at dipyrimidines containing 5-methylcytosine. However, 24-32% of the solar light-induced mutations were at dipyrimidines that contain 5-methylcytosine and most of these mutations were transitions. Thus, CPDs forming preferentially at dipyrimidines with 5-methylcytosine are responsible for a considerable fraction of the mutations induced by sunlight in mammalian cells. Using mouse cell lines harboring photoproduct-specific photolyases and mutational reporter genes, we showed that CPDs (rather than 6-4 photoproducts or other lesions) are responsible for the great majority of UVB-induced mutations. An important component of UVB mutagenesis is the deamination of cytosine and 5-methylcytosine within CPDs. The mutational specificity of long-wave UVA (340-400 nm) is distinct from that of the shorter wavelength UV and is characterized mainly by G to T transversions presumably arising through mechanisms involving oxidized DNA

  17. Mutation induction in repair-deficient strains of Drosophila

    International Nuclear Information System (INIS)

    Wuergler, F.E.; Graf, U.

    1980-01-01

    Experimental evidence indicates a polygenic control of mutagenesis in Drosophila melanogaster. In oocytes chromosome aberrations detected as half-translocations or dominant lethals depend on a repair system which in a number of genetically nonrelated strains shows different repair capacities. Sister chromatid exchanges are easily studied as ring chromosome losses. They develop through a genotype controlled mechanism from, premutational lesions. Stocks with particular pairs of third chromosomes were discovered in which increased sensitivity of larvae to the toxic effects of a monofunctional alkylating agent correlates with high frequencies of x-ray induced SCE's. Sex-linked mutagen-sensitive mutants could be shown to control mutation fixation: pronounced maternal effects were found when sperm carrying particular types of premutational lesions were introduced into different types of mutant oocytes. The mutant mus(1)101D1 was found to be unable to process lesions induced by the crosslinking agent nitrogen mustard into point mutations. Alkylation damage leads to increased point mutation frequencies in the excision repair deficient mutant mei-9L1, but to reduced frequencies in the post-replication repair deficient mutant mei-41D5. It became clear that the study of maternal effects on mutagenized sperm represents an efficient tool to analyze the gentic control of mutagenesis in the eukaryotic genome of Drosophila melanogaster

  18. Increased somatic cell mutant frequency in atomic bomb survivors

    International Nuclear Information System (INIS)

    Hakoda, Masayuki; Akiyama, Mitoshi; Kyoizumi, Seishi; Awa, A.A.; Yamakido, Michio; Otake, Masanori.

    1988-05-01

    Frequencies of mutant T-cells in peripheral blood, which are deficient in the activity of hypoxanthine guanine phosphoribosyltransferase (HPRT) were determined for atomic bomb survivors by direct clonal assay using a previously reported method. Results from 30 exposed survivors (exposed to more than 1 rad) and 17 age- and sex-matched controls (exposed to less than 1 rad) were analyzed. The mean mutant frequency (Mf) in the exposed (5.2 x 10 -6 ; range 0.8 - 14.4 x 10 -6 ) was significantly higher than in controls (3.4 x 10 -6 ; range 1.3 - 9.3 x 10 -6 ), a fact not attributable to lower nonmutant cell cloning efficiencies in the exposed group since cell cloning efficiencies were virtually identical in both groups. An initial analysis of the data did not reveal a significant correlation between individual Mfs and individual radiation dose estimates when the latter were defined by the original, tentative estimates (T65D), even though there was a significant positive correlation of Mfs with individual frequency of lymphocytes bearing chromosome aberration. However, reanalysis using the newer revised individual dose estimates (DS86) for 27 exposed survivors and 17 controls did reveal a significant but shallow positive correlation between T-cell Mf values and individual exposure doses. These results indicate that HPRT mutation in vivo in human T-cells could be detected in these survivors 40 years after the presumed mutational event. (author)

  19. Somatic mutations in leafs of tobacco seedlings induced by ionizing radiation and pesticide

    International Nuclear Information System (INIS)

    Shin, H. S.; Kim, J. K.; Song, H. S.; Lee, Y. I.

    2001-01-01

    Somatic mutations induced by the combined treatment of pesticide and ionizing radiation were analyzed in the leaves of tobacco seedlings. The pesticide (1,5 and 10 ppm of parathion) was sprayed directly onto the seedlings. The seedlings, with or without pretreatment of pesticide, were irradiated with 0.1 ∼10 Gy of gamma ray. The difference in the somatic mutation frequencies were not significant among groups treated with different concentration of pesticide. The somatic mutations in tobacco seedlings irradiated with gamma-ray showed a clear dose-response relationship in a range of 0.1 to 10 Gy. However, the combined treatment of pesticide and radiation did not cause any synergistic enhancement in the mutation frequencies. The highest efficiency in the induction of somatic mutations could be obtained by irradiating the seedlings with 5 Gy, 12 hours after 1 ppm of pesticide treatment, or 24 hours after 5 ppm of pesticide treatment

  20. Frequency of MELAS main mutation in a phenotype-targeted young ischemic stroke patient population.

    Science.gov (United States)

    Tatlisumak, Turgut; Putaala, Jukka; Innilä, Markus; Enzinger, Christian; Metso, Tiina M; Curtze, Sami; von Sarnowski, Bettina; Amaral-Silva, Alexandre; Jungehulsing, Gerhard Jan; Tanislav, Christian; Thijs, Vincent; Rolfs, Arndt; Norrving, Bo; Fazekas, Franz; Suomalainen, Anu; Kolodny, Edwin H

    2016-02-01

    Mitochondrial diseases, predominantly mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS), may occasionally underlie or coincide with ischemic stroke (IS) in young and middle-aged individuals. We searched for undiagnosed patients with MELAS in a target subpopulation of unselected young IS patients enrolled in the Stroke in Young Fabry Patients study (sifap1). Among the 3291 IS patients aged 18-55 years recruited to the sifap1 study at 47 centers across 14 European countries, we identified potential MELAS patients with the following phenotypic features: (a) diagnosed cardiomyopathy or (b) presence of two of the three following findings: migraine, short stature (≤165 cm for males; ≤155 cm for females), and diabetes. Identified patients' blood samples underwent analysis of the common MELAS mutation, m.3243A>G in the MTTL1 gene of mitochondrial DNA. Clinical and cerebral MRI features of the mutation carriers were reviewed. We analyzed blood samples of 238 patients (177 with cardiomyopathy) leading to identification of four previously unrecognized MELAS main mutation carrier-patients. Their clinical and MRI characteristics were within the expectation for common IS patients except for severe hearing loss in one patient and hyperintensity of the pulvinar thalami on T1-weighted MRI in another one. Genetic testing for the m.3243A>G MELAS mutation in young patients with IS based on phenotypes suggestive of mitochondrial disease identifies previously unrecognized carriers of MELAS main mutation, but does not prove MELAS as the putative cause.

  1. Molecular methods for the detection of mutations.

    Science.gov (United States)

    Monteiro, C; Marcelino, L A; Conde, A R; Saraiva, C; Giphart-Gassler, M; De Nooij-van Dalen, A G; Van Buuren-van Seggelen, V; Van der Keur, M; May, C A; Cole, J; Lehmann, A R; Steinsgrimsdottir, H; Beare, D; Capulas, E; Armour, J A

    2000-01-01

    We report the results of a collaborative study aimed at developing reliable, direct assays for mutation in human cells. The project used common lymphoblastoid cell lines, both with and without mutagen treatment, as a shared resource to validate the development of new molecular methods for the detection of low-level mutations in the presence of a large excess of normal alleles. As the "gold standard, " hprt mutation frequencies were also measured on the same samples. The methods under development included i) the restriction site mutation (RSM) assay, in which mutations lead to the destruction of a restriction site; ii) minisatellite length-change mutation, in which mutations lead to alleles containing new numbers of tandem repeat units; iii) loss of heterozygosity for HLA epitopes, in which antibodies can be used to direct selection for mutant cells; iv) multiple fluorescence-based long linker arm nucleotides assay (mf-LLA) technology, for the detection of substitutional mutations; v) detection of alterations in the TP53 locus using a (CA) array as the target for the screening; and vi) PCR analysis of lymphocytes for the presence of the BCL2 t(14:18) translocation. The relative merits of these molecular methods are discussed, and a comparison made with more "traditional" methods.

  2. Mutation Spectrum of GNE Myopathy in the Indian Sub-Continent.

    Science.gov (United States)

    Bhattacharya, Sudha; Khadilkar, Satish V; Nalini, Atchayaram; Ganapathy, Aparna; Mannan, Ashraf U; Majumder, Partha P; Bhattacharya, Alok

    GNE myopathy is an adult onset recessive genetic disorder that affects distal muscles sparing the quadriceps. GNE gene mutations have been identified in GNE myopathy patients all over the world. Homozygosity is a common feature in GNE myopathy patients worldwide. The major objective of this study was to investigate the mutation spectrum of GNE myopathy in India in relation to the population diversity in the country. We have collated GNE mutation data of Indian GNE myopathy patients from published literature and from recently identified patients. We also used data of people of Indian subcontinent from 1000 genomes database, South Asian Genome database and Strand Life Science database to determine frequency of GNE mutations in the general population. A total of 67 GNE myopathy patients were studied, of whom 21% were homozygous for GNE variants, while the rest were compound heterozygous. Thirty-five different mutations in the GNE gene were recorded, of which 5 have not been reported earlier. The most frequent mutation was p.Val727Met (65%) found mainly in the heterozygous form. Another mutation, p.Ile618Thr was also common (16%) but was found mainly in patients from Rajasthan, while p.Val727Met was more widely distributed. The latter was also seen at a high frequency in general population of Indian subcontinent in all the databases. It was also present in Thailand but was absent in general population elsewhere in the world. p.Val727Met is likely to be a founder mutation of Indian subcontinent.

  3. Association between nucleotide mutation of eNOS gene and serum ...

    African Journals Online (AJOL)

    Various mutation on endothelial nitric oxide synthase (eNOs) gene cause reduced production of NO, the expansion factor (VEF) and may accelerate the process of atherosclerosis. The study was designed to investigate the frequency of T-786C polymorphism of the gene or nucleotide mutation of eNOS gene in patients ...

  4. Epidermal growth factor receptor mutation in gastric cancer.

    Science.gov (United States)

    Liu, Zhimin; Liu, Lina; Li, Mei; Wang, Zhaohui; Feng, Lu; Zhang, Qiuping; Cheng, Shihua; Lu, Shen

    2011-04-01

    Epidermal growth factor receptor (EGFR) and Kirsten-RAS (KRAS) mutations have been identified as predictors of response to EGFR tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer. We aimed to screen the mutations of both genes in gastric carcinoma to detect the suitability of EGFR TKIs for patients with gastric carcinoma. We screened EGFR mutation in exons 19-21 and KRAS mutation in exon 2 in 58 gastric adenocarcinomas from China using high resolution melting analysis (HRMA). Positive samples were confirmed by DNA sequencing. Three EGFR missense mutations (5.2%) and 22 single nucleotide polymorphisms (SNP, Q787Q, 37.9%) were identified. To our knowledge, we report for the first time three mutation patterns of EGFR, Y801C, L858R and G863D, in gastric carcinoma. Two samples with EGFR mutation were mucinous adenocarcinoma. These three samples were collected from male patients aged over 75 years old. The frequency of KRAS mutation was 10.3% (6/58). The exclusiveness of EGFR and KRAS mutations was proven for the first time in gastric cancer. Gastric carcinoma of the mucinous adenocarcinoma type collected from older male patients may harbour EGFR mutations. The small subset of gastric adenocarcinoma patients may respond to EGFR TKIs.

  5. Mutation Status and Immunoglobulin Gene Rearrangements in Patients from Northwest and Central Region of Spain with Chronic Lymphocytic Leukemia

    Directory of Open Access Journals (Sweden)

    I. González-Gascón y Marín

    2014-01-01

    Full Text Available The aim of this study was to investigate the frequency and mutation status of the immunoglobulin heavy variable chain (IGHV in a cohort of 224 patients from northwest and central region of Spain diagnosed with chronic lymphocytic leukemia (CLL, and to correlate it with cytogenetic abnormalities, overall survival (OS and time to first treatment (TTFT. 125 patients had mutated IGHV, while 99 had unmutated IGHV. The most frequently used IGHV family was IGHV3, followed by IGHV1 and IGHV4. The regions IGHV3-30, IGHV1-69, IGHV3-23, and IGHV4-34 were the most commonly used. Only 3.1% of the patients belonged to the subfamily IGHV3-21 and we failed to demonstrate a worse clinical outcome in this subgroup. The IGHV4 family appeared more frequently with mutated pattern, similar to IGHV3-23 and IGHV3-74. By contrast, IGHV1-69 was expressed at a higher frequency in unmutated CLL patients. All the cases from IGHV3-11 and almost all from IGHV5-51 subfamily belonged to the group of unmutated CLL.

  6. Mitochondrial mutations in adenoid cystic carcinoma of the salivary glands.

    Directory of Open Access Journals (Sweden)

    Suhail K Mithani

    Full Text Available BACKGROUND: The MitoChip v2.0 resequencing array is an array-based technique allowing for accurate and complete sequencing of the mitochondrial genome. No studies have investigated mitochondrial mutation in salivary gland adenoid cystic carcinomas. METHODOLOGY: The entire mitochondrial genome of 22 salivary gland adenoid cystic carcinomas (ACC of salivary glands and matched leukocyte DNA was sequenced to determine the frequency and distribution of mitochondrial mutations in ACC tumors. PRINCIPAL FINDINGS: Seventeen of 22 ACCs (77% carried mitochondrial mutations, ranging in number from 1 to 37 mutations. A disproportionate number of mutations occurred in the D-loop. Twelve of 17 tumors (70.6% carried mutations resulting in amino acid changes of translated proteins. Nine of 17 tumors (52.9% with a mutation carried an amino acid changing mutation in the nicotinamide adenine dinucleotide dehydrogenase (NADH complex. CONCLUSIONS/SIGNIFICANCE: Mitochondrial mutation is frequent in salivary ACCs. The high incidence of amino acid changing mutations implicates alterations in aerobic respiration in ACC carcinogenesis. D-loop mutations are of unclear significance, but may be associated with alterations in transcription or replication.

  7. Progress of mutation breeding in Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Purivirojkul, Watchara; Vithayatherarat, Pradab [Pathumthani Rice Research Center (Thailand)

    2001-03-01

    The objectives in rice improvement in Thailand are to improve not only for high yielding and good grain quality but also for resistance to diseases and insects and tolerance to biotic stresses. Brief history of research and progress in rice mutation breeding in Thailand is presented. It includes the varieties of method such as using gamma rays, fast neutron and chemical mutagens, for example EMS (ethylmethane sulfonate) and EI (ethylene imine) for mutation works. Among all, improvements of Pathumthani 60 for short-statured plant type, RD23 for blast resistance, Basmati 370 for short-statured plant type, and Pra Doo Daeng for short-statured plant type and awnless grain are reported. To conclude, it is important to find the adequate doses of mutagen treatments that give maximum mutation frequencies, to know the optimal treatments or proper selection methods and to have well-defined objectives to create the success of mutation breeding. (S. Ohno)

  8. Progress of mutation breeding in Thailand

    International Nuclear Information System (INIS)

    Purivirojkul, Watchara; Vithayatherarat, Pradab

    2001-01-01

    The objectives in rice improvement in Thailand are to improve not only for high yielding and good grain quality but also for resistance to diseases and insects and tolerance to biotic stresses. Brief history of research and progress in rice mutation breeding in Thailand is presented. It includes the varieties of method such as using gamma rays, fast neutron and chemical mutagens, for example EMS (ethylmethane sulfonate) and EI (ethylene imine) for mutation works. Among all, improvements of Pathumthani 60 for short-statured plant type, RD23 for blast resistance, Basmati 370 for short-statured plant type, and Pra Doo Daeng for short-statured plant type and awnless grain are reported. To conclude, it is important to find the adequate doses of mutagen treatments that give maximum mutation frequencies, to know the optimal treatments or proper selection methods and to have well-defined objectives to create the success of mutation breeding. (S. Ohno)

  9. Nonsyndromic retinitis pigmentosa is highly prevalent in the Jerusalem region with a high frequency of founder mutations.

    Science.gov (United States)

    Sharon, Dror; Banin, Eyal

    2015-01-01

    Nonsyndromic retinitis pigmentosa (RP) is the most common inherited retinal degeneration, and prevalence of the disease has been reported in populations of American and European origin with a relatively low consanguinity rate. Our aim was to determine the prevalence of nonsyndromic RP in the Jerusalem region, which has a population of about 1 million individuals with a high rate of consanguinity. The patients' clinical data included eye exam findings (visual acuity, anterior segment, and funduscopy) as well as electroretinographic (ERG) testing results under scotopic and photopic conditions. Mutation analysis on a subgroup of patients was performed mainly with candidate gene analysis and homozygosity mapping. We evaluated the medical records of patients with degenerative retinal diseases residing in the Jerusalem region who were examined over the past 20 years in a large tertiary medical center. A total of 453 individuals affected with nonsyndromic RP were diagnosed at our center, according to funduscopic findings and ERG testing. Based on the estimated population size of 945,000 individuals who reside in the vicinity of Jerusalem, the prevalence of nonsyndromic RP in this region is 1:2,086. The prevalence of RP was higher among Arab Muslims (1:1,798) compared to Jews (1:2,230), mainly due to consanguineous marriages that are more common in the Arab Muslim population. To identify the genetic causes of RP in our cohort, we recruited 383 patients from 183 different families for genetic analysis: 70 with autosomal recessive (AR) inheritance, 15 with autosomal dominant, 86 isolate cases, and 12 with an X-linked inheritance pattern. In 64 (35%) of the families, we identified the genetic cause of the disease, and we revised the inheritance pattern of 20 isolate cases to the AR pattern; 49% of the families in our cohort had AR inheritance. Interestingly, in 42 (66%) of the genetically identified families, the cause of disease was a founder mutation. Previous studies

  10. F8 and F9 mutations in US haemophilia patients: correlation with history of inhibitor and race/ethnicity.

    Science.gov (United States)

    Miller, C H; Benson, J; Ellingsen, D; Driggers, J; Payne, A; Kelly, F M; Soucie, J M; Craig Hooper, W

    2012-05-01

    Both genetic and treatment-related risk factors contribute to the development of inhibitors in haemophilia. An inhibitor surveillance system piloted at 12 US sites has the goal of assessing risk factors through prospective data collection. This report examines the relationship of genotype and race/ethnicity to history of inhibitor in a large cohort of US haemophilia patients. Mutation analysis was performed on 676 haemophilia A (HA) and 153 haemophilia B (HB) patients by sequencing, Multiplex Ligation-dependent Probe Amplification, and PCR for inversions in F8 introns 22 (inv22) and 1 (inv1). Two HB patients with deletions had history of inhibitor. In severe HA, frequency of history of inhibitor was: large deletion 57.1%, splice site 35.7%, inv22 26.8%, nonsense 24.5%, frameshift 12.9%, inv1 11.1% and missense 9.5%. In HA, 19.6% of 321 White non-Hispanics (Whites), 37.1% of 35 Black non-Hispanics (Blacks) and 46.9% of 32 Hispanics had history of inhibitor (P = 0.0003). Mutation types and novel mutation rates were similar across ethnicities. When F8 haplotypes were constructed, Whites and Hispanics showed only H1 and H2. Within H1, history of inhibitor was 12.4% in Whites, 40.0% in Blacks (P = 0.009) and 32.4% in Hispanics (P = 0.002). Inhibitor frequency is confirmed to vary by mutation type and race in a large US population. White patients with history of inhibitor did not exhibit rare F8 haplotypes. F8 gene analysis did not reveal a cause for the higher inhibitor frequencies in Black and Hispanic patients. © 2011 Blackwell Publishing Ltd.

  11. Mutation profiling of the hepatitis B virus strains circulating in North Indian population.

    Directory of Open Access Journals (Sweden)

    Amit Tuteja

    Full Text Available AIMS: The aim of this study was to investigate the genomic mutations in the circulating Hepatitis B virus strains causing infection in the Indian population. Further, we wanted to analyze the biological significance of these mutations in HBV mediated disease. METHODS: 222 HBsAg positive patients were enrolled in the study. The genotype and mutation profile was determined for the infecting HBV isolate by sequencing overlapping fragments. These sequences were analyzed by using different tools and compared with previously available HBV sequence information. Mutation Frequency Index (MFI for the Genes and Diagnosis group was also calculated. RESULTS: HBV Genotype D was found in 55% (n = 121 of the patient group and genotype A was found in 30% (n = 66 of samples. The majority (52% of the HBV-infected individuals in the present study were HBeAg-negative in all the age groups studied. Spontaneous drug associated mutations implicated in resistance to antiviral therapy were also identified in about quarter of our patients, which is of therapeutic concern. The MFI approach used in the study indicated that Core peptide was the most conserved region in both genotypes and Surface peptide had highest mutation frequency. Few mutations in X gene (T36A and G50R showed high frequency of association with HCC. A rare recombinant strain of HBV genotype A and D was also identified in the patient group. CONCLUSIONS: HBV genotype D was found out to be most prevalent. More than half of the patients studied had HBeAg negative disease. Core region was found to be most conserved. Drug Associated mutations were detected in 22% of the patient group and T36A and G50R mutations in X gene were found to be associated with HCC.

  12. A common Greenlandic Inuit BRCA1 RING domain founder mutation

    DEFF Research Database (Denmark)

    Hansen, T.v.O.; Ejlertsen, B.; Albrechtsen, Anders

    2009-01-01

    of the families had members with ovarian cancer, suggesting that the RING domain may be an ovarian cancer hotspot. By SNP array analysis, we find that all 13 families share a 4.5 Mb genomic fragment containing the BRCA1 gene, showing that the mutation originates from a founder. Finally, analysis of 1152 Inuit......, representing almost ~2% of the total Greenlandic Inuit population, showed that the frequency of the mutation was 1.0%. We conclude that the BRCA1 nucleotide 234 T > G is a common Greenlandic Inuit founder mutation. The relative high frequency in the general population, together with the ease of screening...... and possibility to reduce mortality in gene carriers, may warrant screening of the Greenlandic Inuit population. Provided screening is efficient, about 5% of breast- and 13% of ovarian cancers, respectively, may be prevented Udgivelsesdato: 2009/5...

  13. Mutation, Witten index, and quiver invariant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Heeyeon [Perimeter Institute for Theoretical Physics,31 Caroline Street North, Waterloo, N2L 2Y5, Ontario (Canada); Lee, Seung-Joo [Department of Physics, Robeson Hall, Virginia Tech,Blacksburg, VA 24061 (United States); Yi, Piljin [School of Physics, Korea Institute for Advanced Study,Seoul 130-722 (Korea, Republic of)

    2015-07-20

    We explore Seiberg-like dualities, or mutations, for N=4 quiver quantum mechanics in the context of wall-crossing. In contrast to higher dimensions, the 1d Seiberg-duality must be performed with much care. With fixed Fayet-Iliopoulos constants, at most two nodes can be mutated, one left and the other right, mapping a chamber of a quiver into a chamber of a mutated quiver. We delineate this complex pattern for triangle quivers and show how the Witten indices are preserved under such finely chosen mutations. On the other hand, the quiver invariants, or wall-crossing-safe part of supersymmetric spectra, mutate more straightforwardly, whereby a quiver is mapped to a quiver. The mutation rule that preserves the quiver invariant is different from the usual one, however, which we explore and confirm numerically.

  14. Mutation, Witten index, and quiver invariant

    International Nuclear Information System (INIS)

    Kim, Heeyeon; Lee, Seung-Joo; Yi, Piljin

    2015-01-01

    We explore Seiberg-like dualities, or mutations, for N=4 quiver quantum mechanics in the context of wall-crossing. In contrast to higher dimensions, the 1d Seiberg-duality must be performed with much care. With fixed Fayet-Iliopoulos constants, at most two nodes can be mutated, one left and the other right, mapping a chamber of a quiver into a chamber of a mutated quiver. We delineate this complex pattern for triangle quivers and show how the Witten indices are preserved under such finely chosen mutations. On the other hand, the quiver invariants, or wall-crossing-safe part of supersymmetric spectra, mutate more straightforwardly, whereby a quiver is mapped to a quiver. The mutation rule that preserves the quiver invariant is different from the usual one, however, which we explore and confirm numerically.

  15. Somatic mtDNA mutation spectra in the aging human putamen.

    Directory of Open Access Journals (Sweden)

    Siôn L Williams

    Full Text Available The accumulation of heteroplasmic mitochondrial DNA (mtDNA deletions and single nucleotide variants (SNVs is a well-accepted facet of the biology of aging, yet comprehensive mutation spectra have not been described. To address this, we have used next generation sequencing of mtDNA-enriched libraries (Mito-Seq to investigate mtDNA mutation spectra of putamen from young and aged donors. Frequencies of the "common" deletion and other "major arc" deletions were significantly increased in the aged cohort with the fold increase in the frequency of the common deletion exceeding that of major arc deletions. SNVs also increased with age with the highest rate of accumulation in the non-coding control region which contains elements necessary for translation and replication. Examination of predicted amino acid changes revealed a skew towards pathogenic SNVs in the coding region driven by mutation bias. Levels of the pathogenic m.3243A>G tRNA mutation were also found to increase with age. Novel multimeric tandem duplications that resemble murine control region multimers and yeast ρ(- mtDNAs, were identified in both young and aged specimens. Clonal ∼50 bp deletions in the control region were found at high frequencies in aged specimens. Our results reveal the complex manner in which the mitochondrial genome alters with age and provides a foundation for studies of other tissues and disease states.

  16. AIP mutations in Brazilian patients with sporadic pituitary adenomas: a single-center evaluation

    Directory of Open Access Journals (Sweden)

    Paula Bruna Araujo

    2017-11-01

    Full Text Available Aryl hydrocarbon receptor-interacting protein (AIP gene mutations (AIPmut are the most frequent germline mutations found in apparently sporadic pituitary adenomas (SPA. Our aim was to evaluate the frequency of AIPmut among young Brazilian patients with SPA. We performed an observational cohort study between 2013 and 2016 in a single referral center. AIPmut screening was carried out in 132 SPA patients with macroadenomas diagnosed up to 40 years or in adenomas of any size diagnosed until 18 years of age. Twelve tumor samples were also analyzed. Leukocyte DNA and tumor tissue DNA were sequenced for the entire AIP-coding region for evaluation of mutations. Eleven (8.3% of the 132 patients had AIPmut, comprising 9/74 (12% somatotropinomas, 1/38 (2.6% prolactinoma, 1/10 (10% corticotropinoma and no non-functioning adenomas. In pediatric patients (≤18 years, AIPmut frequency was 13.3% (2/15. Out of the 5 patients with gigantism, two had AIPmut, both truncating mutations. The Y268* mutation was described in Brazilian patients and the K273Rfs*30 mutation is a novel mutation in our patient. No somatic AIP mutations were found in the 12 tumor samples. A tumor sample from an acromegaly patient harboring the A299V AIPmut showed loss of heterozygosity. In conclusion, AIPmut frequency in SPA Brazilian patients is similar to other populations. Our study identified two mutations exclusively found in Brazilians and also shows, for the first time, loss of heterozygosity in tumor DNA from an acromegaly patient harboring the A299V AIPmut. Our findings corroborate previous observations that AIPmut screening should be performed in young patients with SPA.

  17. Soft sweeps III: the signature of positive selection from recurrent mutation.

    Directory of Open Access Journals (Sweden)

    Pleuni S Pennings

    2006-12-01

    Full Text Available Polymorphism data can be used to identify loci at which a beneficial allele has recently gone to fixation, given that an accurate description of the signature of selection is available. In the classical model that is used, a favored allele derives from a single mutational origin. This ignores the fact that beneficial alleles can enter a population recurrently by mutation during the selective phase. In this study, we present a combination of analytical and simulation results to demonstrate the effect of adaptation from recurrent mutation on summary statistics for polymorphism data from a linked neutral locus. We also analyze the power of standard neutrality tests based on the frequency spectrum or on linkage disequilibrium (LD under this scenario. For recurrent beneficial mutation at biologically realistic rates, we find substantial deviations from the classical pattern of a selective sweep from a single new mutation. Deviations from neutrality in the level of polymorphism and in the frequency spectrum are much less pronounced than in the classical sweep pattern. In contrast, for levels of LD, the signature is even stronger if recurrent beneficial mutation plays a role. We suggest a variant of existing LD tests that increases their power to detect this signature.

  18. Cross-Sectional Study for the Detection of Mutations in the Beta-Globin Gene Among Patients with Hemoglobinopathies in the Bengali Population.

    Science.gov (United States)

    Panja, Amrita; Chowdhury, Prosanto; Chakraborty, Sharmistha; Ghosh, Tapan Kumar; Basu, Anupam

    2017-01-01

    Thalassemia is a common autosomal recessive blood disorder, which is most prevalent in South East Asian and Mediterranean populations. It is considered as a major health burden in the Indian population. The aims of the present study were to investigate the common, as well as uncommon, mutations responsible for thalassemia in the Bengali population. The Bengali state was divided into four sampling zones. Mutation detection was done using Sanger sequencing of the HBB gene. A total of 14 different mutations were observed, including rare mutations IVS1-130(G>C), IVS1-129(A>C), -90(T>C), CD16(-C), -30(T>C), CD15(-T), and a novel mutation CD53(C>T). The frequencies of IVS1-5(G>C) and CD26(G>A) mutations were higher than other mutations. There were also some silent polymorphisms found in the studied group, CD3(T>C), CD10(C>A), IVSII-16(G>C), IVSII-74(T>G), -42(C>G). The present study is the first attempt to screen for β-thalassemia-causing mutations by direct sequencing in different districts of West Bengal. The information obtained from the present study may be helpful for thalassemia management and prenatal mutation detection.

  19. Induction of somatic mutations by low-dose X-rays: the challenge in recognizing radiation-induced events.

    Science.gov (United States)

    Nagashima, Haruki; Shiraishi, Kumiko; Ohkawa, Saori; Sakamoto, Yuki; Komatsu, Kenshi; Matsuura, Shinya; Tachibana, Akira; Tauchi, Hiroshi

    2017-10-19

    It is difficult to distinguish radiation-induced events from spontaneous events during induction of stochastic effects, especially in the case of low-dose or low-dose-rate exposures. By using a hypersensitive system for detecting somatic mutations at the HPRT1 locus, we investigated the frequency and spectrum of mutations induced by low-dose X-rays. The mutant frequencies induced by doses of >0.15 Gy were statistically significant when compared with the spontaneous frequency, and a clear dose dependency was also observed for mutant frequencies at doses of >0.15 Gy. In contrast, mutant frequencies at doses of 0.2 Gy. Our observations suggest that there could be a critical dose for mutation induction at between 0.1 Gy and 0.2 Gy, where mutagenic events are induced by multiple DNA double-strand breaks (DSBs). These observations also suggest that low-dose radiation delivered at doses of <0.1 Gy may not result in DSB-induced mutations but may enhance spontaneous mutagenesis events. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  20. Somatic gene mutation in the human in relation to radiation risk

    International Nuclear Information System (INIS)

    Mendelsohn, M.L.

    1992-01-01

    This report discusses the measurement of somatic gene-mutation frequencies in the human. We ask the following questions. How well can they be measured? Do they respond to radiation? Can they also function as a dosimeter? What do they tell us about the somatic mutation theory of carcinogenesis?

  1. Influence of single and combination treatments of physical and chemical mutagen on chlorophyll mutations in Finger Millet

    International Nuclear Information System (INIS)

    Kumar, Binod; Mahto, Jaylal; Haider, Z.A.

    1993-01-01

    Gamma rays, ethyl methane sulfonate (EMS) and their combined treatments influenced differently in producing chlorophyll mutations. A good number of chlorophyll mutants with varied frequencies were recorded in M 2 generation. The frequency of chlorophyll mutants was higher at lower doses of gamma rays, EMS and their combination treatments. The most frequently observed mutant was Albino type. The other chlorophyll mutants isolated were Xantha, Viridis, Striata and Tigrina. The frequency of tigrina and striata was lowest in variety A-404 and Hr-374, respectively. The efficiency and effectiveness was high at the lower doses of mutagens in both the varieties. EMS (0.2%) was more effective than the corresponding lower dose of gamma rays for both the varieties. (author). 10 refs., 4 tabs

  2. Activation of the SOS response increases the frequency of small colony variants

    DEFF Research Database (Denmark)

    Vestergaard, Martin; Paulander, Wilhelm Erik Axel; Ingmer, Hanne

    2015-01-01

    BACKGROUND: In Staphylococcus aureus sub-populations of slow-growing cells forming small colony variants (SCVs) are associated with persistent and recurrent infections that are difficult to eradicate with antibiotic therapies. In SCVs that are resistant towards aminoglycosides, mutations have been...... with different mechanism of action influence the formation of SCVs that are resistant to otherwise lethal concentrations of the aminoglycoside, gentamicin. We found that exposure of S. aureus to fluoroquinolones and mitomycin C increased the frequency of gentamicin resistant SCVs, while other antibiotic classes...... failed to do so. The higher proportion of SCVs in cultures exposed to fluoroquinolones and mitomycin C compared to un-exposed cultures correlate with an increased mutation rate monitored by rifampicin resistance and followed induction of the SOS DNA damage response. CONCLUSION: Our observations suggest...

  3. SQSTM1 mutations in French patients with frontotemporal dementia or frontotemporal dementia with amyotrophic lateral sclerosis.

    Science.gov (United States)

    Le Ber, Isabelle; Camuzat, Agnès; Guerreiro, Rita; Bouya-Ahmed, Kawtar; Bras, Jose; Nicolas, Gael; Gabelle, Audrey; Didic, Mira; De Septenville, Anne; Millecamps, Stéphanie; Lenglet, Timothée; Latouche, Morwena; Kabashi, Edor; Campion, Dominique; Hannequin, Didier; Hardy, John; Brice, Alexis

    2013-11-01

    Mutations in the SQSTM1 gene, coding for p62, are a cause of Paget disease of bone and amyotrophic lateral sclerosis (ALS). Recently, SQSTM1 mutations were confirmed in ALS, and mutations were also identified in 3 patients with frontotemporal dementia (FTD), suggesting a role for SQSTM1 in FTD. To evaluate the exact contribution of SQSTM1 to FTD and FTD with ALS (FTD-ALS) in an independent cohort of patients. A SQSTM1 mutation was first identified in a multiplex family with FTD by use of whole-exome sequencing. To evaluate the frequency of SQSTM1 mutations, we sequenced this gene in a cohort of patients with FTD or FTD-ALS, with no mutations in known FTD and ALS genes. Primary care or referral center. An overall cohort of 188 French patients, including 132 probands with FTD and 56 probands with FTD-ALS. Frequency of SQSTM1 mutations in patients with FTD or FTD-ALS; description of associated phenotypes. We identified 4 heterozygous missense mutations in 4 unrelated families with FTD; only 1 family had clinical symptoms of Paget disease of bone, and only 1 family had clinical symptoms of FTD-ALS, possibly owing to the low penetrance of some of the clinical manifestations. Although the frequency of the mutations is low in our series (4 of 188 patients [2%]), our results, similar to those already reported, support a direct pathogenic role of p62 in different types of FTD.

  4. Studies of human mutation rates, December 1, 1985--November 30, 1986

    International Nuclear Information System (INIS)

    Neel, J.V.

    1985-01-01

    This program seeks to quantify native human mutation rates and to determine how man's activities may affect these rates. The program is divided into six tasks, i.e. The American Indian mutation rate, monitoring populations for frequency of mutation by electrophoresis of blood proteins, application of molecular biological approaches to the detection and study of mutational events in human populations, development of two-dimensional electrophoresis for identification of mutant proteins, co-operative program with the Radiation Effects Research Foundation in Hiroshima and Nagasaki, Japan, and statistical problems associated with the estimation of mutation rates. Progress of each of the above tasks is related in detail. (DT)

  5. Phenylketonuria mutation analysis in Northern Ireland: A rapid stepwise approach

    Energy Technology Data Exchange (ETDEWEB)

    Zschocke, J.; Graham, C.A.; Nevin, N.C. [Queen`s Univ., Belfast (Australia)] [and others

    1995-12-01

    We present a multistep approach for the rapid analysis of phenylketonuria (PKU) mutations. In the first step, three common mutations and a polymorphic short tandem repeat (STR) system are rapidly analyzed with a fluorescent multiplex assay. In the second step, minihaplotypes combining STR and VNTR data are used to determine rare mutations likely to be present in an investigated patient, which are then confirmed by restriction enzyme analysis. The remaining mutations are analyzed with denaturant gradient-gel electrophoresis and sequencing. The first two steps together identify both mutations in 90%-95% of PKU patients, and results can be obtained within 2 d. We have investigated 121 Northern Irish families with hyperphenylalaninemia, including virtually all patients born since 1972, and have found 34 different mutations on 241 of the 242 mutant alleles. Three mutations (R408W, 165T, and F39L) account for 57.5% of mutations, while 14 mutations occur with a frequency of 1%-6%. The present analysis system is efficient and inexpensive and is particularly well suited to routine mutation analysis in a diagnostic setting. 19 refs., 5 tabs.

  6. Gaucher disease: N370S glucocerebrosidase gene frequency in the Portuguese population

    NARCIS (Netherlands)

    Lacerda, L.; Amaral, O.; Pinto, R.; Oliveira, P.; Aerts, J.; Sá Miranda, M. C.

    1994-01-01

    In the Portuguese population the most frequent form of Gaucher disease is type 1. The N370S glucocerebrosidase gene mutation accounts for 63% of mutated alleles. The frequency of this mutation was accurately determined in the Portuguese population, which does not present an Ashkenazi Jewish genetic

  7. Detection of new MHC mutations in mice by skin grafting, tumor transplantation and monoclonal antibodies: a comparison

    International Nuclear Information System (INIS)

    Egorov, I.K.; Egorov, O.S.

    1988-01-01

    Two mechanisms of major histocompatibility complex (MHC) mutations have been described in mice: gene conversion and homologous but unequal recombination. However, the knowledge of mutations in MHC is incomplete because studies have been limited almost exclusively to two haplotypes, H-2/sup b/ and H-2/sup d/, while hundreds of haplotypes exist in nature; it has been biased by the use of only one procedure of screening for mutation, skin grafting. The authors used three procedures to screen for MHC mutations: (1) conventional techniques of skin grafting, (2) syngeneic tumor transplantation and (3) typing with monoclonal anti-MHC antibodies (mAbs) and complement. The faster technique of tumor transplantation detected mutants similar to those discovered by skin grafting technique. Screening with mAbs allowed us to detect both mutants that are capable of rejecting standard skin grafts and those that are silent in skin grafting tests, and which therefore resulted in a higher apparent mutation frequency. Two mutants of the H-2/sup a/ haplotype were found that carry concomitant class I and class II antigenic alterations. Both MHC mutants silent in skin grafting tests and mutants carrying concomitant class I and class II alterations have never been studied before and are expected to reveal new mechanisms of generating MHC mutations. 1-Ethyl-1-nitrosourea (ENU) failed to induce de novo MHC mutations in our skin grafting series

  8. Utilization of the higher plants in a study on hereditary effect of low-dose irradiation

    International Nuclear Information System (INIS)

    Yamashita, Jun

    1976-01-01

    Some problems in a study of hereditary effect of low-dose irradiation, which used the higher plants (tradescantia, peas, etc.) as materials, were mentioned. Conditions to be used as materials were mentioned as follows: 1) the materials must have high radio-sensitivity, 2) the natural mutation of the materials must be low, 3) hereditary uniformity and stability of genes in the materials were important, and 4) in case of considering the materials as environmental radiation monitors, the observation period must be long and the duration from exposure to detection of mutation must be short. Tradescantia has most of these conditions, but the greatest fault is that the object of its observation is mutation of somatic cells, and hereditary study is impossible. Therefore, it is necessary to find out other materials in order to solve the problem whether there is a difference in relative frequency of chromosomal abnormalities, which occurrs in germinal cells and is transmitted to posterity, between low and high doses or not. (Serizawa, K.)

  9. High frequency of Plasmodium falciparum chloroquine resistance marker (pfcrt T76 mutation) in Yemen: an urgent need to re-examine malaria drug policy.

    Science.gov (United States)

    Al-Mekhlafi, Abdulsalam M; Mahdy, Mohammed A K; Al-Mekhlafi, Hesham M; Azazy, Ahmed A; Fong, Mun Yik

    2011-05-27

    Malaria remains a significant health problem in Yemen with Plasmodium falciparum being the predominant species which is responsible for 90% of the malaria cases. Despite serious concerns regarding increasing drug resistance, chloroquine is still used for the prevention and treatment of malaria in Yemen. This study was carried out to determine the prevalence of choloroquine resistance (CQR) of P. falciparum isolated from Yemen based on the pfcrt T76 mutation. A cross-sectional study was carried out among 511 participants from four governorates in Yemen. Blood samples were screened using microscopic and species-specific nested PCR based on the 18S rRNA gene to detect and identify Plasmodium species. Blood samples positive for P. falciparum were used for detecting the pfcrt T76 mutation using nested-PCR. The prevalence of pfcrt T76 mutation was 81.5% (66 of 81 isolates). Coastal areas/foothills had higher prevalence of pfcrt T76 mutation compared to highland areas (90.5% vs 71.8%) (p = 0.031). The pfcrt T76 mutation had a significant association with parasitaemia (p = 0.045). Univariate analysis shows a significant association of pfcrt T76 mutation with people aged > 10 years (OR = 9, 95% CI = 2.3 - 36.2, p = 0.001), low household income (OR = 5, 95% CI = 1.3 - 19.5, p = 0.027), no insecticide spray (OR = 3.7, 95% CI = 1.16 - 11.86, p = 0.025) and not sleeping under insecticide treated nets (ITNs) (OR = 4.8, 95% CI = 1.38 - 16.78, p = 0.01). Logistic regression model confirmed age > 10 years and low household income as predictors of pfcrt T76 mutation in Yemen P. falciparum isolates. The high prevalence of pfcrt T76 mutation in Yemen could be a predictive marker for the prevalence of P. falciparum CQR. This finding shows the necessity for an in-vivo therapeutic efficacy test for CQ. P. falciparum CQR should be addressed in the national strategy to control malaria.

  10. Wilson's disease in Southern Brazil: genotype-phenotype correlation and description of two novel mutations in ATP7B gene

    Directory of Open Access Journals (Sweden)

    Ricardo Schmitt de Bem

    2013-08-01

    Full Text Available OBJECTIVE: Wilson's disease (WD is an inborn error of metabolism caused by abnormalities of the copper-transporting protein encoding gene ATP7B. In this study, we examined ATP7B for mutations in a group of patients living in southern Brazil. METHODS: 36 WD subjects were studied and classified according to their clinical and epidemiological data. In 23 subjects the ATP7B gene was analyzed. RESULTS: Fourteen distinct mutations were detected in at least one of the alleles. The c.3207C>A substitution at exon 14 was the most common mutation (allelic frequency=37.1% followed by the c.3402delC at exon 15 (allelic frequency=11.4%. The mutations c.2018-2030del13 at exon 7 and c.4093InsT at exon 20 are being reported for the first time. CONCLUSION: The c.3207C>A substitution at exon 14, was the most common mutation, with an allelic frequency of 37.1%. This mutation is the most common mutation described in Europe.

  11. Frequent POLE1 p.S297F mutation in Chinese patients with ovarian endometrioid carcinoma

    International Nuclear Information System (INIS)

    Zou, Yang; Liu, Fa-Ying; Liu, Huai; Wang, Feng; Li, Wei; Huang, Mei-Zhen; Huang, Yan; Yuan, Xiao-Qun; Xu, Xiao-Yun; Huang, Ou-Ping; He, Ming

    2014-01-01

    The catalytic subunit of DNA polymerase epsilon (POLE1) functions primarily in nuclear DNA replication and repair. Recently, POLE1 mutations were detected frequently in colorectal and endometrial carcinomas while with lower frequency in several other types of cancer, and the p.P286R and p.V411L mutations were the potential mutation hotspots in human cancers. Nevertheless, the mutation frequency of POLE1 in ovarian cancer still remains largely unknown. Here, we screened a total of 251 Chinese samples with distinct subtypes of ovarian carcinoma for the presence of POLE1 hotspot mutations by direct sequencing. A heterozygous somatic POLE1 mutation, p.S297F (c.890C>T), but not p.P286R and p.V411L hotspot mutations observed in other cancer types, was identified in 3 out of 37 (8.1%) patients with ovarian endometrioid carcinoma; this mutation was evolutionarily highly conserved from Homo sapiens to Schizosaccharomyces. Of note, the POLE1 mutation coexisted with mutation in the ovarian cancer-associated PPP2R1A (protein phosphatase 2, regulatory subunit A, α) gene in a 46-year-old patient, who was also diagnosed with ectopic endometriosis in the benign ovary. In addition, a 45-year-old POLE1-mutated ovarian endometrioid carcinoma patient was also diagnosed with uterine leiomyoma while the remaining 52-year-old POLE1-mutated patient showed no additional distinctive clinical manifestation. In contrast to high frequency of POLE1 mutations in ovarian endometrioid carcinoma, no POLE1 mutations were identified in patients with other subtypes of ovarian carcinoma. Our results showed for the first time that the POLE1 p.S297F mutation, but not p.P286R and p.V411L hotspot mutations observed in other cancer types, was frequent in Chinese ovarian endometrioid carcinoma, but absent in other subtypes of ovarian carcinoma. These results implicated that POLE1 p.S297F mutation might be actively involved in the pathogenesis of ovarian endometrioid carcinoma, but might not be actively

  12. Frequent POLE1 p.S297F mutation in Chinese patients with ovarian endometrioid carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Yang; Liu, Fa-Ying; Liu, Huai; Wang, Feng [Key Laboratory of Women' s Reproductive Health of Jiangxi Province, Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, Jiangxi 330006 (China); Central Laboratory, Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, Jiangxi 330006 (China); Li, Wei [Key Laboratory of Women' s Reproductive Health of Jiangxi Province, Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, Jiangxi 330006 (China); Central Laboratory, Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, Jiangxi 330006 (China); Graduate School of Nanchang University, Nanchang, Jiangxi 330031 (China); Huang, Mei-Zhen [Graduate School of Nanchang University, Nanchang, Jiangxi 330031 (China); Jiangxi Provincial Cancer Institute, Jiangxi Provincial Cancer Hospital, Nanchang, Jiangxi 330029 (China); Huang, Yan; Yuan, Xiao-Qun [Key Laboratory of Women' s Reproductive Health of Jiangxi Province, Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, Jiangxi 330006 (China); Central Laboratory, Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, Jiangxi 330006 (China); Graduate School of Nanchang University, Nanchang, Jiangxi 330031 (China); Xu, Xiao-Yun [Graduate School of Nanchang University, Nanchang, Jiangxi 330031 (China); Jiangxi Provincial Cancer Institute, Jiangxi Provincial Cancer Hospital, Nanchang, Jiangxi 330029 (China); Huang, Ou-Ping, E-mail: huangouping@gmail.com [Jiangxi Provincial Cancer Institute, Jiangxi Provincial Cancer Hospital, Nanchang, Jiangxi 330029 (China); He, Ming, E-mail: jxhm56@hotmail.com [Department of Pharmacology and Molecular Therapeutics, Nanchang University School of Pharmaceutical Science, Nanchang 330006 (China)

    2014-03-15

    The catalytic subunit of DNA polymerase epsilon (POLE1) functions primarily in nuclear DNA replication and repair. Recently, POLE1 mutations were detected frequently in colorectal and endometrial carcinomas while with lower frequency in several other types of cancer, and the p.P286R and p.V411L mutations were the potential mutation hotspots in human cancers. Nevertheless, the mutation frequency of POLE1 in ovarian cancer still remains largely unknown. Here, we screened a total of 251 Chinese samples with distinct subtypes of ovarian carcinoma for the presence of POLE1 hotspot mutations by direct sequencing. A heterozygous somatic POLE1 mutation, p.S297F (c.890C>T), but not p.P286R and p.V411L hotspot mutations observed in other cancer types, was identified in 3 out of 37 (8.1%) patients with ovarian endometrioid carcinoma; this mutation was evolutionarily highly conserved from Homo sapiens to Schizosaccharomyces. Of note, the POLE1 mutation coexisted with mutation in the ovarian cancer-associated PPP2R1A (protein phosphatase 2, regulatory subunit A, α) gene in a 46-year-old patient, who was also diagnosed with ectopic endometriosis in the benign ovary. In addition, a 45-year-old POLE1-mutated ovarian endometrioid carcinoma patient was also diagnosed with uterine leiomyoma while the remaining 52-year-old POLE1-mutated patient showed no additional distinctive clinical manifestation. In contrast to high frequency of POLE1 mutations in ovarian endometrioid carcinoma, no POLE1 mutations were identified in patients with other subtypes of ovarian carcinoma. Our results showed for the first time that the POLE1 p.S297F mutation, but not p.P286R and p.V411L hotspot mutations observed in other cancer types, was frequent in Chinese ovarian endometrioid carcinoma, but absent in other subtypes of ovarian carcinoma. These results implicated that POLE1 p.S297F mutation might be actively involved in the pathogenesis of ovarian endometrioid carcinoma, but might not be actively

  13. Loss of photoreversibility for UV mutation in E. coli using 405 nm or near-UV challenge

    International Nuclear Information System (INIS)

    Kristoff, S.; Bockrath, R.

    1983-01-01

    E. coli mutagenized with germicidal ultraviolet light (UV) were incubated to allow for development of mutation-fixation processes. Fixation was estimated from the effects on mutation frequency of photoreactivation challenge during the first 60 min post-UV. Two different light sources were used for photoreactivation, one providing effective light primarily at 405 nm and another providing a broad range of near-UV around 365 nm. Kinetics for the loss of photoreversibility (LOP) were determined. The times for completion of LOP in wild-type cells indicated one fixation process for back mutation and another for de novo or converted suppressor mutation regardless of the light source. Using 405-nm light for photoreactivation, the LOP kinetics for back mutation and de novo suppressor mutation in uvrA cells were similar. Hence, classical observations were confirmed here. Immediately post-UV all mutation frequencies were more sensitive to near-UV than 405-nm light. (orig./AJ)

  14. Genetic improvement of 'NPq' rice with induced mutations

    International Nuclear Information System (INIS)

    Ram, Mahabal

    1974-01-01

    Exposure of the seeds of rice to different doses of gamma-rays increased the total mutation frequency with an increase in the dose rate, and the most economic mutations occurred around 30 kr. Induced mutants with dwarf plant type, early maturity, fine grain, high-yielding ability, and resistance to lodging and major diseases were isolated in the M, and M generations. Genetical studies indicated that height is controlled by 4 pairs of additive genes, grass-clumps by 2 pairs of non-allelic interacting genes (inhibitory), and chlorophyll mutations such as albina by 2 pairs of duplicate genes and xantha by a single gene pair. (author)

  15. NPM1 mutations in therapy-related acute myeloid leukemia with uncharacteristic features

    DEFF Research Database (Denmark)

    Andersen, Morten Tolstrup; Andersen, Mette Klarskov; Christiansen, D.H.

    2008-01-01

    Frameshift mutations of the nucleophosmin gene (NPM1) were recently reported as a frequently occurring abnormality in patients with de novo acute myeloid leukemia (AML). To evaluate the frequency of NPM1 mutations in patients with therapy-related myelodysplasia (t-MDS) and therapy-related AML (t......-/-7, the most frequent abnormalities of t-MDS/t-AML, were not observed (P=0.002). This raises the question whether some of the cases presenting NPM1 mutations were in fact cases of de novo leukemia. The close association to class I mutations and the inverse association to class II mutations suggest...

  16. Presence of atypical thrombopoietin receptor (MPL) mutations in triple-negative essential thrombocythemia patients.

    Science.gov (United States)

    Cabagnols, Xénia; Favale, Fabrizia; Pasquier, Florence; Messaoudi, Kahia; Defour, Jean Philippe; Ianotto, Jean Christophe; Marzac, Christophe; Le Couédic, Jean Pierre; Droin, Nathalie; Chachoua, Ilyas; Favier, Remi; Diop, M'boyba Khadija; Ugo, Valérie; Casadevall, Nicole; Debili, Najet; Raslova, Hana; Bellanné-Chantelot, Christine; Constantinescu, Stefan N; Bluteau, Olivier; Plo, Isabelle; Vainchenker, William

    2016-01-21

    Mutations in signaling molecules of the cytokine receptor axis play a central role in myeloproliferative neoplasm (MPN) pathogenesis. Polycythemia vera is mainly related to JAK2 mutations, whereas a wider mutational spectrum is detected in essential thrombocythemia (ET) with mutations in JAK2, the thrombopoietin (TPO) receptor (MPL), and the calreticulin (CALR) genes. Here, we studied the mutational profile of 17 ET patients negative for JAK2V617F, MPLW515K/L, and CALR mutations, using whole-exome sequencing and next-generation sequencing (NGS) targeted on JAK2 and MPL. We found several signaling mutations including JAK2V617F at very low allele frequency, 1 homozygous SH2B3 mutation, 1 MPLS505N, 1 MPLW515R, and 2 MPLS204P mutations. In the remaining patients, 4 presented a clonal and 7 a polyclonal hematopoiesis, suggesting that certain triple-negative ETs are not MPNs. NGS on 26 additional triple-negative ETs detected only 1 MPLY591N mutation. Functional studies on MPLS204P and MPLY591N revealed that they are weak gain-of-function mutants increasing MPL signaling and conferring either TPO hypersensitivity or independence to expressing cells, but with a low efficiency. Further studies should be performed to precisely determine the frequency of MPLS204 and MPLY591 mutants in a bigger cohort of MPN. © 2016 by The American Society of Hematology.

  17. Investigation of mutations in the HBB gene using the 1,000 genomes database.

    Science.gov (United States)

    Carlice-Dos-Reis, Tânia; Viana, Jaime; Moreira, Fabiano Cordeiro; Cardoso, Greice de Lemos; Guerreiro, João; Santos, Sidney; Ribeiro-Dos-Santos, Ândrea

    2017-01-01

    Mutations in the HBB gene are responsible for several serious hemoglobinopathies, such as sickle cell anemia and β-thalassemia. Sickle cell anemia is one of the most common monogenic diseases worldwide. Due to its prevalence, diverse strategies have been developed for a better understanding of its molecular mechanisms. In silico analysis has been increasingly used to investigate the genotype-phenotype relationship of many diseases, and the sequences of healthy individuals deposited in the 1,000 Genomes database appear to be an excellent tool for such analysis. The objective of this study is to analyze the variations in the HBB gene in the 1,000 Genomes database, to describe the mutation frequencies in the different population groups, and to investigate the pattern of pathogenicity. The computational tool SNPEFF was used to align the data from 2,504 samples of the 1,000 Genomes database with the HG19 genome reference. The pathogenicity of each amino acid change was investigated using the databases CLINVAR, dbSNP and HbVar and five different predictors. Twenty different mutations were found in 209 healthy individuals. The African group had the highest number of individuals with mutations, and the European group had the lowest number. Thus, it is concluded that approximately 8.3% of phenotypically healthy individuals from the 1,000 Genomes database have some mutation in the HBB gene. The frequency of mutated genes was estimated at 0.042, so that the expected frequency of being homozygous or compound heterozygous for these variants in the next generation is approximately 0.002. In total, 193 subjects had a non-synonymous mutation, which 186 (7.4%) have a deleterious mutation. Considering that the 1,000 Genomes database is representative of the world's population, it can be estimated that fourteen out of every 10,000 individuals in the world will have a hemoglobinopathy in the next generation.

  18. IRF6 mutation screening in non-syndromic orofacial clefting

    DEFF Research Database (Denmark)

    Leslie, Elizabeth J; Koboldt, Daniel C; Kang, C. J.

    2016-01-01

    -syndromic OFCs. About 70% of causal VWS mutations occur in IRF6, a gene that is also associated with non-syndromic OFCs. Screening for IRF6 mutations in apparently non-syndromic cases has been performed in several modestly sized cohorts with mixed results. In this study, we screened 1521 trios with presumed non......-syndromic OFCs to determine the frequency of causal IRF6 mutations. We identified seven likely causal IRF6 mutations, although a posteriori review identified two misdiagnosed VWS families based on the presence of lip pits. We found no evidence for association between rare IRF6 polymorphisms and non......-syndromic OFCs. We combined our results with other similar studies (totaling 2472 families) and conclude that causal IRF6 mutations are found in 0.24–0.44% of apparently non-syndromic OFC families. We suggest that clinical mutation screening for IRF6 be considered for certain family patterns such as families...

  19. Analysis of common deafness gene mutations in deaf people from unique ethnic groups in Gansu Province, China.

    Science.gov (United States)

    Xu, Bai-Cheng; Bian, Pan-Pan; Liu, Xiao-Wen; Zhu, Yi-Ming; Yang, Xiao-Long; Ma, Jian-Li; Chen, Xing-Jian; Wang, Yan-Li; Guo, Yu-Fen

    2014-09-01

    The GJB2 gene mutation characteristic of Dongxiang was the interaction result of ethnic background and geographical environment, and Yugur exhibited the typical founder effect. The SLC26A4 gene mutation characteristic of Dongxiang was related to caucasian backgrounds and selection of purpose exons, i.e. ethnic background and the penetrance of ethnic specificity caused the low mtDNA1555A>G mutation frequency in Dongxiang. To determine the prevalence of GJB2 and SLC26A4 genes and mtDNA1555A>G mutations and analyze the ethnic specificity in the non-syndromic sensorineural hearing loss (NSHL) of unique ethnic groups in Gansu Province. Peripheral blood samples were obtained from Dongxiang, Yugur, Bonan, and ethnic Han groups with moderately severe to profound NSHL in Gansu Province. Bidirectional sequencing (or enzyme digestion) was applied to identify the sequence variations. The pathogenic allele frequency of the three gene mutations was different. The frequency of the GJB2 gene among the Dongxiang, Yugur, Bonan, and ethnic Han groups was 9.03%, 12.5%, 5.88%, and 12.17%, respectively. No difference was found between the ethnic groups. The frequencies of the SLC26A4 genes were 3.23%, 8.33%, 0%, and 9.81%, respectively. The mutation frequency of mtDNA1555A>G was 0%, 0%, 0%, and 6.03%, respectively. No difference was found between the ethnic groups, except for the Dongxiang and ethnic Han groups, both in SLC26A4 gene and mtDNA1555A>G.

  20. Repair of damage induced by ultraviolet radiation in mutator T-1 Escherichia coli transductants

    International Nuclear Information System (INIS)

    Sideropoulos, A.S.; Greenberg, J.; Warren, G.

    1975-01-01

    To ascertain whether a relationship commonly exists between azide resistance, ultraviolet (uv) resistance, and the mutator property (mut T-1), we performed uv survival and mutation frequency determinations with and without caffeine (2.571 mM) in nonmutator azide resistant (azi/sup r/) and phage mediated mut T-1 transductants of Escherichia coli K-12, B/r, B/r T-, Bs-1, and Bs-8. The strains constructed were assumed to be ''co-isogenic'' except for the mutator factor. The frequency of mutation to streptomycin resistance (str/sup r/) was relatively constant and approximated 2 x 10- 7 . Transductants carrying the azide marker with or without the mut T-1 gene had the same level of uv survival as the parent with the same mutator phenotype. Dark repair of the prelethal uv lesion is equally caffeine sensitive in the nonmutator and mutator HCR+ strains. Our results indicated that the mut T-1 strains possess an efficient dark repair system for uv damage and that the mechanism of mut T-1 action is independent of uv dark repair processes. (auth)

  1. Detection of mutation in isoniazid-resistant Mycobacterium tuberculosis isolates from tuberculosis patients in Belarus

    Directory of Open Access Journals (Sweden)

    Bostanabad S

    2008-01-01

    Full Text Available The aim of this study was to investigate the frequency, location and type of katG mutations in Mycobacterium tuberculosis strains isolated from patients in Belarus. Forty two isoniazid-resistant isolates were identified from sputum of 163 patients with active pulmonary tuberculosis. Drug susceptibility testing was determined by using CDC standard conventional proportional method and BACTEC system. Standard PCR method for detection of isoniazid resistance associated mutations was performed by katG gene amplification and DNA sequencing. Most mutations were found in katG gene codons 315, 316 and 309. Four types of mutations were identified in codon 315: AGC→ACC ( n = 36 85%, AGC→AGG ( n = 1 2.3%, AGC→AAC ( n = 2 4.7%, AGC→GGC ( n = 1 2.3%. One type of mutation was found in codon 316: GGC→AGC ( n = 1841.4%, four types of mutations were detected in codon 309: GGT→GGT ( n = 716.1%, GGT→GCT ( n = 49.2%, GGT→GTC ( n = 36.9%, GGT→GGG ( n = 12.7%. The highest frequency of mutations sharing between primary and secondary infections was found in codon 315.

  2. Introduction to mutation breeding and genetic research of soybean in China

    International Nuclear Information System (INIS)

    Zhan Mingkui; Zhao Jingrong

    1988-01-01

    This paper summarized the achievements and developments in mutation breeding and genetic research of soybean. The optimal irradiation dosage was determined for 22 varieties of soybean which have been released and popularized so far. Analyses of mutants, mutant characters and mutation frequency in the generations of M 1 , M 2 and M 3 of soybean were carried out and a procedure of mutation breeding was described. Discussion of the effect of different radiant agents, the selection of progeny induced by radiation, the breeding method by combining mutation with hybridization and resistant varieties with good quality ones have been conducted

  3. VarWalker: personalized mutation network analysis of putative cancer genes from next-generation sequencing data.

    Science.gov (United States)

    Jia, Peilin; Zhao, Zhongming

    2014-02-01

    A major challenge in interpreting the large volume of mutation data identified by next-generation sequencing (NGS) is to distinguish driver mutations from neutral passenger mutations to facilitate the identification of targetable genes and new drugs. Current approaches are primarily based on mutation frequencies of single-genes, which lack the power to detect infrequently mutated driver genes and ignore functional interconnection and regulation among cancer genes. We propose a novel mutation network method, VarWalker, to prioritize driver genes in large scale cancer mutation data. VarWalker fits generalized additive models for each sample based on sample-specific mutation profiles and builds on the joint frequency of both mutation genes and their close interactors. These interactors are selected and optimized using the Random Walk with Restart algorithm in a protein-protein interaction network. We applied the method in >300 tumor genomes in two large-scale NGS benchmark datasets: 183 lung adenocarcinoma samples and 121 melanoma samples. In each cancer, we derived a consensus mutation subnetwork containing significantly enriched consensus cancer genes and cancer-related functional pathways. These cancer-specific mutation networks were then validated using independent datasets for each cancer. Importantly, VarWalker prioritizes well-known, infrequently mutated genes, which are shown to interact with highly recurrently mutated genes yet have been ignored by conventional single-gene-based approaches. Utilizing VarWalker, we demonstrated that network-assisted approaches can be effectively adapted to facilitate the detection of cancer driver genes in NGS data.

  4. Presence of a consensus DNA motif at nearby DNA sequence of the mutation susceptible CG nucleotides.

    Science.gov (United States)

    Chowdhury, Kaushik; Kumar, Suresh; Sharma, Tanu; Sharma, Ankit; Bhagat, Meenakshi; Kamai, Asangla; Ford, Bridget M; Asthana, Shailendra; Mandal, Chandi C

    2018-01-10

    Complexity in tissues affected by cancer arises from somatic mutations and epigenetic modifications in the genome. The mutation susceptible hotspots present within the genome indicate a non-random nature and/or a position specific selection of mutation. An association exists between the occurrence of mutations and epigenetic DNA methylation. This study is primarily aimed at determining mutation status, and identifying a signature for predicting mutation prone zones of tumor suppressor (TS) genes. Nearby sequences from the top five positions having a higher mutation frequency in each gene of 42 TS genes were selected from a cosmic database and were considered as mutation prone zones. The conserved motifs present in the mutation prone DNA fragments were identified. Molecular docking studies were done to determine putative interactions between the identified conserved motifs and enzyme methyltransferase DNMT1. Collective analysis of 42 TS genes found GC as the most commonly replaced and AT as the most commonly formed residues after mutation. Analysis of the top 5 mutated positions of each gene (210 DNA segments for 42 TS genes) identified that CG nucleotides of the amino acid codons (e.g., Arginine) are most susceptible to mutation, and found a consensus DNA "T/AGC/GAGGA/TG" sequence present in these mutation prone DNA segments. Similar to TS genes, analysis of 54 oncogenes not only found CG nucleotides of the amino acid Arg as the most susceptible to mutation, but also identified the presence of similar consensus DNA motifs in the mutation prone DNA fragments (270 DNA segments for 54 oncogenes) of oncogenes. Docking studies depicted that, upon binding of DNMT1 methylates to this consensus DNA motif (C residues of CpG islands), mutation was likely to occur. Thus, this study proposes that DNMT1 mediated methylation in chromosomal DNA may decrease if a foreign DNA segment containing this consensus sequence along with CG nucleotides is exogenously introduced to dividing

  5. Surfactant protein B deficiency and gene mutations for neonatal respiratory distress syndrome in China Han ethnic population

    Science.gov (United States)

    Yin, Xiaojuan; Meng, Fanping; wang, Yan; Xie, Lu; Kong, Xiangyong; Feng, Zhichun

    2013-01-01

    Objective: To determine whether the SP-B deficiency and gene mutations in exon 4 is associated with neonatal RDS in China Han ethnic population. Methods: The study population consisted of 40 neonates with RDS and 40 neonates with other diseases as control in China Han ethnic population. We Compared SP-B expression in lung tissue and bronchoalveolar lavage fluid with immunoblotting, and analyzed mutations in the SP-B gene with polymerase chain reaction (PCR) and gene sequencing. Results: In RDS group, low mature Surfactant protein B was found in both lung tissue and bronchoalveolar lavage fluid in 8 neonates. In control group, only 4 neonates with low mature Surfactant protein B in both lung tissue and bronchoalveolar lavage fluid. In RDS group, 20 neonates were found to have mutations in exon 4, 12 homozygous mutations with C/C genotype and 8 heterozygous mutations with C/T genotype in surfactant protein B gene+1580 polymorphism. There were 8 cases mutations in control group, 1 in C/C and 7 in C/T genotype. The frequency of homozygotes with C/C genotype was 0.3 and frequency of heterozygotes with C/T genotype was 0.02 in RDS group. In control group, frequency of homozygotes with C/C genotype was 0.025 and frequency of heterozygote with C/T genotype was 0.175. Conclusion: Low mature Surfactant protein B is associated with the pathogenesis of neonatal respiratory distress syndrome (RDS) in China Han ethnic population. Mutations in exon 4 of the surfactant protein B gene demonstrate an association between homozygous mutations with C/C genotype in SP-B gene and neonatal RDS. PMID:23330012

  6. Sun exposure causes somatic second-hit mutations and angiofibroma development in tuberous sclerosis complex

    Science.gov (United States)

    Tyburczy, Magdalena E.; Wang, Ji-an; Li, Shaowei; Thangapazham, Rajesh; Chekaluk, Yvonne; Moss, Joel; Kwiatkowski, David J.; Darling, Thomas N.

    2014-01-01

    Tuberous sclerosis complex (TSC) is characterized by the formation of tumors in multiple organs and is caused by germline mutation in one of two tumor suppressor genes, TSC1 and TSC2. As for other tumor suppressor gene syndromes, the mechanism of somatic second-hit events in TSC tumors is unknown. We grew fibroblast-like cells from 29 TSC skin tumors from 22 TSC subjects and identified germline and second-hit mutations in TSC1/TSC2 using next-generation sequencing. Eighteen of 22 (82%) subjects had a mutation identified, and 8 of the 18 (44%) subjects were mosaic with mutant allele frequencies of 0 to 19% in normal tissue DNA. Multiple tumors were available from four patients, and in each case, second-hit mutations in TSC2 were distinct indicating they arose independently. Most remarkably, 7 (50%) of the 14 somatic point mutations were CC>TT ultraviolet ‘signature’ mutations, never seen as a TSC germline mutation. These occurred exclusively in facial angiofibroma tumors from sun-exposed sites. These results implicate UV-induced DNA damage as a cause of second-hit mutations and development of TSC facial angiofibromas and suggest that measures to limit UV exposure in TSC children and adults should reduce the frequency and severity of these lesions. PMID:24271014

  7. Somatic mutations in breast and serous ovarian cancer young patients: a systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Giselly Encinas

    2015-10-01

    Full Text Available Summary Objective: our aim was to evaluate whether somatic mutations in five genes were associated with an early age at presentation of breast cancer (BC or serous ovarian cancer (SOC. Methods: COSMIC database was searched for the five most frequent somatic mutations in BC and SOC. A systematic review of PubMed was performed. Young age for BC and SOC patients was set at ≤35 and ≤40 years, respectively. Age groups were also classified in <30years and every 10 years thereafter. Results: twenty six (1,980 patients, 111 younger and 16 studies (598, 41 younger, were analyzed for BC and SOC, respectively. In BC, PIK3CA wild type tumor was associated with early onset, not confirmed in binary regression with estrogen receptor (ER status. In HER2-negative tumors, there was increased frequency of PIK3CA somatic mutation in older age groups; in ER-positive tumors, there was a trend towards an increased frequency of PIK3CA somatic mutation in older age groups. TP53 somatic mutation was described in 20% of tumors from both younger and older patients; PTEN, CDH1 and GATA3 somatic mutation was investigated only in 16 patients and PTEN mutation was detected in one of them. In SOC, TP53 somatic mutation was rather common, detected in more than 50% of tumors, however, more frequently in older patients. Conclusion: frequency of somatic mutations in specific genes was not associated with early-onset breast cancer. Although very common in patients with serous ovarian cancer diagnosed at all ages, TP53 mutation was more frequently detected in older women.

  8. Mutation induction by and mutational interaction between monochromatic wavelength radiations in the near-ultraviolet and visible ranges

    International Nuclear Information System (INIS)

    Tyrrell, R.M.

    1980-01-01

    The induction of mutations (reversion to tryptophan independence) by various UV (254, 313, 334 and 365 nm) and visible (405 and 434 nm) wavelengths was measured in exponential phase populations of Escherichia coli B/r thy trp and B/r thy trp uvr A by assay of irradiated populations on semi-enriched media. No mutations were induced in the repair proficient strain at wavelengths longer than 313 nm. Mutations were induced to the excisionless strain at wavelengths as long as 405 nm but less than expected from the known amount of DNA damage induced. Irradiation at the long wavelenths (434, 405, 365 and 334 nm) suppressed the appearance of 254- or 313 nm-induced mutations in the repair competent strain but not in the excision deficient strain. The relative dose-requirement for mutation suppression was related to the relative efficiency of these wavelengths in inducing growth delay. These results suggest that the growth delay induced by near-UV and visible wavelenghts allows more time for the 'error-free' excision repair process to act on the potentially mutagenic lesions induced by 254- and 313-nm radiations, thereby reducing the mutation frequency observed in the repair-proficient strain. The level of near-UV mutation induced in the excision deficient strain is lower than expected from the DNA damage known to be induced. It is possible that near-UV radiation induces a class of lethal lesions that are not susceptible to error-prone repair. (author)

  9. Osteogenesis imperfecta type 3 in South Africa: Causative mutations in FKBP10

    Directory of Open Access Journals (Sweden)

    Alvera Vorster

    2017-05-01

    Full Text Available Background. A relatively high frequency of autosomal recessively inherited osteogenesis imperfecta (OI type 3 (OI-3 is present in the indigenous black southern African population. Affected persons may be severely handicapped as a result of frequent fractures, progressive deformity of the tubular bones and spinal malalignment. Objective. To delineate the molecular basis for the condition. Methods. Molecular investigations were performed on 91 affected persons from seven diverse ethnolinguistic groups in this population. Results. Following polymerase chain reaction amplification and direct cycle sequencing, FKBP10 mutations were identified in 45.1% (41/91 OI-3-affected persons. The homozygous FKBP10 c.831dupC frameshift mutation was confirmed in 35 affected individuals in the study cohort. Haplotype analysis suggests that this mutation is identical among these OI-3-affected persons by descent, thereby confirming that they had a common ancestor. Compound heterozygosity of this founder mutation was observed, in combination with three different deleterious FKBP10 mutations, in six additional persons in the cohort. Four of these individuals had the c.831delC mutation. Conclusion. The burden of the disorder, both in frequency and severity, warrants the establishment of a dedicated service for molecular diagnostic confirmation and genetic management of persons and families with OI in southern Africa.

  10. Concurrent IDH1 and SMARCB1 Mutations in Pediatric Medulloblastoma: A Case Report

    Directory of Open Access Journals (Sweden)

    Moatasem El-Ayadi

    2018-06-01

    Full Text Available Isocitrate Dehydrogenase-1 (IDH1 is a driver gene in several cancers including brain tumors such as low-grade and high-grade gliomas. Mutations of SMARCB1 were described in atypical teratoid rhabdoid tumors and to date have not been associated with the pathogenesis of medulloblastoma. We report concurrent IDH1 and SMARCB1 mutations in a medulloblastoma patient. We searched the catalog of somatic mutations in cancer (COSMIC database and other mutation databases and -to our knowledge- this is the first reported case of medulloblastoma harboring both mutations together. Our patient is a 13-year-old male presenting with headache and vomiting at diagnosis. MRI revealed left cerebellar expansive lesion with no evidence of metastasis. A histopathological diagnosis of desmoplastic/nodular medulloblastoma was made after complete resection of the tumor. Immunophenotypic characterization and methylation profiling suggested a medulloblastoma with SHH activation. Next generation sequencing of a panel of 400 genes revealed heterozygous somatic IDH1(p.R132C, SMARCB1(p.R201Q, and CDH11(p.L625T mutations. The patient was treated according to the HIT-SIOP PNET 4 protocol. He is in complete remission more than 2 years after diagnosis. In conclusion, increasing use of high throughput sequencing will certainly increase the frequency with which rare mutations or mutation combinations are identified. The exact frequency of this mutation combination and whether it has any particular therapeutic implications or prognostic relevance requires further investigation.

  11. Gene Frequency and Heritability of Rh Blood Group Gene in 44 Human Populations

    Directory of Open Access Journals (Sweden)

    Supriyo CHAKRABORTY

    2010-09-01

    Full Text Available The frequency of RhD and Rhd alleles of Rh blood group gene was estimated in 44 human populations distributed all over the world from the RhD phenotypic data. The average frequency of RhD and Rhd allele over these populations was 0.70 and 0.30, respectively. Higher frequency of RhD allele than the expected estimate (0.50 in all the populations, under Hardy-Weinberg equilibrium condition assuming equal frequency of both alleles in the initial population, indicated inbreeding at RhD/d locus as well as natural selection for RhD allele. Very high heritability estimate (84.04% of Rh allele frequency revealed that this trait was under weak selection pressure and resulted in greater genetic variation in existing populations. It is consistent with Fishers fundamental theorem of natural selection. The results from the present study suggest that inbreeding at RhD/d locus and some other factors (possibly mutation, migration and genetic drift other than natural selection alone played major roles in changing the Rh allele frequency in these populations.

  12. Haplotype structure in Ashkenazi Jewish BRCA1 and BRCA2 mutation carriers

    NARCIS (Netherlands)

    Im, Kate M.; Kirchhoff, Tomas; Wang, Xianshu; Green, Todd; Chow, Clement Y.; Vijai, Joseph; Korn, Joshua; Gaudet, Mia M.; Fredericksen, Zachary; Shane Pankratz, V.; Guiducci, Candace; Crenshaw, Andrew; McGuffog, Lesley; Kartsonaki, Christiana; Morrison, Jonathan; Healey, Sue; Sinilnikova, Olga M.; Mai, Phuong L.; Greene, Mark H.; Piedmonte, Marion; Rubinstein, Wendy S.; Hogervorst, Frans B.; Rookus, Matti A.; Collée, J. Margriet; Hoogerbrugge, Nicoline; van Asperen, Christi J.; Meijers-Heijboer, Hanne E. J.; van Roozendaal, Cees E.; Caldes, Trinidad; Perez-Segura, Pedro; Jakubowska, Anna; Lubinski, Jan; Huzarski, Tomasz; Blecharz, Paweł; Nevanlinna, Heli; Aittomäki, Kristiina; Lazaro, Conxi; Blanco, Ignacio; Barkardottir, Rosa B.; Montagna, Marco; D'Andrea, Emma; Devilee, Peter; Olopade, Olufunmilayo I.; Neuhausen, Susan L.; Peissel, Bernard; Bonanni, Bernardo; Peterlongo, Paolo; Singer, Christian F.; Rennert, Gad; Lejbkowicz, Flavio; Andrulis, Irene L.; Glendon, Gord; Ozcelik, Hilmi; Toland, Amanda Ewart; Caligo, Maria Adelaide; Beattie, Mary S.; Chan, Salina; Domchek, Susan M.; Nathanson, Katherine L.; Rebbeck, Timothy R.; Phelan, Catherine; Narod, Steven; John, Esther M.; Hopper, John L.; Buys, Saundra S.; Daly, Mary B.; Southey, Melissa C.; Terry, Mary-Beth; Tung, Nadine; Hansen, Thomas V. O.; Osorio, Ana; Benitez, Javier; Durán, Mercedes; Weitzel, Jeffrey N.; Garber, Judy; Hamann, Ute; Peock, Susan; Cook, Margaret; Oliver, Clare T.; Frost, Debra; Platte, Radka; Evans, D. Gareth; Eeles, Ros; Izatt, Louise; Paterson, Joan; Brewer, Carole; Hodgson, Shirley; Morrison, Patrick J.; Porteous, Mary; Walker, Lisa; Rogers, Mark T.; Side, Lucy E.; Godwin, Andrew K.; Schmutzler, Rita K.; Wappenschmidt, Barbara; Laitman, Yael; Meindl, Alfons; Deissler, Helmut; Varon-Mateeva, Raymonda; Preisler-Adams, Sabine; Kast, Karin; Venat-Bouvet, Laurence; Stoppa-Lyonnet, Dominique; Chenevix-Trench, Georgia; Easton, Douglas F.; Klein, Robert J.; Daly, Mark J.; Friedman, Eitan; Dean, Michael; Clark, Andrew G.; Altshuler, David M.; Antoniou, Antonis C.; Couch, Fergus J.; Offit, Kenneth; Gold, Bert; Gauthier-Villars, Marion; Houdayer, Claude; Moncoutier, Virginie; Belotti, Muriel; de Pauw, Antoine; Bressac-de-Paillerets, Brigitte; Remenieras, Audrey; Byrde, Véronique; Caron, Olivier; Lenoir, Gilbert; Bignon, Yves-Jean; Uhrhammer, Nancy; Lasset, Christine; Bonadona, Valérie; Hardouin, Agnès; Berthet, Pascaline; Sobol, Hagay; Bourdon, Violaine; Noguchi, Tetsuro; Eisinger, François; Coulet, Florence; Colas, Chrystelle; Soubrier, Florent; Coupier, Isabelle; Peyrat, Jean-Philippe; Fournier, Joëlle; Révillion, Françoise; Vennin, Philippe; Adenis, Claude; Rouleau, Etienne; Lidereau, Rosette; Demange, Liliane; Nogues, Catherine; Muller, Danièle; Fricker, Jean-Pierre; Longy, Michel; Sevenet, Nicolas; Toulas, Christine; Guimbaud, Rosine; Gladieff, Laurence; Feillel, Viviane; Leroux, Dominique; Dreyfus, Hélène; Rebischung, Christine; Cassini, Cécile; Faivre, Laurence; Prieur, Fabienne; Ferrer, Sandra Fert; Frénay, Marc; Vénat-Bouvet, Laurence; Lynch, Henry T.; Thorne, Heather; Niedermayr, Eveline; Pierotti, Marco; Manoukian, Siranoush; Zaffaroni, Daniela; Ripamonti, Carla B.; Radice, Paolo; Barile, Monica; Bernard, Loris; Karlsson, Per; Nordling, Margareta; Bergman, Annika; Einbeigi, Zakaria; Stenmark-Askmalm, Marie; Liedgren, Sigrun; Borg, Åke; Loman, Niklas; Olsson, Håkan; Kristoffersson, Ulf; Jernström, Helena; Harbst, Katja; Henriksson, Karin; Lindblom, Annika; Arver, Brita; von Wachenfeldt, Anna; Liljegren, Annelie; Barbany-Bustinza, Gisela; Rantala, Johanna; Melin, Beatrice; Grönberg, Henrik; Stattin, Eva-Lena; Emanuelsson, Monica; Ehrencrona, Hans; Brandell, Richard Rosenquist; Dahl, Niklas; Hogervorst, F. B. L.; Verhoef, S.; Verheus, M.; van 't Veer, L. J.; van Leeuwen, F. E.; Rookus, M. A.; Collée, M.; van den Ouweland, A. M. W.; Jager, A.; Hooning, M. J.; Tilanus-Linthorst, M. M. A.; Seynaeve, C.; van Asperen, C. J.; Wijnen, J. T.; Vreeswijk, M. P.; Tollenaar, R. A.; Devilee, P.; Ligtenberg, M. J.; Hoogerbrugge, N.; Ausems, M. G.; van der Luijt, R. B.; Aalfs, C. M.; van Os, T. A.; Gille, J. J. P.; Waisfisz, Q.; Gomez-Garcia, E. B.; van Roozendaal, C. E.; Blok, Marinus J.; Caanen, B.; Oosterwijk, J. C.; van der Hout, A. H.; Mourits, M. J.; Vasen, H. F.; Miedzybrodzka, Zosia; Gregory, Helen; Morrison, Patrick; Jeffers, Lisa; Cole, Trevor; Ong, Kai-Ren; Hoffman, Jonathan; Donaldson, Alan; James, Margaret; Downing, Sarah; Taylor, Amy; Murray, Alexandra; McCann, Emma; Kennedy, M. John; Barton, David; Drummond, Sarah; Kivuva, Emma; Searle, Anne; Goodman, Selina; Hill, Kathryn; Davidson, Rosemarie; Murday, Victoria; Bradshaw, Nicola; Snadden, Lesley; Longmuir, Mark; Watt, Catherine; Gibson, Sarah; Haque, Eshika; Tobias, Ed; Duncan, Alexis; Jacobs, Chris; Langman, Caroline; Whaite, Anna; Dorkins, Huw; Randhawa, Kashmir; Barwell, Julian; Patel, Nafisa; Adlard, Julian; Chu, Carol; Miller, Julie; Ellis, Ian; Houghton, Catherine; Lalloo, Fiona; Taylor, Jane; Side, Lucy; Male, Alison; Berlin, Cheryl; Eason, Jacqueline; Collier, Rebecca; Douglas, Fiona; Claber, Oonagh; Jobson, Irene; McLeod, Diane; Halliday, Dorothy; Durell, Sarah; Stayner, Barbara; Shanley, Susan; Rahman, Nazneen; Houlston, Richard; Bancroft, Elizabeth; D'Mello, Lucia; Page, Elizabeth; Ardern-Jones, Audrey; Kohut, Kelly; Wiggins, Jennifer; Castro, Elena; Mitra, Anita; Robertson, Lisa; Cook, Jackie; Quarrell, Oliver; Bardsley, Cathryn; Brice, Glen; Winchester, Lizzie; Eddy, Charlotte; Tripathi, Vishakha; Attard, Virginia; Eccles, Diana; Lucassen, Anneke; Crawford, Gillian; McBride, Donna; Smalley, Sarah

    2011-01-01

    Three founder mutations in BRCA1 and BRCA2 contribute to the risk of hereditary breast and ovarian cancer in Ashkenazi Jews (AJ). They are observed at increased frequency in the AJ compared to other BRCA mutations in Caucasian non-Jews (CNJ). Several authors have proposed that elevated allele

  13. CYP1B1 and myocilin gene mutations in Egyptian patients with ...

    African Journals Online (AJOL)

    Purpose: Primary congenital glaucoma (PCG) accounts for 26–29% of childhood blindness in Egypt. The identification of disease causing mutations has not been extensively investigated. We aimed to examine the frequency of CYP1B1 and MYOC mutations in PCG Egyptian patients, and study a possible ...

  14. Maternal effects of the scid mutation on radiation-induced transgenerational instability in mice.

    NARCIS (Netherlands)

    Hatch, T.; Derijck, A.H.A.; Black, P.D.; Heijden, G.W. van der; Boer, P. de; Dubrova, Y.E.

    2007-01-01

    The results of a number of recent studies show that mutation rates in the offspring of irradiated parents are substantially elevated, however, the effect of parental genotype on transgenerational instability remains poorly understood. Here, we have analysed the mutation frequency at an expanded

  15. ERBB2 mutations associated with solid variant of high-grade invasive lobular breast carcinomas.

    Science.gov (United States)

    Deniziaut, Gabrielle; Tille, Jean Christophe; Bidard, François-Clément; Vacher, Sophie; Schnitzler, Anne; Chemlali, Walid; Trémoulet, Laurence; Fuhrmann, Laetitia; Cottu, Paul; Rouzier, Roman; Bièche, Ivan; Vincent-Salomon, Anne

    2016-11-08

    ERBB2 and ERBB3 somatic gain-of-function mutations, which may be targeted by anti-ERBB2 therapies, were reported by high-throughput sequencing studies in 1% and 2% of invasive breast cancers respectively. Our study aims to determine ERBB2 and ERBB3 mutations frequencies in grade 3 and/or ERBB2-positive invasive lobular breast carcinomas (ILC). All the 529 ILC surgically-excised registered at Institut Curie in the years 2005 to 2008 were reviewed. Thirty-nine grade 3 ERBB2-negative ILC and 16 ERBB2-positive ILC were retrieved and subjected to Sanger sequencing of the ERBB2 and ERBB3 activation mutation hotspots (ERBB2: exons 8, 17, 19, 20, 21; ERBB3: exons 3, 6, 7, 8). Among the 39 grade 3 ERBB2-negative ILC, six tumors were found to have at least one detectable ERBB2 activating mutation (incidence rate: 15%, 95%CI [4%-27%]). No ERBB2 mutation was found among the 16 ERBB2-positive ILC. No ERBB3 mutation was found in any of the 55 ILC. ERBB2 mutations were statistically associated with solid ILC features (p=0.01). Survival analyses showed no significant prognostic impact of ERBB2 mutations. Our study demonstrates that high grade ERBB2-negative ILC display a high frequency of ERBB2 mutations, and should be subjected to systematic genetic screening.

  16. Mosaicism of an ELANE mutation in an asymptomatic mother in a familial case of cyclic neutropenia.

    Science.gov (United States)

    Hirata, Osamu; Okada, Satoshi; Tsumura, Miyuki; Karakawa, Shuhei; Matsumura, Itaru; Kimura, Yujiro; Maihara, Toshiro; Yasunaga, Shin'ichiro; Takihara, Yoshihiro; Ohara, Osamu; Kobayashi, Masao

    2015-07-01

    To confirm and characterize mosaicism of the cyclic neutropenia (CyN)-related mutation in the ELANE gene identified in the asymptomatic mother of patients with CyN. We identified sibling cases with CyN due to a novel heterozygous splicing site mutation, IVS4 +5SD G>T, in the ELANE gene, resulting in an internal in-frame deletion of 30 nucleotides (corresponding to a ten amino acid deletion, V161-F170). The mutated allele was also detected in their asymptomatic mother but at low frequency. We measured the frequency of the mutant allele from peripheral blood leukocytes (PBLs) by subcloning, and confirmed the allelic frequency of mosaicism in various cell types by massively parallel DNA sequencing (MPS) analysis. In the subcloning analysis, the mutant allele was identified in 21.36 % of PBLs from the asymptomatic mother, compared with 54.72 % of PBLs from the CyN patient. In the MPS analysis, the mutant allele was observed in approximately 30 % of mononuclear cells, CD3(+) T cells, CD14(+) monocytes and the buccal mucosa. Conversely, it was detected in low frequency in polymorphonuclear leukocytes (PLMLs) (3-4 %) and CD16(+) granulocytes (2-3 %). Mosaicism of the ELANE mutation has only previously been identified in one confirmed and one unconfirmed case of SCN. This is the first report of mosaicism of the ELANE mutation in a case of CyN. The MPS results suggest that this de novo mutation occurred during the two-cell stage of embryogenesis. PLMLs expressing the ELANE mutation were found to be actively undergoing apoptosis.

  17. Aphid thermal tolerance is governed by a point mutation in bacterial symbionts.

    Directory of Open Access Journals (Sweden)

    Helen E Dunbar

    2007-05-01

    Full Text Available Symbiosis is a ubiquitous phenomenon generating biological complexity, affecting adaptation, and expanding ecological capabilities. However, symbionts, which can be subject to genetic limitations such as clonality and genomic degradation, also impose constraints on hosts. A model of obligate symbiosis is that between aphids and the bacterium Buchnera aphidicola, which supplies essential nutrients. We report a mutation in Buchnera of the aphid Acyrthosiphon pisum that recurs in laboratory lines and occurs in field populations. This single nucleotide deletion affects a homopolymeric run within the heat-shock transcriptional promoter for ibpA, encoding a small heat-shock protein. This Buchnera mutation virtually eliminates the transcriptional response of ibpA to heat stress and lowers its expression even at cool or moderate temperatures. Furthermore, this symbiont mutation dramatically affects host fitness in a manner dependent on thermal environment. Following a short heat exposure as juveniles, aphids bearing short-allele symbionts produced few or no progeny and contained almost no Buchnera, in contrast to aphids bearing symbionts without the deletion. Conversely, under constant cool conditions, aphids containing symbionts with the short allele reproduced earlier and maintained higher reproductive rates. The short allele has appreciable frequencies in field populations (up to 20%, further supporting the view that lowering of ibpA expression improves host fitness under some conditions. This recurring Buchnera mutation governs thermal tolerance of aphid hosts. Other cases in which symbiont microevolution has a major effect on host ecological tolerance are likely to be widespread because of the high mutation rates of symbiotic bacteria and their crucial roles in host metabolism and development.

  18. TP53 germline mutation testing in 180 families suspected of Li-Fraumeni syndrome: mutation detection rate and relative frequency of cancers in different familial phenotypes

    NARCIS (Netherlands)

    Ruijs, M.W.G.; Verhoef, S.; Rookus, M.A.; Pruntel, R.; van der Hout, A.H.; Hogervorst, F.B.L.; Kluijt, I.; Sijmons, R.H.; Aalfs, C.M.; Wagner, A.; Ausems, M.G.E.M.; Hoogerbrugge, N.; van Asperen, C.J.; Gómez García, E.B.; Meijers-Heijboer, H.; ten Kate, L.P.; Menko, F.H.; van 't Veer, L.J.

    2010-01-01

    Background Li-Fraumeni syndrome (LFS) is a rare autosomal dominant cancer predisposition syndrome. Most families fulfilling the classical diagnostic criteria harbour TP53 germline mutations. However, TP53 germline mutations may also occur in less obvious phenotypes. As a result, different criteria

  19. MPL mutations in myeloproliferative disorders

    DEFF Research Database (Denmark)

    Beer, Philip A.; Campbell, Peter J.; Scott, Linda M.

    2008-01-01

    Activating mutations of MPL exon 10 have been described in a minority of patients with idiopathic myelofibrosis (IMF) or essential thrombocythemia (ET), but their prevalence and clinical significance are unclear. Here we demonstrate that MPL mutations outside exon 10 are uncommon in platelet c......DNA and identify 4 different exon 10 mutations in granulocyte DNA from a retrospective cohort of 200 patients with ET or IMF. Allele-specific polymerase chain reaction was then used to genotype 776 samples from patients with ET entered into the PT-1 studies. MPL mutations were identified in 8.5% of JAK2 V617F......(-) patients and a single V617F(+) patient. Patients carrying the W515K allele had a significantly higher allele burden than did those with the W515L allele, suggesting a functional difference between the 2 variants. Compared with V617F(+) ET patients, those with MPL mutations displayed lower hemoglobin...

  20. Females with a mutation in a nuclear-encoded mitochondrial protein pay a higher cost of survival than do males in Drosophila.

    Science.gov (United States)

    Melvin, Richard G; Ballard, J William O

    2011-07-01

    Males and females age at different rates in a variety of species, but the mechanisms underlying the difference is not understood. In this study, we investigated sex-specific costs of a naturally occurring mildly deleterious deletion (DTrp85, DVal86) in cytochrome c oxidase subunit 7A (cox7A) in Drosophila simulans. We observed that females and males homozygous for the mutation had 30% and 26% reduced Cox activity, respectively, compared with wild type. Furthermore, 4-day-old females had 34%-42% greater physical activity than males. Greater physical activity in mutant females was correlated with a 19% lower 50% survival compared with wild-type females. Mutant and wild-type males had equal survival. These data suggest that females paid a higher cost of the mutation than did males. The data demonstrate linking population genetics and structural modeling to experimental manipulations that lead to functional predictions of mitochondrial bioenergetics and organism aging.

  1. p16 mutation spectrum in the premalignant condition Barrett's esophagus.

    Directory of Open Access Journals (Sweden)

    Thomas G Paulson

    Full Text Available BACKGROUND: Mutation, promoter hypermethylation and loss of heterozygosity involving the tumor suppressor gene p16 (CDKN2a/INK4a have been detected in a wide variety of human cancers, but much less is known concerning the frequency and spectrum of p16 mutations in premalignant conditions. METHODS AND FINDINGS: We have determined the p16 mutation spectrum for a cohort of 304 patients with Barrett's esophagus, a premalignant condition that predisposes to the development of esophageal adenocarcinoma. Forty seven mutations were detected by sequencing of p16 exon 2 in 44 BE patients (14.5% with a mutation spectrum consistent with that caused by oxidative damage and chronic inflammation. The percentage of patients with p16 mutations increased with increasing histologic grade. In addition, samples from 3 out of 19 patients (15.8% who underwent esophagectomy were found to have mutations. CONCLUSIONS: The results of this study suggest the environment of the esophagus in BE patients can both generate and select for clones with p16 mutations.

  2. Effect of space mutation of photosynthetic characteristics of soybean varieties

    International Nuclear Information System (INIS)

    Liu Xinlei; Ma Yansong; Luan Xiaoyan; Man Weiqun; Xu Dechun; Meng Lifen; Fu Lixin; Zhao Xiao'nan; Liu Qi

    2012-01-01

    In order to elucidate the response of the photosynthetic traits of soybean to space mutation, three soybean varieties (lines) of Heinong 48, Heinong 44 and Ha 2291-Y were carried by artificial satellite in 2006 and the net photo synthetic rate (Pn), stomatal conductance (Cond), intercellular CO 2 concentration (Ci) and stomatal resistance (Rs) from SP 1 to SP 4 generation were determined. The results showed that space mutation affected photosynthesis traits of soy bean. The photosynthetic rate of soybean varieties by space mutation occurred different levels of genetic variation and the positive mutation rate were higher. Coefficient of variation among generations were SP 2 >SP 3 >SP 4 >CK. Results suggest that space mutation can effectively create soybean materials with higher photosynthetic rate. (authors)

  3. Effect of space mutation on photosynthetic characteristics of soybean varieties

    International Nuclear Information System (INIS)

    Liu Xinlei; Ma Yansong; Luan Xiaoyan; Man Weiqun; Xu Dechun; Meng Lifen; Fu Lixin; Zhao Xiaonan; Liu Qi

    2011-01-01

    In order to elucidate the response of the photosynthetic traits of soybean to space mutation, three soybean varieties (lines) of Heinong 48, Heinong 44 and Ha 2291-Y were carried by artificial satellite in 2006 and the net photosynthetic rate (Pn), stomatal conductance (Cond), intercellular CO 2 concentration (Ci) and stomatal resistance (Rs) from SP 1 to SP 4 generation were determined. The results showed that space mutation affected photosynthesis traits of soybean. The photosynthetic rate of soybean varieties by space mutation occurred different levels of genetic variation and the positive mutation rate were higher. Coefficient of variation among generations were SP 2 > SP 3 > SP 4 > CK. Results suggest that space mutation can effectively create soybean materials with higher photosynthetic rate. (authors)

  4. Radiation-induced dominant skeletal mutations in mice

    International Nuclear Information System (INIS)

    Selby, P.B.

    1979-01-01

    Skeletons were chosen for the attempt to determine the overall damage by radiation to one body system largely bacause they can be prepared readily for detailed study. Dominant mutations were of special interest because they are the type of mutations that would account for almost all damage induced in the early generations. The male offsprings derived from spermatogonial irradiation were used in the mutation-rate experiment, and the mutation frequency of 1.4% per gamete was found. The general dominant skeletal mutations are 1) the fusions of bones or other changes in individual bones, 2) the gross changes in bone shapes, usually caused by incomplete or too extensive bone growth, or 3) the shifts in the relative positions of bones. The recessive lethality in the period between implantation and birth can be recognized by the expected high death rate of implants in approximately 1/4 of the crosses that are between heterozygotes for a given mutation. The recessive lethal mutations may account for an important fraction of human genetic disorders owing to their dominant deleterious effects which represent only a small fraction, but because of their easy detection, they have been studied more than other dominants. At least 45, or 27%, of 164 dominant visibles in mice, ignoring those concerned with enzyme polymorphisms and immunological traits, appear to be recessive lethals. (Yamashita, S.)

  5. Development of a human somatic mutation detection method--GPA assay

    International Nuclear Information System (INIS)

    Mao Jianping; Dong Yan; Liu Bin; Lin Ruxian; Sun Zhixian

    2000-01-01

    Objective: To study the damage to human body caused by environmental radiation, and supervise the somatic mutations. Methods: Three monoclonal antibodies specific to M-type(3G4), N-type(6A8), and MN-type (3C5) of glycophorin A, respectively, were prepared. Fluorescence or biotin conjugated antibodies were bound specifically to formalin and/or dimethyl suber-imidate fixed erythrocytes. M, MN and N type cells were divided by cytometry to demonstrate the erythrocyte mutation characteristics (MN→MO, MM, NO, NN) and give out the variant frequency. Results: 1Wa, 1Wb and 2Wa methods of GPA assay were developed. Erythrocytes of MN type individuals could be separated to normal and single locus variant groups by 1W methods and they could be sorted as normal (MN), single gene deletion mutants (MO, NO), homozygous mutants (MM, NN) cell groups by 2Wa method. Conclusion: The assay is applicable to evaluating the frequency of variant erythrocytes from human somatic mutation

  6. A Point Mutation in Suppressor of Cytokine Signalling 2 (Socs2 Increases the Susceptibility to Inflammation of the Mammary Gland while Associated with Higher Body Weight and Size and Higher Milk Production in a Sheep Model.

    Directory of Open Access Journals (Sweden)

    Rachel Rupp

    2015-12-01

    Full Text Available Mastitis is an infectious disease mainly caused by bacteria invading the mammary gland. Genetic control of susceptibility to mastitis has been widely evidenced in dairy ruminants, but the genetic basis and underlying mechanisms are still largely unknown. We describe the discovery, fine mapping and functional characterization of a genetic variant associated with elevated milk leukocytes count, or SCC, as a proxy for mastitis. After implementing genome-wide association studies, we identified a major QTL associated with SCC on ovine chromosome 3. Fine mapping of the region, using full sequencing with 12X coverage in three animals, provided one strong candidate SNP that mapped to the coding sequence of a highly conserved gene, suppressor of cytokine signalling 2 (Socs2. The frequency of the SNP associated with increased SCC was 21.7% and the Socs2 genotype explained 12% of the variance of the trait. The point mutation induces the p.R96C substitution in the SH2 functional domain of SOCS2 i.e. the binding site of the protein to various ligands, as well-established for the growth hormone receptor GHR. Using surface plasmon resonance we showed that the p.R96C point mutation completely abrogates SOCS2 binding affinity for the phosphopeptide of GHR. Additionally, the size, weight and milk production in p.R96C homozygote sheep, were significantly increased by 24%, 18%, and 4.4%, respectively, when compared to wild type sheep, supporting the view that the point mutation causes a loss of SOCS2 functional activity. Altogether these results provide strong evidence for a causal mutation controlling SCC in sheep and highlight the major role of SOCS2 as a tradeoff between the host's inflammatory response to mammary infections, and body growth and milk production, which are all mediated by the JAK/STAT signaling pathway.

  7. Mutation breeding research of wheat (T. aestivum) in China

    International Nuclear Information System (INIS)

    Wang, L.; Zhang, B.; Shi, J.; Tao, S.; Fan, Q.

    1990-01-01

    Full text: 78 cultivars and various valuable strains have been obtained through induced genic mutation and chromosome translocation. Irradiation of hybrid seeds, gametes, zygotes and in vitro cultured cells, gave increased mutation frequency and expanded spectrum. Various physical agents were examined either singly or in combination with chemical agents. Combined use of γ-irradiation by low dose and in vitro culture proved effective in raising the percentage of seed-set in wide-crosses. (author)

  8. ATM/RB1 mutations predict shorter overall survival in urothelial cancer.

    Science.gov (United States)

    Yin, Ming; Grivas, Petros; Emamekhoo, Hamid; Mendiratta, Prateek; Ali, Siraj; Hsu, JoAnn; Vasekar, Monali; Drabick, Joseph J; Pal, Sumanta; Joshi, Monika

    2018-03-30

    Mutations of DNA repair genes, e.g. ATM/RB1 , are frequently found in urothelial cancer (UC) and have been associated with better response to cisplatin-based chemotherapy. Further external validation of the prognostic value of ATM/RB1 mutations in UC can inform clinical decision making and trial designs. In the discovery dataset, ATM/RB1 mutations were present in 24% of patients and were associated with shorter OS (adjusted HR 2.67, 95% CI, 1.45-4.92, p = 0.002). There was a higher mutation load in patients carrying ATM/RB1 mutations (median mutation load: 6.7 versus 5.5 per Mb, p = 0.072). In the validation dataset, ATM/RB1 mutations were present in 22.2% of patients and were non-significantly associated with shorter OS (adjusted HR 1.87, 95% CI, 0.97-3.59, p = 0.06) and higher mutation load (median mutation load: 8.1 versus 7.2 per Mb, p = 0.126). Exome sequencing data of 130 bladder UC patients from The Cancer Genome Atlas (TCGA) dataset were analyzed as a discovery cohort to determine the prognostic value of ATM/RB1 mutations. Results were validated in an independent cohort of 81 advanced UC patients. Cox proportional hazard regression analysis was performed to calculate the hazard ratio (HR) and 95% confidence interval (CI) to compare overall survival (OS). ATM/RB1 mutations may be a biomarker of poor prognosis in unselected UC patients and may correlate with higher mutational load. Further studies are required to determine factors that can further stratify prognosis and evaluate predictive role of ATM/RB1 mutation status to immunotherapy and platinum-based chemotherapy.

  9. Influence of preirradiation history of E. coli WP2 cells on the residual fixation of mutations in rpsL. (strA) locus

    Energy Technology Data Exchange (ETDEWEB)

    Filippov, V D

    1986-07-01

    The values of residual fixation of strA mutations in E.coli culture, irradiated by UV-light (6.8 J/m/sup 2/) in different physiological states and conforming to different in depth strA mutation frequency decrease in postirradiation incubation under conditions unfavourable for protein synthesis are determined. By residual fixation one should mean accumulation of strA mutations stable to antimutagenous effect of photoreactivating light in cell population incubated in buffer after UV radiation. It is established that residual fixation is small in cultures, conforming to deep decrease, and is a factor (about 40% of strA mutations is fixed) in a culture, conforming to moderate decrease (about 60% of strA mutations disappears) of mutation frequency in incubation under conditions unfavourable for protein synthesis. The conclusion is made that the depth of strA mutation frequency decrease, taking place under the influence of mfd system, depends on the level of residual fixation of this mutations. It is supposed that residual fixation is caused by rpsL (strA) locus introduction in replication cycle initiated after radiation.

  10. Analysis of HLA-A antigens and C282Y and H63D mutations of the HFE gene in Brazilian patients with hemochromatosis

    Directory of Open Access Journals (Sweden)

    Bittencourt P.L.

    2002-01-01

    Full Text Available The hemochromatosis gene, HFE, is located on chromosome 6 in close proximity to the HLA-A locus. Most Caucasian patients with hereditary hemochromatosis (HH are homozygous for HLA-A3 and for the C282Y mutation of the HFE gene, while a minority are compound heterozygotes for C282Y and H63D. The prevalence of these mutations in non-Caucasian patients with HH is lower than expected. The objective of the present study was to evaluate the frequencies of HLA-A antigens and the C282Y and H63D mutations of the HFE gene in Brazilian patients with HH and to compare clinical and laboratory profiles of C282Y-positive and -negative patients with HH. The frequencies of HLA-A and C282Y and H63D mutations were determined by PCR-based methods in 15 male patients (median age 44 (20-72 years with HH. Eight patients (53% were homozygous and one (7% was heterozygous for the C282Y mutation. None had compound heterozygosity for C282Y and H63D mutations. All but three C282Y homozygotes were positive for HLA-A3 and three other patients without C282Y were shown to be either heterozygous (N = 2 or homozygous (N = 1 for HLA-A3. Patients homozygous for the C282Y mutation had higher ferritin levels and lower age at onset, but the difference was not significant. The presence of C282Y homozygosity in roughly half of the Brazilian patients with HH, together with the findings of HLA-A homozygosity in C282Y-negative subjects, suggest that other mutations in the HFE gene or in other genes involved in iron homeostasis might also be linked to HH in Brazil.

  11. The Slavic NBN Founder Mutation: A Role for Reproductive Fitness?

    Directory of Open Access Journals (Sweden)

    Eva Seemanova

    Full Text Available The vast majority of patients with Nijmegen Breakage Syndrome (NBS are of Slavic origin and carry a deleterious deletion (c.657del5; rs587776650 in the NBN gene on chromosome 8q21. This mutation is essentially confined to Slavic populations and may thus be considered a Slavic founder mutation. Notably, not a single parenthood of a homozygous c.657del5 carrier has been reported to date, while heterozygous carriers do reproduce but have an increased cancer risk. These observations seem to conflict with the considerable carrier frequency of c.657del5 of 0.5% to 1% as observed in different Slavic populations because deleterious mutations would be eliminated quite rapidly by purifying selection. Therefore, we propose that heterozygous c.657del5 carriers have increased reproductive success, i.e., that the mutation confers heterozygote advantage. In fact, in our cohort study of the reproductive history of 24 NBS pedigrees from the Czech Republic, we observed that female carriers gave birth to more children on average than female non-carriers, while no such reproductive differences were observed for males. We also estimate that c.657del5 likely occurred less than 300 generations ago, thus supporting the view that the original mutation predated the historic split and subsequent spread of the 'Slavic people'. We surmise that the higher fertility of female c.657del5 carriers reflects a lower miscarriage rate in these women, thereby reflecting the role of the NBN gene product, nibrin, in the repair of DNA double strand breaks and their processing in immune gene rearrangements, telomere maintenance, and meiotic recombination, akin to the previously described role of the DNA repair genes BRCA1 and BRCA2.

  12. The effects of maternal irradiation during adulthood on mutation induction and transgenerational instability in mice

    International Nuclear Information System (INIS)

    Abouzeid Ali, Hamdy E.; Barber, Ruth C.; Dubrova, Yuri E.

    2012-01-01

    The long-term genetic effects of maternal irradiation remain poorly understood. To establish the effects of radiation exposure on mutation induction in the germline of directly exposed females and the possibility of transgenerational effects in their non-exposed offspring, adult female BALB/c and CBA/Ca mice were given 1 Gy of acute X-rays and mated with control males. The frequency of mutation at expanded simple tandem repeat (ESTR) loci in the germline of directly exposed females did not differ from that of controls. Using a single-molecule PCR approach, ESTR mutation frequency was also established for both germline and somatic tissues in the first-generation offspring of irradiated parents. While the frequency of ESTR mutation in the offspring of irradiated males was significantly elevated, maternal irradiation did not affect stability in their F 1 offspring. Considering these data and the results of our previous study, we propose that, in sharp contrast to paternal exposure to ionising radiation, the transgenerational effects of maternal high-dose acute irradiation are likely to be negligible.

  13. The Frequency of Factor V Leiden, Prothrombin G20210A and Methylenetetrahydrofolate Reductase C677T Mutations in Migraine Patients

    Directory of Open Access Journals (Sweden)

    Ruhsen Öcal

    2010-12-01

    Full Text Available OBJECTIVE: Migraine is an independent risk factor for ischemic stroke, but its pathophysiology is still unclear. Genetic factors that predispose patients to thrombosis have been studied in patients with migraine to highlight the pathogenesis, but the results remain controversial. In this study, the frequencies of factor V Leiden (FVL, prothrombin (Pt G20210A and methylenetetrahydrofolate reductase (MTHFR C677T mutations were investigated. METHODS: One hundred and sixty patients aged of 15 to 55 years with no history of systemic disease and who had been diagnosed as migraine according to the International Headache Society (IHS diagnostic criteria at Baskent University Hospital Neurology Outpatient Clinics were investigated for FVL, Pt G20210A and MTHFR C677T mutations from their genomic DNA, and the results were compared with those of healthy controls. RESULTS: One hundred and fifty five (96.9% of 160 migraine patients were homozygote normal, 5 (3.1% were heterozygote and none of them were homozygote mutant for FVL. The control group had 9.8% heterozygote individuals but the difference between the percentages was not statistically significant (p> 0.05. There were no homozygote mutant individuals in the Turkish population study in normal subjects like our study. Thirty nine (24.4% of 160 migraine patients were heterozygote and 8 (5% were homozygote mutant for MTHFR C677T. The control group had 37 (34.9% heterozygote and 6 (5.6% homozygote mutant individuals. The difference between the percentages was not statistically significant (p= 0.15. Three (1.9% of 160 migraine patients were heterozygote and 5 (2.9% of the control group were heterozygote mutant for Pt G20210A mutation. The control group had 37 (34.9% heterozygote and 6 (5.6% homozygote mutant individuals. The difference between the percentages was not statistically significant (p= 0.420. CONCLUSION: Our study indicates that FVL, Pt G20210A and MTHFR C677T gene mutations, which are considered

  14. The Frequency of Factor V Leiden, Prothrombin G20210A and Methylenetetrahydrofolate Reductase C677T Mutations in Migraine Patients

    Directory of Open Access Journals (Sweden)

    Ruhsen Öcal

    2010-12-01

    Full Text Available OBJECTIVE: Migraine is an independent risk factor for ischemic stroke, but its pathophysiology is still unclear. Genetic factors that predispose patients to thrombosis have been studied in patients with migraine to highlight the pathogenesis, but the results remain controversial. In this study, the frequencies of factor V Leiden (FVL, prothrombin (Pt G20210A and methylenetetrahydrofolate reductase (MTHFR C677T mutations were investigated. METHODS: One hundred and sixty patients aged of 15 to 55 years with no history of systemic disease and who had been diagnosed as migraine according to the International Headache Society (IHS diagnostic criteria at Baskent University Hospital Neurology Outpatient Clinics were investigated for FVL, Pt G20210A and MTHFR C677T mutations from their genomic DNA, and the results were compared with those of healthy controls. RESULTS: One hundred and fifty five (96.9% of 160 migraine patients were homozygote normal, 5 (3.1% were heterozygote and none of them were homozygote mutant for FVL. The control group had 9.8% heterozygote individuals but the difference between the percentages was not statistically significant (p> 0.05. There were no homozygote mutant individuals in the Turkish population study in normal subjects like our study. Thirty nine (24.4% of 160 migraine patients were heterozygote and 8 (5% were homozygote mutant for MTHFR C677T. The control group had 37 (34.9% heterozygote and 6 (5.6% homozygote mutant individuals. The difference between the percentages was not statistically significant (p= 0.15. Three (1.9% of 160 migraine patients were heterozygote and 5 (2.9% of the control group were heterozygote mutant for Pt G20210A mutation. The control group had 37 (34.9% heterozygote and 6 (5.6% homozygote mutant individuals. The difference between the percentages was not statistically significant (p= 0.420. CONCLUSION: Our study indicates that FVL, Pt G20210A and MTHFR C677T gene mutations, which are considered

  15. Mitochondrial Mutation Rate, Spectrum and Heteroplasmy in Caenorhabditis elegans Spontaneous Mutation Accumulation Lines of Differing Population Size.

    Science.gov (United States)

    Konrad, Anke; Thompson, Owen; Waterston, Robert H; Moerman, Donald G; Keightley, Peter D; Bergthorsson, Ulfar; Katju, Vaishali

    2017-06-01

    Mitochondrial genomes of metazoans, given their elevated rates of evolution, have served as pivotal markers for phylogeographic studies and recent phylogenetic events. In order to determine the dynamics of spontaneous mitochondrial mutations in small populations in the absence and presence of selection, we evolved mutation accumulation (MA) lines of Caenorhabditis elegans in parallel over 409 consecutive generations at three varying population sizes of N = 1, 10, and 100 hermaphrodites. The N =1 populations should have a minimal influence of natural selection to provide the spontaneous mutation rate and the expected rate of neutral evolution, whereas larger population sizes should experience increasing intensity of selection. New mutations were identified by Illumina paired-end sequencing of 86 mtDNA genomes across 35 experimental lines and compared with published genomes of natural isolates. The spontaneous mitochondrial mutation rate was estimated at 1.05 × 10-7/site/generation. A strong G/C→A/T mutational bias was observed in both the MA lines and the natural isolates. This suggests that the low G + C content at synonymous sites is the product of mutation bias rather than selection as previously proposed. The mitochondrial effective population size per worm generation was estimated to be 62. Although it was previously concluded that heteroplasmy was rare in C. elegans, the vast majority of mutations in this study were heteroplasmic despite an experimental regime exceeding 400 generations. The frequencies of frameshift and nonsynonymous mutations were negatively correlated with population size, which suggests their deleterious effects on fitness and a potent role for selection in their eradication. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Pathophysiological consequences and benefits of HFE mutations: 20 years of research

    Science.gov (United States)

    Hollerer, Ina; Bachmann, André; Muckenthaler, Martina U.

    2017-01-01

    Mutations in the HFE (hemochromatosis) gene cause hereditary hemochromatosis, an iron overload disorder that is hallmarked by excessive accumulation of iron in parenchymal organs. The HFE mutation p.Cys282Tyr is pathologically most relevant and occurs in the Caucasian population with a carrier frequency of up to 1 in 8 in specific European regions. Despite this high prevalence, the mutation causes a clinically relevant phenotype only in a minority of cases. In this review, we summarize historical facts and recent research findings about hereditary hemochromatosis, and outline the pathological consequences of the associated gene defects. In addition, we discuss potential advantages of HFE mutations in asymptomatic carriers. PMID:28280078

  17. Frequency of the HFE C282Y and H63D mutations in Danish patients with clinical haemochromatosis initially diagnosed by phenotypic methods

    DEFF Research Database (Denmark)

    Milman, Nils; Koefoed, Pernille; Pedersen, Palle

    2003-01-01

    AIM: To assess the frequency of the C282Y and H63D mutations on the HFE gene in Danish patients with clinical hereditary haemochromatosis initially diagnosed by phenotypic methods. METHODS: In the period 1950-1985, an epidemiological survey in Denmark identified 179 patients with clinical...... diagnosis of clinical idiopathic haemochromatosis was made before blood samples were taken for HFE genotyping. The total series consisted of 58 patients (40 men and 18 women) with a median age of 60 yrs (range 18-74). HFE genotyping was performed by the polymerase chain reaction (PCR) technique. RESULTS...

  18. Development and applications of Bacillus subtilis test systems for mutagens, involving DNA-repair deficiency and suppressible auxotrophic mutations

    International Nuclear Information System (INIS)

    Tanooka, H.

    1977-01-01

    A mutagen-tester of Bacillus subtilis was constructed and tested with known carcinogens. The parental strain HA101 of Okubo and Yanagida carrying suppressible nonsense mutations in his and met genes was transformed to carry an excision-repair deficiency mutation. The constructed strain TKJ5211 showed a 20-30-fold higher sensitivity for His + reversion than the parental strain when treated with UV and UV-mimetic chemicals but unchanged mutation frequency with X-rays and methyl methanesulfonate. The tester strain was used in a spot test of 30 selected chemicals and also for testing with liver homogenate activation. The results showed an almost equivalent but somewhat broader detection spectrum than the Salmonella typhimurium TA100 system. Another test method used a pair of B. subtilis strains differing in their DNA-repair capacity, i.e. the most UV-sensitive mutant HJ-15 and a wild-type strain, to detect repair-dependent DNA damage produced by chemicals. Spores could be used in either test

  19. Inference of directional selection and mutation parameters assuming equilibrium.

    Science.gov (United States)

    Vogl, Claus; Bergman, Juraj

    2015-12-01

    In a classical study, Wright (1931) proposed a model for the evolution of a biallelic locus under the influence of mutation, directional selection and drift. He derived the equilibrium distribution of the allelic proportion conditional on the scaled mutation rate, the mutation bias and the scaled strength of directional selection. The equilibrium distribution can be used for inference of these parameters with genome-wide datasets of "site frequency spectra" (SFS). Assuming that the scaled mutation rate is low, Wright's model can be approximated by a boundary-mutation model, where mutations are introduced into the population exclusively from sites fixed for the preferred or unpreferred allelic states. With the boundary-mutation model, inference can be partitioned: (i) the shape of the SFS distribution within the polymorphic region is determined by random drift and directional selection, but not by the mutation parameters, such that inference of the selection parameter relies exclusively on the polymorphic sites in the SFS; (ii) the mutation parameters can be inferred from the amount of polymorphic and monomorphic preferred and unpreferred alleles, conditional on the selection parameter. Herein, we derive maximum likelihood estimators for the mutation and selection parameters in equilibrium and apply the method to simulated SFS data as well as empirical data from a Madagascar population of Drosophila simulans. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Mutation breeding of bulb crops by means of radioactive irradiation and other methods

    International Nuclear Information System (INIS)

    Alkema, H.Y.

    1974-01-01

    Results of mutation breeding of bulb crops by means of radioactive irradiation, colchicine and heat treatment are discussed. The optimal dose of X radiation is stated. Mutation frequency was low; it is suggested to apply radiation on plant material that is propagated by way of adventitious buds

  1. Ferredoxin Gene Mutation in Iranian Trichomonas Vaginalis Isolates

    Directory of Open Access Journals (Sweden)

    Soudabeh Heidari

    2013-09-01

    Full Text Available Background: Trichomonas vaginalis causes trichomoniasis and metronidazole is its chosen drug for treatment. Ferredoxin has role in electron transport and carbohydrate metabolism and the conversion of an inactive form of metronidazole (CO to its active form (CPR. Ferredoxin gene mutations reduce gene expression and increase its resistance to metronidazole. In this study, the frequency of ferredoxin gene mutations in clinical isolates of T.vaginalis in Tehran has been studied.Methods: Forty six clinical T. vaginalis isolates of vaginal secretions and urine sediment were collected from Tehran Province since 2011 till 2012. DNA was extracted and ferredoxin gene was amplified by PCR technique. The ferredoxin gene PCR products were sequenced to determine gene mutations.Results: In four isolates (8.69% point mutation at nucleotide position -239 (the translation start codon of the ferredoxin gene were detected in which adenosine were converted to thymine.Conclusion: Mutation at nucleotide -239 ferredoxin gene reduces translational regulatory protein’s binding affinity which concludes reduction of ferredoxin expression. For this reduction, decrease in activity and decrease in metronidazole drug delivery into the cells occur. Mutations in these four isolates may lead to resistance of them to metronidazole.

  2. Somatic mutation in larvae of the silkworm, Bombyx mori, induced by heavy ion irradiation to diapause eggs

    Energy Technology Data Exchange (ETDEWEB)

    Kotani, Eiji; Furusawa, Toshiharu [Kyoto Inst. of Tech. (Japan). Faculty of Textile Science; Nagaoka, Shunji [Fujita Health Univ., Toyoake, Aichi (Japan). School of Health Sciences] [and others

    2002-12-01

    In order to investigate whether eggs of the black-striped strain (P{sup S}) of the silkworm, Bombyx mori, represent an appropriate model for estimating the biological effect of cosmic radiation, radiosensitivity of the eggs against X-rays and heavy ion particles was examined as ground-based experiments. The exposure of diapause eggs to X-rays or heavy ion particles resulted in somatic mutations appearing as a white spot on the black integument during larval stage. Irradiation of non-diapause eggs with X-rays demonstrated a significant difference in frequency of the mutation between fractionated and single administration doses, but no difference was observed in diapause eggs. Incidence of the mutation as induced by carbon ion beams for 15-day old eggs was higher for eggs that had been kept at 15 deg C than those kept at 25 deg C. Neon beam irradiation of diapause eggs displayed dose- and linear energy transfer (LET)-dependent effects, causing a maximal rate of the mutation at 150 keV/{mu}m. These results confirm that B. mori eggs represent valid models for estimating the biological effects of cosmic radiation. (author)

  3. High frequency induction of mitotic recombination by ionizing radiation in Mlh1 null mouse cells

    International Nuclear Information System (INIS)

    Wang Qi; Ponomareva, Olga N.; Lasarev, Michael; Turker, Mitchell S.

    2006-01-01

    Mitotic recombination in somatic cells involves crossover events between homologous autosomal chromosomes. This process can convert a cell with a heterozygous deficiency to one with a homozygous deficiency if a mutant allele is present on one of the two homologous autosomes. Thus mitotic recombination often represents the second mutational step in tumor suppressor gene inactivation. In this study we examined the frequency and spectrum of ionizing radiation (IR)-induced autosomal mutations affecting Aprt expression in a mouse kidney cell line null for the Mlh1 mismatch repair (MMR) gene. The mutant frequency results demonstrated high frequency induction of mutations by IR exposure and the spectral analysis revealed that most of this response was due to the induction of mitotic recombinational events. High frequency induction of mitotic recombination was not observed in a DNA repair-proficient cell line or in a cell line with an MMR-independent mutator phenotype. These results demonstrate that IR exposure can initiate a process leading to mitotic recombinational events and that MMR function suppresses these events from occurring

  4. Pediatric-type nodal follicular lymphoma: a biologically distinct lymphoma with frequent MAPK pathway mutations.

    Science.gov (United States)

    Louissaint, Abner; Schafernak, Kristian T; Geyer, Julia T; Kovach, Alexandra E; Ghandi, Mahmoud; Gratzinger, Dita; Roth, Christine G; Paxton, Christian N; Kim, Sunhee; Namgyal, Chungdak; Morin, Ryan; Morgan, Elizabeth A; Neuberg, Donna S; South, Sarah T; Harris, Marian H; Hasserjian, Robert P; Hochberg, Ephraim P; Garraway, Levi A; Harris, Nancy Lee; Weinstock, David M

    2016-08-25

    Pediatric-type nodal follicular lymphoma (PTNFL) is a variant of follicular lymphoma (FL) characterized by limited-stage presentation and invariably benign behavior despite often high-grade histological appearance. It is important to distinguish PTNFL from typical FL in order to avoid unnecessary treatment; however, this distinction relies solely on clinical and pathological criteria, which may be variably applied. To define the genetic landscape of PTNFL, we performed copy number analysis and exome and/or targeted sequencing of 26 PTNFLs (16 pediatric and 10 adult). The most commonly mutated gene in PTNFL was MAP2K1, encoding MEK1, with a mutation frequency of 43%. All MAP2K1 mutations were activating missense mutations localized to exons 2 and 3, which encode negative regulatory and catalytic domains, respectively. Missense mutations in MAPK1 (2/22) and RRAS (1/22) were identified in cases that lacked MAP2K1 mutations. The second most commonly mutated gene in PTNFL was TNFRSF14, with a mutation frequency of 29%, similar to that seen in limited-stage typical FL (P = .35). PTNFL was otherwise genomically bland and specifically lacked recurrent mutations in epigenetic modifiers (eg, CREBBP, KMT2D). Copy number aberrations affected a mean of only 0.5% of PTNFL genomes, compared with 10% of limited-stage typical FL genomes (P < .02). Importantly, the mutational profiles of PTNFLs in children and adults were highly similar. Together, these findings define PTNFL as a biologically and clinically distinct indolent lymphoma of children and adults characterized by a high prevalence of MAPK pathway mutations and a near absence of mutations in epigenetic modifiers. © 2016 by The American Society of Hematology.

  5. An alternative derivation of the stationary distribution of the multivariate neutral Wright-Fisher model for low mutation rates with a view to mutation rate estimation from site frequency data.

    Science.gov (United States)

    Schrempf, Dominik; Hobolth, Asger

    2017-04-01

    Recently, Burden and Tang (2016) provided an analytical expression for the stationary distribution of the multivariate neutral Wright-Fisher model with low mutation rates. In this paper we present a simple, alternative derivation that illustrates the approximation. Our proof is based on the discrete multivariate boundary mutation model which has three key ingredients. First, the decoupled Moran model is used to describe genetic drift. Second, low mutation rates are assumed by limiting mutations to monomorphic states. Third, the mutation rate matrix is separated into a time-reversible part and a flux part, as suggested by Burden and Tang (2016). An application of our result to data from several great apes reveals that the assumption of stationarity may be inadequate or that other evolutionary forces like selection or biased gene conversion are acting. Furthermore we find that the model with a reversible mutation rate matrix provides a reasonably good fit to the data compared to the one with a non-reversible mutation rate matrix. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  6. Isolation and propagation of mutations in dahlia by in vitro culture

    International Nuclear Information System (INIS)

    Asahira, T.; Yamagata, H.; Inagaki, M.; Osuga, S.

    1975-01-01

    The present study was undertaken to search for a successful method for in vitro culture of mutated tissues in dahlia. Preceding the objective, the features of induced mutations and the effects of cutting propagation in dahlia were investigated, and the tissues easily regenerating plantlets in vitro were searched following the examination of effective condition of medium. Induction of mutations: Tuberous roots of two cultivars, 'Kosei' and 'Sunlight', were irradiated with 1,000 - 2,000 R of X-rays. Chlorophyll and flower-color mutations were successfully induced in both cultivars, but the frequency differed with genotypic constitution. The maximum frequency was observed at leaves and shoots on or from the fourth to fifth nodes from the base of plant. The use of M 1 tuberous roots seemed a way for isolating mutations though not so much efficient. Tissue culture: In vitro cultured basal parts of ray florets, exactly the ovary, differentiated shoots. No shoot formation occurred in receptacle and leaf cultures, while roots were differentiated in leaf culture. Supplements of auxin and adenine to the medium besides cytokinin appeared to be necessary for inducing shoots. It is a serious problem in the tissue culture of dahlia that a large number of explants are endogenously comtaminated with bacteria. Taking into consideration low rates of surviving and regenerating explants, it seems difficult at present for dahlia to conclude whether or not the tissue culture may become efficient in mutation breeding as compared with cutting propagation. (author)

  7. Optimal IIR filter design using Gravitational Search Algorithm with Wavelet Mutation

    Directory of Open Access Journals (Sweden)

    S.K. Saha

    2015-01-01

    Full Text Available This paper presents a global heuristic search optimization technique, which is a hybridized version of the Gravitational Search Algorithm (GSA and Wavelet Mutation (WM strategy. Thus, the Gravitational Search Algorithm with Wavelet Mutation (GSAWM was adopted for the design of an 8th-order infinite impulse response (IIR filter. GSA is based on the interaction of masses situated in a small isolated world guided by the approximation of Newtonian’s laws of gravity and motion. Each mass is represented by four parameters, namely, position, active, passive and inertia mass. The position of the heaviest mass gives the near optimal solution. For better exploitation in multidimensional search spaces, the WM strategy is applied to randomly selected particles that enhance the capability of GSA for finding better near optimal solutions. An extensive simulation study of low-pass (LP, high-pass (HP, band-pass (BP and band-stop (BS IIR filters unleashes the potential of GSAWM in achieving better cut-off frequency sharpness, smaller pass band and stop band ripples, smaller transition width and higher stop band attenuation with assured stability.

  8. Early-onset parkinsonism associated with PINK1 mutations: frequency, genotypes, and phenotypes.

    NARCIS (Netherlands)

    Bonifati, V.; Rohe, C.F.; Breedveld, G.J.; Fabrizio, E.; Mari, M. De; Tassorelli, C.; Tavella, A.; Marconi, R.; Nicholl, D.; Chien, H.F.; Fincati, E.; Abbruzzese, G.; Marini, P.; Gaetano, A. De; Horstink, M.W.I.M.; Maat-Kievit, J.A.; Sampaio, C.; Antonini, A.; Stocchi, F.; Montagna, P.; Toni, V.; Guidi, M.; Dalla Libera, A.; Tinazzi, M.; Pandis, F. De; Goldwurm, S.; Klein, A. de; Barbosa, E.; Lopiano, L.; Martignoni, E.; Lamberti, P.; Vanacore, N.; Meco, G.; Oostra, B.A.

    2005-01-01

    OBJECTIVE: To assess the prevalence, nature, and associated phenotypes of PINK1 gene mutations in a large series of patients with early-onset (<50 years) parkinsonism. METHODS: The authors studied 134 patients (116 sporadic and 18 familial; 77% Italian) and 90 Italian controls. The whole PINK1

  9. Piping system damping data at higher frequencies

    International Nuclear Information System (INIS)

    Ware, A.G.

    1987-01-01

    Research has been performed at the Idaho National Engineering Laboratory (INEL) for the United States Nuclear Regulatory Commission (USNRC) to determine best-estimate damping values for dynamic analyses of nuclear piping systems excited in the 20 to 100 Hz frequency range. Vibrations in this frequency range are typical of fluid-induced transients, for which no formal pipe damping guidelines exist. The available data found in the open literature and the USNRC/INEL nuclear piping damping data bank were reviewed, and a series of tests on a straight 3-in. (76-mm) piping system and a 5-in. (127-mm) system with several bends and elbows were conducted as part of this research program. These two systems were supported with typical nuclear piping supports that could be changed from test to test during the series. The resulting damping values were ≥ those of the Pressure Vessel Research Committee (PVRC) proposal for unisulated piping. Extending the PVRC damping curve from 20 to 100 Hz at 3% of critical damping would give a satisfactory representation of the test data. This position has been endorsed by the PVRC Technical Committee on Piping Systems. 14 refs

  10. Clinical presentation of Griscelli syndrome type 2 and spectrum of RAB27A mutations

    DEFF Research Database (Denmark)

    Meeths, Marie; Bryceson, Yenan T; Rudd, Eva

    2010-01-01

    Griscelli syndrome type 2 (GS2) is an autosomal-recessive immunodeficiency caused by mutations in RAB27A, clinically characterized by partial albinism and haemophagocytic lymphohistocytosis (HLH). We evaluated the frequency of RAB27A mutations in 21 unrelated patients with haemophagocytic syndromes...

  11. Improvement of mutation rate and reduction of somatic effects by double treatment of chemical mutagens in barley

    International Nuclear Information System (INIS)

    Koo, B.C.; Maluszynski, M.

    1996-01-01

    Mutation techniques inducing more useful mutations and reducing somatic effects need to be improved for crop breeding. Seeds of barley varieties; Dema, Grosso were treated with two types of mutagens; 1) chemical treatment: single treatment or double treatment of two mutagens (N-nitroso-N-methylurea ; MNH, Sodium Azide; NaN 3 ) 2) gamma ray irradiation treatment. After treatment, half of seeds were used for germination test and half of seeds were sown to the field. With the higher dose of mutagen both chemical and gamma ray were plants treated, the higher rate of growth reduction rate was in M 1 seedling. In chemical treatment, germination rate of seeds, growth rate of coleoptile and root in double treatment of chemical mutagens were better than single treatments, especially in same dose. Growth inhibition rate of plant in double treatment of 1.0 mM MNH (0.5 mM MNH + 0.5 mM MNH), for example, were less than one of plants of single treatment of 1.0 mM MNH in pot and petri dish test. Growth reduction rate of culm and fertility rate in M 1 plants double treated in same dose of single treatment were also less than single one. With the higher dose of mutagen both chemical and gamma ray were plants treated, the higher frequency of chlorophyll mutants was in M 2 seedling. The rate of chlorophyll mutants in double treatment of chemical mutagens were higher than single treatment. Double treatment methods can be a improved method for induction of new good mutants, which were induced more useful mutations and reduced harmful somatic effects

  12. The influence of preirradiation history of E. coli WP2 cells on the residual fixation of mutations in rpsL. (strA) locus

    International Nuclear Information System (INIS)

    Filippov, V.D.

    1986-01-01

    The values of residual fixation of strA mutations in E.coli culture, irradiated by UV-light (6.8 J/m 2 ) in different physiological states and conforming to different in depth strA mutation frequency decrease in postirradiation incubation under conditions unfavourable for protein synthesis are determined. By residual fixation one should mean accumulation of strA mutations stable to antimutagenous effect of photoreactivating light in cell population incubated in buffer after UV radiation. It is established that residual fixation is small in cultures, conforming to deep decrease, and is a factor (about 40% of strA mutations is fixed) in a culture, conforming to moderate decrease (about 60% of strA mutations disappears) of mutation frequency in incubation under conditions unfavourable for protein synthesis. The conclusion is made that the depth of strA mutation frequency decrease, taking place under the influence of mfd system, depends on the level of residual fixation of this mutations. It is supposed that residual fixation is caused by rpsL (strA) locus introduction in replication cycle initiated after radiation

  13. Spontaneous mutation rates and the rate-doubling dose

    International Nuclear Information System (INIS)

    Von Borstel, R.C.; Moustaccki, E.; Latarjet, R.

    1978-01-01

    The amount of radiation required to double the frequency of mutations or tumours over the rate of those that occur spontaneously is called the rate-doubling dose. An equivalent concept has been proposed for exposure to other environmental mutagens. The doubling dose concept is predicated on the assumption that all human populations have the same spontaneous mutation rate, and that this spontaneous mutation rate is known. It is now established for prokaryotes and lower eukaryotes that numerous genes control the spontaneous mutation rate, and it is likely that the same is true for human cells as well. Given that the accepted mode of evolution of human populatons is from small, isolated groups of individuals, it seems likely that each population would have a different spontaneous mutation rate. Given that a minimum of twenty genes control or affect the spontaneous mutation rate, and that each of these in turn is susceptible to spontaneously arising or environmentally induced mutations, it seems likely that every individual within a population (except for siblings from identical multiple births) will have a unique spontaneous mutation rate. If each individual in a population does have a different spontaneous mutation rate, the doubling dose concept, in rigorous terms, is fallacious. Therefore, as with other concepts of risk evaluation, the doubling dose concept is subject to criticism. Nevertheless, until we know individual spontaneous mutation rates with precision, and can evaluate risks based on this information, the doubling dose concept has a heuristic value and is needed for practical assessment of risks for defined populations. (author)

  14. Radiosensitivity, mutation and tetraploid induction in the gamma-ray-irradiated growing shoots in mulberry, Morus alba L

    International Nuclear Information System (INIS)

    Katagiri, Koitsu

    1976-01-01

    The vigorously developing mulberry shoots on the 1 year old grafted trees of the variety Inchinose were separately exposed to 60 Co γ-ray of 6KR at 120 R/hr and 7.5 KR at 150 R/hr in early July, early August and early September. After the irradiation, all of the irradiated shoots developed axially buds with malformed narrow leaves, and after that, all plants subjected to the irradiation in September and 30% of the July irradiation group and 40% of the August irradiation group both with higher exposure ceased shoot development. This type of radiation damage was large for the plants with higher exposure as compared with those with lower one, and it was also severe for the plants irradiated in July in comparison with those in August. From the ceasing of shoot development the LD 50 value of 150 R/hr irradiation was estimated to be a little more than 7.5 KR. The frequencies of mutation and tetraploid in the grafts produced by the propagation of the axially buds below the leafless portion were high in the grafts with higher exposure than those with lower one, and also the frequencies were high in July irradiation in comparison with August irradiation. It was confirmed that the size of mutation or tetraploid sector was large in the shoots derived from the less advanced axially bud primordia at the time of irradiation than that from the advanced ones. All of tetraploids were the cytochimeras having diploid epidermises over tetraploid internal tissues. (Kobatake, H.)

  15. Significance tests in mutagen screening: another method considering historical control frequencies

    International Nuclear Information System (INIS)

    Traut, H.

    1983-01-01

    Recently a method has been devised for testing the significance of the difference between a mutation frequency observed after chemical treatment or iradiation and the historical ('stable') control frequency. Another test is proposed serving the same purpose. Both methods are applied to several examples (experimental frequency versus historical control frequency). The results (P values) obtained agree well. (author)

  16. Molecular Epidemiology of EGFR Mutations in Asian Patients with Advanced Non-Small-Cell Lung Cancer of Adenocarcinoma Histology – Mainland China Subset Analysis of the PIONEER study

    Science.gov (United States)

    Shi, Yuankai; Li, Junling; Zhang, Shucai; Wang, Mengzhao; Yang, Shujun; Li, Ning; Wu, Gang; Liu, Wei; Liao, Guoqing; Cai, Kaican; Chen, Liang’an; Zheng, Meizhen; Yu, Ping; Wang, Xiuwen; Liu, Yunpeng; Guo, Qisen; Nie, Ligong; Liu, Jiwei; Han, Xiaohong

    2015-01-01

    Epidermal growth factor receptor (EGFR) mutations are the strongest response predictors to EGFR tyrosine kinase inhibitors (TKI) therapy, but knowledge of the EGFR mutation frequency on lung adenocarcinoma is still limited to retrospective studies. The PIONEER study (NCT01185314) is a prospective molecular epidemiology study in Asian patients with newly diagnosed advanced lung adenocarcinoma, aiming to prospectively analyze EGFR mutation status in IIIB/IV treatment-naïve lung adenocarcinomas in Asia. We report the mainland China subset results. Eligible patients (≥20 yrs old, IIIB/IV adenocarcinoma and treatment-naïve) were registered in 17 hospitals in mainland China. EGFR was tested for mutations by amplification refractory mutation system using biopsy samples. Demographic and clinical characteristics were collected for subgroup analyses. A total of 747 patients were registered. Successful EGFR mutation analysis was performed in 741, with an overall mutation rate of 50.2%. The EGFR active mutation rate is 48.0% (with 1.3% of combined active and resistance mutations). Tobacco use (>30 pack-year vs. 0–10 pack-year, OR 0.27, 95%CI: 0.17–0.42) and regional lymph nodes involvement (N3 vs. N0, OR 0.47, 95%CI: 0.29–0.76) were independent predictors of EGFR mutation in multivariate analysis. However, even in regular smokers, the EGFR mutation frequency was 35.3%. The EGFR mutation frequency was similar between diverse biopsy sites and techniques. The overall EGFR mutation frequency of the mainland China subset was 50.2%, independently associated with the intensity of tobacco use and regional lymph nodes involvement. The relatively high frequency of EGFR mutations in the mainland China subset suggest that any effort to obtain tissue sample for EGFR mutation testing should be encouraged. PMID:26599344

  17. Intercellular distribution of mutations induced in oopcytes of Drosophila melanogaster by chemical and physical mutagens

    International Nuclear Information System (INIS)

    Traut, H.

    1979-01-01

    When females of Drosophila melanogaster are treated with chemical or physical mutagens, not only in one but also in both of the two homologous X chromosomes of a given oocyte, a recessive sex-linked lethal mutation may be induced. A method is described that discriminates between such single and double mutations. A theory is developed to show how a comparison betweeen the expected and the observer frequency of double mutations yields an indication of the intercellular distribution (random or nonrandom) of recessive lethal mutations induced by mutagenic agents in oocytes and, consequently, of the distribution (homogenous or nonhomogeneous) of those agents. Three agents were tested: FUdR (12.5, 50.0 and 81.0 μg/ml), mitomycin C (130.0 μg/ml) and x rays (2000 R, 150 kV). After FUdR feeding, no increase in the mutation frequency usually observed in D. melanogaster without mutagenic treatment was obtained (u = 0.13%, namely three single mutations among 2332 chromosomes tested). After mitomycin C feeding 104 single and three double mutations were obtained. All of the 50 mutations observed after x irradiation were single mutations. The results obtained in the mitomycin C and radiation experiments favor the assumption of a random intercellular distribution of recessive lethal mutations induced by these two agents in oocytes of D. melanogaster. Reasons are discussed why for other types of mutagenic agents nonrandom distributions may be observed with our technique

  18. Cystic fibrosis transmembrane conductance regulator gene mutations: do they play a role in the aetiology of allergic bronchopulmonary aspergillosis?

    Science.gov (United States)

    Eaton, T E; Weiner Miller, P; Garrett, J E; Cutting, G R

    2002-05-01

    Previous work suggests that cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations may be implicated in the aetiology of allergic bronchopulmonary aspergilosis (ABPA). To compare the frequency of CF gene mutations in asthmatics with ABPA of varying severity with asthmatics who were skin prick test (SPT)-positive to Aspergillus fumigatus (Af) without evidence of ABPA and asthmatics SPT-negative to Af. Thirty-one Caucasian patients with ABPA were identified, together with asthmatics SPT positive to Af without evidence of ABPA (n = 23) and SPT negative to Af (n = 28). Genomic DNA was tested for 16 CF mutations accounting for approximately 85% of CF alleles in Caucasian New Zealanders. Four (12.9%) ABPA patients were found to be carriers of a CF mutation (DeltaF508 n = 3, R117H n = 1), one (4.3%) asthmatic SPT positive to Af without ABPA (DeltaF508), and one (3.6%) asthmatic SPT negative to Af (R117H). All patients with a CF mutation had normal sweat chloride (< 40 mM). There was no significant difference between the frequency of CF mutations in the ABPA patients and asthmatics without ABPA. However, the frequency of CF mutations in the ABPA patients was significantly different (P = 0.0125) to the expected carrier rate in the general population. These results lend further support to a possible link between CF mutations and ABPA.

  19. Mutation and polymorphism of the prion protein gene in Libyan Jews with Creutzfeldt-Jakob disease (CJD)

    Energy Technology Data Exchange (ETDEWEB)

    Gabizon, R.; Rosenmann, H.; Meiner, Z.; Kahana, I. (Hadassah Univ., Jerusalem (Israel)); Kahana, E. (Barzilai Medical Center, Ashkelon (Israel)); Shugart, Y.; Ott, J. (Columbia Univ., New York, NY (United States)); Prusiner, S.B. (Univ. of California, San Francisco, CA (United States))

    1993-10-01

    The inherited prion diseases are neurodegenerative disorders which are not only genetic but also transmissible. More than a dozen mutations in the prion protein gene that result in nonconservative amino acid substitutions segregate with the inherited prion diseases including familial Creutzfeldt-Jakob disease (CJD). In Israel, the incidence of CJD is about 1 case/10[sup 4] Libyan Jews. A Lys[sub 200] substitution segregates with CJD and is reported here to be genetically linked to CJD with a lod score of >4.8. Some healthy elderly Lys[sub 200] carriers > age 65 years were identified, suggesting the possibility of incomplete penetrance. In contrast, no linkage was found between the development of familial CJD and a polymorphism encoding either Met[sub 129] or Val[sub 129]. All Libyan Jewish CJD patients with the Lys[sub 200] mutation encode a Met[sub 129] on the mutant allele. Homozygosity for Met[sub 129] did not correlate with age at disease onset or the duration of illness. The frequency of the Met[sub 129] allele was higher in the affected pedigrees than in a control population of Libyan Jews. The frequency of the Met[sub 129] and Val[sub 129] alleles in the control Libyan population was similar to that found in the general Caucasian population. The identification of three Libyan Jews homozygous for the Lys[sub 200] mutation suggests frequent intrafamilial marriages, a custom documented by genealogical investigations. 26 refs., 3 figs., 6 tabs.

  20. Consumption Frequency of Foods Away from Home Linked with Higher Body Mass Index and Lower Fruit and Vegetable Intake among Adults: A Cross-Sectional Study

    Science.gov (United States)

    Seguin, Rebecca A.; Aggarwal, Anju; Vermeylen, Francoise; Drewnowski, Adam

    2016-01-01

    Introduction. Consumption of foods prepared away from home (FAFH) has grown steadily since the 1970s. We examined the relationship between FAFH and body mass index (BMI) and fruit and vegetable (FV) consumption. Methods. Frequency of FAFH, daily FV intake, height and weight, and sociodemographic data were collected using a telephone survey in 2008-2009. Participants included a representative sample of 2,001 adult men and women (mean age 54 ± 15 years) residing in King County, WA, with an analytical sample of 1,570. Frequency of FAFH was categorized as 0-1, 2–4, or 5+ times per week. BMI was calculated from self-reported height and weight. We examined the relationship between FAFH with FV consumption and BMI using multivariate models. Results. Higher frequency of FAFH was associated with higher BMI, after adjusting for age, income, education, race, smoking, marital status, and physical activity (women: p = 0.001; men: p = 0.003). There was a negative association between frequency of FAFH and FV consumption. FAFH frequency was significantly (p < 0.001) higher among males than females (43.1% versus 54.0% eating out 0-1 meal per week, resp.). Females reported eating significantly (p < 0.001) more FV than males. Conclusion. Among adults, higher frequency of FAFH was related to higher BMI and less FV consumption. PMID:26925111

  1. Consumption Frequency of Foods Away from Home Linked with Higher Body Mass Index and Lower Fruit and Vegetable Intake among Adults: A Cross-Sectional Study

    Directory of Open Access Journals (Sweden)

    Rebecca A. Seguin

    2016-01-01

    Full Text Available Introduction. Consumption of foods prepared away from home (FAFH has grown steadily since the 1970s. We examined the relationship between FAFH and body mass index (BMI and fruit and vegetable (FV consumption. Methods. Frequency of FAFH, daily FV intake, height and weight, and sociodemographic data were collected using a telephone survey in 2008-2009. Participants included a representative sample of 2,001 adult men and women (mean age 54±15 years residing in King County, WA, with an analytical sample of 1,570. Frequency of FAFH was categorized as 0-1, 2–4, or 5+ times per week. BMI was calculated from self-reported height and weight. We examined the relationship between FAFH with FV consumption and BMI using multivariate models. Results. Higher frequency of FAFH was associated with higher BMI, after adjusting for age, income, education, race, smoking, marital status, and physical activity (women: p=0.001; men: p=0.003. There was a negative association between frequency of FAFH and FV consumption. FAFH frequency was significantly (p<0.001 higher among males than females (43.1% versus 54.0% eating out 0-1 meal per week, resp.. Females reported eating significantly (p<0.001 more FV than males. Conclusion. Among adults, higher frequency of FAFH was related to higher BMI and less FV consumption.

  2. Association studies using family pools of outcrossing crops based on allele-frequency estimates from DNA sequencing

    DEFF Research Database (Denmark)

    Ashraf, Bilal; Jensen, Just; Asp, Torben

    2014-01-01

    effect from F2-family pools was verified and it was shown that the underestimation of the allele effect is correctly described. The optimal design for an association study when sequencing budget would be fixed is obtained using large sample size and lower sequence depth, and using higher SNP density......F2 families are frequently used in breeding of outcrossing species, for instance to obtain trait measurements on plots. We propose to perform association studies by obtaining a matching “family genotype” from sequencing a pooled sample of the family, and to directly use allele frequencies computed...... (resulting in higher LD with causative mutations) and lower sequencing depth. Therefore, association studies using genotyping by sequencing are optimal and use low sequencing depth per sample. The developed framework for association studies using allele frequencies from sequencing can be modified for other...

  3. Prothrombin G20210A gene mutation in pregnant females with thrombotic obstetric complications

    International Nuclear Information System (INIS)

    Alam, M.A.; Ali, N.; Ayyub, M.

    2018-01-01

    To determine the frequency of prothrombin G20210A gene mutation in pregnant females with adverse thrombotic obstetric complication and to compare it with prothrombin G20210A gene's frequency in control population. Study Design: Case control study. Place and Duration of Study: Department of Haematology, Army Medical College Rawalpindi and Military Hospital Rawalpindi, from Nov 2013 to Oct 2014. Material and Methods: Sixty pregnant females were included in the study; 30 were cases with adverse thrombotic obstetric complication, while 30 were controls. Detailed history was obtained and 3 ml blood in EDTA tube was collected. DNA was extracted from whole blood and through RT-PCR, presence of prothrombin G20210A gene mutation was looked for in patients and controls. Data was analyzed using SPSS 21. Results: A total of 60 women-30 cases with thrombotic obstetric complications as 'cases' and 30 as 'controls'- were included in the study. Mean age of 'cases' was 28.70 +- 4.23 years while that of 'controls' was 27.33 +- 4.49 years. There was no statistically significant difference among the two groups (p=0.54). In case group only one of 30 (3.3%) patients had heterozygous F2 G20210A mutation while 29 (96.7%) patients had wild type allele. In control group, all the 30 (100%) subjects had wild type allele. The odds of finding the mutation in cases was 1:29 i.e. 0.03 as compared to zero in the control group. The difference was statistically insignificant (p=0.5). Conclusion: Our study shows that the frequency of F2 G20210A gene mutation in pregnant females having adverse thrombotic obstetric complications was not significantly different from its frequency in control population. (author)

  4. Low frequency geomagnetic field fluctuations at low latitude during the passage of a higher pressure solar wind region

    Directory of Open Access Journals (Sweden)

    U. Villante

    1997-06-01

    Full Text Available The passage of a higher pressure solar wind region at the Earth's orbit marked the onset of low latitude (L=1.6 fluctuations in the frequency range (0.8–5.5 mHz for both the horizontal geomagnetic field components. Spectral peaks mostly occur at the same frequencies as the spectral enhancements which appeared in the long term analysis of experimental measurements from the same station and were tentatively interpreted in terms of ground signatures of global magnetospheric modes. A comparison with simultaneous observations discussed by previous investigations allows us to conclude that the same set of frequencies is enhanced in a wide portion of the Earth's magnetosphere.

  5. The frequency of a disease-causing point mutation in the gene coding for medium-chain acyl-CoA dehydrogenase in sudden infant death syndrome

    DEFF Research Database (Denmark)

    Banner, Jytte; Gregersen, N; Kølvraa, S

    1993-01-01

    A number of rare inherited metabolic disorders are known to lead to death in infancy. Deficiency of medium-chain acyl CoA dehydrogenase has, on clinical grounds, been related particularly to sudden infant death syndrome. The contribution of this disorder to the etiology of sudden infant death...... syndrome is still a matter of controversy. The present study investigated 120 well-defined cases of sudden infant death syndrome in order to detect the frequency of the most common disease-causing point mutation in the gene coding for medium-chain acyl-CoA dehydrogenase (G985) compared with the frequency...... in the general population. A highly specific polymerase chain reaction assay was applied on dried blood spots. No over-representation of homo- or heterozygosity for G985 appears to exist in such a strictly defined population, for which reason it may be more relevant to look at a broader spectrum of clinical...

  6. The IARC TP53 mutation database: a resource for studying the significance of TP53 mutations in human cancers

    Directory of Open Access Journals (Sweden)

    Magali Olivier

    2007-02-01

    yeast and human cells to measure the impact of these mutations on various protein properties: (1 transactivation activities (TA of mutant proteins on reporter genes placed under the control of various p53 responseelements, (2 capacity of mutant proteins to induce cellcycle arrest or apoptosis, (3 ability to exert dominantnegative effect (DNE over the wild-type protein, (4 activities of mutant proteins that are independent and unrelated to the wild-type protein (gain of function, GOF. Prediction models based on interspecies protein sequence conservation have also been developed to predict the functional impact of all possible single amino-acid substitutions.

    These data have been used to produce systematic functional classifications of mutant proteins and these classifications have been integrated in the IARC TP53 database. New tools have been implemented to visualize these data and analyze mutation frequencies in relation to their functional impact and intrinsic nucleotide substitution rates.

    Thus, the database allows systematic analyses of the factors that shape the patterns and influence the phenotype of missense mutations in human cancers. In a recent analysis of the database, we showed that that loss of TA capacity is a key factor for the selection of missense mutations, and that difference in mutation frequencies is closely related to nucleotide substitution rates along TP53 coding sequence. TA capacity of inherited missense mutations was also found to be related the age at onset of specific tumor types, mutations with total loss of TA being associated with earlier cancer onset cancers compared to mutations that retain partial trans-activation capacity. Furthermore, 80% of the most common mutants show a capacity to exert dominant-negative effect (DNE over wildtype p53, compared to only 45% of

  7. Epidermal Growth Factor Receptor Activating Mutations in Squamous Histology of Lung Cancer Patients of Southern Bulgaria

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    Genova Silvia N.

    2015-12-01

    Full Text Available There is only limited data on the prevalence of epidermal growth factor receptor (EGFR activating mutations in squamous cell carcinomas and adenosquamous carcinomas of the lung in patients of the Southern Bulgarian region and the efficacy of EGFR tyrosine kinase inhibitors. AIM: Previous reports for Bulgarian population showed high incidence of EGFR mutations in the squamous cell carcinomas, so we set the goal to investigate their frequency in Southern Bulgaria, after precise immunohistochemical verification of lung cancers. MATERIALS AND METHODS: Two hundred and thirty-six lung carcinomas were included in this prospective study. All biopsies were initially analysed with p63, TTF1, Napsin A, CK7, CK34βE12, synaptophysin, CK20 and CDX2. Two hundred and twenty-five non-small cell lung carcinomas were studied with real-time PCR technology to assess the status of the EGFR gene. RESULTS: We detected 132 adenocarcinomas (58.7%, 89 squamous cell carcinomas (39.2%, 4 adenosquamous carcinomas (1.8%, 9 large cell neuroendocrine carcinomas (3.8% and 2 metastatic colorectal adenocarcinomas (0.8%. Activating mutations in the EGF receptor had 3 out of 89 squamous cell carcinomas (3.37%. We have established mutations in L858R, deletion in exon 19 and rare mutation in S7681. One out of four adenosquamous carcinomas had a point mutation in the L858R (25%. CONCLUSIONS: The frequency of EGFR mutations we found in lung squamous cell carcinomas in a Southern Bulgarian region is lower than that in European countries. Ethnic diversity in the region does not play role of an independent predictive factor in terms of mutation frequency.

  8. Induction of specific-locus mutations in the mouse by tritiated water

    International Nuclear Information System (INIS)

    Russell, W.L.; Cumming, R.B.; Kelly, E.M.; Phipps, E.L.

    1978-01-01

    The results reported are the first obtained on transmtted gene mutations induced by tritium in any form in any mammal. They are, therefore, of obvious practical importance in the estimaton of the possible biological hazards of man-made tritium in the environment. Male mice were injected intraperitoneally with either 0.75 or 0.50 mCi per gram of body weight of tritiated water. They were then used in our standard specific-locus mutation test in which the treated wild-type stock of mice is mated to a stock homozygous for seven recessive marker genes. Mutations at any of the seven loci are scored in the offspring. The earlier matings provided information on the mutation frequency in germ cells irradiated in postspermatogonial stages, and the later matings gave the mutation frequency in treated spermatogonia. The spermatogonia are the important cells so far as human risks are concerned, and the mouse results for this germ-cell stage yielded a relative biological effectiveness (RBE) of approximately 2 for tritiated water compared with low-dose-rate gamma irradiation. There are various uncertainties involved in arriving at this figure, and the difference between it and l is probably not statistically significant. However, for risk estimation, it seems prudent to use the RBE value of 2, which is, after all, the best point estimate computed from the present data

  9. Mutations in CARD15 and smoking confer susceptibility to Crohn's disease in the Danish population

    DEFF Research Database (Denmark)

    Ernst, Anja; Jacobsen, Bent Ascanius; Østergaard, Mette

    2007-01-01

    Three CAspase Recruitment Domain (CARD15) mutations have shown to predispose to Crohn's disease in Caucasian populations. The aim of this study was to investigate the mutation frequency in patients with inflammatory bowel disease and in healthy controls in Denmark....

  10. A simple algebraic cancer equation: calculating how cancers may arise with normal mutation rates

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    Shibata Darryl

    2010-01-01

    Full Text Available Abstract Background The purpose of this article is to present a relatively easy to understand cancer model where transformation occurs when the first cell, among many at risk within a colon, accumulates a set of driver mutations. The analysis of this model yields a simple algebraic equation, which takes as inputs the number of stem cells, mutation and division rates, and the number of driver mutations, and makes predictions about cancer epidemiology. Methods The equation [p = 1 - (1 - (1 - (1 - udkNm ] calculates the probability of cancer (p and contains five parameters: the number of divisions (d, the number of stem cells (N × m, the number of critical rate-limiting pathway driver mutations (k, and the mutation rate (u. In this model progression to cancer "starts" at conception and mutations accumulate with cell division. Transformation occurs when a critical number of rate-limiting pathway mutations first accumulates within a single stem cell. Results When applied to several colorectal cancer data sets, parameter values consistent with crypt stem cell biology and normal mutation rates were able to match the increase in cancer with aging, and the mutation frequencies found in cancer genomes. The equation can help explain how cancer risks may vary with age, height, germline mutations, and aspirin use. APC mutations may shorten pathways to cancer by effectively increasing the numbers of stem cells at risk. Conclusions The equation illustrates that age-related increases in cancer frequencies may result from relatively normal division and mutation rates. Although this equation does not encompass all of the known complexity of cancer, it may be useful, especially in a teaching setting, to help illustrate relationships between small and large cancer features.

  11. Comparative analysis of primary versus relapse/refractory DLBCL identifies shifts in mutation spectrum.

    Science.gov (United States)

    Greenawalt, Danielle M; Liang, Winnie S; Saif, Sakina; Johnson, Justin; Todorov, Petar; Dulak, Austin; Enriquez, Daniel; Halperin, Rebecca; Ahmed, Ambar; Saveliev, Vladislav; Carpten, John; Craig, David; Barrett, J Carl; Dougherty, Brian; Zinda, Michael; Fawell, Stephen; Dry, Jonathan R; Byth, Kate

    2017-11-21

    Current understanding of the mutation spectrum of relapsed/refractory (RR) tumors is limited. We performed whole exome sequencing (WES) on 47 diffuse large B cell lymphoma (DLBCL) tumors that persisted after R-CHOP treatment, 8 matched to primary biopsies. We compared genomic alterations from the RR cohort against two treatment-naïve DLBCL cohorts (n=112). While the overall number and types of mutations did not differ significantly, we identified frequency changes in DLBCL driver genes. The overall frequency of MYD88 mutant samples increased (12% to 19%), but we noted a decrease in p.L265P (8% to 4%) and increase in p.S219C mutations (2% to 6%). CARD11 p.D230N, PIM1 p.K115N and CD79B p.Y196C mutations were not observed in the RR cohort, although these mutations were prominent in the primary DLBCL samples. We observed an increase in BCL2 mutations (21% to 38% of samples), BCL2 amplifications (3% to 6% of samples) and CREBBP mutations (31% to 42% of samples) in the RR cohort, supported by acquisition of mutations in these genes in relapsed compared to diagnostic biopsies from the same patient. These increases may reflect the genetic characteristics of R-CHOP RR tumors expected to be enriched for during clinical trial enrollment. These findings hold significance for a number of emerging targeted therapies aligned to genetic targets and biomarkers in DLBCL, reinforcing the importance of time-of-treatment biomarker screening during DLBCL therapy selection.

  12. Mutations of the phenylalanine hydroxylase gene in patients with phenylketonuria in Shanxi, China

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    Yong-An Zhou

    2012-01-01

    Full Text Available The variation in mutations in exons 3, 6, 7, 11 and 12 of the phenylalanine hydroxylase (PAH gene was investigated in 59 children with phenylketonuria (PKU and 100 normal children. Three single nucleotide polymorphisms were detected by sequence analysis. The mutational frequencies of cDNA 696, cDNA 735 and cDNA 1155 in patients were 96.2%, 76.1% and 7.6%, respectively, whereas in healthy children the corresponding frequencies were 97.0%, 77.3% and 8.3%. In addition, 81 mutations accounted for 61.0% of the mutant alleles. R111X, H64 > TfsX9 and S70 del accounted for 5.1%, 0.8% and 0.8% mutation of alleles in exon 3, whereas EX6-96A > G accounted for 10.2% mutation of alleles in exon 6. R243Q had the highest incidence in exon 7 (12.7%, followed by Ivs7 +2T>A (5.1% and T278I (2.5%. G247V, R252Q, L255S, R261Q and E280K accounted for 0.8% while Y356X and V399V accounted for 5.9% and 5.1%, respectively, in exon 11. R413P and A434D accounted for 5.9% and 2.5%, respectively, in exon 12. Seventy-two variant alleles accounted for the 16 mutations observed here. The mutation characteristics and distributions demonstrated that EX6-96A > G and R243Q were the hot regions for mutations in the PAH gene in Shanxi patients with PKU.

  13. Mutation exposed: a neutral explanation for extreme base composition of an endosymbiont genome.

    Science.gov (United States)

    Wernegreen, Jennifer J; Funk, Daniel J

    2004-12-01

    The influence of neutral mutation pressure versus selection on base composition evolution is a subject of considerable controversy. Yet the present study represents the first explicit population genetic analysis of this issue in prokaryotes, the group in which base composition variation is most dramatic. Here, we explore the impact of mutation and selection on the dynamics of synonymous changes in Buchnera aphidicola, the AT-rich bacterial endosymbiont of aphids. Specifically, we evaluated three forms of evidence. (i) We compared the frequencies of directional base changes (AT-->GC vs. GC-->AT) at synonymous sites within and between Buchnera species, to test for selective preference versus effective neutrality of these mutational categories. Reconstructed mutational changes across a robust intraspecific phylogeny showed a nearly 1:1 AT-->GC:GC-->AT ratio. Likewise, stationarity of base composition among Buchnera species indicated equal rates of AT-->GC and GC-->AT substitutions. The similarity of these patterns within and between species supported the neutral model. (ii) We observed an equivalence of relative per-site AT mutation rate and current AT content at synonymous sites, indicating that base composition is at mutational equilibrium. (iii) We demonstrated statistically greater equality in the frequency of mutational categories in Buchnera than in parallel mammalian studies that documented selection on synonymous sites. Our results indicate that effectively neutral mutational pressure, rather than selection, represents the major force driving base composition evolution in Buchnera. Thus they further corroborate recent evidence for the critical role of reduced N(e) in the molecular evolution of bacterial endosymbionts.

  14. The mutational spectrum of Lynch syndrome in cyprus.

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    Maria A Loizidou

    Full Text Available Lynch syndrome is the most common form of hereditary colorectal cancer and is caused by germline mutations in the mismatch repair (MMR genes MLH1, MSH2, MSH6 and PMS2. Mutation carriers have an increased lifetime risk of developing colorectal cancer as well as other extracolonic tumours. The aim of the current study was to evaluate the frequency and distribution of mutations in the MLH1, MSH2 and MSH6 genes within a cohort of Cypriot families that fulfilled the revised Bethesda guidelines. The study cohort included 77 patients who fulfilled at least one of the revised Bethesda guidelines. Mutational analysis revealed the presence of 4 pathogenic mutations, 3 in the MLH1 gene and 1 in the MSH2 gene, in 5 unrelated individuals. It is noted that out of the 4 pathogenic mutations detected, one is novel (c.1610delG in exon 14 of the MLH1 and has been detected for the first time in the Cypriot population. Overall, the pathogenic mutation detection rate in our patient cohort was 7%. This percentage is relatively low but could be explained by the fact that the sole criterion for genetic screening was compliance to the revised Bethesda guidelines. Larger numbers of Lynch syndrome families and screening of the two additional predisposition genes, PMS2 and EPCAM, are needed in order to decipher the full spectrum of mutations associated with Lynch syndrome predisposition in Cyprus.

  15. Performance of mitochondrial DNA mutations detecting early stage cancer

    International Nuclear Information System (INIS)

    Jakupciak, John P; Srivastava, Sudhir; Sidransky, David; O'Connell, Catherine D; Maragh, Samantha; Markowitz, Maura E; Greenberg, Alissa K; Hoque, Mohammad O; Maitra, Anirban; Barker, Peter E; Wagner, Paul D; Rom, William N

    2008-01-01

    Mutations in the mitochondrial genome (mtgenome) have been associated with cancer and many other disorders. These mutations can be point mutations or deletions, or admixtures (heteroplasmy). The detection of mtDNA mutations in body fluids using resequencing microarrays, which are more sensitive than other sequencing methods, could provide a strategy to measure mutation loads in remote anatomical sites. We determined the mtDNA mutation load in the entire mitochondrial genome of 26 individuals with different early stage cancers (lung, bladder, kidney) and 12 heavy smokers without cancer. MtDNA was sequenced from three matched specimens (blood, tumor and body fluid) from each cancer patient and two matched specimens (blood and sputum) from smokers without cancer. The inherited wildtype sequence in the blood was compared to the sequences present in the tumor and body fluid, detected using the Affymetrix Genechip ® Human Mitochondrial Resequencing Array 1.0 and supplemented by capillary sequencing for noncoding region. Using this high-throughput method, 75% of the tumors were found to contain mtDNA mutations, higher than in our previous studies, and 36% of the body fluids from these cancer patients contained mtDNA mutations. Most of the mutations detected were heteroplasmic. A statistically significantly higher heteroplasmy rate occurred in tumor specimens when compared to both body fluid of cancer patients and sputum of controls, and in patient blood compared to blood of controls. Only 2 of the 12 sputum specimens from heavy smokers without cancer (17%) contained mtDNA mutations. Although patient mutations were spread throughout the mtDNA genome in the lung, bladder and kidney series, a statistically significant elevation of tRNA and ND complex mutations was detected in tumors. Our findings indicate comprehensive mtDNA resequencing can be a high-throughput tool for detecting mutations in clinical samples with potential applications for cancer detection, but it is

  16. Mutation Induction with UV- and X-radiations in spores and vegetative cells of Bacillus subtilis

    International Nuclear Information System (INIS)

    Tanooka, H.; Munakata, N.; Kitahara, S.

    1978-01-01

    Spores and vegetative cells of Bacillus subtilis strains with various defects in DNA-repair capacities (hcr - , ssp - , hcr - ssp - ) were irradiated with UV radiation or X-rays. Induced mutation frequency was determined from the observed frequency of prototrophic reversion of a suppressible auxotropic mutation. At equal physical dose, after either UV- or X-irradiation, spores were more resistant to mutations as well as to killing than were vegetative cells. However, quantitative comparison revealed that, at equally lethal doses, spores and vegetative cells were almost equally mutable by X-rays whereas spores were considerably less mutable by UV than were vegetative cells. Thus, as judged from their mutagenic efficiency relative to the lethality, X-ray-induced damage in the spore DNA and the vegetative DNA were equally mutagenic, while UV-induced DNA photoproducts in the spore were less mutagenic than those in vegetative cells. Post-treatment of UV-irradiated cells with caffeine decreased the survival and the induced mutation frequency for either spores or vegetative cells for all the strains. In X-irradiated spores however, a similar suppressing effect of caffeine was observed only for mutability of a strain lacking DNA polymerase I activity

  17. The frequency of CCR5 promoter polymorphisms and CCR5 32 mutation in Iranian populations

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    Mohammad Zare-Bidaki

    2015-04-01

    Full Text Available Evidence showed that chemokines serve as pro-migratory factors for immune cells. CCL3, CCL4 and CCL5, as the main CC  chemokines subfamily members, activate immune cells through binding to CC chemokine receptor 5 or CCR5. Macrophages, NK cells and T lymphocytes express CCR5 and thus, affected CCR5 expression or functions could be associated with altered immune responses. Deletion of 32 base pairs (D 32 in the exon 1 of the CCR5 gene, which is known as CCR5 D 32 mutation causes down regulation and malfunction of the molecule. Furthermore, it has been evidenced that three polymorphisms in the promoter region of CCR5 modulate its expression. Altered CCR5 expression in microbial infection and immune related diseases have been reported by several researchers but the role of CCR5 promoter polymorphisms and CCR5 D 32 mutation in Iranian patients suffering from these diseases are controversial. Due to the fact that Iranian people have different genetic backgrounds compared to other ethnics, hence, CCR5 promoter polymorphisms and CCR5 D 32 mutation association with the diseases may be different in Iranian patients. Therefore, this review addresses the most recent information regarding the prevalence as well as association of the mutation and polymorphisms in Iranian patients with microbial infection and immune related diseases as along with normal population.

  18. Identification of a novel frameshift mutation in the ILDR1 gene in a UAE family, mutations review and phenotype genotype correlation.

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    Abdelaziz Tlili

    Full Text Available Autosomal recessive non-syndromic hearing loss is one of the most common monogenic diseases. It is characterized by high allelic and locus heterogeneities that make a precise diagnosis difficult. In this study, whole-exome sequencing was performed for an affected patient allowing us to identify a new frameshift mutation (c.804delG in the Immunoglobulin-Like Domain containing Receptor-1 (ILDR1 gene. Direct Sanger sequencing and segregation analysis were performed for the family pedigree. The mutation was homozygous in all affected siblings but heterozygous in the normal consanguineous parents. The present study reports a first ILDR1 gene mutation in the UAE population and confirms that the whole-exome sequencing approach is a robust tool for the diagnosis of monogenic diseases with high levels of allelic and locus heterogeneity. In addition, by reviewing all reported ILDR1 mutations, we attempt to establish a genotype phenotype correlation to explain the phenotypic variability observed at low frequencies.

  19. MPL515 mutations in myeloproliferative and other myeloid disorders: a study of 1182 patients.

    Science.gov (United States)

    Pardanani, Animesh D; Levine, Ross L; Lasho, Terra; Pikman, Yana; Mesa, Ruben A; Wadleigh, Martha; Steensma, David P; Elliott, Michelle A; Wolanskyj, Alexandra P; Hogan, William J; McClure, Rebecca F; Litzow, Mark R; Gilliland, D Gary; Tefferi, Ayalew

    2006-11-15

    Recently, a gain-of-function MPL mutation, MPLW515L, was described in patients with JAK2V617F-negative myelofibrosis with myeloid metaplasia (MMM). To gain more information on mutational frequency, disease specificity, and clinical correlates, genomic DNA from 1182 patients with myeloproliferative and other myeloid disorders and 64 healthy controls was screened for MPL515 mutations, regardless of JAK2V617F mutational status: 290 with MMM, 242 with polycythemia vera, 318 with essential thrombocythemia (ET), 88 with myelodysplastic syndrome, 118 with chronic myelomonocytic leukemia, and 126 with acute myeloid leukemia (AML). MPL515 mutations, either MPLW515L (n = 17) or a previously undescribed MPLW515K (n = 5), were detected in 20 patients. The diagnosis of patients with mutant MPL alleles at the time of molecular testing was de novo MMM in 12 patients, ET in 4, post-ET MMM in 1, and MMM in blast crisis in 3. Six patients carried the MPLW515L and JAK2V617F alleles concurrently. We conclude that MPLW515L or MPLW515K mutations are present in patients with MMM or ET at a frequency of approximately 5% and 1%, respectively, but are not observed in patients with polycythemia vera (PV) or other myeloid disorders. Furthermore, MPL mutations may occur concurrently with the JAK2V617F mutation, suggesting that these alleles may have functional complementation in myeloproliferative disease.

  20. Iron overload and HFE gene mutations in Czech patients with chronic liver diseases.

    Science.gov (United States)

    Dostalikova-Cimburova, Marketa; Kratka, Karolina; Stransky, Jaroslav; Putova, Ivana; Cieslarova, Blanka; Horak, Jiri

    2012-01-01

    The aim of the study was to identify the prevalence of HFE gene mutations in Czech patients with chronic liver diseases and the influence of the mutations on iron status. The presence of HFE gene mutations (C282Y, H63D, and S65C) analyzed by the PCR-RFLP method, presence of cirrhosis, and serum iron indices were compared among 454 patients with different chronic liver diseases (51 with chronic hepatitis B, 122 with chronic hepatitis C, 218 with alcoholic liver disease, and 63 patients with hemochromatosis). Chronic liver diseases patients other than hemochromatics did not have an increased frequency of HFE gene mutations compared to controls. Although 33.3% of patients with hepatitis B, 43% of patients with hepatitis C, and 73.2% of patients with alcoholic liver disease had elevated transferrin saturation or serum ferritin levels, the presence of HFE gene mutations was not significantly associated with iron overload in these patients. Additionally, patients with cirrhosis did not have frequencies of HFE mutations different from those without cirrhosis. This study emphasizes the importance, not only of C282Y, but also of the H63D homozygous genetic constellation in Czech hemochromatosis patients. Our findings show that increased iron indices are common in chronic liver diseases but {\\it HFE} mutations do not play an important role in the pathogenesis of chronic hepatitis B, chronic hepatitis C, and alcoholic liver disease.