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Sample records for ptpn11 mutation compared

  1. Somatic PTPN11 mutations in childhood acute myeloid leukaemia.

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    Tartaglia, Marco; Martinelli, Simone; Iavarone, Ivano; Cazzaniga, Giovanni; Spinelli, Monica; Giarin, Emanuela; Petrangeli, Valentina; Carta, Claudio; Masetti, Riccardo; Aricò, Maurizio; Locatelli, Franco; Basso, Giuseppe; Sorcini, Mariella; Pession, Andrea; Biondi, Andrea

    2005-05-01

    Somatic mutations in PTPN11, the gene encoding the transducer SHP-2, have emerged as a novel class of lesions that upregulate RAS signalling and contribute to leukaemogenesis. In a recent study of 69 children and adolescents with de novo acute myeloid leukaemia (AML), we documented a non-random distribution of PTPN11 mutations among French-American-British (FAB) subtypes. Lesions were restricted to FAB-M5 cases, where they were relatively common (four of 12 cases). Here, we report on the results of a molecular screening performed on 181 additional unselected patients, enrolled in participating institutions of the Associazione Italiana Ematologia Oncologia Pediatrica-AML Study Group, to provide a more accurate picture of the prevalence, spectrum and distribution of PTPN11 mutations in childhood AML and to investigate their clinical relevance. We concluded that PTPN11 defects do not represent a frequent event in this heterogeneous group of malignancies (4.4%), although they recur in a considerable percentage of patients with FAB-M5 (18%). PTPN11 lesions rarely occur in other subtypes. Within the FAB-M5 group no clear association of PTPN11 mutations with any clinical variable was evident. Nearly two third of the patients with this subtype were found to harbour an activating mutation in PTPN11, NRAS, KRAS2 or FLT3.

  2. Gain-of-function mutation in PTPN11 in histiocytic sarcomas of Bernese Mountain Dogs.

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    Thaiwong, T; Sirivisoot, S; Takada, M; Yuzbasiyan-Gurkan, V; Kiupel, M

    2017-09-20

    Histiocytic sarcoma (HS) is an aggressive malignant neoplasm of dendritic cell origin that is common in certain breeds of dogs. High prevalence of fatal, disseminated HS has been described in Bernese Mountain Dogs (BMDs). Support for genetic predisposition to develop HS has been presented in several studies, but to date, causative genetic events have not been reported. In addition, no driver mutations have been identified in tumours. Recently, E76K gain-of-function mutation in SHP2 encoded by the PTPN11 gene has been described in human histiocytic malignancies. In our study, we identified the PTPN11(E76K) in HS of BMDs. Amplification of exon 3 of the PTPN11 gene followed by Sanger sequencing was used to detect the mutation and estimate the prevalence in HS from 30 BMDs, 13 Golden Retrievers and 10 other dog breeds. The overall prevalence of PTPN11(E76K) in HS of BMDs was 36.67% compared with 8.69% in other breeds. No mutation was identified in normal tissues from 10 BMDs with HS that carried the mutation and 12 control dogs with no neoplastic disease, including 6 BMDs. Increased immunoreactivity for AKT, phosphorylated ERK1/2 and phosphorylated AKT in a small subset of BMDs with PTPN11(E76K) suggests that a gain-of-function might be mediated by the ERK and AKT pathways. These data suggest PTPN11(E76K) as an important driver mutation of HS in BMDs. This information may not only aid in unravelling the tumourigenic events associated with HS in BMDs, but also help in identifying more promising therapeutic strategies. © 2017 John Wiley & Sons Ltd.

  3. [Analysis of PTPN11 mutation in children leukemia and its clinical significance].

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    Yang, San-Zhen; Chen, Bing-Qiang; Lu, Su-Ying; Zhang, Bi-Hong; Xue, Hong-Man; Chen, Chun

    2012-02-01

    This study was aimed to explore the frequency of PTPN11 mutation in children with leukemia and its clinical significance. Genomic DNAs were extracted from peripheral leukocytes of 131 patients with leukemia, including 101 cases of ALL, 26 cases of AML, 3 cases of CML and 1 case of juvenil myelomonocytic leukemia (JMML). The sequences of PTPN11 exons 3, 8, 13 were amplified by polymerase chain reaction (PCR), and the clinical characteristics of positive patients were analyzed. The results indicated that the PTPN11 mutation was found in 10 cases (9.9%) from newly diagnosed 101 cases of ALL. Grouping the newly diagnosed ALL children by various clinical features, it was found that the PTPN11 mutation did not show associations with sex, age, white blood cell (WBC) count, prednisone test sensitivity, clinical risk and disease recurrences at the first visit (P > 0.05). PTPN11 mutations were found in 2 cases out of 26 AML patients, including one AML-M(2) and one AML-M(4). No PTPN11 mutation in 3 CML patients was found. Exon 13 mutation of PTPN11 gene was found in 1 case of JMML. It is concluded that the E76 of exon 3 is the hot spot of PTPN11 mutation in children leukemia. The novel G503E (1508G > A) mutation is detected in one JMML patient. The PTPN11 mutation does not associate with the sex, age, WBC count, prednisone sensitive test and early recurrence.

  4. Loss-of-function mutations in PTPN11 cause metachondromatosis, but not Ollier disease or Maffucci syndrome.

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    Bowen, Margot E; Boyden, Eric D; Holm, Ingrid A; Campos-Xavier, Belinda; Bonafé, Luisa; Superti-Furga, Andrea; Ikegawa, Shiro; Cormier-Daire, Valerie; Bovée, Judith V; Pansuriya, Twinkal C; de Sousa, Sérgio B; Savarirayan, Ravi; Andreucci, Elena; Vikkula, Miikka; Garavelli, Livia; Pottinger, Caroline; Ogino, Toshihiko; Sakai, Akinori; Regazzoni, Bianca M; Wuyts, Wim; Sangiorgi, Luca; Pedrini, Elena; Zhu, Mei; Kozakewich, Harry P; Kasser, James R; Seidman, Jon G; Kurek, Kyle C; Warman, Matthew L

    2011-04-01

    Metachondromatosis (MC) is a rare, autosomal dominant, incompletely penetrant combined exostosis and enchondromatosis tumor syndrome. MC is clinically distinct from other multiple exostosis or multiple enchondromatosis syndromes and is unlinked to EXT1 and EXT2, the genes responsible for autosomal dominant multiple osteochondromas (MO). To identify a gene for MC, we performed linkage analysis with high-density SNP arrays in a single family, used a targeted array to capture exons and promoter sequences from the linked interval in 16 participants from 11 MC families, and sequenced the captured DNA using high-throughput parallel sequencing technologies. DNA capture and parallel sequencing identified heterozygous putative loss-of-function mutations in PTPN11 in 4 of the 11 families. Sanger sequence analysis of PTPN11 coding regions in a total of 17 MC families identified mutations in 10 of them (5 frameshift, 2 nonsense, and 3 splice-site mutations). Copy number analysis of sequencing reads from a second targeted capture that included the entire PTPN11 gene identified an additional family with a 15 kb deletion spanning exon 7 of PTPN11. Microdissected MC lesions from two patients with PTPN11 mutations demonstrated loss-of-heterozygosity for the wild-type allele. We next sequenced PTPN11 in DNA samples from 54 patients with the multiple enchondromatosis disorders Ollier disease or Maffucci syndrome, but found no coding sequence PTPN11 mutations. We conclude that heterozygous loss-of-function mutations in PTPN11 are a frequent cause of MC, that lesions in patients with MC appear to arise following a "second hit," that MC may be locus heterogeneous since 1 familial and 5 sporadically occurring cases lacked obvious disease-causing PTPN11 mutations, and that PTPN11 mutations are not a common cause of Ollier disease or Maffucci syndrome.

  5. Loss-of-function mutations in PTPN11 cause metachondromatosis, but not Ollier disease or Maffucci syndrome.

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    Margot E Bowen

    2011-04-01

    Full Text Available Metachondromatosis (MC is a rare, autosomal dominant, incompletely penetrant combined exostosis and enchondromatosis tumor syndrome. MC is clinically distinct from other multiple exostosis or multiple enchondromatosis syndromes and is unlinked to EXT1 and EXT2, the genes responsible for autosomal dominant multiple osteochondromas (MO. To identify a gene for MC, we performed linkage analysis with high-density SNP arrays in a single family, used a targeted array to capture exons and promoter sequences from the linked interval in 16 participants from 11 MC families, and sequenced the captured DNA using high-throughput parallel sequencing technologies. DNA capture and parallel sequencing identified heterozygous putative loss-of-function mutations in PTPN11 in 4 of the 11 families. Sanger sequence analysis of PTPN11 coding regions in a total of 17 MC families identified mutations in 10 of them (5 frameshift, 2 nonsense, and 3 splice-site mutations. Copy number analysis of sequencing reads from a second targeted capture that included the entire PTPN11 gene identified an additional family with a 15 kb deletion spanning exon 7 of PTPN11. Microdissected MC lesions from two patients with PTPN11 mutations demonstrated loss-of-heterozygosity for the wild-type allele. We next sequenced PTPN11 in DNA samples from 54 patients with the multiple enchondromatosis disorders Ollier disease or Maffucci syndrome, but found no coding sequence PTPN11 mutations. We conclude that heterozygous loss-of-function mutations in PTPN11 are a frequent cause of MC, that lesions in patients with MC appear to arise following a "second hit," that MC may be locus heterogeneous since 1 familial and 5 sporadically occurring cases lacked obvious disease-causing PTPN11 mutations, and that PTPN11 mutations are not a common cause of Ollier disease or Maffucci syndrome.

  6. Mutation analysis of PTPN11 gene in Noonan syndrome%Noonan综合征患者PTPN11基因突变分析

    Institute of Scientific and Technical Information of China (English)

    杨涛; 孟岩; 施惠平; 赵时敏; 王刚; 黄尚志

    2010-01-01

    目的 研究中国人Noonan综合征患者非受体型蛋白酪氨酸磷酸酯酶(protein-tyrosine phosphatase,nonreceptor-type 11,PTPN11)基因的突变.方法 收集遗传咨询门诊3例散发的Noonan综合征患者及其无症状父母,外周血提取基因组DNA,PCR产物直接测序法对患者PTPN11基因的全部15个编码区外显子及其邻接的内含子区域进行测序,检出突变后再对其父母的相应外显子区域进行测序,并通过限制性内切酶检测100名无亲缘关系的正常人相应碱基改变以排除多态性,利用网上ClustalW工具分析突变位点所在氨基酸在多个物种中的保守性.结果 在1例患者的第3外显子区域检出一杂合的c.181G>A碱基取代,导致第61位的天冬氨酸改变为天冬酰胺(p.D61N),在其无症状父母和100名正常个体中无此突变;该位点在多个物种中高度保守.另外2例患者PTPN11基因的编码区未检到突变.结论 p.D61N突变在文献中已有报道,本例患者为新生突变.本研究进一步肯定了 p.D61N为Noonan综合征的致病突变,基因诊断的结果验证了该患者的临床诊断.另外两例Noonan综合征患者可能由其他基因的突变所致,反映了该病的遗传异质性.%Objective To investigate the mutations in protein tyrosine phosphatase, nonreceptor-type 11 (PTPN11)gene in patients with Noonan syndrome (NS). Methods Three sporadic patients with NS were studied. Genomic DNAs were extracted from peripheral blood leukocytes. All 15 coding exons and their flanking intronic boundaries of the PTPN11 gene were amplified by polymerase chain reaction and followed by direct sequencing. DNAs from parents were sequenced in the corresponding region when the mutation was detected in their affected child. The identified mutation was screened in 100 healthy individuals for exclusion of polymorphism by restriction endonuclease digestion of the PCR products. Protein conservation analysis was performed among 10 species using

  7. Protein tyrosine phosphatase SHP2/PTPN11 mistargeting as a consequence of SH2-domain point mutations associated with Noonan Syndrome and leukemia

    DEFF Research Database (Denmark)

    Müller, Pia J; Rigbolt, Kristoffer T G; Paterok, Dirk

    2013-01-01

    SHP2/PTPN11 is a key regulator of cytokine, growth factor and integrin signaling. SHP2 influences cell survival, proliferation and differentiation by regulating major signaling pathways. Mutations in PTPN11 cause severe diseases like Noonan, LEOPARD syndrome or leukemia. Whereas several of these ......SHP2/PTPN11 is a key regulator of cytokine, growth factor and integrin signaling. SHP2 influences cell survival, proliferation and differentiation by regulating major signaling pathways. Mutations in PTPN11 cause severe diseases like Noonan, LEOPARD syndrome or leukemia. Whereas several...

  8. Gain-of-function mutations of Ptpn11 (Shp2) cause aberrant mitosis and increase susceptibility to DNA damage-induced malignancies.

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    Liu, Xia; Zheng, Hong; Li, Xiaobo; Wang, Siying; Meyerson, Howard J; Yang, Wentian; Neel, Benjamin G; Qu, Cheng-Kui

    2016-01-26

    Gain-of-function (GOF) mutations of protein tyrosine phosphatase nonreceptor type 11 Ptpn11 (Shp2), a protein tyrosine phosphatase implicated in multiple cell signaling pathways, are associated with childhood leukemias and solid tumors. The underlying mechanisms are not fully understood. Here, we report that Ptpn11 GOF mutations disturb mitosis and cytokinesis, causing chromosomal instability and greatly increased susceptibility to DNA damage-induced malignancies. We find that Shp2 is distributed to the kinetochore, centrosome, spindle midzone, and midbody, all of which are known to play critical roles in chromosome segregation and cytokinesis. Mouse embryonic fibroblasts with Ptpn11 GOF mutations show a compromised mitotic checkpoint. Centrosome amplification and aberrant mitosis with misaligned or lagging chromosomes are significantly increased in Ptpn11-mutated mouse and patient cells. Abnormal cytokinesis is also markedly increased in these cells. Further mechanistic analyses reveal that GOF mutant Shp2 hyperactivates the Polo-like kinase 1 (Plk1) kinase by enhancing c-Src kinase-mediated tyrosine phosphorylation of Plk1. This study provides novel insights into the tumorigenesis associated with Ptpn11 GOF mutations and cautions that DNA-damaging treatments in Noonan syndrome patients with germ-line Ptpn11 GOF mutations could increase the risk of therapy-induced malignancies.

  9. Mutated Ptpn11 alters leukemic stem cell frequency and reduces the sensitivity of acute myeloid leukemia cells to Mcl1 inhibition.

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    Chen, L; Chen, W; Mysliwski, M; Serio, J; Ropa, J; Abulwerdi, F A; Chan, R J; Patel, J P; Tallman, M S; Paietta, E; Melnick, A; Levine, R L; Abdel-Wahab, O; Nikolovska-Coleska, Z; Muntean, A G

    2015-06-01

    PTPN11 encodes the Shp2 non-receptor protein-tyrosine phosphatase implicated in several signaling pathways. Activating mutations in Shp2 are commonly associated with juvenile myelomonocytic leukemia but are not as well defined in other neoplasms. Here we report that Shp2 mutations occur in human acute myeloid leukemia (AML) at a rate of 6.6% (6/91) in the ECOG E1900 data set. We examined the role of mutated Shp2 in leukemias harboring MLL translocations, which co-occur in human AML. The hyperactive Shp2E76K mutant, commonly observed in leukemia patients, significantly accelerated MLL-AF9-mediated leukemogenesis in vivo. Shp2E76K increased leukemic stem cell frequency and affords MLL-AF9 leukemic cells IL3 cytokine hypersensitivity. As Shp2 is reported to regulate anti-apoptotic genes, we investigated Bcl2, Bcl-xL and Mcl1 expression in MLL-AF9 leukemic cells with and without Shp2E76K. Although the Bcl2 family of genes was upregulated in Shp2E76K cells, Mcl1 showed the highest upregulation in MLL-AF9 cells in response to Shp2E76K. Indeed, expression of Mcl1 in MLL-AF9 cells phenocopies expression of Shp2E76K, suggesting Shp2 mutations cooperate through activation of anti-apoptotic genes. Finally, we show Shp2E76K mutations reduce sensitivity of AML cells to small-molecule-mediated Mcl1 inhibition, suggesting reduced efficacy of drugs targeting MCL1 in patients with hyperactive Shp2.

  10. Abnormal PTPN11 enhancer methylation promotes rheumatoid arthritis fibroblast-like synoviocyte aggressiveness and joint inflammation

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    Maeshima, Keisuke; Stanford, Stephanie M.; Hammaker, Deepa; Sacchetti, Cristiano; Zeng, Li-fan; Ai, Rizi; Zhang, Vida; Boyle, David L.; Aleman Muench, German R.; Feng, Gen-Sheng; Whitaker, John W.; Zhang, Zhong-Yin; Wang, Wei; Bottini, Nunzio; Firestein, Gary S.

    2016-01-01

    The PTPN11 gene, encoding the tyrosine phosphatase SHP-2, is overexpressed in rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS) compared with osteoarthritis (OA) FLS and promotes RA FLS invasiveness. Here, we explored the molecular basis for PTPN11 overexpression in RA FLS and the role of SHP-2 in RA pathogenesis. Using computational methods, we identified a putative enhancer in PTPN11 intron 1, which contained a glucocorticoid receptor–binding (GR-binding) motif. This region displayed enhancer function in RA FLS and contained 2 hypermethylation sites in RA compared with OA FLS. RA FLS stimulation with the glucocorticoid dexamethasone induced GR binding to the enhancer and PTPN11 expression. Glucocorticoid responsiveness of PTPN11 was significantly higher in RA FLS than OA FLS and required the differentially methylated CpGs for full enhancer function. SHP-2 expression was enriched in the RA synovial lining, and heterozygous Ptpn11 deletion in radioresistant or innate immune cells attenuated K/BxN serum transfer arthritis in mice. Treatment with SHP-2 inhibitor 11a-1 reduced RA FLS migration and responsiveness to TNF and IL-1β stimulation and reduced arthritis severity in mice. Our findings demonstrate how abnormal epigenetic regulation of a pathogenic gene determines FLS behavior and demonstrate that targeting SHP-2 or the SHP-2 pathway could be a therapeutic strategy for RA. PMID:27275015

  11. Myeloid Dysregulation in a Human Induced Pluripotent Stem Cell Model of PTPN11-Associated Juvenile Myelomonocytic Leukemia

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    Sonia Mulero-Navarro

    2015-10-01

    Full Text Available Somatic PTPN11 mutations cause juvenile myelomonocytic leukemia (JMML. Germline PTPN11 defects cause Noonan syndrome (NS, and specific inherited mutations cause NS/JMML. Here, we report that hematopoietic cells differentiated from human induced pluripotent stem cells (hiPSCs harboring NS/JMML-causing PTPN11 mutations recapitulated JMML features. hiPSC-derived NS/JMML myeloid cells exhibited increased signaling through STAT5 and upregulation of miR-223 and miR-15a. Similarly, miR-223 and miR-15a were upregulated in 11/19 JMML bone marrow mononuclear cells harboring PTPN11 mutations, but not those without PTPN11 defects. Reducing miR-223’s function in NS/JMML hiPSCs normalized myelogenesis. MicroRNA target gene expression levels were reduced in hiPSC-derived myeloid cells as well as in JMML cells with PTPN11 mutations. Thus, studying an inherited human cancer syndrome with hiPSCs illuminated early oncogenesis prior to the accumulation of secondary genomic alterations, enabling us to discover microRNA dysregulation, establishing a genotype-phenotype association for JMML and providing therapeutic targets.

  12. Protein Tyrosine Phosphatase SHP-2 (PTPN11 in Hematopoiesis and Leukemogenesis

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    Xia Liu

    2011-01-01

    Full Text Available SHP-2 (PTPN11, a ubiquitously expressed protein tyrosine phosphatase, is critical for hematopoietic cell development and function owing to its essential role in growth factor/cytokine signaling. More importantly, germline and somatic mutations in this phosphatase are associated with Noonan syndrome, Leopard syndrome, and childhood hematologic malignancies. The molecular mechanisms by which SHP-2 mutations induce these diseases are not fully understood, as the biochemical bases of SHP-2 functions still remain elusive. Further understanding SHP-2 signaling activities and identification of its interacting proteins/substrates will shed light on the pathogenesis of PTPN11-associated hematologic malignancies, which, in turn, may lead to novel therapeutics for these diseases.

  13. A common variant in the PTPN11 gene contributes to the risk of tetralogy of Fallot.

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    Goodship, Judith A; Hall, Darroch; Topf, Ana; Mamasoula, Chrysovalanto; Griffin, Helen; Rahman, Thahira J; Glen, Elise; Tan, Huay; Palomino Doza, Julian; Relton, Caroline L; Bentham, Jamie; Bhattacharya, Shoumo; Cosgrove, Catherine; Brook, David; Granados-Riveron, Javier; Bu'Lock, Frances A; O'Sullivan, John; Stuart, A Graham; Parsons, Jonathan; Cordell, Heather J; Keavney, Bernard

    2012-06-01

    Tetralogy of Fallot (TOF) is the commonest cyanotic form of congenital heart disease. In 80% of cases, TOF behaves as a complex genetic condition exhibiting significant heritability. As yet, no common genetic variants influencing TOF risk have been robustly identified. Two hundred and seven haplotype-tagging single nucleotide polymorphisms in 22 candidate genes were genotyped in a test cohort comprising 362 nonsyndromic British white patients with TOF together with 717 unaffected parents of patients and 183 unrelated healthy controls. Single nucleotide polymorphisms with suggestive evidence of association in the test cohort (P<0.01) were taken forward for genotyping in an independent replication cohort comprising 392 cases of TOF, 218 unaffected parents of patients, and 1319 controls. Significant association was observed for 1 single nucleotide polymorphism, rs11066320 in the PTPN11 gene, in both the test and the replication cohort. Genotype at rs11066320 was associated with a per-allele odds ratio of 1.34 (95% confidence interval [CI], 1.19 to 1.52; P=2.9 × 10(-6)) in the total cohort of TOF cases and controls; this remained highly significant after Bonferroni correction for 207 analyses (corrected P=0.00061). Genotype at rs11066320 was responsible for a population-attributable risk of TOF of approximately 10%. Common variation in the linkage disequilibrium block including the PTPN11 gene contributes to the risk of nonsyndromic TOF. Rare mutations in PTPN11 are known to cause the autosomal dominant condition Noonan syndrome, which includes congenital heart disease, by upregulating Ras/mitogen-activated protein kinase (MAPK) signaling. Our results suggest a role for milder perturbations in PTPN11 function in sporadic, nonsyndromic congenital heart disease.

  14. Correlation of PTPN11 polymorphism at intron 3 with gastric cancer

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    Li ZHANG

    2011-05-01

    Full Text Available Objective To explore the correlation of protein-tyrosine-phosphatase nonreceptor-type 11(PTPN11 polymorphism at intron 3 with gastric cancer in Chinese population,and the feasibility and accuracy of employing mastrix-assisted laser desorption ionization time-of-flight mass spectrogram(MALDI-TOF-MS in genotyping of this SNP.Methods Two hundred and forty-seven patients with gastric cancer,212 cancer-free patients and 160 cord blood samples were enrolled in present study.Genotypes of PTPN11 G/A polymorphism at intron 3 were determined by MALDI-TOF-MS analysis,and direct sequencing of PCR products with 20 samples of the gene locus was done for checking the accuracy of MALDI-TOF-MS.Histological examination,Helicobacter pylori culture,rapid urease test,serum anti-H.pylori antibodies(ELISA and urease colloidal gold test were performed to evaluate H.pylori infection.Results Direct sequencing of 20 random selected samples were well consistent with the MALDI-TOF-MS results.The rates of H.pylori infection were 73.68% in gastric cancer patients and 75.47% in cancer-free patients,implying no significant difference between the two groups.The distributions of genotypes were in Hardy Weinberg equilibrium in both gastric cancer patients and controls.There were no significant differences in the genotype frequencies between the 2 groups(P>0.05.Compared with the GG genotype,GA+AA genotype could not influence the risk of gastric cancer.When stratified for status,PTPN11 polymorphism was not associated with age,gender and H.pylori infection states in both cancer patients and controls.Conclusion It seems that PTPN11 G/A polymorphism at intron 3 has no affection on the risk of gastric cancer in Chinese population.

  15. A PTPN11 allele encoding a catalytically impaired SHP2 protein in a patient with a Noonan syndrome phenotype.

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    Edwards, Jonathan J; Martinelli, Simone; Pannone, Luca; Lo, Ivan Fai-Man; Shi, Lisong; Edelmann, Lisa; Tartaglia, Marco; Luk, Ho-Ming; Gelb, Bruce D

    2014-09-01

    The RASopathies are a relatively common group of phenotypically similar and genetically related autosomal dominant genetic syndromes caused by missense mutations affecting genes participating in the RAS/mitogen-activated protein kinase (MAPK) pathway that include Noonan syndrome (NS) and Noonan syndrome with multiple lentigines (NSML, formerly LEOPARD syndrome). NS and NSML can be difficult to differentiate during infancy, but the presence of multiple lentigines, café au lait spots, and specific cardiac defects facilitate the diagnosis. Furthermore, individual PTPN11 missense mutations are highly specific to each syndrome and engender opposite biochemical alterations on the function of SHP-2, the protein product of that gene. Here, we report on a 5-year-old male with two de novo PTPN11 mutations in cis, c.1471C>T (p.Pro491Ser), and c.1492C>T (p.Arg498Trp), which are associated with NS and NSML, respectively. This boy's phenotype is intermediate between NS and NSML with facial dysmorphism, short stature, mild global developmental delay, pulmonic stenosis, and deafness but absence of café au lait spots or lentigines. The double-mutant SHP-2 was found to be catalytically impaired. This raises the question of whether clinical differences between NS and NSML can be ascribed solely to the relative SHP-2 catalytic activity.

  16. Critical role of SHP2 (PTPN11) signaling in germinal center-derived lymphoma.

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    Jiang, Xin; Guo, Honggang; Wu, Jianguo; He, Qiang; Li, Yiqiao; Wang, Miao; Pan, Hongyang; Li, Wande; Wang, Jinjie; Wang, Qingqing; Shen, Jing; Ke, Yuehai; Zhou, Ren

    2014-12-01

    Germinal center lymphoma is a heterogeneous human lymphoma entity. Here we report that constitutive activity of SHP2 (PTPN11) and its downstream kinase ERK is essential for the viability of germinal center lymphoma cells and disease progression. Mechanistically, SHP2/ERK inhibition impedes c-Myc transcriptional activity, which results in the repression of proliferative phenotype signatures of germinal center lymphoma. Furthermore, SHP2/ERK signaling is required to maintain the CD19/c-Myc loop, which preferentially promotes survival of a distinct subtype of germinal center lymphoma cells carrying the MYC/IGH translocation. These findings demonstrate a critical function for SHP2/ERK signaling upstream of c-Myc in germinal center lymphoma cells and provide a rationale for targeting SHP2 in the therapy of germinal center lymphoma.

  17. Germline PTPN11 and somatic PIK3CA variant in a boy with megalencephaly-capillary malformation syndrome (MCAP) - pure coincidence?

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    Döcker, Dennis; Schubach, Max; Menzel, Moritz; Spaich, Christiane; Gabriel, Heinz-Dieter; Zenker, Martin; Bartholdi, Deborah; Biskup, Saskia

    2015-01-01

    Megalencephaly-capillary malformation (MCAP) syndrome is an overgrowth syndrome that is diagnosed by clinical criteria. Recently, somatic and germline variants in genes that are involved in the PI3K-AKT pathway (AKT3, PIK3R2 and PIK3CA) have been described to be associated with MCAP and/or other related megalencephaly syndromes. We performed trio-exome sequencing in a 6-year-old boy and his healthy parents. Clinical features were macrocephaly, cutis marmorata, angiomata, asymmetric overgrowth, developmental delay, discrete midline facial nevus flammeus, toe syndactyly and postaxial polydactyly—thus, clearly an MCAP phenotype. Exome sequencing revealed a pathogenic de novo germline variant in the PTPN11 gene (c.1529A>G; p.(Gln510Arg)), which has so far been associated with Noonan, as well as LEOPARD syndrome. Whole-exome sequencing (>100 × coverage) did not reveal any alteration in the known megalencephaly genes. However, ultra-deep sequencing results from saliva (>1000 × coverage) revealed a 22% mosaic variant in PIK3CA (c.2740G>A; p.(Gly914Arg)). To our knowledge, this report is the first description of a PTPN11 germline variant in an MCAP patient. Data from experimental studies show a complex interaction of SHP2 (gene product of PTPN11) and the PI3K-AKT pathway. We hypothesize that certain PTPN11 germline variants might drive toward additional second-hit alterations. PMID:24939587

  18. Germline PTPN11 and somatic PIK3CA variant in a boy with megalencephaly-capillary malformation syndrome (MCAP)--pure coincidence?

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    Döcker, Dennis; Schubach, Max; Menzel, Moritz; Spaich, Christiane; Gabriel, Heinz-Dieter; Zenker, Martin; Bartholdi, Deborah; Biskup, Saskia

    2015-03-01

    Megalencephaly-capillary malformation (MCAP) syndrome is an overgrowth syndrome that is diagnosed by clinical criteria. Recently, somatic and germline variants in genes that are involved in the PI3K-AKT pathway (AKT3, PIK3R2 and PIK3CA) have been described to be associated with MCAP and/or other related megalencephaly syndromes. We performed trio-exome sequencing in a 6-year-old boy and his healthy parents. Clinical features were macrocephaly, cutis marmorata, angiomata, asymmetric overgrowth, developmental delay, discrete midline facial nevus flammeus, toe syndactyly and postaxial polydactyly--thus, clearly an MCAP phenotype. Exome sequencing revealed a pathogenic de novo germline variant in the PTPN11 gene (c.1529A>G; p.(Gln510Arg)), which has so far been associated with Noonan, as well as LEOPARD syndrome. Whole-exome sequencing (>100 × coverage) did not reveal any alteration in the known megalencephaly genes. However, ultra-deep sequencing results from saliva (>1000 × coverage) revealed a 22% mosaic variant in PIK3CA (c.2740G>A; p.(Gly914Arg)). To our knowledge, this report is the first description of a PTPN11 germline variant in an MCAP patient. Data from experimental studies show a complex interaction of SHP2 (gene product of PTPN11) and the PI3K-AKT pathway. We hypothesize that certain PTPN11 germline variants might drive toward additional second-hit alterations.

  19. Tanshinone IIA induced cell death via miR30b-p53-PTPN11/SHP2 signaling pathway in human hepatocellular carcinoma cells.

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    Ren, Xuanqi; Wang, Cui; Xie, Binbin; Hu, Linfeng; Chai, Hui; Ding, Lei; Tang, Lihua; Xia, Yongliang; Dou, Xiaobing

    2017-02-05

    Tanshinone IIA, a multi-pharmaceutical compound from traditional Chinese herb, has been reported to have anti-hepatocarcinomic (HCC) properties through cell death induction. Apart from the typical p53-dependent pathway, mechanisms of the anti-carcinogenic role of Tanshinone remain scarce. In an effort to explore the mechanism behind Tanshinone IIA, we detected the upstream of the p53 and the potential novel pathway. Tanshinone IIA dose-dependently initiated HepG2 cell apoptosis and cell cycle arrest at the G1 checkpoint. In the miR30 family, only the transcription of miR30b was downregulated by Tanshinone IIA, which subsequently upregulated both the genomic and protein levels of p53. Further, we screened that PTPN11 and Tp53 are the two critical genomes involved in the pharmacology of Tanshinone IIA. Building upon LASAGNA-search and kinetics binding assay, p53 was found to be a potential transcription factor for PTPN11. Concomitant with the expression of p53, Tanshinone IIA stimulated both PTPN11 and its encoded protein SHP2. Inhibition miR30b attenuated the Tanshinone IIA-induced cytotoxicity, level of p53 and PTPN11 in HepG2 cells. Finally, the apoptotic molecules such as Bax/Bcl2, cleavage caspase 3 and the cell cycle regulation factors including p21, cyclin D1, and CDK6 were changed by Tanshinone IIA. Several cytotoxic endpoints induced by Tanshinone IIA were also checked in Hep3B cells. This study confirmed that Tanshinone IIA may induce hepatoma cell death through the miR30b-p53- PTPN11/SHP2 pathway. With regard to the complicated tumorigenesis of HCC and the multi-targets of Tanshinone IIA, our results propose developing Tanshinone IIA for clinic therapy and the interference of HCC.

  20. Gain-of-function SOS1 mutations cause a distinctive form of noonansyndrome

    Energy Technology Data Exchange (ETDEWEB)

    Tartaglia, Marco; Pennacchio, Len A.; Zhao, Chen; Yadav, KamleshK.; Fodale, Valentina; Sarkozy, Anna; Pandit, Bhaswati; Oishi, Kimihiko; Martinelli, Simone; Schackwitz, Wendy; Ustaszewska, Anna; Martin, Joes; Bristow, James; Carta, Claudio; Lepri, Francesca; Neri, Cinzia; Vasta,Isabella; Gibson, Kate; Curry, Cynthia J.; Lopez Siguero, Juan Pedro; Digilio, Maria Cristina; Zampino, Giuseppe; Dallapiccola, Bruno; Bar-Sagi, Dafna; Gelb, Brude D.

    2006-09-01

    Noonan syndrome (NS) is a developmental disordercharacterized by short stature, facial dysmorphia, congenital heartdefects and skeletal anomalies1. Increased RAS-mitogenactivated proteinkinase (MAPK) signaling due to PTPN11 and KRAS mutations cause 50 percentof NS2-6. Here, we report that 22 of 129 NS patients without PTPN11 orKRAS mutation (17 percent) have missense mutations in SOS1, which encodesa RAS-specific guanine nucleotide exchange factor (GEF). SOS1 mutationscluster at residues implicated in the maintenance of SOS1 in itsautoinhibited form and ectopic expression of two NS-associated mutantsinduced enhanced RAS activation. The phenotype associated with SOS1defects is distinctive, although within NS spectrum, with a highprevalence of ectodermal abnormalities but generally normal developmentand linear growth. Our findings implicate for the first timegain-of-function mutations in a RAS GEF in inherited disease and define anew mechanism by which upregulation of the RAS pathway can profoundlychange human development.

  1. Germline mutation of CBL is associated with moyamoya disease in a child with juvenile myelomonocytic leukemia and Noonan syndrome-like disorder.

    Science.gov (United States)

    Hyakuna, Nobuyuki; Muramatsu, Hideki; Higa, Takeshi; Chinen, Yasutsugu; Wang, Xinan; Kojima, Seiji

    2015-03-01

    Germline mutations in CBL have been identified in patients with Noonan syndrome-like phenotypes, while juvenile myelomonocytic leukemia (JMML) harbors duplication of a germline CBL, resulting in acquired isodisomy. The association between moyamoya disease and Noonan syndrome carrying a PTPN11 mutation has recently been reported. We present a patient with JMML who developed moyamoya disease and neovascular glaucoma. Our patient exhibited a Noonan syndrome-like phenotype. Genetic analysis revealed acquired isodisomy and a germline heterozygous mutation in CBL. This is a rare case of CBL mutation associated with moyamoya disease. Prolonged RAS pathway signaling may cause disruption of cerebrovascular development.

  2. Constitutional NRAS mutations are rare among patients with Noonan syndrome or juvenile myelomonocytic leukemia.

    Science.gov (United States)

    Kraoua, Lilia; Journel, Hubert; Bonnet, Philippe; Amiel, Jeanne; Pouvreau, Nathalie; Baumann, Clarisse; Verloes, Alain; Cavé, Hélène

    2012-10-01

    Recently, germline mutations of NRAS have been shown to be associated with Noonan syndrome (NS), a relatively common developmental disorder characterized by short stature, congenital heart disease, and distinctive facial features. We report on the mutational analysis of NRAS in a cohort of 125 French patients with NS and no known mutation for PTPN11, KRAS, SOS1, MEK1, MEK2, RAF1, BRAF, and SHOC2. The c.179G>A (p.G60E) mutation was identified in two patients with typical NS, confirming that NRAS germline mutations are a rare cause of this syndrome. We also screened our cohort of 95 patients with juvenile myelomonocytic leukemia (JMML). Among 17 patients with NRAS-mutated JMML, none had clinical features suggestive of NS. None of the 11 JMML patients for which germline DNA was available had a constitutional NRAS mutation.

  3. BRCA1 founder mutations compared to ovarian cancer in Belarus.

    Science.gov (United States)

    Savanevich, Alena; Oszurek, Oleg; Lubiński, Jan; Cybulski, Cezary; Dębniak, Tadeusz; Narod, Steven A; Gronwald, Jacek

    2014-09-01

    In Belarus and other Slavic countries, founder mutations in the BRCA1 gene are responsible for a significant proportion of breast cancer cases, but the data on contribution of these mutations to ovarian cancers are limited. To estimate the proportion of ovarian cancers in Belarus, which are dependent on BRCA1 Slavic founder mutations, we sought the presence of three most frequent mutations (BRCA1: 5382insC, C61G and, 4153delA) in 158 consecutive unselected cases of ovarian cancer. One of the three founder mutations was present in 25 of 158 unselected cases of ovarian cancer (15.8 %). We recommend that all cases of ovarian cancer in Belarus be offered genetic testing for these founder mutations. Furthermore, genetic testing of the Belarusian population will provide the opportunity to prevent a significant proportion of ovarian cancer.

  4. Artificial Bee Colony with Different Mutation Schemes: A comparative study

    Directory of Open Access Journals (Sweden)

    Iyad Abu Doush

    2014-03-01

    Full Text Available Artificial Bee Colony (ABC is a swarm-based metaheuristic for continuous optimization. Recent work hybridized this algorithm with other metaheuristics in order to improve performance. The work in this paper, experimentally evaluates the use of different mutation operators with the ABC algorithm. The introduced operator is activated according to a determined probability called mutation rate (MR. The results on standard benchmark function suggest that the use of this operator improves performance in terms of convergence speed and quality of final obtained solution. It shows that Power and Polynomial mutations give best results. The fastest convergence was for the mutation rate value (MR=0.2.

  5. Determining mutation density using Restriction Enzyme Sequence Comparative Analysis (RESCAN)

    Science.gov (United States)

    The average mutation density of a mutant population is a major consideration when developing resources for the efficient, cost-effective implementation of reverse genetics methods such as Targeting of Induced Local Lesions in Genomes (TILLING). Reliable estimates of mutation density can be achieved ...

  6. 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.

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

    Science.gov (United States)

    Eboreime, Jordan; Choi, Soo-Kung; Yoon, Song-Ro; Arnheim, Norman; Calabrese, Peter

    2016-01-01

    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.

  8. De Novo Identification of Single Nucleotide Mutations in Caenorhabditis elegans Using Array Comparative Genomic Hybridization

    Science.gov (United States)

    Maydan, Jason S.; Okada, H. Mark; Flibotte, Stephane; Edgley, Mark L.; Moerman, Donald G.

    2009-01-01

    Array comparative genomic hybridization (aCGH) has been used primarily to detect copy-number variants between two genomes. Here we report using aCGH to detect single nucleotide mutations on oligonucleotide microarrays with overlapping 50-mer probes. This technique represents a powerful method for rapidly detecting novel homozygous single nucleotide mutations in any organism with a sequenced reference genome. PMID:19189945

  9. The Mutational Landscape of Acute Promyelocytic Leukemia Reveals an Interacting Network of Co-Occurrences and Recurrent Mutations.

    Directory of Open Access Journals (Sweden)

    Mariam Ibáñez

    Full Text Available Preliminary Acute Promyelocytic Leukemia (APL whole exome sequencing (WES studies have identified a huge number of somatic mutations affecting more than a hundred different genes mainly in a non-recurrent manner, suggesting that APL is a heterogeneous disease with secondary relevant changes not yet defined. To extend our knowledge of subtle genetic alterations involved in APL that might cooperate with PML/RARA in the leukemogenic process, we performed a comprehensive analysis of somatic mutations in APL combining WES with sequencing of a custom panel of targeted genes by next-generation sequencing. To select a reduced subset of high confidence candidate driver genes, further in silico analysis were carried out. After prioritization and network analysis we found recurrent deleterious mutations in 8 individual genes (STAG2, U2AF1, SMC1A, USP9X, IKZF1, LYN, MYCBP2 and PTPN11 with a strong potential of being involved in APL pathogenesis. Our network analysis of multiple mutations provides a reliable approach to prioritize genes for additional analysis, improving our knowledge of the leukemogenesis interactome. Additionally, we have defined a functional module in the interactome of APL. The hypothesis is that the number, or the specific combinations, of mutations harbored in each patient might not be as important as the disturbance caused in biological key functions, triggered by several not necessarily recurrent mutations.

  10. The Mutational Landscape of Acute Promyelocytic Leukemia Reveals an Interacting Network of Co-Occurrences and Recurrent Mutations.

    Science.gov (United States)

    Ibáñez, Mariam; Carbonell-Caballero, José; García-Alonso, Luz; Such, Esperanza; Jiménez-Almazán, Jorge; Vidal, Enrique; Barragán, Eva; López-Pavía, María; LLop, Marta; Martín, Iván; Gómez-Seguí, Inés; Montesinos, Pau; Sanz, Miguel A; Dopazo, Joaquín; Cervera, José

    2016-01-01

    Preliminary Acute Promyelocytic Leukemia (APL) whole exome sequencing (WES) studies have identified a huge number of somatic mutations affecting more than a hundred different genes mainly in a non-recurrent manner, suggesting that APL is a heterogeneous disease with secondary relevant changes not yet defined. To extend our knowledge of subtle genetic alterations involved in APL that might cooperate with PML/RARA in the leukemogenic process, we performed a comprehensive analysis of somatic mutations in APL combining WES with sequencing of a custom panel of targeted genes by next-generation sequencing. To select a reduced subset of high confidence candidate driver genes, further in silico analysis were carried out. After prioritization and network analysis we found recurrent deleterious mutations in 8 individual genes (STAG2, U2AF1, SMC1A, USP9X, IKZF1, LYN, MYCBP2 and PTPN11) with a strong potential of being involved in APL pathogenesis. Our network analysis of multiple mutations provides a reliable approach to prioritize genes for additional analysis, improving our knowledge of the leukemogenesis interactome. Additionally, we have defined a functional module in the interactome of APL. The hypothesis is that the number, or the specific combinations, of mutations harbored in each patient might not be as important as the disturbance caused in biological key functions, triggered by several not necessarily recurrent mutations.

  11. Features of 5'-splice-site efficiency derived from disease-causing mutations and comparative genomics

    DEFF Research Database (Denmark)

    Roca, Xavier; Olson, Andrew J; Rao, Atmakuri R

    2007-01-01

    Many human diseases, including Fanconi anemia, hemophilia B, neurofibromatosis, and phenylketonuria, can be caused by 5'-splice-site (5'ss) mutations that are not predicted to disrupt splicing, according to position weight matrices. By using comparative genomics, we identify pairwise dependencies...

  12. Comparative analysis of clinicoradiologic characteristics of lung adenocarcinomas with ALK rearrangements or EGFR mutations

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, J.Y.; Zheng, J.; Chen, X.; Zhou, J.Y. [Zhejiang University, Department of Respiratory Disease, Thoracic Disease Center, First Affiliated Hospital, College of Medicine, Hangzhou (China); Yu, Z.F.; Xiao, W.B.; Jiang, L.N. [Zhejiang University, Department of Radiology, First Affiliated Hospital, College of Medicine, Hangzhou (China); Zhao, J.; Sun, K.; Wang, B.; Ding, W. [Zhejiang University, Department of Pathology, First Affiliated Hospital, College of Medicine, Hangzhou (China)

    2015-05-01

    To compare the clinicoradiologic features of tumours with echinoderm anaplastic lymphoma kinase (ALK) rearrangements, epidermal growth factor receptor (EGFR) mutations, or wild type (WT) for both genes in a cohort of patients with lung adenocarcinoma to identify useful characteristics of different gene statuses. In 346 lung adenocarcinoma patients, ALK rearrangements were confirmed with fluorescence in situ hybridisation, and EGFR mutations were determined by pyrosequencing assay. Patients were divided into three groups: ALK rearrangement (ALK+ group, n = 48), EGFR mutation (EGFR+ group, n = 166), and WT for both genes (WT group, n = 132). Chest computed tomography (CT) examinations were performed in all patients. The percentages of ground-glass opacity volume (pGGO) and tumour shadow disappearance rate (TDR) were measured using semi-automated nodule assessment software. The pGGO was significantly lower in the ALK+ group (25.1 % ± 24.3) than in the EGFR+ group (37.2 % ± 25.7, p < 0.001) and the WT group (36.1 % ± 24.6, p = 0.001). The TDR in the ALK+ group (17.3 % ± 25.1) was significantly lower than in the EGFR+ group (26.8 % ± 24.9, p = 0.002) and the WT group (25.7 % ± 24.6, p = 0.003). Solid pattern with lower incidence of lobulated border, finely spiculated margins, pleural retraction, and bubble-like lucency on CT imaging are the main characteristics of ALK rearrangement tumours. (orig.)

  13. Protein structure guided discovery of functional mutations across 19 cancer types

    Science.gov (United States)

    Niu, Beifang; Scott, Adam D.; Sengupta, Sohini; Bailey, Matthew H.; Batra, Prag; Ning, Jie; Wyczalkowski, Matthew A.; Liang, Wen-Wei; Zhang, Qunyuan; McLellan, Michael D.; Sun, Sam Q.; Tripathi, Piyush; Lou, Carolyn; Ye, Kai; Mashl, R. Jay; Wallis, John; Wendl, Michael C.; Chen, Feng; Ding, Li

    2017-01-01

    Local concentrations of mutations are well-known in human cancers. However, their 3-dimensional (3D) spatial relationships have yet to be systematically explored. We developed a computational tool, HotSpot3D, to identify such spatial hotspots (clusters) and to interpret the potential function of variants within them. We applied HotSpot3D to >4,400 TCGA tumors across 19 cancer types, discovering >6,000 intra- and inter-molecular clusters, some of which showed tumor/tissue specificity. In addition, we identified 369 rare mutations from genes including TP53, PTEN, VHL, EGFR, and FBXW7 and 99 medium recurrence mutations from genes such as RUNX1, MTOR, CA3, PI3, and PTPN11, all residing within clusters having potential functional implications. As a proof of concept, we validated our predictions in EGFR using high throughput phosphorylation data and cell-line based experimental evaluation. Finally, drug-mutation cluster/network analysis predicted over 800 promising candidates of druggable mutations, raising new possibilities for designing personalized treatments for patients carrying specific mutations. PMID:27294619

  14. Visualizing the origins of selfish de novo mutations in individual seminiferous tubules of human testes.

    Science.gov (United States)

    Maher, Geoffrey J; McGowan, Simon J; Giannoulatou, Eleni; Verrill, Clare; Goriely, Anne; Wilkie, Andrew O M

    2016-03-01

    De novo point mutations arise predominantly in the male germline and increase in frequency with age, but it has not previously been possible to locate specific, identifiable mutations directly within the seminiferous tubules of human testes. Using microdissection of tubules exhibiting altered expression of the spermatogonial markers MAGEA4, FGFR3, and phospho-AKT, whole genome amplification, and DNA sequencing, we establish an in situ strategy for discovery and analysis of pathogenic de novo mutations. In 14 testes from men aged 39-90 y, we identified 11 distinct gain-of-function mutations in five genes (fibroblast growth factor receptors FGFR2 and FGFR3, tyrosine phosphatase PTPN11, and RAS oncogene homologs HRAS and KRAS) from 16 of 22 tubules analyzed; all mutations have known associations with severe diseases, ranging from congenital or perinatal lethal disorders to somatically acquired cancers. These results support proposed selfish selection of spermatogonial mutations affecting growth factor receptor-RAS signaling, highlight its prevalence in older men, and enable direct visualization of the microscopic anatomy of elongated mutant clones.

  15. Comparative analysis of Dendrobium plastomes and utility of plastomic mutational hotspots.

    Science.gov (United States)

    Zhitao, Niu; Shuying, Zhu; Jiajia, Pan; Ludan, Li; Jing, Sun; Xiaoyu, Ding

    2017-05-18

    Dendrobium is one of the largest genera in Orchidaceae, comprising about 800-1500 species mainly distributed in tropical Asia, Australasia, and Australia. There are 74 species and two varieties of this genus in China. Because of their ornamental and commercial value, Dendrobium orchids have been studied at low taxonomic levels. However, structural changes and effective mutational hotspots of Dendrobium plastomes have rarely been documented. Here, 30 Dendrobium plastomes were compared, comprising 25 newly sequenced in this study and five previously published. Except for their differences in NDH genes, these plastomes shared identical gene content and order. Comparative analyses revealed that the variation in size of Dendroubium plastomes was associated with dramatically changed length of InDels. Furthermore, ten loci were identified as the top-ten mutational hotspots, whose sequence variability was almost unchanged with more than 10 plastomes sampled, suggesting that they may be powerful markers for Dendrobium species. In addition, primer pairs of 47 polymorphic microsatellites were developed. After assessing the mean BS values of all combinations derived from the top-ten hotspots, we recommend that the combination of five hotspots-trnT-trnL, rpl32-trnL, clpP-psbB, trnL intron, and rps16-trnQ-should be used in the phylogenetic and identification studies of Dendrobium.

  16. Human aging and somatic point mutations in mtDNA: a comparative study of generational differences (grandparents and grandchildren

    Directory of Open Access Journals (Sweden)

    Anderson Nonato do Rosário Marinho

    2011-01-01

    Full Text Available The accumulation of somatic mutations in mtDNA is correlated with aging. In this work, we sought to identify somatic mutations in the HVS-1 region (D-loop of mtDNA that might be associated with aging. For this, we compared 31 grandmothers (mean age: 63 ± 2.3 years and their 62 grandchildren (mean age: 15 ± 4.1 years, the offspring of their daughters. Direct DNA sequencing showed that mutations absent in the grandchildren were detected in a presumably homoplasmic state in three grandmothers and in a heteroplasmic state in an additional 13 grandmothers; no mutations were detected in the remaining 15 grandmothers. However, cloning followed by DNA sequencing in 12 grandmothers confirmed homoplasia in only one of the three mutations previously considered to be homoplasmic and did not confirm heteroplasmy in three out of nine grandmothers found to be heteroplasmic by direct sequencing. Thus, of 12 grandmothers in whom mtDNA was analyzed by cloning, eight were heteroplasmic for mutations not detected in their grandchildren. In this study, the use of genetically related subjects allowed us to demonstrate the occurrence of age-related (> 60 years old mutations (homoplasia and heteroplasmy. It is possible that both of these situations (homoplasia and heteroplasmy were a long-term consequence of mitochondrial oxidative phosphorylation that can lead to the accumulation of mtDNA mutations throughout life.

  17. Comparative analysis of charged particle-induced autosomal mutations in murine cells and tissues

    Science.gov (United States)

    Kronenberg, Amy; Gauny, Stacey; Turker, Mitchell; Dan, Cristian; Kwoh, Ely

    exposed to 2 Gy of Fe ions. Mutant spectra were analyzed via PCR using a series of heterozygous markers along mouse chromosome 8. Cytotoxicity assays were performed immediately after Fe ion exposure of cells from two primary clones. Cells irradiated in vitro demonstrated a dose-dependent decrement in cloning efficiency with no evidence of a shoulder. The results demonstrate the two clones behave similarly (unpaired t-test, p>0.3) with a D0 of 84.3 cGy for the combined data set. Mutation data were obtained using cells from one of the primary clones. In three experiments, we observed a linear dose-response for Aprt mutation with an induced mutant frzction of 1.06 x 10-3 /Gy. Kidney epithelial cells irradiated in vivo and incubated for 2-4 months in situ prior to harvest also showed an exponential reduction of cloning efficiency. Cells harvested 8-10 months postirradiation showed evidence of recovery for doses up to 1.5 Gy, but there was no improvement in cloning efficiency for kidney cells exposed to 2 Gy Fe ions in vivo evaluated at the late time point. Results for Aprt mutation induction in vivo indicated considerable inter-animal variation within each dose group (0, 1.0, 1.5 and 2 Gy). Fe ion exposures were mutagenic to the kidney, even at the lowest dose (p<0.01). A comparison of the mutant frequency results at the two harvest times indicates that the dose response did not vary with incubation time in vivo. Analysis of the pooled data from the 2-4 months harvests and the 8-10 month harvests indicated an increase in mutant frequency of 1.49 fold per Gy (p=0.01, CI 1.11-2.01). Molecular analysis of Aprtdeficient cells collected after a 2 Gy exposure to Fe ions in vitro showed an increased proportion of mutants arising via interstitial deletion or mitotic recombination, with an indication of an increase in chromosome loss. Similar results have been obtained for Aprt mutants isolated from mice exposed to 2 Gy of Fe ions, as compared with mutants collected from sham

  18. Comparing the DNA hypermethylome with gene mutations in human colorectal cancer.

    Directory of Open Access Journals (Sweden)

    Kornel E Schuebel

    2007-09-01

    Full Text Available We have developed a transcriptome-wide approach to identify genes affected by promoter CpG island DNA hypermethylation and transcriptional silencing in colorectal cancer. By screening cell lines and validating tumor-specific hypermethylation in a panel of primary human colorectal cancer samples, we estimate that nearly 5% or more of all known genes may be promoter methylated in an individual tumor. When directly compared to gene mutations, we find larger numbers of genes hypermethylated in individual tumors, and a higher frequency of hypermethylation within individual genes harboring either genetic or epigenetic changes. Thus, to enumerate the full spectrum of alterations in the human cancer genome, and to facilitate the most efficacious grouping of tumors to identify cancer biomarkers and tailor therapeutic approaches, both genetic and epigenetic screens should be undertaken.

  19. Evolutionary pattern of mutation in the factor IX genes of great apes: How does it compare to the pattern of recent germline mutation in patients with hemophilia B?

    Energy Technology Data Exchange (ETDEWEB)

    Grouse, L.H.; Ketterling, R.P.; Sommer, S.S. [Mayo Clinic/Foundation, Rochester, MN (United States)

    1994-09-01

    Most mutations causing hemophilia B have arisen within the past 150 years. By correcting for multiple biases, the underlying rates of spontaneous germline mutation have been estimated in the factor IX gene. From these rates, an underlying pattern of mutation has emerged. To determine if this pattern compares to a underlying pattern found in the great apes, sequence changes were determined in intronic regions of the factor IX gene. The following species were studied: Gorilla gorilla, Pan troglodytes (chimpanzee), Pongo pygmacus (orangutan) and Homo sapiens. Intronic sequences at least 200 bp from a splice junction were randomly chosen, amplified by cross-species PCR, and sequenced. These regions are expected to be subject to little if any selective pressure. Early diverged species of Old World monkeys were also studied to help determine the direction of mutational changes. A total of 62 sequence changes were observed. Initial data suggest that the average pattern since evolution of the great apes has a paucity of transitions at CpG dinucleotides and an excess of microinsertions to microdeletions when compared to the pattern observed in humans during the past 150 years (p<.05). A larger study is in progress to confirm these results.

  20. Comparative screening of FMF mutations in various communities of the Israeli society.

    Science.gov (United States)

    Sharkia, Rajech; Mahajnah, Muhammad; Zalan, Abdelnaser; Athamna, Muhammad; Azem, Abdussalam; Badarneh, Khader; Faris, Fuad

    2013-07-01

    Familial Mediterranean Fever (FMF) is an autosomal recessive disease that is widely spread in the populations of the Mediterranean region. It is characterized by recurrent fever and inflammatory attacks. A total of 1700 suspected patients, belonging to various communities in Israel: Jews (Ashkenazi and non-Ashkenazi), Arabs (Muslims and Christians) and Druze, was subjected to examination for FMF mutation screening. The patients were screened for the most common six MEFV gene mutations namely, M680I, M694V, M694I, V726A, E148Q and K695R. Fifty-five percent of the cases were confirmed to have MEFV mutations. The most common mutations among all the cases studied were M694V, E148Q and V726A. The common mutations in the respective communities were: among the Jews M694V with a frequency of 69.9% (76.8% for non-Ashkenazi Jews and 43.6% for Ashkenazi Jews), among the Arabs V726A with a frequency of 32.7% (32.7% for Muslims and 32.1% for Christians) and among Druze it was E148Q with a frequency of 52.1%. The characteristic mutation present in Jews was K695R and the one in Arabs was M680I, while no characteristic mutation was found in Druze. On the other hand, mutation E148Q was observed to have a considerable occurrence in patients of all ethnic groups studied. Furthermore, our results revealed that homozygous mutations accounted for 168 cases (18%). The homozygote mutation M694V was the most prevalent among Jews and the E148Q mutation was the most common among Druze, while, among Arabs there were three homozygous mutations having maximum prevalence, namely, V726A, M694V and M694I. Our study comprehensively provided a spectrum of FMF mutations in various communities of Israeli society. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  1. Novel association of neurofibromatosis type 1-causing mutations in families with neurofibromatosis-Noonan syndrome.

    Science.gov (United States)

    Ekvall, Sara; Sjörs, Kerstin; Jonzon, Anders; Vihinen, Mauno; Annerén, Göran; Bondeson, Marie-Louise

    2014-03-01

    Neurofibromatosis-Noonan syndrome (NFNS) is a rare condition with clinical features of both neurofibromatosis type 1 (NF1) and Noonan syndrome (NS). All three syndromes belong to the RASopathies, which are caused by dysregulation of the RAS-MAPK pathway. The major gene involved in NFNS is NF1, but co-occurring NF1 and PTPN11 mutations in NFNS have been reported. Knowledge about possible involvement of additional RASopathy-associated genes in NFNS is, however, very limited. We present a comprehensive clinical and molecular analysis of eight affected individuals from three unrelated families displaying features of NF1 and NFNS. The genetic etiology of the clinical phenotypes was investigated by mutation analysis, including NF1, PTPN11, SOS1, KRAS, NRAS, BRAF, RAF1, SHOC2, SPRED1, MAP2K1, MAP2K2, and CBL. All three families harbored a heterozygous NF1 variant, where the first family had a missense variant, c.5425C>T;p.R1809C, the second family a recurrent 4bp-deletion, c.6789_6792delTTAC;p.Y2264Tfs*6, and the third family a splice-site variant, c.2991-1G>A, resulting in skipping of exon 18 and an in-frame deletion of 41 amino acids. These NF1 variants have all previously been reported in NF1 patients. Surprisingly, both c.6789_6792delTTAC and c.2991-1G>A are frequently associated with NF1, but association to NFNS has, to our knowledge, not previously been reported. Our results support the notion that NFNS represents a variant of NF1, genetically distinct from NS, and is caused by mutations in NF1, some of which also cause classical NF1. Due to phenotypic overlap between NFNS and NS, we propose screening for NF1 mutations in NS patients, preferentially when café-au-lait spots are present. © 2013 Wiley Periodicals, Inc.

  2. NF1-mutated melanoma tumors harbor distinct clinical and biological characteristics.

    Science.gov (United States)

    Cirenajwis, Helena; Lauss, Martin; Ekedahl, Henrik; Törngren, Therese; Kvist, Anders; Saal, Lao H; Olsson, Håkan; Staaf, Johan; Carneiro, Ana; Ingvar, Christian; Harbst, Katja; Hayward, Nicholas K; Jönsson, Göran

    2017-03-07

    In general, melanoma can be considered as a UV-driven disease with an aggressive metastatic course and high mutational load, with only few tumors (acral, mucosal, and uveal melanomas) not induced by sunlight and possessing a lower mutational load. The most commonly activated pathway in melanoma is the mitogen-activated protein kinase (MAPK) pathway. However, the prognostic significance of mutational stratification is unclear and needs further investigation. Here, in silico we combined mutation data from 162 melanomas subjected to targeted deep sequencing with mutation data from three published studies. Tumors from 870 patients were grouped according to BRAF, RAS, NF1 mutation or triple-wild-type status and correlated with tumor and patient characteristics. We found that the NF1-mutated subtype had a higher mutational burden and strongest UV mutation signature. Searching for co-occurring mutated genes revealed the RASopathy genes PTPN11 and RASA2, as well as another RAS domain-containing gene RASSF2 enriched in the NF1 subtype after adjustment for mutational burden. We found that a larger proportion of the NF1-mutant tumors were from males and with older age at diagnosis. Importantly, we found an increased risk of death from melanoma (disease-specific survival, DSS; HR, 1.9; 95% CI, 1.21-3.10; P = 0.046) and poor overall survival (OS; HR, 2.0; 95% CI, 1.28-2.98; P = 0.01) in the NF1 subtype, which remained significant after adjustment for age, gender, and lesion type (DSS P = 0.03, OS P = 0.06, respectively). Melanoma genomic subtypes display different biological and clinical characteristics. The poor outcome observed in the NF1 subtype highlights the need for improved characterization of this group.

  3. Multiplex high-throughput gene mutation analysis in acute myeloid leukemia.

    Science.gov (United States)

    Dunlap, Jennifer; Beadling, Carol; Warrick, Andrea; Neff, Tanaya; Fleming, William H; Loriaux, Marc; Heinrich, Michael C; Kovacsovics, Tibor; Kelemen, Katalin; Leeborg, Nicky; Gatter, Ken; Braziel, Rita M; Press, Richard; Corless, Christopher L; Fan, Guang

    2012-12-01

    Classification of acute myeloid leukemia increasingly depends on genetic analysis. However, the number of known mutations in acute myeloid leukemia is expanding rapidly. Therefore, we tested a high-throughput screening method for acute myeloid leukemia mutation analysis using a multiplex mass spectrometry-based approach. To our knowledge, this is the first reported application of this approach to genotype leukemias in a clinical setting. One hundred seven acute myeloid leukemia cases were screened for mutations using a panel that covers 344 point mutations across 31 genes known to be associated with leukemia. The analysis was performed by multiplex polymerase chain reaction for mutations in genes of interest followed by primer extension reactions. Products were analyzed on a Sequenom MassARRAY system (San Diego, CA). The multiplex panel yielded mutations in 58% of acute myeloid leukemia cases with normal cytogenetics and 21% of cases with abnormal cytogenetics. Cytogenetics and routine polymerase chain reaction-based screening of NPM1, CEBPA, FLT3-ITD, and KIT was also performed on a subset of cases. When combined with the results of these standard polymerase chain reaction-based tests, the mutation frequency reached 78% in cases with normal cytogenetics. Of these, 42% harbored multiple mutations primarily involving NPM1 with NRAS, KRAS, CEBPA, PTPN11, IDH1, or FLT3. In contrast, cases with abnormal cytogenetics rarely harbored more than 1 mutation (1.5%), suggesting different underlying biology. This study demonstrates the feasibility and utility of broad-based mutation profiling of acute myeloid leukemia in a clinical setting. This approach will be helpful in defining prognostic subgroups of acute myeloid leukemia and contribute to the selection of patients for enrollment into trials with novel inhibitors.

  4. Somatic mutation spectrum in monoclonal gammopathy of undetermined significance indicates a less complex genomic landscape compared to multiple myeloma.

    Science.gov (United States)

    Mikulasova, Aneta; Wardell, Christopher P; Murison, Alexander; Boyle, Eileen M; Jackson, Graham H; Smetana, Jan; Kufova, Zuzana; Pour, Ludek; Sandecka, Viera; Almasi, Martina; Vsianska, Pavla; Gregora, Evzen; Kuglik, Petr; Hajek, Roman; Davies, Faith E; Morgan, Gareth J; Walker, Brian A

    2017-05-26

    Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant precursor of multiple myeloma with a 1% risk of progression per year. Although targeted analyses have shown the presence of specific genetic abnormalities such as IGH translocations, RB1 deletion, 1q gain, hyperdiploidy or RAS genes mutations, little is known about the molecular mechanism of malignant transformation. We have performed whole exome sequencing together with CGH+SNP array analysis in 33 flow-cytometry separated abnormal plasma cell samples from MGUS patients to describe somatic gene mutations and chromosome changes at the genome-wide level. Non-synonymous mutations and copy-number alterations were present in 97.0% and in 60.6% of cases, respectively. Importantly, the number of somatic mutations was significantly lower in MGUS compared to myeloma (P < 10-4) and we identified six genes that were significantly mutated in myeloma (KRAS, NRAS, DIS3, HIST1H1E, EGR1 and LTB) within the MGUS dataset. We also found a positive correlation with increasing chromosome changes and somatic gene mutations. IGH translocations were present in 27.3% of cases comprising t(4;14), t(11;14), t(14;16) or t(14;20) and were present in a similar frequency to myeloma, consistent with the primary lesion hypothesis. MYC translocations and TP53 deletions or mutations were not detected in MGUS samples indicating they may be drivers of progression to myeloma. Data from this study show that MGUS is genetically similar to myeloma, however overall genetic abnormalities are present at significantly lower levels compared to myeloma. Copyright © 2017, Ferrata Storti Foundation.

  5. Comparative Analysis of Phenylalanine Hydroxylase Mutations Spectrum in Novosibirsk and Kemerovo regions of Western Siberia, Russia

    Directory of Open Access Journals (Sweden)

    Olga A. Baturina

    2016-03-01

    Full Text Available Results of phenylalanine hydroxylase (PAH locus molecular genotyping for 115 phenylketonuria (PKU patients and their family members from Novosibirsk and Kemerovo regions of Western Siberia are presented. The direct exons and adjacent introns regions sequencing was used to identify PKU-associated mutations. Mutations typical for Europe (p.R158Q, p.R252W, p.P281L, IVS10-11G>A, p.R408W, IVS12+1G>A and typical for South-Eastern Asia and Turkey (p.R261Q и p.R243Q were identified as well as a bunch of rare mutations (IVS2+5G>A, p.R155H, p.Y168H, p.W187R, E221_D222>Efs, p.A342T, p.Y386C, IVS11+1G>C. The p.R408W mutation was prevailing. Mutations spectrum for Novosibirsk region appeared to be more diverse than one for Kemerovo region.

  6. Comparative active-site mutation study of human and Caenorhabditis elegans thymidine kinase 1

    DEFF Research Database (Denmark)

    Skovgaard, Tine; Uhlin, Ulla; Munch-Petersen, Birgitte

    2012-01-01

    The first step for the intracellular retention of several anticancer or antiviral nucleoside analogues is the addition of a phosphate group catalysed by a deoxyribonucleoside kinase such as thymidine kinase 1 (TK1). Recently, human TK1 (HuTK1) has been crystallized and characterized using different...... surrounding the substrate base. In CeTK1, some of these mutations led to increased activity with deoxycytidine and deoxyguanosine, two unusual substrates for TK1-like kinases. In HuTK1, mutation of T163 to S resulted in a kinase with a 140-fold lower K(m) for the antiviral nucleoside analogue 3'-azido-3...

  7. NPM1 mutation is a stable marker for minimal residual disease monitoring in acute myeloid leukaemia patients with increased sensitivity compared to WT1 expression*

    DEFF Research Database (Denmark)

    Kristensen, Thomas; Møller, Michael B; Friis, Lone;

    2011-01-01

    Mutation in the NPM1 gene occurs in 60% of acute myeloid leukaemia (AML) patients with normal karyotype. NPM1 mutation is potentially a superior minimal residual disease (MRD) marker compared to WT1 gene overexpression by being specific to the malignant clone, although experimental evidence...... published so far includes very limited numbers of relapsed cases. Also, the stability of the NPM1 mutation has been questioned by reports of the mutation being lost at relapse. In the present study we compared NPM1 mutation and WT1 overexpression as MRD markers in 20 cases of relapsed AML. The 20 patients...... experienced a total of 28 morphological relapses. Karyotypic evolution was detected in 56% of relapses. All relapses were accompanied by high levels of NPM1 mutation, along with high WT1 mRNA levels, thus demonstrating complete stability of both markers during relapse. Detectable NPM1 mutation following...

  8. Differences Among a Modern Cohort of BRCA Mutation Carriers Choosing Bilateral Prophylactic Mastectomies Compared to Breast Surveillance.

    Science.gov (United States)

    Gilbert, Elizabeth; Zabor, Emily C; Stempel, Michelle; Mangino, Debra; Heerdt, Alexandra; Pilewskie, Melissa

    2017-08-01

    Women with a BRCA mutation have significantly elevated breast cancer risk, which can be reduced by >90% with bilateral prophylactic mastectomy (BPM). We sought to compare a cohort of BRCA mutation carriers choosing BPM versus breast surveillance to better elucidate factors that may impact decision making. Women with a BRCA mutation were retrospectively identified from a prospectively maintained database. The surveillance cohort (n = 313) consisted of women seen in a high-risk clinic between 2014 and 2016, while the surgery cohort (n = 142) consisted of women who underwent BPM between 2010 and 2016. Clinical and familial factors were compared between the groups. Women choosing BPM were more likely to have a BRCA1 than BRCA2 mutation compared with the surveillance group (57 vs. 45%, p = 0.02) and were less likely to have a personal history of ovarian cancer (10 vs. 20%, p = 0.01). Furthermore, women undergoing BPM were more likely to be married (78 vs. 62%, p = 0.01), to have more children (median 2 vs. 1, p BPM had more first-degree relatives (63 vs. 48%, p = 0.01) or a sister (23 vs. 14%, p = 0.02) with a history of breast cancer and were more likely to have a family member with ovarian cancer under the age of 40 years (9 vs. 4%, p = 0.03). There was no difference in the number of prior breast biopsies or history of atypia/lobular carcinoma in situ. The decision to undergo BPM appears multifactorial, with gene mutation, family history, and relationships appearing to have the strongest influence on decision making.

  9. Age-dependent germline mosaicism of the most common noonan syndrome mutation shows the signature of germline selection.

    Science.gov (United States)

    Yoon, Song-Ro; Choi, Soo-Kung; Eboreime, Jordan; Gelb, Bruce D; Calabrese, Peter; Arnheim, Norman

    2013-06-06

    Noonan syndrome (NS) is among the most common Mendelian genetic diseases (∼1/2,000 live births). Most cases (50%-84%) are sporadic, and new mutations are virtually always paternally derived. More than 47 different sites of NS de novo missense mutations are known in the PTPN11 gene that codes for the protein tyrosine phosphatase SHP-2. Surprisingly, many of these mutations are recurrent with nucleotide substitution rates substantially greater than the genome average; the most common mutation, c.922A>G, is at least 2,400 times greater. We examined the spatial distribution of the c.922A>G mutation in testes from 15 unaffected men and found that the mutations were not uniformly distributed across each testis as would be expected for a mutation hot spot but were highly clustered and showed an age-dependent germline mosaicism. Computational modeling that used different stem cell division schemes confirmed that the data were inconsistent with hypermutation, but consistent with germline selection: mutated spermatogonial stem cells gained an advantage that allowed them to increase in frequency. SHP-2 interacts with the transcriptional activator STAT3. Given STAT3's function in mouse spermatogonial stem cells, we suggest that this interaction might explain the mutant's selective advantage by means of repression of stem cell differentiation signals. Repression of STAT3 activity by cyclin D1 might also play a previously unrecognized role in providing a germline-selective advantage to spermatogonia for the recurrent mutations in the receptor tyrosine kinases that cause Apert syndrome and MEN2B. Looking at recurrent mutations driven by germline selection in different gene families can help highlight common causal signaling pathways.

  10. Comparing mutation rates under the Luria-Delbrück protocol.

    Science.gov (United States)

    Zheng, Qi

    2016-06-01

    Comparison of microbial mutation rates under the Luria-Delbrück protocol is a routine laboratory task. However, execution of this important task has been hampered by the lack of proper statistical methods. Visual inspection or improper use of the t test and the Mann-Whitney test can impair the quality of genetic research. This paper proposes a unified framework for constructing likelihood ratio tests that overcome three important obstacles to the proper comparison of microbial mutation rates. Specifically, algorithms for likelihood ratio tests have been devised that allow for partial plating, differential growth rates and unequal terminal cell population sizes. The new algorithms were assessed by computer simulations. In addition, a strategy for multiple comparison was illustrated by reanalyzing the experimental data from a study of bacterial resistance against tuberculosis antibiotics.

  11. Comparative exome sequencing of metastatic lesions provides insights into the mutational progression of melanoma

    Directory of Open Access Journals (Sweden)

    Gartner Jared J

    2012-09-01

    Full Text Available Abstract Background Metastasis is characterized by spreading of neoplastic cells to an organ other than where they originated and is the predominant cause of death among cancer patients. This holds true for melanoma, whose incidence is increasing more rapidly than any other cancer and once disseminated has few therapeutic options. Here we performed whole exome sequencing of two sets of matched normal and metastatic tumor DNAs. Results Using stringent criteria, we evaluated the similarities and differences between the lesions. We find that in both cases, 96% of the single nucleotide variants are shared between the two metastases indicating that clonal populations gave rise to the distant metastases. Analysis of copy number variation patterns of both metastatic sets revealed a trend similar to that seen with our single nucleotide variants. Analysis of pathway enrichment on tumor sets shows commonly mutated pathways enriched between individual sets of metastases and all metastases combined. Conclusions These data provide a proof-of-concept suggesting that individual metastases may have sufficient similarity for successful targeting of driver mutations.

  12. Optimizing Construction Project Labor Utilization Using Differential Evolution: A Comparative Study of Mutation Strategies

    Directory of Open Access Journals (Sweden)

    Nhat-Duc Hoang

    2015-01-01

    Full Text Available In construction management, the task of planning project schedules with consideration of labor utilization is very crucial. However, the commonly used critical path method (CPM does not inherently take into account this issue. Consequently, the labor utilization of the project schedule derived from the CPM method often has substantial low ebbs and high peaks. This research proposes a model to obtain project schedule with the least fluctuation in labor demand while still satisfying the project deadline and maintain the project cost. The Differential Evolution (DE, a fast and efficient metaheuristic, is employed to search for the most desirable solution of project execution among numerous combinations of activities’ crew sizes and start times. Furthermore, seven DE’s mutation strategies have also been employed for solving the optimization at hand. Experiment results point out that the Target-to-Best 1 and a new hybrid mutation strategy can attain the best solution of project schedule with the least fluctuation in labor demand. Accordingly, the proposed framework can be an effective tool to assist decision-makers in the project planning phase.

  13. Automated Breast Volumetric Sonography Compared with Magnetic Resonance Imaging in Jewish BRCA 1/2 Mutation Carriers.

    Science.gov (United States)

    Halshtok Neiman, Osnat; Erlich, Zippy; Friedman, Eitan; Rundstein, Arie; Shalmon, Anat; Servadio, Yael; Sklair Levy, Miri

    2016-10-01

    Automated breast volumetric sonography (ABVS) is a new technology with various possible applications. To compare ABVS and breast magnetic resonance imaging (MRI) in the surveillance of women with BRCA1/2 gene mutation carriers. We conducted a prospective study in Jewish female BRCA1/2 mutation carriers who underwent breast MRI and ABVS. The results of both exams performed 6 months apart or less, and relevant clinical data, were reviewed. The BIRADS results were divided into three subgroups according to subsequent expected management: BIRADS 1-2 (normal study), BIRADS 3 (probably benign finding), and BIRADS 4 and 5 (suspicious findings). BIRADS 0 and 6 scores were excluded from the study. Distribution of ABVS and MRI BIRADS scores were compared using McNemar's test, and concordance was calculated using the Cohen kappa test. Overall, 68 women, 40 BRCA1 and 28 BRCA2 mutation carriers, age range 26-69 (mean 44.55 ± 12.1 years), underwent 79 paired ABVS and MRI examinations. McNemar's test calculations showed no significant difference between MRI and ABVS BIRADS score distribution. Cohen's kappa test resulted in k = 0.158, an agreement that can be described as only "slight agreement" between both modalities. Of 14 discordant cases there was one cancer, revealed by MRI and not by ABVS performed 6 months prior to MRI. ABVS showed slight agreement with MRI in BRCA1/2 mutation carriers. These preliminary results on a small group of healthy high risk patients suggest that the diagnostic abilities of ABVS are inferior to MRI. Further studies encompassing larger groups are needed.

  14. PTPN11 Is a Central Node in Intrinsic and Acquired Resistance to Targeted Cancer Drugs

    NARCIS (Netherlands)

    Prahallad, Anirudh; Heynen, Guus J J E; Germano, Giovanni; Willems, Stefan M; Evers, Bastiaan; Vecchione, Loredana; Gambino, Valentina; Lieftink, Cor; Beijersbergen, Roderick L; Di Nicolantonio, Federica; Bardelli, Alberto; Bernards, Rene

    2015-01-01

    Most BRAF (V600E) mutant melanomas are sensitive to selective BRAF inhibitors, but BRAF mutant colon cancers are intrinsically resistant to these drugs because of feedback activation of EGFR. We performed an RNA-interference-based genetic screen in BRAF mutant colon cancer cells to search for phosph

  15. Patterns of human genetic variation inferred from comparative analysis of allelic mutations in blood group antigen genes.

    Science.gov (United States)

    Patnaik, Santosh Kumar; Blumenfeld, Olga O

    2011-03-01

    Comparative analysis of allelic variation of a gene sheds light on the pattern and process of its diversification at the population level. Gene families for which a large number of allelic forms have been verified by sequencing provide a useful resource for such studies. In this regard, human blood group-encoding genes are unique in that differences of cell surface traits among individuals and populations can be readily detected by serological screening, and correlation between the variant cell surface phenotype and the genotype is, in most cases, unequivocal. Here, we perform a comprehensive analysis of allelic forms, compiled in the Blood Group Antigen Gene Mutation database, of ABO, RHD/CE, GYPA/B/E and FUT1/2 gene families that encode the ABO, RH, MNS, and H/h blood group system antigens, respectively. These genes are excellent illustrative examples showing distinct mutational patterns among the alleles, and leading to speculation on how their origin may have been driven by recurrent but different molecular mechanisms. We illustrate how alignment of alleles of a gene may provide an additional insight into the DNA variation process and its pathways, and how this approach may serve to catalog alleles of a gene, simplifying the task and content of mutation databases.

  16. Comparative analysis of dideoxy sequencing,the KRAS StripAssay and pyrosequencing for detection of KRAS mutation

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    AIM:To compare the differences between dideoxy sequencing/KRAS StripAssay/pyrosequencing for detection of KRAS mutation in Chinese colorectal cancer (CRC) patients.METHODS:Formalin-f ixed, paraff in-embedded (FFPE) samples with tumor cells ≥ 50% were collected from 100 Chinese CRC patients at Beijing Cancer Hospital. After the extraction of genome DNA from FFPE samples, fragments contained codons 12 and 13 of KRAS exon 2 were amplified by polymerase chain reaction and analyzed by dideoxy sequencing, the KRA...

  17. Comparative Methods to Improve the Detection of BRAF V600 Mutations in Highly Pigmented Melanoma Specimens.

    Science.gov (United States)

    Frouin, Eric; Maudelonde, Thierry; Senal, Romain; Larrieux, Marion; Costes, Valérie; Godreuil, Sylvain; Vendrell, Julie A; Solassol, Jérôme

    2016-01-01

    Genotyping BRAF in melanoma samples is often challenging. The presence of melanin greatly interferes with thermostable DNA polymerases and/or nucleic acids in traditional polymerase chain reaction (PCR)-based methods. In the present work, we evaluated three easy-to-use strategies to improve the detection of pigmented DNA refractory to PCR amplification. These pre-PCR processing methods include the addition of bovine serum albumin (BSA), the dilution of DNA, and the purification of DNA using the NucleoSpin® gDNA Clean-up XS Kit. We found that BRAF genotyping in weakly and moderately pigmented samples was more efficient when the sample was processed with BSA or purified with a NucleoSpin® gDNA Clean-up XS Kit prior to PCR amplification. In addition, the combination of both methods resulted in successful detection of BRAF mutation in pigmented specimens, including highly pigmented samples, thereby increasing the chance of patients being elicited for anti-BRAF treatment. These solutions to overcome melanin-induced PCR inhibition are of tremendous value and provide a simple solution for clinical chemistry and routine laboratory medicine.

  18. Comparative study of the antimutagenic properties of vitamins C and E against mutation induced by norfloxacin

    Science.gov (United States)

    Alba, Myriam Arriaga; Sánchez, Roberto Rivera; Pérez, Nancy Jannet Ruíz; Navarrete, Jaime Sánchez; Paz, Rocío Flores; Montoya-Estrada, Araceli; Gómez, Juan José Hicks

    2008-01-01

    Background Norfloxacin like other fluoroquinolones, is known to be mutagenic for Salmonella typhimurium TA102 strain. This mutagenic effect is due to free oxygen radicals (ROS), because it is inhibited by antioxidants such as β-carotene and naturally occurring antioxidants of Roheo discolor and other plants. The aim of this work was to evaluate combination therapy with norfloxacin and vitamins C and E, to reduce the possible genotoxic risk associated with fluoroquinolones. Method The antimutagenicity of α-tocoferol (Vitamin E) and ascorbic acid (Vitamin C) against norfloxacin-induced mutation was evaluated on S. typhimurium TA102, using the aroclor-1254-induced S9 rat liver homogenate. The minimum inhibitory concentration (MIC) a measure of the bactericidal effect of norfloxacin, was obtained in vitro by the plate dilution method. Results Vitamin E (0.5 mg per Petri dish) induced a statistically significant reduction (P norfloxacin, whereas Vitamin C (1 mg per Petri dish) had no such effect. Neither of these vitamins altered the MIC for norfloxacin against 25 uropathogenic strains of Escherichia coli. Conclusion These results suggest that Vitamin E is a potent antimutagen that would be worthwhile being used in conjunction with fluoroquinolone treatment. The minimal antimutagenic effect of Vitamin C observed under these experimental conditions may have been because Vitamin C in the Ames test induces a Fenton reaction, and if divalent cations are present, it can act as a pro-oxidant rather than an antioxidant. Ascorbic acid should be further evaluated in the presence of different divalent cations concentrations. PMID:18267022

  19. Chronically ultraviolet-exposed human skin shows a higher mutation frequency of mitochondrial DNA as compared to unexposed skin and the hematopoietic system.

    Science.gov (United States)

    Berneburg, M; Gattermann, N; Stege, H; Grewe, M; Vogelsang, K; Ruzicka, T; Krutmann, J

    1997-08-01

    Normal ageing processes are associated with an accumulation of mutations within the mitochondrial (mt) DNA. The most frequent mutation is a 4977 base pair (bp) deletion known as common deletion. In order to test the hypothesis that chronically sun-exposed skin is characterized by an increased mutation frequency of mtDNA, the mutation frequency of the common deletion between skin and another replicating tissue (the hematopoietic system) and chronically sun-exposed versus sun-protected skin was compared in the same individuals. This was done by comparing the amount of mutated mtDNA molecules with the whole mitochondrial genome in the same specimen with a semiquantitative polymerase chain reaction method, thus allowing direct comparison of different tissues. In all skin specimens the common deletion could be observed. In contrast only 3 of 10 blood samples revealed detectable amounts of the common deletion. Comparison of sun-exposed versus sun-protected skin exhibited a higher content of the common deletion in sun-exposed skin in 7 of 10 individuals. Additionally, a hitherto undescribed mtDNA mutation was detected exclusively in human skin. These studies indicate that exposure of human skin to solar radiation leads to an accumulation of mtDNA mutations, possibly via oxidative damage, which may play an important role in photoageing.

  20. Comparable frequencies of coding mutations and loss of imprinting in human pluripotent cells derived by nuclear transfer and defined factors.

    Science.gov (United States)

    Johannesson, Bjarki; Sagi, Ido; Gore, Athurva; Paull, Daniel; Yamada, Mitsutoshi; Golan-Lev, Tamar; Li, Zhe; LeDuc, Charles; Shen, Yufeng; Stern, Samantha; Xu, Nanfang; Ma, Hong; Kang, Eunju; Mitalipov, Shoukhrat; Sauer, Mark V; Zhang, Kun; Benvenisty, Nissim; Egli, Dieter

    2014-11-06

    The recent finding that reprogrammed human pluripotent stem cells can be derived by nuclear transfer into human oocytes as well as by induced expression of defined factors has revitalized the debate on whether one approach might be advantageous over the other. Here we compare the genetic and epigenetic integrity of human nuclear-transfer embryonic stem cell (NT-ESC) lines and isogenic induced pluripotent stem cell (iPSC) lines, derived from the same somatic cell cultures of fetal, neonatal, and adult origin. The two cell types showed similar genome-wide gene expression and DNA methylation profiles. Importantly, NT-ESCs and iPSCs had comparable numbers of de novo coding mutations, but significantly more than parthenogenetic ESCs. As iPSCs, NT-ESCs displayed clone- and gene-specific aberrations in DNA methylation and allele-specific expression of imprinted genes. The occurrence of these genetic and epigenetic defects in both NT-ESCs and iPSCs suggests that they are inherent to reprogramming, regardless of derivation approach.

  1. Comparable rate of EGFR kinase domain mutation in lung adenocarcinomas from Chinese male and female never-smokers

    Institute of Scientific and Technical Information of China (English)

    Yi-hua SUN; Rong FANG; Bin GAO; Xiang-kun HAN; Jun-hua ZHANG; William PAO; Hai-quan CHEN; Hong-bin JI

    2010-01-01

    @@ Lung cancer patients with the epidermal growth factor receptor (EGFR) kinase domain mutations frequently show good responses to small molecule tyrosine kinase inhibitors, including Iressa and Tarceva, in clinical studies[1-3]. Previous studies have demonstrated that EGFR kinase domain mutations are commonly observed in lung adenocarcinomas, never-smokers,East Asian, and females[4-8].

  2. MYD88 mutant lymphoplasmacytic lymphoma/Waldenström macroglobulinemia has distinct clinical and pathological features as compared to its mutation negative counterpart.

    Science.gov (United States)

    Patkar, Nikhil; Subramanian, P G; Deshpande, Prashant; Ghodke, Kiran; Tembhare, Prashant; Mascarenhas, Russel; Muranjan, Aditi; Chaudhary, Shruti; Bagal, Bhausaheb; Gujral, Sumeet; Sengar, Manju; Menon, Hari

    2015-02-01

    In a first series from India, we report 32 cases of lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM) over 7 years. Here, we analyzed 32 patients with LPL/WM for MYD88 L265P mutation and correlated mutation staus with hematological and biochemical parameters and also with the International Prognostic Scoring System (ISSWM) and treatment response. Twenty-seven out of 32 cases of LPL/WM (84.3%) harbored the MYD88 L265P mutation. MYD88 wild-type WM was associated with a lower number of tumor cells (p<0.01) and older age (p=0.02) and a lower ISSWM score at presentation (p=0.03) as compared to mutated LPL/WM. On evaluation of response (n=23), 44.4% of patients with MYD88 mutated LPL/WM had progressive disease, whereas no patient in the MYD88 unmutated group changed their baseline status. We confirm the high frequency of MYD88 mutations in LPL/WM. Although the number of MYD88 wild-type cases was limited, our data indicate that MYD88 may represent an adverse prognostic marker for LPL/WM.

  3. Mice with missense and nonsense NF1 mutations display divergent phenotypes compared with human neurofibromatosis type I.

    Science.gov (United States)

    Li, Kairong; Turner, Ashley N; Chen, Min; Brosius, Stephanie N; Schoeb, Trenton R; Messiaen, Ludwine M; Bedwell, David M; Zinn, Kurt R; Anastasaki, Corina; Gutmann, David H; Korf, Bruce R; Kesterson, Robert A

    2016-07-01

    Neurofibromatosis type 1 (NF1) is a common genetic disorder characterized by the occurrence of nerve sheath tumors and considerable clinical heterogeneity. Some translational studies have been limited by the lack of animal models available for assessing patient-specific mutations. In order to test therapeutic approaches that might restore function to the mutated gene or gene product, we developed mice harboring NF1 patient-specific mutations including a nonsense mutation (c.2041C>T; p.Arg681*) and a missense mutation (c.2542G>C; p.Gly848Arg). The latter is associated with the development of multiple plexiform neurofibromas along spinal nerve roots. We demonstrate that the human nonsense NF1(Arg681*) and missense NF1(Gly848Arg) mutations have different effects on neurofibromin expression in the mouse and each recapitulates unique aspects of the NF1 phenotype, depending upon the genetic context when assessed in the homozygous state or when paired with a conditional knockout allele. Whereas the missense Nf1(Gly848Arg) mutation fails to produce an overt phenotype in the mouse, animals homozygous for the nonsense Nf1(Arg681*) mutation are not viable. Mice with one Nf1(Arg681*) allele in combination with a conditional floxed Nf1 allele and the DhhCre transgene (Nf1(4F/Arg681*); DhhCre) display disorganized nonmyelinating axons and neurofibromas along the spinal column, which leads to compression of the spinal cord and paralysis. This model will be valuable for preclinical testing of novel nonsense suppression therapies using drugs to target in-frame point mutations that create premature termination codons in individuals with NF1.

  4. Mice with missense and nonsense NF1 mutations display divergent phenotypes compared with human neurofibromatosis type I

    Directory of Open Access Journals (Sweden)

    Kairong Li

    2016-07-01

    Full Text Available Neurofibromatosis type 1 (NF1 is a common genetic disorder characterized by the occurrence of nerve sheath tumors and considerable clinical heterogeneity. Some translational studies have been limited by the lack of animal models available for assessing patient-specific mutations. In order to test therapeutic approaches that might restore function to the mutated gene or gene product, we developed mice harboring NF1 patient-specific mutations including a nonsense mutation (c.2041C>T; p.Arg681* and a missense mutation (c.2542G>C; p.Gly848Arg. The latter is associated with the development of multiple plexiform neurofibromas along spinal nerve roots. We demonstrate that the human nonsense NF1Arg681* and missense NF1Gly848Arg mutations have different effects on neurofibromin expression in the mouse and each recapitulates unique aspects of the NF1 phenotype, depending upon the genetic context when assessed in the homozygous state or when paired with a conditional knockout allele. Whereas the missense Nf1Gly848Arg mutation fails to produce an overt phenotype in the mouse, animals homozygous for the nonsense Nf1Arg681* mutation are not viable. Mice with one Nf1Arg681* allele in combination with a conditional floxed Nf1 allele and the DhhCre transgene (Nf14F/Arg681*; DhhCre display disorganized nonmyelinating axons and neurofibromas along the spinal column, which leads to compression of the spinal cord and paralysis. This model will be valuable for preclinical testing of novel nonsense suppression therapies using drugs to target in-frame point mutations that create premature termination codons in individuals with NF1.

  5. Previous estimates of mitochondrial DNA mutation level variance did not account for sampling error: comparing the mtDNA genetic bottleneck in mice and humans.

    Science.gov (United States)

    Wonnapinij, Passorn; Chinnery, Patrick F; Samuels, David C

    2010-04-09

    In cases of inherited pathogenic mitochondrial DNA (mtDNA) mutations, a mother and her offspring generally have large and seemingly random differences in the amount of mutated mtDNA that they carry. Comparisons of measured mtDNA mutation level variance values have become an important issue in determining the mechanisms that cause these large random shifts in mutation level. These variance measurements have been made with samples of quite modest size, which should be a source of concern because higher-order statistics, such as variance, are poorly estimated from small sample sizes. We have developed an analysis of the standard error of variance from a sample of size n, and we have defined error bars for variance measurements based on this standard error. We calculate variance error bars for several published sets of measurements of mtDNA mutation level variance and show how the addition of the error bars alters the interpretation of these experimental results. We compare variance measurements from human clinical data and from mouse models and show that the mutation level variance is clearly higher in the human data than it is in the mouse models at both the primary oocyte and offspring stages of inheritance. We discuss how the standard error of variance can be used in the design of experiments measuring mtDNA mutation level variance. Our results show that variance measurements based on fewer than 20 measurements are generally unreliable and ideally more than 50 measurements are required to reliably compare variances with less than a 2-fold difference.

  6. Transcriptional profiling of fibroblasts from patients with mutations in MCT8 and comparative analysis with the human brain transcriptome

    NARCIS (Netherlands)

    W.E. Visser (Wil Edward); S.M.A. Swagemakers (Sigrid); Z. Özgür (Zeliha); R. Schot (Rachel); F.W. Verheijen (Frans); W.F.J. van IJcken (Wilfred); P.J. van der Spek (Peter)

    2010-01-01

    textabstractThyroid hormone (TH) is crucial for normal brain development. TH transporters control TH homeostasis in brain as evidenced by the complex endocrine and neurological phenotype of patients with mutations in monocarboxylate transporter 8 (MCT8). We investigated the mechanisms of disease by

  7. Predictors of prophylactic bilateral salpingo-oophorectomy compared with gynecologic screening use in BRCA1/2 mutation carriers.

    NARCIS (Netherlands)

    Madalinska, J.B.; Beurden, M. van; Bleiker, E.M.A.; Valdimarsdottir, H.B.; Lubsen-Brandsma, L.; Massuger, L.F.A.G.; Mourits, M.J.E.; Gaarenstroom, K.N.; Dorst, E.B.L. van; Putten, H. van der; Boonstra, H.; Aaronson, N.K.

    2007-01-01

    PURPOSE: Women with BRCA1/2 gene mutations who have completed their childbearing are strong candidates for risk-reducing prophylactic bilateral salpingo-oophorectomy (PBSO). The aim of the current study was to identify baseline predictors of PBSO versus gynecologic screening (GS) in this group of

  8. Comparative analysis of cell killing and autosomal mutation in mouse kidney epithelium exposed to 1 GeV protons in vitro or in vivo.

    Science.gov (United States)

    Kronenberg, Amy; Gauny, Stacey; Kwoh, Ely; Grossi, Gianfranco; Dan, Cristian; Grygoryev, Dmytro; Lasarev, Michael; Turker, Mitchell S

    2013-05-01

    Human exposure to high-energy protons occurs in space flight scenarios or, where necessary, during radiotherapy for cancer or benign conditions. However, few studies have assessed the mutagenic effectiveness of high-energy protons, which may contribute to cancer risk. Mutations cause cancer and most cancer-associated mutations occur at autosomal loci. This study addresses the cytotoxic and mutagenic effects of 1 GeV protons in mouse kidney epithelium. Mutant fractions were measured for an endogenous autosomal locus (Aprt) that detects all types of mutagenic events. Results for kidneys irradiated in vivo are compared with the results for kidney cells from the same strain exposed in vitro. The results demonstrate dose-dependent cell killing in vitro and for cells explanted 3-4 months postirradiation in vivo. Incubation in vivo for longer periods (8-9 months) further attenuates proton-induced cell killing. Protons are mutagenic to cells in vitro and for in vivo irradiated kidneys. The dose-response for Aprt mutation is curvilinear after in vitro or in vivo exposure, bending upward at the higher doses. While the absolute mutant fractions are higher in vivo, the fold-increase over background is similar for both in vitro and in situ exposures. Results are also presented for a limited study on the effect of dose fractionation on the induction of Aprt mutations in kidney epithelial cells. Dose-fractionation reduces the fraction of proton-induced Aprt mutants in vitro and in vivo and also results in less cell killing. Taken together, the mutation burden in the epithelium is slightly reduced by dose-fractionation. Autosomal mutations accumulated during clinical exposure to high-energy protons may contribute to the risk of treatment-associated neoplasms, thereby highlighting the need for rigorous treatment planning to reduce the dose to normal tissues. For low dose exposures that occur during most space flight scenarios, the mutagenic effects of protons appear to be modest.

  9. Comparative Evaluation of Sloppy Molecular Beacon and Dual-Labeled Probe Melting Temperature Assays to Identify Mutations in Mycobacterium tuberculosis Resulting in Rifampin, Fluoroquinolone and Aminoglycoside Resistance

    Science.gov (United States)

    Lee, Jong Seok; Via, Laura E.; Barry, Clifton E.; Alland, David; Chakravorty, Soumitesh

    2015-01-01

    Several molecular assays to detect resistance to Rifampin, the Fluoroquinolones, and Aminoglycosides in Mycobacterium tuberculosis (M. tuberculosis) have been recently described. A systematic approach for comparing these assays in the laboratory is needed in order to determine the relative advantage of each assay and to decide which ones should be advanced to evaluation. We performed an analytic comparison of a Sloppy Molecular Beacon (SMB) melting temperature (Tm) assay and a Dual labeled probe (DLP) Tm assay. Both assays targeted the M. tuberculosis rpoB, gyrA, rrs genes and the eis promoter region. The sensitivity and specificity to detect mutations, analytic limit of detection (LOD) and the detection of heteroresistance were tested using a panel of 56 clinical DNA samples from drug resistant M. tuberculosis strains. Both SMB and DLP assays detected 29/29 (100%) samples with rpoB RRDR mutations and 3/3 (100%) samples with eis promoter mutations correctly. The SMB assay detected all 17/17 gyrA mutants and 22/22 rrs mutants, while the DLP assay detected 16/17 (94%) gyrA mutants and 12/22 (55%) rrs mutants. Both assays showed comparable LODs for detecting rpoB and eis mutations; however, the SMB assay LODs were at least two logs better for detecting wild type and mutants in gyrA and rrs targets. The SMB assay was also moderately better at detecting heteroresistance. In summary, both assays appeared to be promising methods to detect drug resistance associated mutations in M. tuberculosis; however, the relative advantage of each assay varied under each test condition. PMID:25938476

  10. Comparative Evaluation of Sloppy Molecular Beacon and Dual-Labeled Probe Melting Temperature Assays to Identify Mutations in Mycobacterium tuberculosis Resulting in Rifampin, Fluoroquinolone and Aminoglycoside Resistance.

    Directory of Open Access Journals (Sweden)

    Sandy S Roh

    Full Text Available Several molecular assays to detect resistance to Rifampin, the Fluoroquinolones, and Aminoglycosides in Mycobacterium tuberculosis (M. tuberculosis have been recently described. A systematic approach for comparing these assays in the laboratory is needed in order to determine the relative advantage of each assay and to decide which ones should be advanced to evaluation. We performed an analytic comparison of a Sloppy Molecular Beacon (SMB melting temperature (Tm assay and a Dual labeled probe (DLP Tm assay. Both assays targeted the M. tuberculosis rpoB, gyrA, rrs genes and the eis promoter region. The sensitivity and specificity to detect mutations, analytic limit of detection (LOD and the detection of heteroresistance were tested using a panel of 56 clinical DNA samples from drug resistant M. tuberculosis strains. Both SMB and DLP assays detected 29/29 (100% samples with rpoB RRDR mutations and 3/3 (100% samples with eis promoter mutations correctly. The SMB assay detected all 17/17 gyrA mutants and 22/22 rrs mutants, while the DLP assay detected 16/17 (94% gyrA mutants and 12/22 (55% rrs mutants. Both assays showed comparable LODs for detecting rpoB and eis mutations; however, the SMB assay LODs were at least two logs better for detecting wild type and mutants in gyrA and rrs targets. The SMB assay was also moderately better at detecting heteroresistance. In summary, both assays appeared to be promising methods to detect drug resistance associated mutations in M. tuberculosis; however, the relative advantage of each assay varied under each test condition.

  11. Comparative analysis of cell killing and autosomal mutation in mouse kidney epithelium exposed to 1 GeV/nucleon iron ions in vitro or in situ.

    Science.gov (United States)

    Kronenberg, Amy; Gauny, Stacey; Kwoh, Ely; Connolly, Lanelle; Dan, Cristian; Lasarev, Michael; Turker, Mitchell S

    2009-11-01

    Astronauts receive exposures to high-energy heavy ions from galactic cosmic radiation. Although high-energy heavy ions are mutagenic and carcinogenic, their mutagenic potency in epithelial cells, where most human cancers develop, is poorly understood. Mutations are a critical component of human cancer, and mutations involving autosomal loci predominate. This study addresses the cytotoxic and mutagenic effects of 1 GeV/nucleon iron ions in mouse kidney epithelium. Mutant fractions were measured for an endogenous autosomal locus (Aprt) that detects all types of mutagenic events contributing to human cancer. Results for kidneys irradiated in situ are compared with results for kidney cells from the same strain exposed in vitro. The results demonstrate dose-dependent cell killing in vitro and for cells explanted 3-4 months postirradiation in situ, but in situ exposures were less likely to result in cell death than in vitro exposures. Prolonged incubation in situ (8-9 months) further attenuated cell killing at lower doses. Iron ions were mutagenic to cells in vitro and for irradiated kidneys. No sparing was seen for mutant frequency with a long incubation period in situ. In addition, the degree of mutation induction (relative increase over background) was similar for cells exposed in vitro or in situ. We speculate that the latent effects of iron-ion exposure contribute to the maintenance of an elevated mutation burden in an epithelial tissue.

  12. A comparative evaluation of NB30, NB54 and PTC124 in translational read-through efficacy for treatment of an USH1C nonsense mutation

    Science.gov (United States)

    Goldmann, Tobias; Overlack, Nora; Möller, Fabian; Belakhov, Valery; van Wyk, Michiel; Baasov, Timor; Wolfrum, Uwe; Nagel-Wolfrum, Kerstin

    2012-01-01

    Translational read-through-inducing drugs (TRIDs) promote read-through of nonsense mutations, placing them in the spotlight of current gene-based therapeutic research. Here, we compare for the first time the relative efficacies of new-generation aminoglycosides NB30, NB54 and the chemical compound PTC124 on retinal toxicity and read-through efficacy of a nonsense mutation in the USH1C gene, which encodes the scaffold protein harmonin. This mutation causes the human Usher syndrome, the most common form of inherited deaf-blindness. We quantify read-through efficacy of the TRIDs in cell culture and show the restoration of harmonin function. We do not observe significant differences in the read-through efficacy of the TRIDs in retinal cultures; however, we show an excellent biocompatibility in retinal cultures with read-through versus toxicity evidently superior for NB54 and PTC124. In addition, in vivo administration of NB54 and PTC124 induced recovery of the full-length harmonin a1 with the same efficacy. The high biocompatibilities combined with the sustained read-through efficacies of these drugs emphasize the potential of NB54 and PTC124 in treating nonsense mutation-based retinal disorders. PMID:23027640

  13. Crossover versus Mutation: A Comparative Analysis of the Evolutionary Strategy of Genetic Algorithms Applied to Combinatorial Optimization Problems

    Directory of Open Access Journals (Sweden)

    E. Osaba

    2014-01-01

    Full Text Available Since their first formulation, genetic algorithms (GAs have been one of the most widely used techniques to solve combinatorial optimization problems. The basic structure of the GAs is known by the scientific community, and thanks to their easy application and good performance, GAs are the focus of a lot of research works annually. Although throughout history there have been many studies analyzing various concepts of GAs, in the literature there are few studies that analyze objectively the influence of using blind crossover operators for combinatorial optimization problems. For this reason, in this paper a deep study on the influence of using them is conducted. The study is based on a comparison of nine techniques applied to four well-known combinatorial optimization problems. Six of the techniques are GAs with different configurations, and the remaining three are evolutionary algorithms that focus exclusively on the mutation process. Finally, to perform a reliable comparison of these results, a statistical study of them is made, performing the normal distribution z-test.

  14. Crossover versus mutation: a comparative analysis of the evolutionary strategy of genetic algorithms applied to combinatorial optimization problems.

    Science.gov (United States)

    Osaba, E; Carballedo, R; Diaz, F; Onieva, E; de la Iglesia, I; Perallos, A

    2014-01-01

    Since their first formulation, genetic algorithms (GAs) have been one of the most widely used techniques to solve combinatorial optimization problems. The basic structure of the GAs is known by the scientific community, and thanks to their easy application and good performance, GAs are the focus of a lot of research works annually. Although throughout history there have been many studies analyzing various concepts of GAs, in the literature there are few studies that analyze objectively the influence of using blind crossover operators for combinatorial optimization problems. For this reason, in this paper a deep study on the influence of using them is conducted. The study is based on a comparison of nine techniques applied to four well-known combinatorial optimization problems. Six of the techniques are GAs with different configurations, and the remaining three are evolutionary algorithms that focus exclusively on the mutation process. Finally, to perform a reliable comparison of these results, a statistical study of them is made, performing the normal distribution z-test.

  15. Crossover versus Mutation: A Comparative Analysis of the Evolutionary Strategy of Genetic Algorithms Applied to Combinatorial Optimization Problems

    Science.gov (United States)

    Osaba, E.; Carballedo, R.; Diaz, F.; Onieva, E.; de la Iglesia, I.; Perallos, A.

    2014-01-01

    Since their first formulation, genetic algorithms (GAs) have been one of the most widely used techniques to solve combinatorial optimization problems. The basic structure of the GAs is known by the scientific community, and thanks to their easy application and good performance, GAs are the focus of a lot of research works annually. Although throughout history there have been many studies analyzing various concepts of GAs, in the literature there are few studies that analyze objectively the influence of using blind crossover operators for combinatorial optimization problems. For this reason, in this paper a deep study on the influence of using them is conducted. The study is based on a comparison of nine techniques applied to four well-known combinatorial optimization problems. Six of the techniques are GAs with different configurations, and the remaining three are evolutionary algorithms that focus exclusively on the mutation process. Finally, to perform a reliable comparison of these results, a statistical study of them is made, performing the normal distribution z-test. PMID:25165731

  16. Comparative analysis of meiotic progression in female mice bearing mutations in genes of the DNA mismatch repair pathway.

    Science.gov (United States)

    Kan, Rui; Sun, Xianfei; Kolas, Nadine K; Avdievich, Elena; Kneitz, Burkhard; Edelmann, Winfried; Cohen, Paula E

    2008-03-01

    The DNA mismatch repair (MMR) family functions in a variety of contexts to preserve genome integrity in most eukaryotes. In particular, members of the MMR family are involved in the process of meiotic recombination in germ cells. MMR gene mutations in mice result in meiotic disruption during prophase I, but the extent of this disruption often differs between male and female meiocytes. To address the role of MMR proteins specifically in female meiosis, we explored the progression of oocytes through prophase I and the meiotic divisions in mice harboring deletions in members of the MMR pathway (Mlh1, Mlh3, Exo1, and an ATPase-deficient variant of Mlh1, Mlh1(G67R)). The colocalization of MLH1 and MLH3, key proteins involved in stabilization of nascent crossovers, was dependent on intact heterodimer formation and was highly correlated with the ability of oocytes to progress through to metaphase II. The exception was Exo1(-/-) oocytes, in which normal MLH1/MLH3 localization was observed followed by failure to proceed to metaphase II. All mutant oocytes were able to resume meiosis after dictyate arrest, but they showed a dramatic decline in chiasmata (to less than 25% of normal), accompanied by varied progression through metaphase I. Taken together, these results demonstrate that MMR function is required for the formation and stabilization of crossovers in mammalian oocytes and that, in the absence of a functional MMR system, the failure to maintain chiasmata results in a reduced ability to proceed normally through the first and second meiotic divisions, despite near-normal levels of meiotic resumption after dictyate arrest.

  17. Development of severe skeletal defects in induced SHP-2-deficient adult mice: a model of skeletal malformation in humans with SHP-2 mutations

    Directory of Open Access Journals (Sweden)

    Timothy J. Bauler

    2011-03-01

    SHP-2 (encoded by PTPN11 is a ubiquitously expressed protein tyrosine phosphatase required for signal transduction by multiple different cell surface receptors. Humans with germline SHP-2 mutations develop Noonan syndrome or LEOPARD syndrome, which are characterized by cardiovascular, neurological and skeletal abnormalities. To study how SHP-2 regulates tissue homeostasis in normal adults, we used a conditional SHP-2 mouse mutant in which loss of expression of SHP-2 was induced in multiple tissues in response to drug administration. Induced deletion of SHP-2 resulted in impaired hematopoiesis, weight loss and lethality. Most strikingly, induced SHP-2-deficient mice developed severe skeletal abnormalities, including kyphoses and scolioses of the spine. Skeletal malformations were associated with alterations in cartilage and a marked increase in trabecular bone mass. Osteoclasts were essentially absent from the bones of SHP-2-deficient mice, thus accounting for the osteopetrotic phenotype. Studies in vitro revealed that osteoclastogenesis that was stimulated by macrophage colony-stimulating factor (M-CSF and receptor activator of nuclear factor kappa B ligand (RANKL was defective in SHP-2-deficient mice. At least in part, this was explained by a requirement for SHP-2 in M-CSF-induced activation of the pro-survival protein kinase AKT in hematopoietic precursor cells. These findings illustrate an essential role for SHP-2 in skeletal growth and remodeling in adults, and reveal some of the cellular and molecular mechanisms involved. The model is predicted to be of further use in understanding how SHP-2 regulates skeletal morphogenesis, which could lead to the development of novel therapies for the treatment of skeletal malformations in human patients with SHP-2 mutations.

  18. An isothermal primer extension method for whole genome amplification of fresh and degraded DNA: applications in comparative genomic hybridization, genotyping and mutation screening.

    Science.gov (United States)

    Lee, Cheryl I P; Leong, Siew Hong; Png, Adrian E H; Choo, Keng Wah; Syn, Christopher; Lim, Dennis T H; Law, Hai Yang; Kon, Oi Lian

    2006-01-01

    We describe a protocol that uses a bioinformatically optimized primer in an isothermal whole genome amplification (WGA) reaction. Overnight incubation at 37 degrees C efficiently generates several hundred- to several thousand-fold increases in input DNA. The amplified product retains reasonably faithful quantitative representation of unamplified whole genomic DNA (gDNA). We provide protocols for applying this isothermal primer extension WGA protocol in three different techniques of genomic analysis: comparative genomic hybridization (CGH), genotyping at simple tandem repeat (STR) loci and screening for single base mutations in a common monogenic disorder, beta-thalassemia. gDNA extracted from formalin-fixed paraffin-embedded (FFPE) tissues can also be amplified with this protocol.

  19. Three kinds of mutation

    CERN Document Server

    Buan, Aslak Bakke; Thomas, Hugh

    2010-01-01

    For a finite dimensional hereditary algebra, we consider: exceptional sequences in the category of finite dimensional modules, silting objects in the bounded derived category, and m-cluster tilting objects in the m-cluster category. There are mutation operations on both the set of m-cluster tilting objects and the set of exceptional sequences. It is also possible to define a mutation operation for silting objects. We compare these three different notions of mutation.

  20. Which screening strategy should be offered to women with BRCA1 or BRCA2 mutations? A simulation of comparative cost-effectiveness.

    Science.gov (United States)

    de Bock, G H; Vermeulen, K M; Jansen, L; Oosterwijk, J C; Siesling, S; Dorrius, M D; Feenstra, T; Houssami, N; Greuter, M J W

    2013-04-30

    There is no consensus on the most effective strategy (mammography or magnetic resonance imaging (MRI)) for screening women with BRCA1 or BRCA2 mutations. The effectiveness and cost-effectiveness of the Dutch, UK and US screening strategies, which involve mammography and MRI at different ages and intervals were evaluated in high-risk women with BRCA1 or BRCA2 mutations. Into a validated simulation screening model, outcomes and cost parameters were integrated from published and cancer registry data. Main outcomes were life-years gained and incremental cost-effectiveness ratios. The simulation was situated in the Netherlands as well as in the United Kingdom, comparing the Dutch, UK and US strategies with the population screening as a reference. A discount rate of 3% was applied to both costs and health benefits. In terms of life-years gained, the strategies from least to most cost-effective were the UK, Dutch and US screening strategy, respectively. However, the differences were small. Applying the US strategy in the Netherlands, the costs were €43 800 and 68 800 for an additional life-year gained for BRCA1 and BRCA2, respectively. At a threshold of €20 000 per life-year gained, implementing the US strategy in the Netherlands has a very low probability of being cost-effective. Stepping back to the less-effective UK strategy would save relatively little in costs and results in life-years lost. When implementing the screening strategies in the United Kingdom, the Dutch, as well as the US screening strategy have a high probability of being cost-effective. From a cost-effectiveness perspective, the Dutch screening strategy is preferred for screening high-risk women in the Netherlands as well as in the United Kingdom.

  1. Cystic fibrosis transmembrane conductance regulator protein (CFTR) expression in the developing human brain: comparative immunohistochemical study between patients with normal and mutated CFTR.

    Science.gov (United States)

    Marcorelles, Pascale; Friocourt, Gaëlle; Uguen, Arnaud; Ledé, Françoise; Férec, Claude; Laquerrière, Annie

    2014-11-01

    Cystic Fibrosis Transmembrane conductance Regulator (CFTR) protein has recently been shown to be expressed in the human adult central nervous system (CNS). As CFTR expression has also been documented during embryonic development in several organs, such as the respiratory tract, the intestine and the male reproductive system, suggesting a possible role during development we decided to investigate the expression of CFTR in the human developing CNS. In addition, as some, although rare, neurological symptoms have been reported in patients with CF, we compared the expression of normal and mutated CFTR at several fetal stages. Immunohistochemistry was performed on brain and spinal cord samples of foetuses between 13 and 40 weeks of gestation and compared with five patients with cystic fibrosis (CF) of similar ages. We showed in this study that CFTR is only expressed in neurons and has an early and widespread distribution during development. Although we did not observe any cerebral abnormality in patients with CF, we observed a slight delay in the maturation of several brain structures. We also observed different expression and localization of CFTR depending on the brain structure or the cell maturation stage. Our findings, along with a literature review on the neurological phenotypes of patients with CF, suggest that this gene may play previously unsuspected roles in neuronal maturation or function.

  2. Comparative study of mutation spectrums of MT-RNR1 m.1555A>G,GJB2, and SLC26A4 between familial and sporadic patients with nonsyndromic sensorineural hearing loss in Chinese Han

    Institute of Scientific and Technical Information of China (English)

    Li Qian; Ji Yubin; Han Bing; Zong Liang; Lan Lan; Zhao Yali; Wang Hongyang

    2014-01-01

    Background The mutation frequencies of three common deafness genes (MT-RNR1 m.1555A>G,GJB2,and SLC26A4) among patients with nonsyndromic sensorineural hearing loss (NSHL) were different in previous studies.Inconsistent selection criteria for recruiting patients could have led to differences in estimating the frequencies of genetic mutations thus resulting in different mutation frequencies among these studies.The aim of this study was to reveal the differences in the mutation spectrums of the three common genes between familial and sporadic Chinese Han patients.Methods Totally,301 familial probands and 703 sporadic patients with NSHL were enrolled in this study.Three genes,MT-RNR1 m.1555A>G,GJB2,and SLC26A4,were screened for mutation in our study cohort.A X2 test was performed to compare the mutation frequencies between the two groups.Results The study showed that the disease-causing mutation frequencies of MT-RNR1 m.1555A>G,GJB2,and SLC26A4 were 12.29%,14.62%,and 18.27% in familial probands and 3.56%,18.63%,and 18.92% in sporadic patients,respectively.The mutation frequency of MT-RNR1 m.1555A>G in familial probands was significantly higher than in sporadic patients (X2 test,P=0.000),while there were no significant differences in the mutation frequencies of GJB2 and SLC26A4 between the familial and sporadic groups (X2 test,P >0.05).Conclusions It is necessary to reveal the differences in gene mutation frequencies between patients of different sources or characteristics by comparative studies in order to avoid selection bias.The mutations of GJB2,SLC26A4,and MTRNR1 m.1555A>G are the most important etiological factors in Chinese Han patients,among which SLC26A4 might be the most frequent.

  3. Identification of an IMPDH1 mutation in autosomal dominant retinitis pigmentosa (RP10) revealed following comparative microarray analysis of transcripts derived from retinas of wild-type and Rho(-/-) mice

    DEFF Research Database (Denmark)

    Kennan, Avril; Aherne, Aileen; Palfi, Arpad

    2002-01-01

    Comparative analysis of the transcriptional profiles of approximately 6000 genes in the retinas of wild-type mice with those carrying a targeted disruption of the rhodopsin gene was undertaken by microarray analysis. This revealed a series of transcripts, of which some were derived from genes known...... is not present in healthy, unrelated individuals of European origin. These data provide strong evidence that mutations within the IMPDH1 gene cause adRP, and validate approaches to mutation detection involving comparative analysis of global transcription profiles in normal and degenerating retinal tissues. Other...

  4. Determination of the catalytic activity of LEOPARD syndrome-associated SHP2 mutants toward parafibromin, a bona fide SHP2 substrate involved in Wnt signaling

    Energy Technology Data Exchange (ETDEWEB)

    Noda, Saori [Division of Microbiology, Graduate School of Medicine, The University of Tokyo, Tokyo (Japan); Department of Biochemistry, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba (Japan); Takahashi, Atsushi; Hayashi, Takeru [Division of Microbiology, Graduate School of Medicine, The University of Tokyo, Tokyo (Japan); Tanuma, Sei-ichi [Department of Biochemistry, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba (Japan); Hatakeyama, Masanori, E-mail: mhata@m.u-tokyo.ac.jp [Division of Microbiology, Graduate School of Medicine, The University of Tokyo, Tokyo (Japan)

    2016-01-22

    SHP2, encoded by the PTPN11 gene, is a protein tyrosine phosphatase that plays a key role in the proliferation of cells via RAS-ERK activation. SHP2 also promotes Wnt signaling by dephosphorylating parafibromin. Germline missense mutations of PTPN11 are found in more than half of patients with Noonan syndrome (NS) and LEOPARD syndrome (LS), both of which are congenital developmental disorders with multiple common symptoms. However, whereas NS-associated PTPN11 mutations give rise to gain-of-function SHP2 mutants, LS-associated SHP2 mutants are reportedly loss-of-function mutants. To determine the phosphatase activity of LS-associated SHP2 more appropriately, we performed an in vitro phosphatase assay using tyrosine-phosphorylated parafibromin, a biologically relevant substrate of SHP2 and the positive regulator of Wnt signaling that is activated through SHP2-mediated dephosphorylation. We found that LS-associated SHP2 mutants (Y279C, T468M, Q506P, and Q510E) exhibited a substantially reduced phosphatase activity toward parafibromin when compared with wild-type SHP2. Furthermore, each of the LS-associated mutants displayed a differential degree of decrease in phosphatase activity. Deviation of the SHP2 catalytic activity from a certain range, either too strong or too weak, may therefore lead to similar clinical outcomes in NS and LS, possibly through an imbalanced Wnt signal caused by inadequate dephosphorylation of parafibromin. - Highlights: • LS-associated SHP2 mutants dephosphorylate parafibromin on Y290, Y293, and Y315. • LS-associated SHP2 mutants display a reduced tyrosine phosphatase activity. • LS-specific SHP2-Y279C is catalytically less active than LS-specific SHP2-T468M. • NS/LS-associated SHP2-Q506P has both hyper- and hypomorphic enzymatic properties.

  5. Comparative analysis of BRAF, NRAS and c-KIT mutation status between tumor tissues and autologous tumor cell-lines of stage III/IV melanoma.

    Science.gov (United States)

    Knol, Anne-Chantal; Pandolfino, Marie-Christine; Vallée, Audrey; Nguyen, Frédérique; Lella, Virginie; Khammari, Amir; Denis, Marc; Puaux, Anne-Laure; Dréno, Brigitte

    2015-01-01

    In the last decade, advances in molecular biology have provided evidence of the genotypic heterogeneity of melanoma. We analysed BRAF, NRAS and c-KIT alterations in tissue samples from 63 stage III/IV melanoma patients and autologous cell-lines, using either allele-specific or quantitative PCR. The expression of BRAF V600E protein was also investigated using an anti-BRAF antibody in the same tissue samples. 81% of FFPE samples and tumor cell-lines harboured a genetic alteration in either BRAF (54%) or NRAS (27%) oncogenes. There was a strong concordance (100%) between tissue samples and tumor cell-lines. The BRAF V600E mutant-specific antibody showed high sensitivity (96%) and specificity (100%) for detecting the presence of a BRAF V600E mutation. The correlation was of 98% between PCR and immunohistochemistry results for BRAF mutation. These results suggest that BRAF and NRAS mutation status of tumor cells is not affected by culture conditions.

  6. Mucopolysaccharidosis IVA mutations in Chinese patients: 16 novel mutations.

    Science.gov (United States)

    Wang, Zheng; Zhang, Weimin; Wang, Yun; Meng, Yan; Su, Liang; Shi, Huiping; Huang, Shangzhi

    2010-08-01

    Mucopolysaccharidosis IVA (MPS IVA; Morquio A syndrome) is a lysosomal storage disease caused by deficiency of N-acetylgalactosamine-6-sulfatase (GALNS) and transmitted as an autosomal recessive trait. This is the first systematic mutation screen in Chinese MPS IVA patients. Mutation detections in 24 unrelated Chinese MPS IVA patients were performed by PCR and direct sequencing of exons or the mRNA of GALNS. A total of 42 mutant alleles were identified, belonging to 27 different mutations. Out of the 27 mutations, 16 were novel, including 2 splicing mutations (c.567-1G>T and c.634-1G>A), 2 nonsense mutations (p.W325X and p.Q422X) and 12 missense mutations (p.T88I, p.H142R, p.P163H, p.G168L, p.H236D, p.N289S, p.T312A, p.G316V, p.A324E, p.L366P, p.Q422K and p.F452L). p.G340D was found to be a common mutation in the Chinese MPS IVA patients, accounting for 16.7% of the total number of mutant alleles. The results show that the mutations in Chinese MPS IVA patients are also family specific but have a different mutation spectrum as compared to those of other populations.

  7. Comparative in vitro and in silico analyses of variants in splicing regions of BRCA1 and BRCA2 genes and characterization of novel pathogenic mutations.

    Directory of Open Access Journals (Sweden)

    Mara Colombo

    Full Text Available Several unclassified variants (UVs have been identified in splicing regions of disease-associated genes and their characterization as pathogenic mutations or benign polymorphisms is crucial for the understanding of their role in disease development. In this study, 24 UVs located at BRCA1 and BRCA2 splice sites were characterized by transcripts analysis. These results were used to evaluate the ability of nine bioinformatics programs in predicting genetic variants causing aberrant splicing (spliceogenic variants and the nature of aberrant transcripts. Eleven variants in BRCA1 and 8 in BRCA2, including 8 not previously characterized at transcript level, were ascertained to affect mRNA splicing. Of these, 16 led to the synthesis of aberrant transcripts containing premature termination codons (PTCs, 2 to the up-regulation of naturally occurring alternative transcripts containing PTCs, and one to an in-frame deletion within the region coding for the DNA binding domain of BRCA2, causing the loss of the ability to bind the partner protein DSS1 and ssDNA. For each computational program, we evaluated the rate of non-informative analyses, i.e. those that did not recognize the natural splice sites in the wild-type sequence, and the rate of false positive predictions, i.e., variants incorrectly classified as spliceogenic, as a measure of their specificity, under conditions setting sensitivity of predictions to 100%. The programs that performed better were Human Splicing Finder and Automated Splice Site Analyses, both exhibiting 100% informativeness and specificity. For 10 mutations the activation of cryptic splice sites was observed, but we were unable to derive simple criteria to select, among the different cryptic sites predicted by the bioinformatics analyses, those actually used. Consistent with previous reports, our study provides evidences that in silico tools can be used for selecting splice site variants for in vitro analyses. However, the latter

  8. [Comparing performance of "TB-BIOCHIP", "Xpert MTB/RIF" and "genotype MTBDRplus" assays for fast identification of mutations in the Mycobacterium tuberculosis complex in sputum from TB patients].

    Science.gov (United States)

    Nosova, E Iu; Krasnova, M A; Galkina, K Iu; Makarova, M V; Litvinov, V I; Moroz, A M

    2013-01-01

    The frequency of mutations causing drug resistance in MTB isolates were studied in the respiratory material obtained from TB-patients in the Moscow Region. In izoniazid-resistant isolates, the most prevalent mutation was found to be the Ser315Thr substitution in the katG gene (15.8%) whereas the most frequent mutations in multidrug-resistant isolates were Ser531Leu and Ser315Thr in the rpoB and katG genes (26.3%), or a combination of these two substitutions with a T15 mutation in the inhA gene (5.3%). We compared performance of three molecular assays--"TB-BIOCHIP" ("BIOCHIP-IMB", Ltd, Russia), Xpert MTB/RIF ("Cepheid", USA) and GenoType MTBDRplus ("Hain Life-science", Germany), with the efficiency of luminescent microscopy, and phenotypic drug-suscepibility testing in an automated system BACTEC MGIT 960 (Becton, Disckinson and Company, USA). Xpert MTB/RIF, TB-BIOCHIP and GenoType MTBDRplus detected MTB in sputum in 92, 78 and 49% of all culture-positive cases, respectively. The agreement between standard cultural data and molecular DST results for Xpert MTB/RIF (resistance towards rifampicin), for TB-BIOCHIP and GenoType MTBDRplus (resistance towards rifampicin and izoniazid) amounted to 100, 97 and 100% respectively. Summing up, Xpert MTB/RIF was concluded to be the most efficient assay for primary detection of MTB, whereas the TB-BIOCHIP was shown to be the only molecular assay sensitive enough for simultaneous detection of MTB DNA and for revealing multidrug resistance in sputum (i.e. resistance to both first-line anti-TB drugs, rifampicin and izoniazid).

  9. Comparative assessment on the prevalence of mutations in the Plasmodium falciparum drug-resistant genes in two different ecotypes of Odisha state, India.

    Science.gov (United States)

    Kar, Narayani Prasad; Chauhan, Kshipra; Nanda, Nutan; Kumar, Ashwani; Carlton, Jane M; Das, Aparup

    2016-07-01

    Considering malaria as a local and focal disease, epidemiological understanding of different ecotypes of malaria can help in devising novel control measures. One of the major hurdles in malaria control lies on the evolution and dispersal of the drug-resistant malaria parasite, Plasmodium falciparum. We herewith present data on genetic variation at the Single Nucleotide Polymorphism (SNP) level in four different genes of P. falciparum (Pfcrt, Pfmdr1, Pfdhfr, and Pfdhps) that confer resistance to different antimalarials in two different eco-epidemiological settings, i.e. Hilly-Forest (HF) and Riverine-Plain (RP), in a high malaria endemic district of Odisha state, India. Greater frequency of antimalarial resistance conferring SNPs and haplotypes was observed in all four genes in P. falciparum, and Pfdhps was the most variable gene among the four. No significant genetic differentiation could be observed in isolates from HF and RP ecotypes. Twelve novel, hitherto unreported nucleotide mutations could be observed in the Pfmdr1 and Pfdhps genes. While the Pfdhps gene presented highest haplotype diversity, the Pfcrt gene displayed the highest nucleotide diversity. When the data on all the four genes were complied, the isolates from HF ecotype were found to harbour higher average nucleotide diversity than those coming from RP ecotype. High and positive Tajima's D values were obtained for the Pfcrt and Pfdhfr genes in isolates from both the HF and RP ecotypes, with statistically significant deviation from neutrality in the RP ecotype. Different patterns of Linkage Disequilibrium (LD) among SNPs located in different drug-resistant genes were found in the isolates collected from HF and RP ecotypes. Whereas in the HF ecotype, SNPs in the Pfmdr1 and Pfdhfr were significantly associated, in the RP ecotype, SNPs located in Pfcrt were associated with Pfmdr1, Pfdhfr and Pfdhps. These findings provide a baseline understanding on how different micro eco-epidemiological settings

  10. CF Mutation Panel

    Science.gov (United States)

    ... Testing; Cystic Fibrosis Transmembrane Conductance Regulator Mutation Analysis; CFTR Mutation Analysis Formal name: Cystic Fibrosis Gene Mutation ... an elevated immunoreactive trypsinogen (IRT) or positive sweat chloride test , to confirm the diagnosis of cystic fibrosis. ...

  11. Comparative study of mutation detection method in glioma epidermal growth factor receptor gene%胶质瘤表皮生长因子受体基因突变检测方法的对比研究

    Institute of Scientific and Technical Information of China (English)

    王敏; 李兴涛

    2013-01-01

    Objective To analyse mutation detection effect of the ordinary polymerase chain reaction (PCR) method with direct sequencing method and real-time polymerase chain reaction-high resolution melting curve analysis techniques(qPCR-HRM ) curve analysis technology on the detection of glioma epidermal growth factor receptor (EG-FR) gene .Methods Ordinary PCR with sequencing method and qPCR-HRM curve analysis technical were used to detect EGFR gene mutation type in patients with glioma ,the chi test was used for results comparison .Results The consistency of detection results was up to 90 .91% between ordinary PCR with direct sequencing method and qPCR-HRM curve analysis technology on tumor tissue in patients with glioma EGFR mutation ,the difference was statisti-cally significant (P>0 .05) .Conclusion Compare to ordinary PCR with direct sequencing method ,the operation of qPCR-HRM curve analysis technical might more simple ,the experimental time might shorter ,the risk of cross con-tamination might less ,and its test results could identify the samples of genotype .%  目的分析普通聚合酶链式反应(PCR)联合直接测序法与实时聚合酶链式反应-高分辨率融解(qPCR-HRM )曲线分析技术对胶质瘤表皮生长因子受体(EGFR)基因突变的检测效果。方法用普通 PCR联合直接测序法与qPCR-HRM 曲线分析技术检测胶质瘤患者 EGFR 基因突变类型,检测结果比较采用χ2检验。结果普通PCR联合直接测序法与qPCR-HRM曲线分析技术对胶质瘤患者肿瘤组织EGFR突变的检测结果一致性较高,达90.91%,两者间差异无统计学意义(P>0.05)。结论qPCR-HRM 曲线分析技术操作较普通PCR联合直接测序法简便,实验时间较短,降低了交叉污染的风险,通过 HRM 曲线分析检测结果可以实现对样品基因型的判定。

  12. Disease: H01018 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available single proband together with linkage analysis identifies a Mendelian disease gene. PLoS Genet 6:e1000991 (2010) ... ...matosis, but not Ollier disease or Maffucci syndrome. PLoS Genet 7:e1002050 (2011) PMID:6602353 (description...kewich HP, Kasser JR, Seidman JG, Kurek KC, Warman ML Loss-of-function mutations in PTPN11 cause metachondro

  13. A comprehensive comparative analysis of the histomorphological features of ALK-rearranged lung adenocarcinoma based on driver oncogene mutations: frequent expression of epithelial-mesenchymal transition markers than other genotype.

    Directory of Open Access Journals (Sweden)

    Hyojin Kim

    Full Text Available Molecular classification of lung cancer correlates well with histomorphological features. However, specific histomorphological features that differentiate anaplastic lymphoma kinase (ALK-rearranged tumors from ALK-negative tumors have not been fully evaluated. Eighty ALK-rearranged and 213 ALK-negative (91 epidermal growth factor receptor-mutated; 29 K-ras-mutated; 93 triple-negative resected lung adenocarcinomas were analyzed for several histomorphological parameters and histological subtype. ALK-rearranged tumors were associated with younger age at presentation, frequent nodal metastasis, and higher stage of disease at diagnosis. ALK-rearranged tumors were more likely to show a solid predominant pattern than ALK-negative tumors (43.8%; 35/80; p<0.001. Unlike ALK-negative tumors, a lepidic predominant pattern was not observed in ALK-rearranged tumors (p<0.001. In multivariate analysis, the most significant morphological features that distinguished ALK-rearranged tumors from ALK-negative tumors were cribriform formation (odds ratio [OR], 3.253; p = 0.028, presence of mucin-containing cells (OR, 4.899; p = 0.008, close relationship to adjacent bronchioles (OR, 5.361; p = 0.001, presence of psammoma bodies (OR, 4.026; p = 0.002, and a solid predominant pattern (OR, 13.685; p = 0.023. ALK-rearranged tumors exhibited invasive histomorphological features, aggressive behavior and frequent expression of epithelial-mesenchymal transition markers (loss of E-cadherin and expression of vimentin compared with other genotype (p = 0.015. Spatial proximity between bronchus and ALK-rearranged tumors and frequent solid histologic subtype with p63 expression may cause diagnostic difficulties to differentiate squamous cell carcinoma in the small biopsy, whereas p40 was rarely expressed in ALK-rearranged adenocarcinoma. Knowledge of these features may improve the diagnostic accuracy and lead to a better understanding of the characteristic behavior of ALK

  14. HNPCC: Six new pathogenic mutations

    Directory of Open Access Journals (Sweden)

    Epplen Joerg T

    2004-06-01

    Full Text Available Abstract Background Hereditary non-polyposis colorectal cancer (HNPCC is an autosomal dominant disease with a high risk for colorectal and endometrial cancer caused by germline mutations in DNA mismatch-repair genes (MMR. HNPCC accounts for approximately 2 to 5% of all colorectal cancers. Here we present 6 novel mutations in the DNA mismatch-repair genes MLH1, MSH2 and MSH6. Methods Patients with clinical diagnosis of HNPCC were counselled. Tumor specimen were analysed for microsatellite instability and immunohistochemistry for MLH1, MSH2 and MSH6 protein was performed. If one of these proteins was not detectable in the tumor mutation analysis of the corresponding gene was carried out. Results We identified 6 frameshift mutations (2 in MLH1, 3 in MSH2, 1 in MSH6 resulting in a premature stop: two mutations in MLH1 (c.2198_2199insAACA [p.N733fsX745], c.2076_2077delTG [p.G693fsX702], three mutations in MSH2 (c.810_811delGT [p.C271fsX282], c.763_766delAGTGinsTT [p.F255fsX282], c.873_876delGACT [p.L292fsX298] and one mutation in MSH6 (c.1421_1422dupTG [p.C475fsX480]. All six tumors tested for microsatellite instability showed high levels of microsatellite instability (MSI-H. Conclusions HNPCC in families with MSH6 germline mutations may show an age of onset that is comparable to this of patients with MLH1 and MSH2 mutations.

  15. Androgen receptor gene mutation, rearrangement, polymorphism.

    Science.gov (United States)

    Eisermann, Kurtis; Wang, Dan; Jing, Yifeng; Pascal, Laura E; Wang, Zhou

    2013-09-01

    Genetic aberrations of the androgen receptor (AR) caused by mutations, rearrangements, and polymorphisms result in a mutant receptor that has varied functions compared to wild type AR. To date, over 1,000 mutations have been reported in the AR with most of these being associated with androgen insensitivity syndrome (AIS). While mutations of AR associated with prostate cancer occur less often in early stage localized disease, mutations in castration-resistant prostate cancer (CRPC) patients treated with anti-androgens occur more frequently with 10-30% of these patients having some form of mutation in the AR. Resistance to anti-androgen therapy usually results from gain-of-function mutations in the LBD such as is seen with bicalutamide and more recently with enzalutamide (MDV3100). Thus, it is crucial to investigate these new AR mutations arising from drug resistance to anti-androgens and other small molecule pharmacological agents.

  16. Prediction of Plasmodium falciparum resistance to sulfadoxine/pyrimethamine in vivo by mutations in the dihydrofolate reductase and dihydropteroate synthetase genes: a comparative study between sites of differing endemicity

    DEFF Research Database (Denmark)

    Alifrangis, Michael; Enosse, Sonja; Khalil, Insaf F;

    2003-01-01

    Plasmodium falciparum resistance to sulfadoxine/pyrimethamine (S/P) is due to mutations in the dihydrofolate reductase (dhfr) and dihydropteroate synthetase (dhfr) genes. Large-scale screening of the prevalence of these mutations could facilitate the surveillance of the level of S/P resistance...... marker seems debatable. The differences may reflect variation in the duration and magnitude of S/P usage (or other antifolate drugs) between the sites. Thus, triple dhfr mutations may prove suitable only as a general guideline for detecting emerging S/P resistance in areas where S/P has been introduced...... in vivo. The prevalence of mutations in dhfr and dhps in relation to S/P efficacy was studied in four sites of differing endemicity in Sudan, Mozambique, and Tanzania. The sites were organized in order of increasing resistance and a significant increase in the prevalence of triple mutations in codons c51...

  17. Structural Effects of L16Q, S20G, and L16Q-S20G Mutations on hlAPP: A Comparative Molecular Dynamics Study%Structural Effects of L16Q, S20G, and L16Q-S20G Mutations on hlAPP: A Comparative Molecular Dynamics Study

    Institute of Scientific and Technical Information of China (English)

    Wang, Mian; Yang, Jipeng; Wang, Jianyi; Wang, Xiaojuan

    2012-01-01

    The conformation change picture of human islet amyloid polypeptide (hlAPP) is outlined using molecular dynamics simulation, and the structural influences of L16Q, S20G, and L16Q-S20G mutations on the conformation of hlAPP are analyzed. Particularly, the conformational changes of the amyloidogenic-related regions of residues 15-- 17 and 20--29 are emphasized. Our studies find that, for WT hlAPP, residues 15--17 always maintain a stable a-helix structure, residues 20--25 structurally fluctuate between turn and 5-helix, and residues 26--29 mainly adopt coil and bend structures. The hydrogen bonds between the polar groups of hlAPP, long-rang van der Waals forces between the residues, and hydrophobic interactions between the residues of hlAPP are important driving forces to maintain the secondary structure of hlAPP. The replacement of leucine 16 by glutamine stabilizes the helix structure of residues 15--17 and 20--23 of hlAPP monomer, and the structure of residues 24--29 fluctuates be- tween helix and turn. The relatively stable helix structures of residues 15--17 and 20--29 are supposed to be beneficial for L16Q hlAPP to resist the aggregation as observed in the experiment. The substitution of serine20 by glycinc drives residues 15--17 and 20--29 of hlAPP to transform from helix structure to β-strands or coil structures with higher extension and flexibility, which may promote the aggregation of hlAPP as the experiments reported. These results are significant to understand the aggregation mechanism of hlAPP monomer into the dimer, trimer, oligomers and fibrils associated with the type 2 diabetes at the atomic level.

  18. Emerging patterns of somatic mutations in cancer

    OpenAIRE

    Watson, Ian R.; Takahashi, Koichi; Futreal, P. Andrew; Chin, Lynda

    2013-01-01

    The advance in technological tools for massively parallel, high-throughput sequencing of DNA has enabled the comprehensive characterization of somatic mutations in large number of tumor samples. Here, we review recent cancer genomic studies that have assembled emerging views of the landscapes of somatic mutations through deep sequencing analyses of the coding exomes and whole genomes in various cancer types. We discuss the comparative genomics of different cancers, including mutation rates, s...

  19. Transgenic Animal Mutation Assays

    Institute of Scientific and Technical Information of China (English)

    Tao Chen; Ph.D.D.A.B.T.

    2005-01-01

    @@ The novel transgenic mouse and rat mutation assays have provided a tool for analyzing in vivo mutation in any tissue, thus permitting the direct comparison of cancer incidence with mutant frequency.

  20. Aberrant neuronal activity-induced signaling and gene expression in a mouse model of RASopathy

    Science.gov (United States)

    Nakhaei-Rad, Saeideh; Montenegro-Venegas, Carolina; Pina-Fernández, Eneko; Marini, Claudia; Santos, Monica; Ahmadian, Mohammad R.; Stork, Oliver; Zenker, Martin

    2017-01-01

    Noonan syndrome (NS) is characterized by reduced growth, craniofacial abnormalities, congenital heart defects, and variable cognitive deficits. NS belongs to the RASopathies, genetic conditions linked to mutations in components and regulators of the Ras signaling pathway. Approximately 50% of NS cases are caused by mutations in PTPN11. However, the molecular mechanisms underlying cognitive impairments in NS patients are still poorly understood. Here, we report the generation and characterization of a new conditional mouse strain that expresses the overactive Ptpn11D61Y allele only in the forebrain. Unlike mice with a global expression of this mutation, this strain is viable and without severe systemic phenotype, but shows lower exploratory activity and reduced memory specificity, which is in line with a causal role of disturbed neuronal Ptpn11 signaling in the development of NS-linked cognitive deficits. To explore the underlying mechanisms we investigated the neuronal activity-regulated Ras signaling in brains and neuronal cultures derived from this model. We observed an altered surface expression and trafficking of synaptic glutamate receptors, which are crucial for hippocampal neuronal plasticity. Furthermore, we show that the neuronal activity-induced ERK signaling, as well as the consecutive regulation of gene expression are strongly perturbed. Microarray-based hippocampal gene expression profiling revealed profound differences in the basal state and upon stimulation of neuronal activity. The neuronal activity-dependent gene regulation was strongly attenuated in Ptpn11D61Y neurons. In silico analysis of functional networks revealed changes in the cellular signaling beyond the dysregulation of Ras/MAPK signaling that is nearly exclusively discussed in the context of NS at present. Importantly, changes in PI3K/AKT/mTOR and JAK/STAT signaling were experimentally confirmed. In summary, this study uncovers aberrant neuronal activity-induced signaling and regulation

  1. Novel PORCN mutations in focal dermal hypoplasia.

    Science.gov (United States)

    Froyen, G; Govaerts, K; Van Esch, H; Verbeeck, J; Tuomi, M-L; Heikkilä, H; Torniainen, S; Devriendt, K; Fryns, J-P; Marynen, P; Järvelä, I; Ala-Mello, S

    2009-12-01

    Focal dermal hypoplasia (FDH), Goltz or Goltz-Gorlin syndrome, is an X-linked dominant multisystem disorder characterized primarily by involvement of the skin, skeletal system and eyes. We screened for mutations in the PORCN gene in eight patients of Belgian and Finnish origin with firm clinical suspicion of FDH. First, we performed quantitative PCR (qPCR) analysis to define the copy number at this locus. Next, we sequenced the coding regions and flanking intronic sequences of the PORCN gene. Three de novo mutations were identified in our patients with FDH: a 150-kb deletion removing six genes including PORCN, as defined by qPCR and X-array-CGH, and two heterozygous missense mutations; c.992T>G (p.L331R) in exon 11 and c.1094G>A (p.R365Q) in exon 13 of the gene. Both point mutations changed highly conserved amino acids and were not found in 300 control X chromosomes. The three patients in whom mutations were identified all present with characteristic dermal findings together with limb manifestations, which were not seen in our mutation-negative patients. The clinical characteristics of our patients with PORCN mutations were compared with the previously reported mutation-positive cases. In this report, we summarize the literature on PORCN mutations and associated phenotypes.

  2. Maize Mutator transposon

    Institute of Scientific and Technical Information of China (English)

    Yijun WANG; Mingliang XU; Dexiang DENG; Yunlong BIAN

    2008-01-01

    Transposable elements are widely distributed in eukaryotes. Due to its high copy numbers, high forward mutation rate and preferential insertion into low-copy DNA sequences, among others, the Mutator system has been widely used as a mutagen in genomic research. The discovery, classification, transposition specificity and epige-netic regulation of Mutator transposons were described. The application of Mutator tagging in plant genomic research was also presented. The role of Mu-like elements in genome evolution was briefly depicted. Moreover, the direction of Mutator transposon research in the future was discussed.

  3. Common Β- Thalassaemia Mutations in

    Directory of Open Access Journals (Sweden)

    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.

  4. Adaptive synonymous mutations in an experimentally evolved Pseudomonas fluorescens population

    DEFF Research Database (Denmark)

    Bailey, Susan; Hinz, Aaron; Kassen, Rees

    2014-01-01

    in an experimentally evolved population of Pseudomonas fluorescens. We show experimentally that these mutations increase fitness by an amount comparable to non-synonymous mutations and that the fitness increases stem from increased gene expression. These results provide unequivocal evidence that synonymous mutations...

  5. Comparative analysis of real-time quantitative PCR-Sanger sequencing method and TaqMan probe method for detection of KRAS/BRAF mutation in colorectal carcinomas%即时定量PCR-Sanger测序与TaqMan探针法检测结直肠癌KRAS、BRAF基因突变的对比分析

    Institute of Scientific and Technical Information of China (English)

    张汛; 王跃华; 高宁; 王晋芬

    2014-01-01

    Objective To compare the application values of real-time quantitative PCR-Sanger sequencing and TaqMan probe method in the detection of KRAS and BRAF mutations,and to correlate KRAS/BRAF mutations with the clinicopathological characteristics in colorectal carcinomas.Methods Genomic DNA of the tumor cells was extracted from formalin fixed paraffin embedded (FFPE) tissue samples of 344 colorectal carcinomas by microdissection.Real-time quantitative PCR-Sanger sequencing and TaqMan probe method were performed to detect the KRAS/BRAF mutations.The frequency and types of KRAS/BRAF mutations,clinicopathological characteristics and survival time were analyzed.Results KRAS mutations were detected in 39.8% (137/344) and 38.7% (133/344) of 344 colorectal carcinomas by using real-time quantitative PCR-Sanger sequencing and TaqMan probe method,respectively.BRAF mutation was detected in 4.7% (16/344) and 4.1% (14/344),respectively.There was no significant correlation between the two methods.The frequency of the KRAS mutation in female was higher than that in male (P <0.05).The frequency of the BRAF mutation in colon was higher than that in rectum.The frequency of the BRAF mutation in stage Ⅲ-Ⅳ cases was higher than that in stage Ⅰ-Ⅱ cases.The frequency of the BRAF mutation in signet ring cell carcinoma was higher than that in mucinous carcinoma and nonspecific adenocarcinoma had the lowest mutation rate.The frequency of the BRAF mutation in grade Ⅲ cases was higher than that in grade Ⅱ cases (P < 0.05).The overall concordance for the two methods of KRAS/BRAF mutation detection was 98.8% (kappa =0.976).There was statistic significance between BRAF and KRAS mutations for the survival time of colorectal carcinomas (P =0.039).There were no statistic significance between BRAF mutation type and BRAF/KRAS wild type (P =0.058).Conclusions (1) Compared with real-time quantitative PCR-Sanger sequencing,TaqMan probe method is better with regard to handling time

  6. LMNA mutations in progeroid syndromes.

    Science.gov (United States)

    Huang, Shurong; Kennedy, Brian K; Oshima, Junko

    2005-01-01

    Segmental progeroid syndromes are disorders in which affected individuals. present various features that suggest accelerated ageing. The two best-known examples are Hutchinson-Gilford progeria syndrome (HGPS, 'Progeria of childhood') and Werner syndrome (WS, 'Progeria of the adult'). A novel, recurrent de novo mutation in the LMNA gene, responsible for the majority of HGPS cases, results in an in-frame deletion of 50 amino acids, including endoproteolytic sites required for processing of prelamin A to mature lamin A protein. Another mutation results in a 35 amino acid in-frame deletion with a milder HGPS phenotype. WRN, the gene responsible for the majority of WS cases, encodes a multifunctional nuclear protein with exonuclease and helicase activities and may participate in optimizing DNA repair/recombination. A subset of WS patients do not show mutations at the WRN locus (atypical WS), but show heterozygous amino acid substitutions in the heptad repeat region of lamin A. Structural analysis suggests that mutations in atypical WS may interfere with protein-protein interactions. When compared to WRN-mutant WS, LMNA-mutant atypical WS patients appear to show earlier onset and possibly more severe ageing-related symptoms.

  7. Modelling mutational landscapes of human cancers in vitro

    Science.gov (United States)

    Olivier, Magali; Weninger, Annette; Ardin, Maude; Huskova, Hana; Castells, Xavier; Vallée, Maxime P.; McKay, James; Nedelko, Tatiana; Muehlbauer, Karl-Rudolf; Marusawa, Hiroyuki; Alexander, John; Hazelwood, Lee; Byrnes, Graham; Hollstein, Monica; Zavadil, Jiri

    2014-03-01

    Experimental models that recapitulate mutational landscapes of human cancers are needed to decipher the rapidly expanding data on human somatic mutations. We demonstrate that mutation patterns in immortalised cell lines derived from primary murine embryonic fibroblasts (MEFs) exposed in vitro to carcinogens recapitulate key features of mutational signatures observed in human cancers. In experiments with several cancer-causing agents we obtained high genome-wide concordance between human tumour mutation data and in vitro data with respect to predominant substitution types, strand bias and sequence context. Moreover, we found signature mutations in well-studied human cancer driver genes. To explore endogenous mutagenesis, we used MEFs ectopically expressing activation-induced cytidine deaminase (AID) and observed an excess of AID signature mutations in immortalised cell lines compared to their non-transgenic counterparts. MEF immortalisation is thus a simple and powerful strategy for modelling cancer mutation landscapes that facilitates the interpretation of human tumour genome-wide sequencing data.

  8. Gestational mutations in radiation carcinogenesis

    Science.gov (United States)

    Meza, R.; Luebeck, G.; Moolgavkar, S.

    Mutations in critical genes during gestation could increase substantially the risk of cancer. We examine the consequences of such mutations using the Luebeck-Moolgavkar model for colorectal cancer and the Lea-Coulson modification of the Luria-Delbruck model for the accumulation of mutations during gestation. When gestational mutation rates are high, such mutations make a significant contribution to cancer risk even for adult tumors. Furthermore, gestational mutations ocurring at distinct times during emryonic developmemt lead to substantially different numbers of mutated cells at birth, with early mutations leading to a large number (jackpots) of mutated cells at birth and mutation occurring late leading to only a few mutated cells. Thus gestational mutations could confer considerable heterogeneity of the risk of cancer. If the fetus is exposed to an environmental mutagen, such as ionizing radiation, the gestational mutation rate would be expected to increase. We examine the consequences of such exposures during gestation on the subsequent development of cancer.

  9. Exonuclease mutations in DNA polymerase epsilon reveal replication strand specific mutation patterns and human origins of replication.

    Science.gov (United States)

    Shinbrot, Eve; Henninger, Erin E; Weinhold, Nils; Covington, Kyle R; Göksenin, A Yasemin; Schultz, Nikolaus; Chao, Hsu; Doddapaneni, HarshaVardhan; Muzny, Donna M; Gibbs, Richard A; Sander, Chris; Pursell, Zachary F; Wheeler, David A

    2014-11-01

    Tumors with somatic mutations in the proofreading exonuclease domain of DNA polymerase epsilon (POLE-exo*) exhibit a novel mutator phenotype, with markedly elevated TCT→TAT and TCG→TTG mutations and overall mutation frequencies often exceeding 100 mutations/Mb. Here, we identify POLE-exo* tumors in numerous cancers and classify them into two groups, A and B, according to their mutational properties. Group A mutants are found only in POLE, whereas Group B mutants are found in POLE and POLD1 and appear to be nonfunctional. In Group A, cell-free polymerase assays confirm that mutations in the exonuclease domain result in high mutation frequencies with a preference for C→A mutation. We describe the patterns of amino acid substitutions caused by POLE-exo* and compare them to other tumor types. The nucleotide preference of POLE-exo* leads to increased frequencies of recurrent nonsense mutations in key tumor suppressors such as TP53, ATM, and PIK3R1. We further demonstrate that strand-specific mutation patterns arise from some of these POLE-exo* mutants during genome duplication. This is the first direct proof of leading strand-specific replication by human POLE, which has only been demonstrated in yeast so far. Taken together, the extremely high mutation frequency and strand specificity of mutations provide a unique identifier of eukaryotic origins of replication.

  10. Mutation and premating isolation.

    Science.gov (United States)

    Woodruff, R C; Thompson, J N

    2002-11-01

    While premating isolation might be traceable to different genetic mechanisms in different species, evidence supports the idea that as few as one or two genes may often be sufficient to initiate isolation. Thus, new mutation can theoretically play a key role in the process. But it has long been thought that a new isolation mutation would fail, because there would be no other individuals for the isolation-mutation-carrier to mate with. We now realize that premeiotic mutations are very common and will yield a cluster of progeny carrying the same new mutant allele. In this paper, we discuss the evidence for genetically simple premating isolation barriers and the role that clusters of an isolation mutation may play in initiating allopatric, and even sympatric, species divisions.

  11. Differential expression of GNAS and KRAS mutations in pancreatic cysts.

    Science.gov (United States)

    Lee, Linda S; Doyle, Leona A; Houghton, Jeffrey; Sah, Sachin; Bellizzi, Andrew M; Szafranska-Schwarzbach, Anna E; Conner, James R; Kadiyala, Vivek; Suleiman, Shadeah L; Banks, Peter A; Andruss, Bernard F; Conwell, Darwin L

    2014-11-28

    KRAS mutations play an important role in pancreatic cancer. GNAS mutations were discovered in intraductal papillary mucinous neoplasms (IPMN). Our aim was to identify the frequency of KRAS and GNAS mutations in pancreatic cystic neoplasms and pancreatic ductal adenocarcinoma (PDAC). Sixty-eight surgically resected formalin fixed, paraffin embedded pancreatic specimens were analyzed, including: 1) benign (20 serous cystadenoma (SCA)), 2) pre-malignant (10 mucinous cystic neoplasm (MCN), 10 branch duct intraductal papillary mucinous neoplasm (BD-IPMN), 9 main duct IPMN (MD-IPMN)), 3) malignant (19 PDAC). Total nucleic acid extraction was performed. KRAS codon 12/13 and GNAS codon 201 mutations were interrogated via targeted sequencing using the Ion Torrent's Personal Genome Machine (PGM). Mean age of 68 patients was 61.9±8.4 with 72% female. KRAS and GNAS mutations were more common in PDAC and IPMN. KRAS mutations predominated in PDAC compared to pancreatic cysts (16/19, 84% versus 10/49, 20%; P<0.001). GNAS mutations were more common in IPMN compared to non-IPMN lesions (8/19, 42% versus 2/49, 4%; P=0.0003). No GNAS mutations were detected in PDAC and MCN while 2 SCA carried GNAS mutations. Double mutations with KRAS and GNAS were only present in IPMN (5/19 versus 0/30 SCA and MCN, P=0.006). KRAS and GNAS mutations were more common in PDAC and IPMN with KRAS mutations primarily in PDAC and GNAS mutations more frequent in IPMN. No GNAS mutations occurred in MCN and double mutations were only present in IPMN.

  12. Mutation rates among RNA viruses

    OpenAIRE

    Drake, John W.; Holland, John J.

    1999-01-01

    The rate of spontaneous mutation is a key parameter in modeling the genetic structure and evolution of populations. The impact of the accumulated load of mutations and the consequences of increasing the mutation rate are important in assessing the genetic health of populations. Mutation frequencies are among the more directly measurable population parameters, although the information needed to convert them into mutation rates is often lacking. A previous analysis of mutation rates in RNA viru...

  13. Mutational robustness of gene regulatory networks.

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    Aalt D J van Dijk

    Full Text Available Mutational robustness of gene regulatory networks refers to their ability to generate constant biological output upon mutations that change network structure. Such networks contain regulatory interactions (transcription factor-target gene interactions but often also protein-protein interactions between transcription factors. Using computational modeling, we study factors that influence robustness and we infer several network properties governing it. These include the type of mutation, i.e. whether a regulatory interaction or a protein-protein interaction is mutated, and in the case of mutation of a regulatory interaction, the sign of the interaction (activating vs. repressive. In addition, we analyze the effect of combinations of mutations and we compare networks containing monomeric with those containing dimeric transcription factors. Our results are consistent with available data on biological networks, for example based on evolutionary conservation of network features. As a novel and remarkable property, we predict that networks are more robust against mutations in monomer than in dimer transcription factors, a prediction for which analysis of conservation of DNA binding residues in monomeric vs. dimeric transcription factors provides indirect evidence.

  14. EGFR Mutation Status in Uighur Lung Adenocarcinoma Patients

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    Li SHAN

    2013-02-01

    Full Text Available Background and objective Epidermal growth factor receptor (EGFR, a transmembrane protein, is a member of the tyrosine kinase family. Gefitinib, an EGFR tyrosine-kinase inhibitors, has shown a high response rate in the treatment of lung cancer in patients with EGFR mutation. However, significant differences in EGFR mutations exist among different ethnic groups. The aim of this study is to investigate the prevalence of EGFR mutations in Uighur lung adenocarcinoma patients by using a rapid and sensitive detection method and to analyze EGFR mutation differences compared with Han lung adenocarcinoma patients. Methods We examined lung adenocarcinoma tissues from 138 patients, including 68 Uighur lung adenocarcinoma patients and 70 Han lung adenocarcinoma patients, for EGFR mutations in exons 18, 19, 20, and 21 by using the amplification refractory mutation system (ARMS PCR method. The mutation differences between Uighur and Han lung adenocarcinoma were compared by using the chi-square test method. Results EGFR mutations were detected in 43 (31.2% of the 138 lung adenocarcinoma patients. EGFR mutations were detected in 11 (16.2% of the 68 Uighur lung adenocarcinoma patients and in 32 (45.7% of the 70 Han lung adenocarcinoma patients. Significant differences were observed in the EGFR mutations between Uighur lung adenocarcinoma patients and Han lung adenocarcinoma patients (P<0.001. Conclusion Our results indicate that the EGFR mutation in Uighur lung adenocarcinoma patients (16.2% is significantly lower than that in Han lung adenocarcinoma patients (45.7%.

  15. Radiation mutation breeding

    Energy Technology Data Exchange (ETDEWEB)

    Song, Hi Sup; Kim, Jae Sung; Kim, Jin Kyu; Shin, In Chul; Lim, Young Taek

    1998-04-01

    In order to develop an advanced technical knowledge for the selection of better mutants, some of the crops were irradiated and the mutation rate, the survival rate and the method for selction of a mutant were studied. Furthermore, this study aimed to obtain basic data applicable to the development of genetic resources by evaluation and analysis the specific character for selection of the superior mutant and its plant breeding. 1. selection of the mutant with a superior resistance against environment in the principal crops 1) New varieties of mutant rices such as Wonpyeongbyeo, Wongwangbyeo, Winmibyeo, and heogseon chalbeyeo (sticky forma) were registered in the national variety list and made an application to crop variety protection right. They are under review now. 2) We also keep on studying on the number of a grain of 8 lines of excellent mutant rice for the purpose of improvement of breeding . 3) We selected 3 lines which have a resistance to pod and stem blight in large soybean, 31 lines with small grain size and higher yield, 112 lines of soybean of cooking, 7 lines of low lipoxygenase content, and 12 lines with decreased phytic acid content by 20 % compared to the previous level. 2. Selection of advanced Mugunwha (Rose of Sharon) mutant 1) Bagseul, a new variety of mutant, was developed and 30 plantlets of it are being proliferated. 2) Fifty-three lines of a mutant having a various morphologies were selected.

  16. PIK3CA mutations frequently coexist with RAS and BRAF mutations in patients with advanced cancers.

    Directory of Open Access Journals (Sweden)

    Filip Janku

    Full Text Available BACKGROUND: Oncogenic mutations of PIK3CA, RAS (KRAS, NRAS, and BRAF have been identified in various malignancies, and activate the PI3K/AKT/mTOR and RAS/RAF/MEK pathways, respectively. Both pathways are critical drivers of tumorigenesis. METHODS: Tumor tissues from 504 patients with diverse cancers referred to the Clinical Center for Targeted Therapy at MD Anderson Cancer Center starting in October 2008 were analyzed for PIK3CA, RAS (KRAS, NRAS, and BRAF mutations using polymerase chain reaction-based DNA sequencing. RESULTS: PIK3CA mutations were found in 54 (11% of 504 patients tested; KRAS in 69 (19% of 367; NRAS in 19 (8% of 225; and BRAF in 31 (9% of 361 patients. PIK3CA mutations were most frequent in squamous cervical (5/14, 36%, uterine (7/28, 25%, breast (6/29, 21%, and colorectal cancers (18/105, 17%; KRAS in pancreatic (5/9, 56%, colorectal (49/97, 51%, and uterine cancers (3/20, 15%; NRAS in melanoma (12/40, 30%, and uterine cancer (2/11, 18%; BRAF in melanoma (23/52, 44%, and colorectal cancer (5/88, 6%. Regardless of histology, KRAS mutations were found in 38% of patients with PIK3CA mutations compared to 16% of patients with wild-type (wtPIK3CA (p = 0.001. In total, RAS (KRAS, NRAS or BRAF mutations were found in 47% of patients with PIK3CA mutations vs. 24% of patients wtPIK3CA (p = 0.001. PIK3CA mutations were found in 28% of patients with KRAS mutations compared to 10% with wtKRAS (p = 0.001 and in 20% of patients with RAS (KRAS, NRAS or BRAF mutations compared to 8% with wtRAS (KRAS, NRAS or wtBRAF (p = 0.001. CONCLUSIONS: PIK3CA, RAS (KRAS, NRAS, and BRAF mutations are frequent in diverse tumors. In a wide variety of tumors, PIK3CA mutations coexist with RAS (KRAS, NRAS and BRAF mutations.

  17. Emerging patterns of somatic mutations in cancer.

    Science.gov (United States)

    Watson, Ian R; Takahashi, Koichi; Futreal, P Andrew; Chin, Lynda

    2013-10-01

    Recent advances in technological tools for massively parallel, high-throughput sequencing of DNA have enabled the comprehensive characterization of somatic mutations in a large number of tumour samples. In this Review, we describe recent cancer genomic studies that have assembled emerging views of the landscapes of somatic mutations through deep-sequencing analyses of the coding exomes and whole genomes in various cancer types. We discuss the comparative genomics of different cancers, including mutation rates and spectra, as well as the roles of environmental insults that influence these processes. We highlight the developing statistical approaches that are used to identify significantly mutated genes, and discuss the emerging biological and clinical insights from such analyses, as well as the future challenges of translating these genomic data into clinical impacts.

  18. Stereoselective metabolism of the environmental mammary carcinogen 6-nitrochrysene to trans-1,2-dihydroxy-1,2-dihydro-6-nitrochrysene by aroclor 1254-treated rat liver microsomes and their comparative mutation profiles in a laci mammary epithelial cell line.

    Science.gov (United States)

    Sun, Yuan-Wan; Guttenplan, Joseph B; Khmelnitsky, Michael; Krzeminski, Jacek; Boyiri, Telih; Amin, Shantu; El-Bayoumy, Karam

    2009-12-01

    The environmental pollutant 6-nitrochrysene (6-NC) is a powerful mammary carcinogen and mutagen in rats. Our previous studies have shown that 6-NC is metabolized to trans-1,2-dihydroxy-1,2-dihydro-6-nitrochrysene (1,2-DHD-6-NC) in rats and in several in vitro systems, including human breast tissue, and the latter is the proximate carcinogenic form in the rat mammary gland. Because optically active enantiomers of numerous polynuclear aromatic hydrocarbon (PAH) metabolites including chrysene have different biological activities, we hypothesized that the stereochemical course of 6-NC metabolism might play a significant role in the carcinogenic/mutagenic activities of the parent 6-NC. The goal of this study is to evaluate the effect of stereochemistry on the mutagenicity of 1,2-DHD-6-NC using the cII gene of lacI mammary epithelial cells in vitro. Resolution of (+/-)-1,2-DHD-6-NC was obtained by either nonchiral or chiral stationary phase HPLC methods. We determined that the ratio of (-)-[R,R]- and (+)-[S,S]-1,2-DHD-6-NC formed in the metabolism of 6-NC by rat liver microsomes is 88:12. The mutation fractions and mutation spectra of [R,R] and [S,S]-enantiomers were examined. Our results showed that the [R,R]-isomer is a significantly (p GC, AT > TA, and GC > TA substitutions, and these are similar to those obtained from 6-NC in vivo in the mammary glands of rats treated with 6-NC. The mutation spectra of the [S,S]-isomer were similar to the [R,R]-isomer, but a higher percentage of AT > GC substitutions in the [R,R]-isomer was noted. On the basis of the results of the present study, we hypothesize that [R,R]-1,2-DHD-6-NC is the proximate carcinogen of 6-NC in the rat mammary gland in vivo and will test this hypothesis in a future study.

  19. Mutations in GABRB3

    DEFF Research Database (Denmark)

    Møller, Rikke S; Wuttke, Thomas V; Helbig, Ingo

    2017-01-01

    OBJECTIVE: To examine the role of mutations in GABRB3 encoding the β3 subunit of the GABAA receptor in individual patients with epilepsy with regard to causality, the spectrum of genetic variants, their pathophysiology, and associated phenotypes. METHODS: We performed massive parallel sequencing...... of GABRB3 in 416 patients with a range of epileptic encephalopathies and childhood-onset epilepsies and recruited additional patients with epilepsy with GABRB3 mutations from other research and diagnostic programs. RESULTS: We identified 22 patients with heterozygous mutations in GABRB3, including 3...... probands from multiplex families. The phenotypic spectrum of the mutation carriers ranged from simple febrile seizures, genetic epilepsies with febrile seizures plus, and epilepsy with myoclonic-atonic seizures to West syndrome and other types of severe, early-onset epileptic encephalopathies...

  20. 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.

  1. Mapping Mutations on Phylogenies

    DEFF Research Database (Denmark)

    Nielsen, Rasmus

    2005-01-01

    This chapter provides a short review of recent methodologies developed for mapping mutations on phylogenies. Mapping of mutations, or character changes in general, using the maximum parsimony principle has been one of the most powerful tools in phylogenetics, and it has been used in a variety...... of different applications, for example, in the detection of correlated evolution and to identify selection acting on DNA sequences. However, many uses of parsimony mappings have been criticized because they focus on only one of many possible mappings and/or because they do not incorporate statistical...... uncertainty in the mapping. Recently developed probabilistic methods can incorporate statistical uncertainty in the character mappings. In these methods, focus is on a probability distribution of mutational mappings instead of a single estimate of the mutational mapping....

  2. TET2 gene mutation is unfavorable prognostic factor in cytogenetically normal acute myeloid leukemia patients with NPM1+ and FLT3-ITD - mutations.

    Science.gov (United States)

    Tian, Xiaopeng; Xu, Yang; Yin, Jia; Tian, Hong; Chen, Suning; Wu, Depei; Sun, Aining

    2014-07-01

    Cytogenetically normal acute myeloid leukemia (cn-AML) is a group of heterogeneous diseases. Gene mutations are increasingly used to assess the prognosis of cn-AML patients and guide risk-adapted treatment. In the present study, we analyzed the molecular genetics characteristics of 373 adult cn-AML patients and explored the relationship between TET2 gene mutations or different genetic mutation patterns and prognosis. We found that 16.1 % of patients had TET2 mutations, 31.6 % had FLT3 internal tandem duplications (ITDs), 6.2 % had FLT3 tyrosine kinase domain mutations, 2.4 % had c-KIT mutations, 37.8 % had NPM1 mutations, 11.3 % had WT1 mutations, 5.9 % had RUNX1 mutations, 11.5 % had ASXL1 mutations, 3.8 % had MLL-PTDs, 7.8 % had IDH1 mutations, 7.8 % had NRAS mutations, 12.3 % had IDH2 mutations, 1.6 % had EZH2 mutations, and 14.7 % had DNMT3A mutations, while none had CBL mutations. Gene mutations were detected in 76.94 % (287/373) of all patients. In the NPM1m(+) patients, those with TET2 mutations were associated with a shorter median overall survival (OS) as compared to TET2 wild-type (wt) patients (9.9 vs. 27.0 months, respectively; P = 0.023); Interestingly, the TET2 mutation was identified as an unfavorable prognostic factor and was closely associated with a shorter median OS as compared to TET2-wt (9.5 vs. 32.2 months, respectively; P = 0.013) in the NPM1m(+)/FLT3-ITDm(-) patient group. Thus, identification of TET2 combined with classic NPM1 and FLT3-ITD mutations allowed us to stratify cn-AML into distinct subtypes.

  3. PRRT2 gene mutations

    Science.gov (United States)

    Gardiner, Alice R.; Bhatia, Kailash P.; Stamelou, Maria; Dale, Russell C.; Kurian, Manju A.; Schneider, Susanne A.; Wali, G.M.; Counihan, Tim; Schapira, Anthony H.; Spacey, Sian D.; Valente, Enza-Maria; Silveira-Moriyama, Laura; Teive, Hélio A.G.; Raskin, Salmo; Sander, Josemir W.; Lees, Andrew; Warner, Tom; Kullmann, Dimitri M.; Wood, Nicholas W.; Hanna, Michael

    2012-01-01

    ABSTRACT Objective: The proline-rich transmembrane protein (PRRT2) gene was recently identified using exome sequencing as the cause of autosomal dominant paroxysmal kinesigenic dyskinesia (PKD) with or without infantile convulsions (IC) (PKD/IC syndrome). Episodic neurologic disorders, such as epilepsy, migraine, and paroxysmal movement disorders, often coexist and are thought to have a shared channel-related etiology. To investigate further the frequency, spectrum, and phenotype of PRRT2 mutations, we analyzed this gene in 3 large series of episodic neurologic disorders with PKD/IC, episodic ataxia (EA), and hemiplegic migraine (HM). Methods: The PRRT2 gene was sequenced in 58 family probands/sporadic individuals with PKD/IC, 182 with EA, 128 with HM, and 475 UK and 96 Asian controls. Results: PRRT2 genetic mutations were identified in 28 out of 58 individuals with PKD/IC (48%), 1/182 individuals with EA, and 1/128 individuals with HM. A number of loss-of-function and coding missense mutations were identified; the most common mutation found was the p.R217Pfs*8 insertion. Males were more frequently affected than females (ratio 52:32). There was a high proportion of PRRT2 mutations found in families and sporadic cases with PKD associated with migraine or HM (10 out of 28). One family had EA with HM and another large family had typical HM alone. Conclusions: This work expands the phenotype of mutations in the PRRT2 gene to include the frequent occurrence of migraine and HM with PKD/IC, and the association of mutations with EA and HM and with familial HM alone. We have also extended the PRRT2 mutation type and frequency in PKD and other episodic neurologic disorders. PMID:23077024

  4. Sexual selection, germline mutation rate and sperm competition

    Directory of Open Access Journals (Sweden)

    Møller AP

    2003-04-01

    Full Text Available Abstract Background An important component of sexual selection arises because females obtain viability benefits for their offspring from their mate choice. Females choosing extra-pair fertilization generally favor males with exaggerated secondary sexual characters, and extra-pair paternity increases the variance in male reproductive success. Furthermore, females are assumed to benefit from 'good genes' from extra-pair sires. How additive genetic variance in such viability genes is maintained despite strong directional selection remains an evolutionary enigma. We propose that sexual selection is associated with elevated mutation rates, changing the balance between mutation and selection, thereby increasing variance in fitness and hence the benefits to be obtained from good genes sexual selection. Two hypotheses may account for such elevated mutation: (1 Increased sperm production associated with sperm competition may increase mutation rate. (2 Mutator alleles increase mutation rates that are revealed by the expression of condition-dependent secondary sexual characters used by choosy females during their mate choice. M Petrie has independently developed the idea that mutator alleles may account for the maintenance of genetic variation in viability despite strong directional selection. Results A comparative study of birds revealed a positive correlation between mutation rate at minisatellite loci and extra-pair paternity, but not between mutation rate and relative testes mass which is a measure of relative sperm production. Minisatellite mutation rates were not related to longevity, suggesting a meiotic rather than a mitotic origin of mutations. Conclusion We found evidence of increased mutation rate in species with more intense sexual selection. Increased mutation was not associated with increased sperm production, and we suggest that species with intense sexual selection may maintain elevated mutation rates because sexual selection continuously

  5. Telomerase reverse transcriptase (TERT) promoter mutations in Korean melanoma patients.

    Science.gov (United States)

    Roh, Mi Ryung; Park, Kyu-Hyun; Chung, Kee Yang; Shin, Sang Joon; Rha, Sun Young; Tsao, Hensin

    2017-01-01

    Telomerase reverse transcriptase (TERT) is the reverse transcriptase component of the telomeric complex, which synthesizes terminal DNA to protect chromosomal ends and to maintain genomic integrity. In melanoma, mutation in TERT promoter region is a common event and theses promoter variants have been shown to be associated with increased gene expression, decreased telomere length and poorer outcome. In this study, we determined the frequency of TERT promoter mutation in 88 Korean primary melanoma patients and aimed to see the association of TERT promoter mutation status to other major molecular features, such as BRAF, NRAS, KIT mutations and correlate with clinicopathological features. In our study, acral melanoma (n=46, 52.3%) was the most common type. Overall, TERT promoter mutation was observed in 15 cases (17%) with ten c. -124C>T altertions and five c. -146C>T alterations. None of our samples showed CC>TT mutation which is considered pathognomonic of UV induction. Among the 46 acral melanoma patients, 5 patients (10.9%) harbored TERT promoter mutation. Tumors with TERT promoter mutation showed significantly greater Breslow thickness compared to WT tumors (P=0.039). A combined analysis for the presence of TERT promoter and BRAF mutations showed that patients with both TERT promoter and BRAF mutation showed decreased survival compared with those with only TERT promoter mutation, only BRAF mutation, or without mutations in either TERT promoter or BRAF (P=0.035). Our data provides additional evidence that UV-induced TERT promoter mutation frequencies vary depending on melanoma subtype, but preserves its prognostic value.

  6. Differential Expression of GNAS and KRAS Mutations in Pancreatic Cysts

    Directory of Open Access Journals (Sweden)

    Linda S Lee

    2014-11-01

    Full Text Available Context KRAS mutations play an important role in pancreatic cancer. GNAS mutations were discovered in intraductal papillary mucinous neoplasms (IPMN. Objectives Our aim was to identify the frequency of KRAS and GNAS mutations in pancreatic cystic neoplasms and pancreatic ductal adenocarcinoma (PDAC. Methods Sixty-eight surgically resected formalin fixed, paraffin embedded pancreatic specimens were analyzed, including: 1 benign [20 serous cystadenoma (SCA], 2 pre-malignant [10 mucinous cystic neoplasm (MCN, 10 branch duct intraductal papillary mucinous neoplasm (BD-IPMN, 9 main duct IPMN (MD-IPMN], 3 malignant [19 PDAC]. Total nucleic acid extraction was performed. KRAS codon 12/13 and GNAS codon 201 mutations were interrogated via targeted sequencing using the Ion Torrent's Personal Genome Machine (PGM. Results Mean age of 68 patients was 61.9± 8.4 with 72% female. KRAS and GNAS mutations were more common in PDAC and IPMN. KRAS mutations predominated in PDAC compared to pancreatic cysts (16/19, 84%versus 10/49, 20%; p0.001. GNAS mutatins were more common in IPMN compared to non-IPMN lesions (8/19, 42% versus 2/49, 4%;p=0.0003. No GNAS mutations were detected in PDAC and MCN while 2 SCA carried GNAS mutations. Double mutations with KRAS and GNAS were only present in IPMN (5/19 versus 0/30 SCA and MCN, p=0.006. Conclusions KRAS and GNAS mutations were more common in PDAC and IPMN with KRAS mutations primarily in PDAC and GNAS mutations more frequent in IPMN. No GNAS mutations occurred in MCN and double mutations were only present in IPMN.

  7. Subquivers of mutation-acyclic quivers are mutation-acyclic

    CERN Document Server

    Warkentin, Matthias

    2011-01-01

    Quiver mutation plays a crucial role in the definition of cluster algebras by Fomin and Zelevinsky. It induces an equivalence relation on the set of all quivers without loops and two-cycles. A quiver is called mutation-acyclic if it is mutation-equivalent to an acyclic quiver. The aim of this note is to show that full subquivers of mutation-acyclic quivers are mutation-acyclic.

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    B.N. Murtaza

    2014-01-01

    Full Text Available 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.

  10. Filaggrin Mutation in Korean Patients with Atopic Dermatitis

    Science.gov (United States)

    On, Hye Rang; Lee, Sang Eun; Kim, Song-Ee; Hong, Won Jin; Kim, Hyun Jung; Nomura, Toshifumi; Suzuki, Shotaro; Shimizu, Hiroshi

    2017-01-01

    Purpose Atopic dermatitis (AD) is a chronic, relapsing eczematous inflammatory skin disease. Mutations in the filaggrin gene (FLG) are major predisposing factors for AD. Ethnic differences exist between Asian and European populations in the frequency and spectrum of FLG mutations. Moreover, a distinct set of FLG mutations has been reported in Asian populations. The aim of this study was to examine the spectrum of FLG mutations in Koreans with AD. We also investigated the association of FLG mutations and clinical features of AD and compared the Korean FLG landscape with that of other East Asian countries. Materials and Methods Seventy Korean patients with AD were enrolled in this study. Fourteen FLG mutations previously detected in Korean, Japanese, and Chinese patients were screened by genotyping. Results Four FLG null mutations (3321delA, K4022X, S3296X, and S2889X) were identified in eleven patients (15.7%). The most commonly detected mutations in Korean patients with AD were 3321delA (n=6, 9.1%) and K4022X (n=3, 4.5%). FLG mutations were significantly associated with elevated IgE (≥200 KIU/L and/or MAST-CLA >3+, p=0.005), palmar hyperlinearity (p<0.001), and a family history of allergic disease (p=0.021). Conclusion This study expanded our understanding of the landscape of FLG mutations in Koreans and revealed an association between FLG mutations and AD phenotype. PMID:28120571

  11. Prognostic value of KTT mutation in gastrointestinal stromal tumors

    Institute of Scientific and Technical Information of China (English)

    Xiao-Hong Liu; Chen-Guang Bai; Qiang Xie; Fei Feng; Zhi-Yun Xu; Da-Lie Ma

    2005-01-01

    AIM: To examine the prevalence and prognostic significance of C-kit gene mutation and analysis the correlation of Ckit gene mutation and the clinicalpathologic parameters of GISTs.METHODS: Eighty-two GISTs were studied for the mutation of C-kit gene by PCR-SSCP, DNA sequence.Statistical comparison were used to analysis the correlation of C-kit gene mutation and clinicalpathology,clinical behavior, recurrence.RESULTS: (1) Mutation-positive and mutation-negative GISTs were 34 and 48,respectively; (2) Among these patients with C-kit mutation remained a significantly poor prognosis associated with 59% 3-year survival compared to those whose tumors did not; (3) Tunor size, PCNA index, mitotic cell number, presence of necrosis, microscopic invasion to adjacent tissues, recurrence and distant metastasis among mutation-positive and mutation-negative GISTs were significantly different.CONCLUSION: C-kit mutation is a undoubtedly pivotal event in GIST and may be associated with poor prognosis.Evaluation of C-kit gene mutation may have both prognosis and therapeutic significances.

  12. A germ-line-selective advantage rather than an increased mutation rate can explain some unexpectedly common human disease mutations.

    Science.gov (United States)

    Choi, Soo-Kyung; Yoon, Song-Ro; Calabrese, Peter; Arnheim, Norman

    2008-07-22

    Two nucleotide substitutions in the human FGFR2 gene (C755G or C758G) are responsible for virtually all sporadic cases of Apert syndrome. This condition is 100-1,000 times more common than genomic mutation frequency data predict. Here, we report on the C758G de novo Apert syndrome mutation. Using data on older donors, we show that spontaneous mutations are not uniformly distributed throughout normal testes. Instead, we find foci where C758G mutation frequencies are 3-4 orders of magnitude greater than the remaining tissue. We conclude this nucleotide site is not a mutation hot spot even after accounting for possible Luria-Delbruck "mutation jackpots." An alternative explanation for such foci involving positive selection acting on adult self-renewing Ap spermatogonia experiencing the rare mutation could not be rejected. Further, the two youngest individuals studied (19 and 23 years old) had lower mutation frequencies and smaller foci at both mutation sites compared with the older individuals. This implies that the mutation frequency of foci increases as adults age, and thus selection could explain the paternal age effect for Apert syndrome and other genetic conditions. Our results, now including the analysis of two mutations in the same set of testes, suggest that positive selection can increase the relative frequency of premeiotic germ cells carrying such mutations, although individuals who inherit them have reduced fitness. In addition, we compared the anatomical distribution of C758G mutation foci with both new and old data on the C755G mutation in the same testis and found their positions were not correlated with one another.

  13. Mutational spectrum drives the rise of mutator bacteria.

    Directory of Open Access Journals (Sweden)

    Alejandro Couce

    Full Text Available Understanding how mutator strains emerge in bacterial populations is relevant both to evolutionary theory and to reduce the threat they pose in clinical settings. The rise of mutator alleles is understood as a result of their hitchhiking with linked beneficial mutations, although the factors that govern this process remain unclear. A prominent but underappreciated fact is that each mutator allele increases only a specific spectrum of mutational changes. This spectrum has been speculated to alter the distribution of fitness effects of beneficial mutations, potentially affecting hitchhiking. To study this possibility, we analyzed the fitness distribution of beneficial mutations generated from different mutator and wild-type Escherichia coli strains. Using antibiotic resistance as a model system, we show that mutational spectra can alter these distributions substantially, ultimately determining the competitive ability of each strain across environments. Computer simulation showed that the effect of mutational spectrum on hitchhiking dynamics follows a non-linear function, implying that even slight spectrum-dependent fitness differences are sufficient to alter mutator success frequency by several orders of magnitude. These results indicate an unanticipated central role for the mutational spectrum in the evolution of bacterial mutation rates. At a practical level, this study indicates that knowledge of the molecular details of resistance determinants is crucial for minimizing mutator evolution during antibiotic therapy.

  14. Differential Persistence of Transmitted HIV-1 Drug Resistance Mutation Classes

    Science.gov (United States)

    Jain, Vivek; Sucupira, Maria C.; Bacchetti, Peter; Hartogensis, Wendy; Diaz, Ricardo S.; Kallas, Esper G.; Janini, Luiz M.; Liegler, Teri; Pilcher, Christopher D.; Grant, Robert M.; Cortes, Rodrigo; Deeks, Steven G.

    2011-01-01

    Background. Transmitted human immunodeficiency virus type 1 (HIV-1) drug resistance (TDR) mutations can become replaced over time by emerging wild-type viral variants with improved fitness. The impact of class-specific mutations on this rate of mutation replacement is uncertain. Methods. We studied participants with acute and/or early HIV infection and TDR in 2 cohorts (San Francisco, California, and São Paulo, Brazil). We followed baseline mutations longitudinally and compared replacement rates between mutation classes with use of a parametric proportional hazards model. Results. Among 75 individuals with 195 TDR mutations, M184V/I became undetectable markedly faster than did nonnucleoside reverse-transcriptase inhibitor (NNRTI) mutations (hazard ratio, 77.5; 95% confidence interval [CI], 14.7–408.2; P < .0001), while protease inhibitor and NNRTI replacement rates were similar. Higher plasma HIV-1 RNA level predicted faster mutation replacement, but this was not statistically significant (hazard ratio, 1.71 log10 copies/mL; 95% CI, .90–3.25 log10 copies/mL; P = .11). We found substantial person-to-person variability in mutation replacement rates not accounted for by viral load or mutation class (P < .0001). Conclusions. The rapid replacement of M184V/I mutations is consistent with known fitness costs. The long-term persistence of NNRTI and protease inhibitor mutations suggests a risk for person-to-person propagation. Host and/or viral factors not accounted for by viral load or mutation class are likely influencing mutation replacement and warrant further study. PMID:21451005

  15. Silting mutation in triangulated categories

    CERN Document Server

    Aihara, Takuma

    2010-01-01

    In representation theory of algebras the notion of `mutation' often plays important roles, and two cases are well known, i.e. `cluster tilting mutation' and `exceptional mutation'. In this paper we focus on `tilting mutation', which has a disadvantage that it is often impossible, i.e. some of summands of a tilting object can not be replaced to get a new tilting object. The aim of this paper is to take away this disadvantage by introducing `silting mutation' for silting objects as a generalization of `tilting mutation'. We shall develope a basic theory of silting mutation. In particular, we introduce a partial order on the set of silting objects and establish the relationship with `silting mutation' by generalizing the theory of Riedmann-Schofield and Happel-Unger. We show that iterated silting mutation act transitively on the set of silting objects for local, hereditary or canonical algebras. Finally we give a bijection between silting subcategories and certain t-structures.

  16. MUTATIONS IN CALMODULIN GENES

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to an isolated polynucleotide encoding at least a part of calmodulin and an isolated polypeptide comprising at least a part of a calmodulin protein, wherein the polynucleotide and the polypeptide comprise at least one mutation associated with a cardiac disorder. The ...... the binding of calmodulin to ryanodine receptor 2 and use of such compound in a treatment of an individual having a cardiac disorder. The invention further provides a kit that can be used to detect specific mutations in calmodulin encoding genes....

  17. MUTATIONS IN CALMODULIN GENES

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to an isolated polynucleotide encoding at least a part of calmodulin and an isolated polypeptide comprising at least a part of a calmodulin protein, wherein the polynucleotide and the polypeptide comprise at least one mutation associated with a cardiac disorder...... the binding of calmodulin to ryanodine receptor 2 and use of such compound in a treatment of an individual having a cardiac disorder. The invention further provides a kit that can be used to detect specific mutations in calmodulin encoding genes....

  18. Are There Mutator Polymerases?

    Directory of Open Access Journals (Sweden)

    Miguel Garcia-Diaz

    2003-01-01

    Full Text Available DNA polymerases are involved in different cellular events, including genome replication and DNA repair. In the last few years, a large number of novel DNA polymerases have been discovered, and the biochemical analysis of their properties has revealed a long list of intriguing features. Some of these polymerases have a very low fidelity and have been suggested to play mutator roles in different processes, like translesion synthesis or somatic hypermutation. The current view of these processes is reviewed, and the current understanding of DNA polymerases and their role as mutator enzymes is discussed.

  19. Applications of homemade kit in mutation detection of genes

    Institute of Scientific and Technical Information of China (English)

    ZHAO Chunxia; XU Guowang; SHI Xianzhe; MA Jianmei; ZHANG Yan; L(U) Shen; YANG Qing

    2004-01-01

    Several methods of mutation detection, such as single-strand conformation polymorphism (SSCP), tandem SSCP/heteroduplex analysis and SNaPshot analysis were developed using homemade kit on ABI 310 genetic analyzer, and were successfully applied to mutation detection of 31 colorectal tumor samples. The sieving capability of homemade kit and commercial kit were compared, results demonstrate that homemade kit has higher resolution and shorter analysis time. In clinical tumor samples, 26% K-ras (exon 1) and 24% p53 (exons 7-8) were found to have mutations, and all mutations were single point variations. A majority of mutations occurred in one gene, only 1 tumor contained alterations in the two genes, which indicates that development of colorectal cancer lies on alternate pathways, and may correlate with different gene mutations.

  20. 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...... whole-genome and exome data from probands of 34 melanoma families lacking pathogenic mutations in known high penetrance melanoma susceptibility genes: CDKN2A, CDK4, BAP1, TERT, POT1, ACD and TERF2IP. We found a novel germline mutation, POLE p.(Trp347Cys), in a 7-case cutaneous melanoma family....... Functional assays in S. pombe showed that this mutation led to an increased DNA mutation rate comparable to that seen with a Pol ε mutant with no exonuclease activity. We then performed targeted sequencing of POLE in 1243 cutaneous melanoma cases and found that a further ten probands had novel or rare...

  1. Msx1 Mutations

    Science.gov (United States)

    Wang, Y.; Kong, H.; Mues, G.; D’Souza, R.

    2011-01-01

    Mutations in the transcription factors PAX9 and MSX1 cause selective tooth agenesis in humans. In tooth bud mesenchyme of mice, both proteins are required for the expression of Bmp4, which is the key signaling factor for progression to the next step of tooth development. We have previously shown that Pax9 can transactivate a 2.4-kb Bmp4 promoter construct, and that most tooth-agenesis-causing PAX9 mutations impair DNA binding and Bmp4 promoter activation. We also found that Msx1 by itself represses transcription from this proximal Bmp4 promoter, and that, in combination with Pax9, it acts as a potentiator of Pax9-induced Bmp4 transactivation. This synergism of Msx1 with Pax9 is significant, because it is currently the only documented mechanism for Msx1-mediated activation of Bmp4. In this study, we investigated whether the 5 known tooth-agenesis-causing MSX1 missense mutations disrupt this Pax9-potentiation effect, or if they lead to deficiencies in protein stability, protein-protein interactions, nuclear translocation, and DNA-binding. We found that none of the studied molecular mechanisms yielded a satisfactory explanation for the pathogenic effects of the Msx1 mutations, calling for an entirely different approach to the investigation of this step of odontogenesis on the molecular level. PMID:21297014

  2. The impact of point mutations in the human androgen receptor: classification of mutations on the basis of transcriptional activity.

    Directory of Open Access Journals (Sweden)

    Colin W Hay

    Full Text Available Androgen receptor mediated signaling drives prostate cancer cell growth and survival. Mutations within the receptor occur infrequently in prostate cancer prior to hormonal therapy but become prevalent in incurable androgen independent and metastatic tumors. Despite the determining role played by the androgen receptor in all stages of prostate cancer progression, there is a conspicuous dearth of comparable data on the consequences of mutations. In order to remedy this omission, we have combined an expansive study of forty five mutations which are predominantly associated with high Gleason scores and metastatic tumors, and span the entire length of the receptor, with a literature review of the mutations under investigation. We report the discovery of a novel prevalent class of androgen receptor mutation that possesses loss of function at low levels of androgen yet transforms to a gain of function at physiological levels. Importantly, mutations introducing constitutive gain of function are uncommon, with the majority of mutations leading to either loss of function or no significant change from wild-type activity. Therefore, the widely accepted supposition that androgen receptor mutations in prostate cancer result in gain of function is appealing, but mistaken. In addition, the transcriptional outcome of some mutations is dependent upon the androgen receptor responsive element. We discuss the consequences of these findings and the role of androgen receptor mutations for prostate cancer progression and current treatment options.

  3. High-throughput oncogene mutation profiling shows demographic differences in BRAF mutation rates among melanoma patients.

    Science.gov (United States)

    van den Hurk, Karin; Balint, Balazs; Toomey, Sinead; O'Leary, Patrick C; Unwin, Louise; Sheahan, Kieran; McDermott, Enda W; Murphy, Ian; van den Oord, Joost J; Rafferty, Mairin; FitzGerald, Dara M; Moran, Julie; Cummins, Robert; MacEneaney, Owen; Kay, Elaine W; O'Brien, Cathal P; Finn, Stephen P; Heffron, Cynthia C B B; Murphy, Michelle; Yela, Ruben; Power, Derek G; Regan, Padraic J; McDermott, Clodagh M; O'Keeffe, Allan; Orosz, Zsolt; Donnellan, Paul P; Crown, John P; Hennessy, Bryan T; Gallagher, William M

    2015-06-01

    Because of advances in targeted therapies, the clinical evaluation of cutaneous melanoma is increasingly based on a combination of traditional histopathology and molecular pathology. Therefore, it is necessary to expand our knowledge of the molecular events that accompany the development and progression of melanoma to optimize clinical management. The central objective of this study was to increase our knowledge of the mutational events that complement melanoma progression. High-throughput genotyping was adapted to query 159 known single nucleotide mutations in 33 cancer-related genes across two melanoma cohorts from Ireland (n=94) and Belgium (n=60). Results were correlated with various clinicopathological characteristics. A total of 23 mutations in 12 genes were identified, that is--BRAF, NRAS, MET, PHLPP2, PIK3R1, IDH1, KIT, STK11, CTNNB1, JAK2, ALK, and GNAS. Unexpectedly, we discovered significant differences in BRAF, MET, and PIK3R1 mutations between the cohorts. That is, cases from Ireland showed significantly lower (PBRAF(V600E) mutation rates (19%) compared with the mutation frequency observed in Belgian patients (43%). Moreover, MET mutations were detected in 12% of Irish cases, whereas none of the Belgian patients harbored these mutations, and Irish patients significantly more often (P=0.027) had PIK3R1-mutant (33%) melanoma versus 17% of Belgian cases. The low incidence of BRAF(V600E)(-) mutant melanoma among Irish patients was confirmed in five independent Irish cohorts, and in total, only 165 of 689 (24%) Irish cases carried mutant BRAF(V600E). Together, our data show that melanoma-driving mutations vary by demographic area, which has important implications for the clinical management of this disease.

  4. Benchmarking mutation effect prediction algorithms using functionally validated cancer-related missense mutations.

    Science.gov (United States)

    Martelotto, Luciano G; Ng, Charlotte Ky; De Filippo, Maria R; Zhang, Yan; Piscuoglio, Salvatore; Lim, Raymond S; Shen, Ronglai; Norton, Larry; Reis-Filho, Jorge S; Weigelt, Britta

    2014-10-28

    Massively parallel sequencing studies have led to the identification of a large number of mutations present in a minority of cancers of a given site. Hence, methods to identify the likely pathogenic mutations that are worth exploring experimentally and clinically are required. We sought to compare the performance of 15 mutation effect prediction algorithms and their agreement. As a hypothesis-generating aim, we sought to define whether combinations of prediction algorithms would improve the functional effect predictions of specific mutations. Literature and database mining of single nucleotide variants (SNVs) affecting 15 cancer genes was performed to identify mutations supported by functional evidence or hereditary disease association to be classified either as non-neutral (n = 849) or neutral (n = 140) with respect to their impact on protein function. These SNVs were employed to test the performance of 15 mutation effect prediction algorithms. The accuracy of the prediction algorithms varies considerably. Although all algorithms perform consistently well in terms of positive predictive value, their negative predictive value varies substantially. Cancer-specific mutation effect predictors display no-to-almost perfect agreement in their predictions of these SNVs, whereas the non-cancer-specific predictors showed no-to-moderate agreement. Combinations of predictors modestly improve accuracy and significantly improve negative predictive values. The information provided by mutation effect predictors is not equivalent. No algorithm is able to predict sufficiently accurately SNVs that should be taken forward for experimental or clinical testing. Combining algorithms aggregates orthogonal information and may result in improvements in the negative predictive value of mutation effect predictions.

  5. Isocitrate dehydrogenase 1 and 2 mutations in cholangiocarcinoma.

    Science.gov (United States)

    Kipp, Benjamin R; Voss, Jesse S; Kerr, Sarah E; Barr Fritcher, Emily G; Graham, Rondell P; Zhang, Lizhi; Highsmith, W Edward; Zhang, Jun; Roberts, Lewis R; Gores, Gregory J; Halling, Kevin C

    2012-10-01

    Somatic mutations in isocitrate dehydrogenase 1 and 2 genes are common in gliomas and help stratify patients with brain cancer into histologic and molecular subtypes. However, these mutations are considered rare in other solid tumors. The aims of this study were to determine the frequency of isocitrate dehydrogenase 1 and 2 mutations in cholangiocarcinoma and to assess histopathologic differences between specimens with and without an isocitrate dehydrogenase mutation. We sequenced 94 formalin-fixed, paraffin-embedded cholangiocarcinoma (67 intrahepatic and 27 extrahepatic) assessing for isocitrate dehydrogenase 1 (codon 132) and isocitrate dehydrogenase 2 (codons 140 and 172) mutations. Multiple histopathologic characteristics were also evaluated and compared with isocitrate dehydrogenase 1/2 mutation status. Of the 94 evaluated specimens, 21 (22%) had a mutation including 14 isocitrate dehydrogenase 1 and 7 isocitrate dehydrogenase 2 mutations. Isocitrate dehydrogenase mutations were more frequently observed in intrahepatic cholangiocarcinoma than in extrahepatic cholangiocarcinoma (28% versus 7%, respectively; P = .030). The 14 isocitrate dehydrogenase 1 mutations were R132C (n = 9), R132S (n = 2), R132G (n = 2), and R132L (n = 1). The 7 isocitrate dehydrogenase 2 mutations were R172K (n = 5), R172M (n = 1), and R172G (n = 1). Isocitrate dehydrogenase mutations were more frequently observed in tumors with clear cell change (P < .001) and poorly differentiated histology (P = .012). The results of this study show for the first time that isocitrate dehydrogenase 1 and 2 genes are mutated in cholangiocarcinoma. The results of this study are encouraging because it identifies a new potential target for genotype-directed therapeutic trials and may represent a potential biomarker for earlier detection of cholangiocarcinoma in a subset of cases.

  6. Transcranial sonography and functional imaging in glucocerebrosidase mutation Parkinson disease.

    Science.gov (United States)

    Barrett, M J; Hagenah, J; Dhawan, V; Peng, S; Stanley, K; Raymond, D; Deik, A; Gross, S J; Schreiber-Agus, N; Mirelman, A; Marder, K; Ozelius, L J; Eidelberg, D; Bressman, S B; Saunders-Pullman, R

    2013-02-01

    Heterozygous glucocerebrosidase (GBA) mutations are the leading genetic risk factor for Parkinson disease, yet imaging correlates, particularly transcranial sonography, have not been extensively described. To determine whether GBA mutation heterozygotes with Parkinson disease demonstrate hyperechogenicity of the substantia nigra, transcranial sonography was performed in Ashkenazi Jewish Parkinson disease subjects, tested for the eight most common Gaucher disease mutations and the LRRK2 G2019S mutation, and in controls. [(18)F]-fluorodeoxyglucose or [(18)F]-fluorodopa positron emission tomography is also reported from a subset of Parkinson disease subjects with heterozygous GBA mutations. Parkinson disease subjects with heterozygous GBA mutations (n = 23) had a greater median maximal area of substantia nigral echogenicity compared to controls (n = 34, aSNmax = 0.30 vs. 0.18, p = 0.007). There was no difference in median maximal area of nigral echogenicity between Parkinson disease groups defined by GBA and LRRK2 genotype: GBA heterozygotes; GBA homozygotes/compound heterozygotes (n = 4, aSNmax = 0.27); subjects without LRRK2 or GBA mutations (n = 32, aSNmax = 0.27); LRRK2 heterozygotes/homozygotes without GBA mutations (n = 27, aSNmax = 0.28); and GBA heterozygotes/LRRK2 heterozygotes (n = 4, aSNmax = 0.32, overall p = 0.63). In secondary analyses among Parkinson disease subjects with GBA mutations, maximal area of nigral echogenicity did not differ based on GBA mutation severity or mutation number. [(18)F]-fluorodeoxyglucose (n = 3) and [(18)F]-fluorodopa (n = 2) positron emission tomography in Parkinson disease subjects with heterozygous GBA mutations was consistent with findings in idiopathic Parkinson disease. Both transcranial sonography and positron emission tomography are abnormal in GBA mutation associated Parkinson disease, similar to other Parkinson disease subjects. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Mutations in galactosemia

    Energy Technology Data Exchange (ETDEWEB)

    Reichardt, J.K.V. [Univ. of Southern California School of Medicine, Los Angeles, CA (United States)

    1995-10-01

    This Letter raises four issues concerning two papers on galactosemia published in the March 1995 of the Journal. First, table 2 in the paper by Elsas et al. incorrectly attributes seven galactose-l-phosphate uridyl transferase (GALT) mutations (S135L, L195P, K285N, N314D, R333W, R333G, and K334R). The table also fails to mention that others have reported the same two findings attributed to {open_quotes}Leslie et al.; Elsas et al. and in press{close_quotes} and {open_quotes}Leslie et al.; Elsas et al.{close_quotes} The first finding on the prevalence of the Q188R galactosemia mutation in the G/G Caucasian population has also been described by Ng et al., and the second finding on the correlation of the N314D GALT mutation with the Duarte variant was reported by Lin et al. Second, Elsas et al. suggest that the E203K and N314D mutations may {open_quotes}produce intra-allelic complementation when in cis{close_quotes}. This speculation is supported by the activity data of individual III-2 but is inconsistent with the activities of three other individuals I-1, II-1, and III-1 of the same pedigree. The GALT activity measured in these three individuals suggests a dominant negative effect of E203K in E203K-N314D chromosomes, since they all have less than normal activity. Thus, the preponderance of the data in this paper is at odds with the authors speculation. It is worth recalling that Lin et al. also identified four N314D GALT mutations on 95 galactosemic chromosomes examined. A similar situation also appears to be the case in proband III-1 (with genotype E203K-N314D/IVSC) in the Elsas et al. paper. 9 refs.

  8. Evolutionary Stability Against Multiple Mutations

    CERN Document Server

    Ghatak, Anirban; Shaiju, A J

    2012-01-01

    It is known (see e.g. Weibull (1995)) that ESS is not robust against multiple mutations. In this article, we introduce robustness against multiple mutations and study some equivalent formulations and consequences.

  9. BRAF mutations in conjunctival melanoma

    DEFF Research Database (Denmark)

    Larsen, Ann-Cathrine; Dahl, Christina; Dahmcke, Christina M.

    2016-01-01

    Purpose: To investigate incidence, clinicopathological features and prognosis of BRAF-mutated conjunctival melanoma in Denmark. Furthermore, to determine BRAF mutations in paired premalignant lesions and evaluate immunohistochemical BRAF V600E oncoprotein detection. Methods: Data from 139 patients...

  10. Mutational analysis of paediatric patients with tuberous sclerosis complex in Korea: genotype and epilepsy.

    Science.gov (United States)

    Lee, Jin Sook; Lim, Byung Chan; Chae, Jong-Hee; Hwang, Yong Seung; Seong, Moon-Woo; Park, Sung Sup; Kim, Ki Joong

    2014-12-01

    To date, only a few studies have reported that, in tuberous sclerosis, TSC2 mutations are more frequently associated with infantile spasms and cognitive impairment compared to TSC1 mutations. We analyzed the mutational spectrum of patients with tuberous sclerosis in Korea and attempted to explore the associations between genotype and seizure type/outcome. We performed mutational analyses on 70 unrelated patients with clinically confirmed tuberous sclerosis by using direct DNA sequencing and/or multiplex ligation-dependent probe amplification. The patients' medical records, including epilepsy type and outcome, were reviewed retrospectively. We identified pathogenic mutations in 55 patients (79%), 25 of which were novel. There were 12 TSC1 mutations and 43 TSC2 mutations. TSC1 mutations included 8 frameshift and 4 nonsense mutations. TSC2 mutations included 12 frameshift, 10 nonsense, 6 splicing, and 6 missense mutations, as well as 4 in-frame deletions and 5 large deletions. Fifty-eight patients had epilepsy (83%), including 19 patients with a history of infantile spasms. Compared to patients with TSC1 mutations, individuals with TSC2 mutations had a significantly higher frequency of epilepsy (p<0.05) and tended to have a higher frequency of infantile spasms (37% vs 17%; p<0.3). Most of the patients with TSC2 mutations who developed infantile spasms exhibited subsequent epilepsy (13/14; 93%). However, the presence/absence of infantile spasms did not influence seizure remission or cognitive outcome.

  11. Absence of R140Q mutation of isocitrate dehydrogenase 2 in gliomas and breast cancers.

    Science.gov (United States)

    Raynaud, Stéphane; Carbuccia, Nadine; Colin, Carole; Adélaïde, José; Mozziconacci, Marie-Joelle; Metellus, Philippe; Chinot, Olivier; Birnbaum, Daniel; Chaffanet, Max; Figarella-Branger, Dominique

    2010-09-01

    Somatic mutations of isocitrate dehydrogenase (IDH)-1 and IDH2 proteins have been described in gliomas. The mutations target the R132 amino acid residue and the R172 residue in IDH1 and IDH2, respectively. The same mutations were observed in acute myeloid leukemias with normal karyotype, but a new mutation in IDH2 (R140Q substitution) was detected in malignant myeloid diseases and appears to be the most frequent IDH mutation in these pathologies. To the best of our knowledge, no study thus far has reported the presence of this R140Q mutation in IDH2 in tumors of the nervous system and breast cancers. We evaluated IDH1 and IDH2 exon 4 in 48 low-grade gliomas, 58 primary glioblastomas and 94 breast cancers to evaluate the frequency of mutation and investigated the R140Q substitution in IDH2. The results were compared to our recently obtained results in hematopoietic diseases. The frequency of IDH1 and IDH2 mutations in our panel of gliomas was similar to previously reported mutations. No IDH2 R140 mutation was observed. Compared to hematopoietic diseases, the IDH2 R172 mutation was also more rare and IDH1 mutations more prominent in tumors of the nervous system. No IDH1 or IDH2 mutation was detected in the 94 breast cancer samples. Thus, the IDH2 R140 mutation appears to be restricted to hematopoietic diseases.

  12. Association of TERT Promoter Mutation, But Not BRAF Mutation, With Increased Mortality in PTC.

    Science.gov (United States)

    George, Jonathan R; Henderson, Ying C; Williams, Michelle D; Roberts, Dianna B; Hei, Hu; Lai, Stephen Y; Clayman, Gary L

    2015-12-01

    Papillary thyroid carcinoma (PTC) carrying the BRAF mutation has been reported to be associated with high recurrence and potentially increased mortality. PTC carrying the TERT promoter mutation has been associated with older age, recurrence, and aggressive disease. The objective of this study was to determine the association of BRAF and TERT promoter gene alterations with recurrence and survival in a high-risk population. Genomic DNA was analyzed for the BRAF mutation from 256 persistent/recurrent PTC (p/rPTC; 202 new, 54 previously reported) and for the TERT promoter mutation and polymorphism (242 p/rPTC). Two-tailed Fisher exact tests or the Pearson χ(2) test were performed for the associations between mutations and other variables. Overall and disease-free survivals were compared by log rank tests on Kaplan-Meier plots and by Cox regression analysis. TERT promoter constructs were tested in PTC cell lines to determine their activities in these cells. BRAF V600E mutation was identified in 235 of 256 (91.8%), TERT promoter mutation at -124 was detected in 77 of 242 (31.8%), and TERT promoter polymorphism at -245 was found in 113 of 242 (46.7%) p/rPTC patients. A significant difference in survival was found in p/rPTC patients with the TERT promoter mutation, which also displayed increased activity in vitro as compared to the nonmutated promoter sequence. No association was noted between the BRAF mutation or TERT promoter polymorphism and recurrence or survival. A drawback of our study could be the limited number of patients with nonmutated BRAF (21 of 256 [8.2%]). Mutation in the TERT promoter, but not in BRAF, was associated with decreased survival in 19 (24.7%) p/rPTC patients who died of disease and in 38 (49.4%) p/rPTC patients who died at last contact. The presence or absence of the BRAF mutation and TERT promoter polymorphism, however, was not significantly correlated with survival.

  13. Kin Selection - Mutation Balance

    DEFF Research Database (Denmark)

    Dyken, J. David Van; Linksvayer, Timothy Arnold; Wade, Michael J.

    2011-01-01

    Abstract Social conflict, in the form of intraspecific selfish "cheating" has been observed in a number of natural systems. However, a formal, evolutionary genetic theory of social cheating that provides an explanatory, predictive framework for these observations is lacking. Here we derive the kin...... selection-mutation balance, which provides an evolutionary null hypothesis for the statics and dynamics of cheating. When social interactions have linear fitness effects and Hamilton´s rule is satisfied, selection is never strong enough to eliminate recurrent cheater mutants from a population, but cheater...... lineages are transient and do not invade. Instead, cheating lineages are eliminated by kin selection but are constantly reintroduced by mutation, maintaining a stable equilibrium frequency of cheaters. The presence of cheaters at equilibrium creates a "cheater load" that selects for mechanisms of cheater...

  14. Mutation of Auslander generators

    CERN Document Server

    Lada, Magdalini

    2009-01-01

    Let $\\Lambda$ be an artin algebra with representation dimension equal to three and $M$ an Auslander generator of $\\Lambda$. We show how, under certain assumptions, we can mutate $M$ to get a new Auslander generator whose endomorphism ring is derived equivalent to the endomorphism ring of $M$. We apply our results to selfinjective algebras with radical cube zero of infinite representation type, where we construct an infinite set of Auslander generators.

  15. Sex and deleterious mutations.

    Science.gov (United States)

    Gordo, Isabel; Campos, Paulo R A

    2008-05-01

    The evolutionary advantage of sexual reproduction has been considered as one of the most pressing questions in evolutionary biology. While a pluralistic view of the evolution of sex and recombination has been suggested by some, here we take a simpler view and try to quantify the conditions under which sex can evolve given a set of minimal assumptions. Since real populations are finite and also subject to recurrent deleterious mutations, this minimal model should apply generally to all populations. We show that the maximum advantage of recombination occurs for an intermediate value of the deleterious effect of mutations. Furthermore we show that the conditions under which the biggest advantage of sex is achieved are those that produce the fastest fitness decline in the corresponding asexual population and are therefore the conditions for which Muller's ratchet has the strongest effect. We also show that the selective advantage of a modifier of the recombination rate depends on its strength. The quantification of the range of selective effects that favors recombination then leads us to suggest that, if in stressful environments the effect of deleterious mutations is enhanced, a connection between sex and stress could be expected, as it is found in several species.

  16. Septin mutations in human cancers

    Directory of Open Access Journals (Sweden)

    Elias T Spiliotis

    2016-11-01

    Full Text Available Septins are GTP-binding proteins that are evolutionarily and structurally related to the RAS oncogenes. Septin expression levels are altered in many cancers and new advances point to how abnormal septin expression may contribute to the progression of cancer. In contrast to the RAS GTPases, which are frequently mutated and actively promote tumorigenesis, little is known about the occurrence and role of septin mutations in human cancers. Here, we review septin missense mutations that are currently in the Catalog of Somatic Mutations in Cancer (COSMIC database. The majority of septin mutations occur in tumors of the large intestine, skin, endometrium and stomach. Over 25% of the annotated mutations in SEPT2, SEPT4 and SEPT9 belong to large intestine tumors. From all septins, SEPT9 and SEPT14 exhibit the highest mutation frequencies in skin, stomach and large intestine cancers. While septin mutations occur with frequencies lower than 3%, recurring mutations in several invariant and highly conserved amino acids are found across different septin paralogs and tumor types. Interestingly, a significant number of these mutations occur in the GTP-binding pocket and septin dimerization interfaces. Future studies may determine how these somatic mutations affect septin structure and function, whether they contribute to the progression of specific cancers and if they could serve as tumor-specific biomarkers.

  17. Calreticulin Mutations in Myeloproliferative Neoplasms

    Directory of Open Access Journals (Sweden)

    Noa Lavi

    2014-10-01

    Full Text Available With the discovery of the JAK2V617F mutation in patients with Philadelphia chromosome-negative (Ph− myeloproliferative neoplasms (MPNs in 2005, major advances have been made in the diagnosis of MPNs, in understanding of their pathogenesis involving the JAK/STAT pathway, and finally in the development of novel therapies targeting this pathway. Nevertheless, it remains unknown which mutations exist in approximately one-third of patients with non-mutated JAK2 or MPL essential thrombocythemia (ET and primary myelofibrosis (PMF. At the end of 2013, two studies identified recurrent mutations in the gene encoding calreticulin (CALR using whole-exome sequencing. These mutations were revealed in the majority of ET and PMF patients with non-mutated JAK2 or MPL but not in polycythemia vera patients. Somatic 52-bp deletions (type 1 mutations and recurrent 5-bp insertions (type 2 mutations in exon 9 of the CALR gene (the last exon encoding the C-terminal amino acids of the protein calreticulin were detected and found always to generate frameshift mutations. All detected mutant calreticulin proteins shared a novel amino acid sequence at the C-terminal. Mutations in CALR are acquired early in the clonal history of the disease, and they cause activation of JAK/STAT signaling. The CALR mutations are the second most frequent mutations in Ph− MPN patients after the JAK2V617F mutation, and their detection has significantly improved the diagnostic approach for ET and PMF. The characteristics of the CALR mutations as well as their diagnostic, clinical, and pathogenesis implications are discussed in this review.

  18. Mitochondrial DNA mutations in mutator mice confer respiration defects and B-cell lymphoma development.

    Directory of Open Access Journals (Sweden)

    Takayuki Mito

    Full Text Available Mitochondrial DNA (mtDNA mutator mice are proposed to express premature aging phenotypes including kyphosis and hair loss (alopecia due to their carrying a nuclear-encoded mtDNA polymerase with a defective proofreading function, which causes accelerated accumulation of random mutations in mtDNA, resulting in expression of respiration defects. On the contrary, transmitochondrial mito-miceΔ carrying mtDNA with a large-scale deletion mutation (ΔmtDNA also express respiration defects, but not express premature aging phenotypes. Here, we resolved this discrepancy by generating mtDNA mutator mice sharing the same C57BL/6J (B6J nuclear background with that of mito-miceΔ. Expression patterns of premature aging phenotypes are very close, when we compared between homozygous mtDNA mutator mice carrying a B6J nuclear background and selected mito-miceΔ only carrying predominant amounts of ΔmtDNA, in their expression of significant respiration defects, kyphosis, and a short lifespan, but not the alopecia. Therefore, the apparent discrepancy in the presence and absence of premature aging phenotypes in mtDNA mutator mice and mito-miceΔ, respectively, is partly the result of differences in the nuclear background of mtDNA mutator mice and of the broad range of ΔmtDNA proportions of mito-miceΔ used in previous studies. We also provided direct evidence that mtDNA abnormalities in homozygous mtDNA mutator mice are responsible for respiration defects by demonstrating the co-transfer of mtDNA and respiration defects from mtDNA mutator mice into mtDNA-less (ρ(0 mouse cells. Moreover, heterozygous mtDNA mutator mice had a normal lifespan, but frequently developed B-cell lymphoma, suggesting that the mtDNA abnormalities in heterozygous mutator mice are not sufficient to induce a short lifespan and aging phenotypes, but are able to contribute to the B-cell lymphoma development during their prolonged lifespan.

  19. Impact of TP53 Mutations on Outcome in EGFR-Mutated Patients Treated with First-Line Tyrosine Kinase Inhibitors.

    Science.gov (United States)

    Canale, Matteo; Petracci, Elisabetta; Delmonte, Angelo; Chiadini, Elisa; Dazzi, Claudio; Papi, Maximilian; Capelli, Laura; Casanova, Claudia; De Luigi, Nicoletta; Mariotti, Marita; Gamboni, Alessandro; Chiari, Rita; Bennati, Chiara; Calistri, Daniele; Ludovini, Vienna; Crinò, Lucio; Amadori, Dino; Ulivi, Paola

    2016-10-25

    Purpose: To analyze the impact of TP53 mutations on response to first-line tyrosine kinase inhibitors (TKI) in patients with EGFR-mutated non-small cell lung cancer (NSCLC).Experimental Design: 136 EGFR-mutated NSCLC patients receiving first-line TKIs were analyzed. TP53 mutations were evaluated in 123 patients in relation to disease control rate (DCR), objective response rate (ORR), progression-free survival (PFS), and overall survival (OS).Results:TP53 mutations were observed in 37 (30.1%), 10 (27.0%), 6 (16.2%), 9 (24.3%), and 12 (32.4%) patients in exons 5, 6, 7, and 8, respectively. DCR was 70% in TP53-mutated patients compared with 88% in TP53-wild type (wt) patients [relative risk, RR, of disease progression: 3.17 (95% CI, 1.21-8.48), P = 0.019]. In particular, a 42% DCR was observed in patients with TP53 exon 8 mutation versus 87% in exon 8 wt patients [RR of disease progression 9.6 (2.71-36.63), P TP53 exon 8 mutations compared with others (4.2 vs. 12.5, P = 0.058, and 16.2 vs. 32.3, P = 0.114, respectively); these differences became significant in the subgroup with EGFR exon 19 deletion (4.2 vs. 16.8, P TP53 mutations, especially exon 8 mutations, reduce responsiveness to TKIs and worsen prognosis in EGFR-mutated NSCLC patients, mainly those carrying exon 19 deletions. Clin Cancer Res; 1-8. ©2016 AACR.

  20. Molecular characterization of a balanced rearrangement of chromosome 12 in two siblings with Noonan syndrome.

    Science.gov (United States)

    Yatsenko, Svetlana A; del Valle Torrado, Maria; Fernandes, Priscilla H; Wiszniewska, Joanna; Gallego, Marta; Herrera, Jorge; Bacino, Carlos A

    2009-12-01

    The etiology of Noonan syndrome (NS) has been greatly elucidated with the discovery of the disease causative genes PTPN11, KRAS, SOS1, and RAF1, all involved in the RAS/MAPK-signaling cascade. Given that overall mutations are identified in about 70% of patients, identification of other NS associated genes remains a high priority to fully understand the etiopathogenesis of the condition. We report two affected siblings with an apparently balanced rearrangement of chromosome 12 ins(12)(q12p11.2p12.3) which segregates with the Noonan phenotype. The rearrangement was inherited from the phenotypically normal mother who had mosaicism for the derivative chromosome 12. There were no mutations of PTPN11, KRAS, SOS1, or RAF1 genes detected in the probands. Using fluorescence in situ hybridization analysis we identified the three breakpoints involved at 12p12.3, 12p11.2, and 12q12. By microarray analysis, there were no gains or losses near the breakpoints. Neither, the PTPN11 or KRAS region on chromosome 12 was involved in the rearrangement. We hypothesize that other NS candidate gene(s) may be located in the breakpoint regions of chromosome 12 causing the Noonan phenotype in both of these children.

  1. Discovery of Single Nucleotide Polymorphisms and Mutations by Pyrosequencing

    OpenAIRE

    2006-01-01

    Comparative genomics, analyzing variation among individual genomes, is an area of intense investigation. DNA sequencing is usually employed to look for polymorphisms and mutations. Pyrosequencing, a real-time DNA sequencing method, is emerging as a popular platform for comparative genomics. Here we review the use of this technology for mutation scanning, polymorphism discovery and chemical haplotyping. We describe the methodology and accuracy of this technique and discuss how t...

  2. Hypothesis: Obesity Is Associated with a Lower Mutation Threshold in Colon Cancer.

    Science.gov (United States)

    Bordonaro, Michael; Lazarova, Darina

    2015-01-01

    Neoplastic progression requires accumulation of several mutations (mutation threshold). We hypothesize that obesity raises the risk of microsatellite stable (MSS) colon cancer (CC) at least in part by decreasing the mutation threshold. Thus, we posit that obese patients require fewer mutations, particularly driver mutations, compared to their normal BMI counterparts. Further, we suggest that the reduced number of required mutations in obese patients could be due to several factors, including the high levels of cytokines that accompany obesity. Cytokine-activated ERK, AKT, and JAK/STAT signaling could synergize with CC-initiating mutations to promote intestinal neoplastic development. Therefore, driver mutations that induce these specific pathways may not be "required" for neoplastic development in obesity; alteration in cell signaling consequent to obesity can substitute for some driver mutations in neoplastic progression. This hypothesis is supported by preliminary analyses of data from The Cancer Genome Atlas (TCGA). Thus, we observed that, compared to normal weight patients, cancer genomes of obese MSS CC patients exhibit fewer somatic mutations, and correspondingly lower numbers of mutations in driver genes (P = 0.026).The most striking observation was the lower number of KRAS mutations detected in patients with high body-mass index (BMI). These intriguing observations require further validation with increased number of patients, taking into account all possible confounding factors. If the hypothesis is confirmed, future studies should also address several possible explanations for the observed lower mutation threshold in obese MSS CC patients.

  3. Clinical implications of TP53 mutations in myelodysplastic syndromes treated with hypomethylating agents.

    Science.gov (United States)

    Takahashi, Koichi; Patel, Keyur; Bueso-Ramos, Carlos; Zhang, Jianhua; Gumbs, Curtis; Jabbour, Elias; Kadia, Tapan; Andreff, Michael; Konopleva, Marina; DiNardo, Courtney; Daver, Naval; Cortes, Jorge; Estrov, Zeev; Futreal, Andrew; Kantarjian, Hagop; Garcia-Manero, Guillermo

    2016-03-22

    We screened TP53 mutations in 168 MDS patients who were treated with HMA and evaluated predictive and prognostic value of TP53 mutations. Overall response to HMA was not different based on TP53 mutation status (45% vs. 32% in TP53-mutated and wild type [WT], respectively, P = 0.13). However, response duration was significantly shorter in TP53-mutated patients compared to WT patients (5.7 months vs. 28.5 months, P = 0.003). Longitudinal analysis of TP53 mutations after HMA showed that TP53 mutations almost always persisted at times of disease progression. TP53-mutated patients showed significantly worse overall survival (OS) compared to WT patients (9.4 months vs. 20.7 months, P TP53 mutations distinguished prognosis in the subgroup of patients with complex karyotype and Revised International Prognostic Scoring System (IPSS-R) defined very high-risk disease. Multivariate analysis showed that TP53 mutation status is significantly prognostic for OS after adjusting prognostic effect from other factors. The current study provides evidence that TP53 mutations are independently prognostic in MDS patients treated with HMA. While TP53-mutated MDS patients initially respond well to HMA, their duration of response is significantly shorter than WT patients. Novel strategies to improve duration of response in TP53-mutated MDS are urgently needed.

  4. Lynch Syndrome Caused by Germline PMS2 Mutations

    DEFF Research Database (Denmark)

    Ten Broeke, Sanne W; Brohet, Richard M; Tops, Carli M

    2015-01-01

    . Standardized incidence ratios (SIRs) were calculated to estimate risks for other Lynch syndrome-associated cancers. RESULTS: The cumulative risk (CR) of CRC for male mutation carriers by age 70 years was 19%. The CR among female carriers was 11% for CRC and 12% for EC. The mean age of CRC development was 52......PURPOSE: The clinical consequences of PMS2 germline mutations are poorly understood compared with other Lynch-associated mismatch repair gene (MMR) mutations. The aim of this European cohort study was to define the cancer risk faced by PMS2 mutation carriers. METHODS: Data were collected from 98...... years, and there was a significant difference in mean age of CRC between the probands (mean, 47 years; range, 26 to 68 years) and other family members with a PMS2 mutation (mean, 58 years; range, 31 to 86 years; P

  5. Somatic mutation patterns and compound response in cancers

    Directory of Open Access Journals (Sweden)

    Ningning He

    2013-02-01

    Full Text Available The use of various cancer cell lines can recapitulate knowntumor-associated mutations and genetically define cancersubsets. This approach also enables comparative surveys ofassociations between cancer mutations and drug responses.Here, we analyzed the effects of ∼40,000 compounds oncancer cell lines that showed diverse mutation-dependentsensitivity profiles. Over 1,000 compounds exhibited uniquesensitivity on cell lines with specific mutational genotypes,and these compounds were clustered into six different classesof mutation-oriented sensitivity. The present analysis providesnew insights into the relationship between somatic mutationsand selectivity response of chemicals, and these results shouldhave applications related to predicting and optimizing therapeuticwindows for anti-cancer agents. [BMB Reports 2013;46(2: 97-102

  6. Analyzing the H19- and T65-epitopes in 38 kd phosphorylated protein of Marek's disease viruses and comparing chicken immunological reactions to viruses point-mutated in the epitopes

    Institute of Scientific and Technical Information of China (English)

    CUI Zhizhong; ZHANG Zhi; QIN Aijian; Lee Lucy F

    2004-01-01

    DNA sequencing analysis in 38 kd phosphorylated protein (pp38) ORF of Marek's disease viruses (MDV) indicated that all tested 10 virulent strains with different pathotypes had 'A' at base #320 and glutamine at aa#107 while reacted with monoclonal antibody (Mab) H19 in indirect fluorescence antibody test (IFA). However, vaccine strain CVI988 had 'G' at base#320 and arginine at aa#107 instead, when it was negative in IFA with Mab H19. Some strains were also reactive with Mab T65 in IFA while there was 'G' at base #326 and glycine at aa#109, but the other strains, which had 'A' at base #326 and glutamic acid at aa#109, did not react with Mab T65. By comparison of CVI988 to its point mutants CVI/rpp38(AG) and CVI/rpp38(AA) with 1 or 2 base(s) changes at bases #320 and /or #326 of pp38 gene for their reactivity with Mab H19 and T65, it was confirmed that the glutamine at aa#107 and glycine at aa#109 were critical to epitopes H19 and T65 respectively. Immuno-reactions to MDV were compared in SPF chickens inoculated with cloned CVI988 and its mutant CVI/rpp38(AG). It was found that antibody responses to MDV in chickens inoculated with CVI/rpp38(AG) were delayed and significantly lower than that in chickens inoculated with the native CVI988. By differential comparison of antibody titers to different antigens, a third epitope specific to CVI988 and dependent on arginine at aa#107 was suggested to be responsible for the big difference in antibody responses induced by native CVI988 and its mutant.

  7. Oxidative stress is not a major contributor to somatic mitochondrial DNA mutations.

    Directory of Open Access Journals (Sweden)

    Leslie S Itsara

    2014-02-01

    Full Text Available The accumulation of somatic mitochondrial DNA (mtDNA mutations is implicated in aging and common diseases of the elderly, including cancer and neurodegenerative disease. However, the mechanisms that influence the frequency of somatic mtDNA mutations are poorly understood. To develop a simple invertebrate model system to address this matter, we used the Random Mutation Capture (RMC assay to characterize the age-dependent frequency and distribution of mtDNA mutations in the fruit fly Drosophila melanogaster. Because oxidative stress is a major suspect in the age-dependent accumulation of somatic mtDNA mutations, we also used the RMC assay to explore the influence of oxidative stress on the somatic mtDNA mutation frequency. We found that many of the features associated with mtDNA mutations in vertebrates are conserved in Drosophila, including a comparable somatic mtDNA mutation frequency (∼10(-5, an increased frequency of mtDNA mutations with age, and a prevalence of transition mutations. Only a small fraction of the mtDNA mutations detected in young or old animals were G∶C to T∶A transversions, a signature of oxidative damage, and loss-of-function mutations in the mitochondrial superoxide dismutase, Sod2, had no detectable influence on the somatic mtDNA mutation frequency. Moreover, a loss-of-function mutation in Ogg1, which encodes a DNA repair enzyme that removes oxidatively damaged deoxyguanosine residues (8-hydroxy-2'-deoxyguanosine, did not significantly influence the somatic mtDNA mutation frequency of Sod2 mutants. Together, these findings indicate that oxidative stress is not a major cause of somatic mtDNA mutations. Our data instead suggests that somatic mtDNA mutations arise primarily from errors that occur during mtDNA replication. Further studies using Drosophila should aid in the identification of factors that influence the frequency of somatic mtDNA mutations.

  8. Role of mutation in Pseudomonas aeruginosa biofilm development.

    Directory of Open Access Journals (Sweden)

    Tim C R Conibear

    Full Text Available The survival of bacteria in nature is greatly enhanced by their ability to grow within surface-associated communities called biofilms. Commonly, biofilms generate proliferations of bacterial cells, called microcolonies, which are highly recalcitrant, 3-dimensional foci of bacterial growth. Microcolony growth is initiated by only a subpopulation of bacteria within biofilms, but processes responsible for this differentiation remain poorly understood. Under conditions of crowding and intense competition between bacteria within biofilms, microevolutionary processes such as mutation selection may be important for growth; however their influence on microcolony-based biofilm growth and architecture have not previously been explored. To study mutation in-situ within biofilms, we transformed Pseudomonas aeruginosa cells with a green fluorescent protein gene containing a +1 frameshift mutation. Transformed P. aeruginosa cells were non-fluorescent until a mutation causing reversion to the wildtype sequence occurs. Fluorescence-inducing mutations were observed in microcolony structures, but not in other biofilm cells, or in planktonic cultures of P. aeruginosa cells. Thus microcolonies may represent important foci for mutation and evolution within biofilms. We calculated that microcolony-specific increases in mutation frequency were at least 100-fold compared with planktonically grown cultures. We also observed that mutator phenotypes can enhance microcolony-based growth of P. aeruginosa cells. For P. aeruginosa strains defective in DNA fidelity and error repair, we found that microcolony initiation and growth was enhanced with increased mutation frequency of the organism. We suggest that microcolony-based growth can involve mutation and subsequent selection of mutants better adapted to grow on surfaces within crowded-cell environments. This model for biofilm growth is analogous to mutation selection that occurs during neoplastic progression and tumor

  9. Filaggrin mutations and the skin

    Directory of Open Access Journals (Sweden)

    Dipankar De

    2012-01-01

    Full Text Available Filaggrin is very important in the terminal differentiation of the skin and the formation of cornified envelope in the stratum corneum. Several mutations in the filaggrin gene have been identified in the last decade, mostly from the European countries. Loss of function mutations in the filaggrin gene results in reduced production of filaggrin, depending on the type and site of mutation. Such mutations in the filaggrin gene have been shown to be the most significant genetic risk factor for development of atopic dermatitis and undoubtedly has a role in the pathogenesis of ichthyosis vulgaris. Though there is theoretical possibility of association with hand eczema and allergic contact dermatitis; in clinical studies, the strength of these associations was not significantly strong. In this review, we have discussed the structure and function of filaggrin, basic genetics, type of mutations in filaggrin gene, and association of such mutations with different dermatoses.

  10. Muller's ratchet with compensatory mutations

    CERN Document Server

    Pfaffelhuber, Peter; Wakolbinger, Anton

    2011-01-01

    We consider an infinite dimensional system of stochastic differential equations which describes the evolution of type frequencies in a large population. Random reproduction is modeled by a Wright-Fisher noise whose inverse diffusion coefficient $N$ corresponds to the total population size. The type of an individual is the number $k$ of deleterious mutations it carries. We assume that fitness of individuals carrying $k$ mutations is decreased by $\\alpha k$ for some $\\alpha >0$. Along the individual lines of descent, (new) mutations accumulate at rate $\\lambda$ per generation, and each of these mutations has a small probability $\\gamma$ per generation to disappear. While the case $\\gamma =0 $ is known as (the Fleming-Viot version of) {\\em Muller's ratchet}, the case $\\gamma > 0$ is referred to as that of {\\em compensatory mutations} in the biological literature. In the former case ($\\gamma=0$), an ever increasing number of mutations is accumulated over time, while in the latter ($\\gamma > 0$) this is prevented ...

  11. Filaggrin mutations and the skin.

    Science.gov (United States)

    De, Dipankar; Handa, Sanjeev

    2012-01-01

    Filaggrin is very important in the terminal differentiation of the skin and the formation of cornified envelope in the stratum corneum. Several mutations in the filaggrin gene have been identified in the last decade, mostly from the European countries. Loss of function mutations in the filaggrin gene results in reduced production of filaggrin, depending on the type and site of mutation. Such mutations in the filaggrin gene have been shown to be the most significant genetic risk factor for development of atopic dermatitis and undoubtedly has a role in the pathogenesis of ichthyosis vulgaris. Though there is theoretical possibility of association with hand eczema and allergic contact dermatitis; in clinical studies, the strength of these associations was not significantly strong. In this review, we have discussed the structure and function of filaggrin, basic genetics, type of mutations in filaggrin gene, and association of such mutations with different dermatoses.

  12. SARS病毒和其他冠状病毒中性突变速率初步的比较研究%The preliminary comparative study of the neutral mutation rate of SARS-CoV and other groups of Coronavirus

    Institute of Scientific and Technical Information of China (English)

    孙慧敏; 唐晓凤; 王波; 谭雅慧; 于晓寒; 张景霞; 闫永平; 夏结来; 徐德忠

    2011-01-01

    not the main reason for low R2 in this volume. Conclusions The comparative study on neutral mutation rate of SARS-CoV and the other three groups of coronaviruses using the same method shows there are significant differences or different modes between the two groups. It seems that there are some special aspects on the mode of molecular evolution or origin of SARS-CoV compared with the other three groups of coronavirus.

  13. Mutations induced in plant breeding

    Energy Technology Data Exchange (ETDEWEB)

    Barriga B, P. (Universidad Austral de Chile, Valdivia. Inst. de Produccion y Sanidad Vegetal)

    1984-10-01

    The most significant aspects of the use of ionizing radiations in plant breeding are reviewed. Aspects such as basic principles of mutation, expression and selection in obtention of mutants, methods for using induced mutations and sucess achieved with this methodology in plant breeding are reviewed. Results obtained in a program of induced mutation on wheat for high content of protein and lysine at the Universidad Austral de Chile are presented.

  14. TP53 mutations in older adults with acute myeloid leukemia.

    Science.gov (United States)

    Yanada, Masamitsu; Yamamoto, Yukiya; Iba, Sachiko; Okamoto, Akinao; Inaguma, Yoko; Tokuda, Masutaka; Morishima, Satoko; Kanie, Tadaharu; Mizuta, Shuichi; Akatsuka, Yoshiki; Okamoto, Masataka; Emi, Nobuhiko

    2016-04-01

    The net benefits of induction therapy for older adults with acute myeloid leukemia (AML) remain controversial. Because AML in older adults is a heterogeneous disease, it is important to identify those who are unlikely to benefit from induction therapy based on information available at the initial assessment. We used next-generation sequencing to analyze TP53 mutation status in AML patients aged 60 years or older, and evaluated its effects on outcomes. TP53 mutations were detected in 12 of 77 patients (16 %), and there was a significant association between TP53 mutations and monosomal karyotype. Patients with TP53 mutations had significantly worse survival than those without (P = 0.009), and multivariate analysis identified TP53 mutation status as the most significant prognostic factor for survival. Neverthelsess, TP53-mutated patients had a 42 % chance of complete remission and a median survival of 8.0 months, which compares favorably with those who did not undergo induction therapy, even in the short term. These results suggest that screening for TP53 mutations at diagnosis is useful for identifying older adults with AML who are least likely to respond to chemotherapy, although the presence of this mutation alone does not seem to justify rejecting induction therapy.

  15. AKT1 and BRAF mutations in pediatric aggressive fibromatosis.

    Science.gov (United States)

    Meazza, Cristina; Belfiore, Antonino; Busico, Adele; Settanni, Giulio; Paielli, Nicholas; Cesana, Luca; Ferrari, Andrea; Chiaravalli, Stefano; Massimino, Maura; Gronchi, Alessandro; Colombo, Chiara; Pilotti, Silvana; Perrone, Federica

    2016-06-01

    Aside from the CTNNB1 and adenomatous polyposis coli (APC) mutations, the genetic profile of pediatric aggressive fibromatosis (AF) has remained poorly characterized. The aim of this study was to shed more light on the mutational spectrum of pediatric AF, comparing it with its adult counterpart, with a view to identifying biomarkers for use as prognostic factors or new potential therapeutic targets. CTNNB1, APC, AKT1, BRAF TP53, and RET Sanger sequencing and next-generation sequencing (NGS) with the 50-gene Ion AmpliSeq Cancer Hotspot Panel v2 were performed on formalin-fixed samples from 28 pediatric and 33 adult AFs. The prognostic value of CTNNB1, AKT1, and BRAF mutations in pediatric AF patients was investigated. Recurrence-free survival (RFS) curves were estimated with the Kaplan-Meier method and statistical comparisons were drawn using the log-rank test. In addition to the CTNNB1 mutation (64%), pediatric AF showed AKT1 (31%), BRAF (19%), and TP53 (9%) mutations, whereas only the CTNNB1 mutation was found in adult AF. The polymorphism Q472H VEGFR was identified in both pediatric (56%) and adult (40%) AF. Our results indicate that the mutational spectrum of pediatric AF is more complex than that of adult AF, with multiple gene mutations involving not only CTNNB1 but also AKT1 and BRAF. This intriguing finding may have clinical implications and warrants further investigations. © 2016 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  16. Differential evolution with ranking-based mutation operators.

    Science.gov (United States)

    Gong, Wenyin; Cai, Zhihua

    2013-12-01

    Differential evolution (DE) has been proven to be one of the most powerful global numerical optimization algorithms in the evolutionary algorithm family. The core operator of DE is the differential mutation operator. Generally, the parents in the mutation operator are randomly chosen from the current population. In nature, good species always contain good information, and hence, they have more chance to be utilized to guide other species. Inspired by this phenomenon, in this paper, we propose the ranking-based mutation operators for the DE algorithm, where some of the parents in the mutation operators are proportionally selected according to their rankings in the current population. The higher ranking a parent obtains, the more opportunity it will be selected. In order to evaluate the influence of our proposed ranking-based mutation operators on DE, our approach is compared with the jDE algorithm, which is a highly competitive DE variant with self-adaptive parameters, with different mutation operators. In addition, the proposed ranking-based mutation operators are also integrated into other advanced DE variants to verify the effect on them. Experimental results indicate that our proposed ranking-based mutation operators are able to enhance the performance of the original DE algorithm and the advanced DE algorithms.

  17. A Novel Technique to Detect EGFR Mutations in Lung Cancer

    Directory of Open Access Journals (Sweden)

    Yuanbin Liu

    2016-05-01

    Full Text Available Epidermal growth factor receptor (EGFR gene mutations occur in multiple human cancers; therefore, the detection of EGFR mutations could lead to early cancer diagnosis. This study describes a novel EGFR mutation detection technique. Compared to direct DNA sequencing detection methods, this method is based on allele-specific amplification (ASA, recombinase polymerase amplification (RPA, peptide nucleic acid (PNA, and SYBR Green I (SYBR, referred to as the AS-RPA-PNA-SYBR (ARPS system. The principle of this technique is based on three continuous steps: ASA or ASA combined with PNA to prevent non-target sequence amplification (even single nucleotide polymorphisms, SNPs, the rapid amplification advantage of RPA, and appropriate SYBR Green I detection (the samples harboring EGFR mutations show a green signal. Using this method, the EGFR 19Del(2 mutation was detected in 5 min, while the EGFR L858R mutation was detected in 10 min. In this study, the detection of EGFR mutations in clinical samples using the ARPS system was compatible with that determined by polymerase chain reaction (PCR and DNA sequencing methods. Thus, this newly developed methodology that uses the ARPS system with appropriate primer sets is a rapid, reliable, and practical way to assess EGFR mutations in clinical samples.

  18. Whole genome sequencing of mutation accumulation lines reveals a low mutation rate in the social amoeba Dictyostelium discoideum.

    Directory of Open Access Journals (Sweden)

    Gerda Saxer

    Full Text Available Spontaneous mutations play a central role in evolution. Despite their importance, mutation rates are some of the most elusive parameters to measure in evolutionary biology. The combination of mutation accumulation (MA experiments and whole-genome sequencing now makes it possible to estimate mutation rates by directly observing new mutations at the molecular level across the whole genome. We performed an MA experiment with the social amoeba Dictyostelium discoideum and sequenced the genomes of three randomly chosen lines using high-throughput sequencing to estimate the spontaneous mutation rate in this model organism. The mitochondrial mutation rate of 6.76×10(-9, with a Poisson confidence interval of 4.1×10(-9 - 9.5×10(-9, per nucleotide per generation is slightly lower than estimates for other taxa. The mutation rate estimate for the nuclear DNA of 2.9×10(-11, with a Poisson confidence interval ranging from 7.4×10(-13 to 1.6×10(-10, is the lowest reported for any eukaryote. These results are consistent with low microsatellite mutation rates previously observed in D. discoideum and low levels of genetic variation observed in wild D. discoideum populations. In addition, D. discoideum has been shown to be quite resistant to DNA damage, which suggests an efficient DNA-repair mechanism that could be an adaptation to life in soil and frequent exposure to intracellular and extracellular mutagenic compounds. The social aspect of the life cycle of D. discoideum and a large portion of the genome under relaxed selection during vegetative growth could also select for a low mutation rate. This hypothesis is supported by a significantly lower mutation rate per cell division in multicellular eukaryotes compared with unicellular eukaryotes.

  19. MtDNA mutation pattern in tumors and human evolution are shaped by similar selective constraints.

    Science.gov (United States)

    Zhidkov, Ilia; Livneh, Erez A; Rubin, Eitan; Mishmar, Dan

    2009-04-01

    Multiple human mutational landscapes of normal and cancer conditions are currently available. However, while the unique mutational patterns of tumors have been extensively studied, little attention has been paid to similarities between malignant and normal conditions. Here we compared the pattern of mutations in the mitochondrial genomes (mtDNAs) of cancer (98 sequences) and natural populations (2400 sequences). De novo mtDNA mutations in cancer preferentially colocalized with ancient variants in human phylogeny. A significant portion of the cancer mutations was organized in recurrent combinations (COMs), reaching a length of seven mutations, which also colocalized with ancient variants. Thus, by analyzing similarities rather than differences in patterns of mtDNA mutations in tumor and human evolution, we discovered evidence for similar selective constraints, suggesting a functional potential for these mutations.

  20. Tissue-specific mutation accumulation in human adult stem cells during life

    Science.gov (United States)

    Blokzijl, Francis; de Ligt, Joep; Jager, Myrthe; Sasselli, Valentina; Roerink, Sophie; Sasaki, Nobuo; Huch, Meritxell; Boymans, Sander; Kuijk, Ewart; Prins, Pjotr; Nijman, Isaac J.; Martincorena, Inigo; Mokry, Michal; Wiegerinck, Caroline L.; Middendorp, Sabine; Sato, Toshiro; Schwank, Gerald; Nieuwenhuis, Edward E. S.; Verstegen, Monique M. A.; van der Laan, Luc J. W.; de Jonge, Jeroen; Ijzermans, Jan N. M.; Vries, Robert G.; van de Wetering, Marc; Stratton, Michael R.; Clevers, Hans; Cuppen, Edwin; van Boxtel, Ruben

    2016-10-01

    The gradual accumulation of genetic mutations in human adult stem cells (ASCs) during life is associated with various age-related diseases, including cancer. Extreme variation in cancer risk across tissues was recently proposed to depend on the lifetime number of ASC divisions, owing to unavoidable random mutations that arise during DNA replication. However, the rates and patterns of mutations in normal ASCs remain unknown. Here we determine genome-wide mutation patterns in ASCs of the small intestine, colon and liver of human donors with ages ranging from 3 to 87 years by sequencing clonal organoid cultures derived from primary multipotent cells. Our results show that mutations accumulate steadily over time in all of the assessed tissue types, at a rate of approximately 40 novel mutations per year, despite the large variation in cancer incidence among these tissues. Liver ASCs, however, have different mutation spectra compared to those of the colon and small intestine. Mutational signature analysis reveals that this difference can be attributed to spontaneous deamination of methylated cytosine residues in the colon and small intestine, probably reflecting their high ASC division rate. In liver, a signature with an as-yet-unknown underlying mechanism is predominant. Mutation spectra of driver genes in cancer show high similarity to the tissue-specific ASC mutation spectra, suggesting that intrinsic mutational processes in ASCs can initiate tumorigenesis. Notably, the inter-individual variation in mutation rate and spectra are low, suggesting tissue-specific activity of common mutational processes throughout life.

  1. Glucocerebrosidase mutations in clinical and pathologically proven Parkinson's disease.

    Science.gov (United States)

    Neumann, Juliane; Bras, Jose; Deas, Emma; O'Sullivan, Sean S; Parkkinen, Laura; Lachmann, Robin H; Li, Abi; Holton, Janice; Guerreiro, Rita; Paudel, Reema; Segarane, Badmavady; Singleton, Andrew; Lees, Andrew; Hardy, John; Houlden, Henry; Revesz, Tamas; Wood, Nicholas W

    2009-07-01

    Mutations in the glucocerebrosidase gene (GBA) are associated with Gaucher's disease, the most common lysosomal storage disorder. Parkinsonism is an established feature of Gaucher's disease and an increased frequency of mutations in GBA has been reported in several different ethnic series with sporadic Parkinson's disease. In this study, we evaluated the frequency of GBA mutations in British patients affected by Parkinson's disease. We utilized the DNA of 790 patients and 257 controls, matched for age and ethnicity, to screen for mutations within the GBA gene. Clinical data on all identified GBA mutation carriers was reviewed and analysed. Additionally, in all cases where brain material was available, a neuropathological evaluation was performed and compared to sporadic Parkinson's disease without GBA mutations. The frequency of GBA mutations among the British patients (33/790 = 4.18%) was significantly higher (P = 0.01; odds ratio = 3.7; 95% confidence interval = 1.12-12.14) when compared to the control group (3/257 = 1.17%). Fourteen different GBA mutations were identified, including three previously undescribed mutations, K7E, D443N and G193E. Pathological examination revealed widespread and abundant alpha-synuclein pathology in all 17 GBA mutation carriers, which were graded as Braak stage of 5-6, and had McKeith's limbic or diffuse neocortical Lewy body-type pathology. Diffuse neocortical Lewy body-type pathology tended to occur more frequently in the group with GBA mutations compared to matched Parkinson's disease controls. Clinical features comprised an early onset of the disease, the presence of hallucinations in 45% (14/31) and symptoms of cognitive decline or dementia in 48% (15/31) of patients. This study demonstrates that GBA mutations are found in British subjects at a higher frequency than any other known Parkinson's disease gene. This is the largest study to date on a non-Jewish patient sample with a detailed genotype/phenotype/pathological analyses

  2. Escherichia coli frameshift mutation rate depends on the chromosomal context but not on the GATC content near the mutation site.

    Directory of Open Access Journals (Sweden)

    Mariana A Martina

    Full Text Available Different studies have suggested that mutation rate varies at different positions in the genome. In this work we analyzed if the chromosomal context and/or the presence of GATC sites can affect the frameshift mutation rate in the Escherichia coli genome. We show that in a mismatch repair deficient background, a condition where the mutation rate reflects the fidelity of the DNA polymerization process, the frameshift mutation rate could vary up to four times among different chromosomal contexts. Furthermore, the mismatch repair efficiency could vary up to eight times when compared at different chromosomal locations, indicating that detection and/or repair of frameshift events also depends on the chromosomal context. Also, GATC sequences have been proved to be essential for the correct functioning of the E. coli mismatch repair system. Using bacteriophage heteroduplexes molecules it has been shown that GATC influence the mismatch repair efficiency in a distance- and number-dependent manner, being almost nonfunctional when GATC sequences are located at 1 kb or more from the mutation site. Interestingly, we found that in E. coli genomic DNA the mismatch repair system can efficiently function even if the nearest GATC sequence is located more than 2 kb away from the mutation site. The results presented in this work show that even though frameshift mutations can be efficiently generated and/or repaired anywhere in the genome, these processes can be modulated by the chromosomal context that surrounds the mutation site.

  3. Escherichia coli frameshift mutation rate depends on the chromosomal context but not on the GATC content near the mutation site.

    Science.gov (United States)

    Martina, Mariana A; Correa, Elisa M E; Argaraña, Carlos E; Barra, José L

    2012-01-01

    Different studies have suggested that mutation rate varies at different positions in the genome. In this work we analyzed if the chromosomal context and/or the presence of GATC sites can affect the frameshift mutation rate in the Escherichia coli genome. We show that in a mismatch repair deficient background, a condition where the mutation rate reflects the fidelity of the DNA polymerization process, the frameshift mutation rate could vary up to four times among different chromosomal contexts. Furthermore, the mismatch repair efficiency could vary up to eight times when compared at different chromosomal locations, indicating that detection and/or repair of frameshift events also depends on the chromosomal context. Also, GATC sequences have been proved to be essential for the correct functioning of the E. coli mismatch repair system. Using bacteriophage heteroduplexes molecules it has been shown that GATC influence the mismatch repair efficiency in a distance- and number-dependent manner, being almost nonfunctional when GATC sequences are located at 1 kb or more from the mutation site. Interestingly, we found that in E. coli genomic DNA the mismatch repair system can efficiently function even if the nearest GATC sequence is located more than 2 kb away from the mutation site. The results presented in this work show that even though frameshift mutations can be efficiently generated and/or repaired anywhere in the genome, these processes can be modulated by the chromosomal context that surrounds the mutation site.

  4. Computer simulations of human interferon gamma mutated forms

    Science.gov (United States)

    Lilkova, E.; Litov, L.; Petkov, P.; Petkov, P.; Markov, S.; Ilieva, N.

    2010-01-01

    In the general framework of the computer-aided drug design, the method of molecular-dynamics simulations is applied for investigation of the human interferon-gamma (hIFN-γ) binding to its two known ligands (its extracellular receptor and the heparin-derived oligosaccharides). A study of 100 mutated hIFN-γ forms is presented, the mutations encompassing residues 86-88. The structural changes are investigated by comparing the lengths of the α-helices, in which these residues are included, in the native hIFN-γ molecule and in the mutated forms. The most intriguing cases are examined in detail.

  5. 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 cDNA...

  6. 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.

  7. Mutational signatures of ionizing radiation in second malignancies

    OpenAIRE

    Behjati, Sam; Gundem, Gunes; Wedge, David C.; Roberts, Nicola D.; Tarpey, Patrick S.; Cooke, Susanna L; Van Loo, Peter; Alexandrov, Ludmil B; Ramakrishna, Manasa; Davies, Helen; Nik-Zainal, Serena; Hardy, Claire; Latimer, Calli; Raine, Keiran M.; Stebbings, Lucy

    2016-01-01

    Ionizing radiation is a potent carcinogen, inducing cancer through DNA damage. The signatures of mutations arising in human tissues following in vivo exposure to ionizing radiation have not been documented. Here, we searched for signatures of ionizing radiation in 12 radiation-associated second malignancies of different tumour types. Two signatures of somatic mutation characterize ionizing radiation exposure irrespective of tumour type. Compared with 319 radiation-naive tumours, radiation-ass...

  8. Mutational meltdown in laboratory yeast populations

    NARCIS (Netherlands)

    Zeyl, C.; Mizesko, M.; Visser, de J.A.G.M.

    2001-01-01

    In small or repeatedly bottlenecked populations, mutations are expected to accumulate by genetic drift, causing fitness declines. In mutational meltdown models, such fitness declines further reduce population size, thus accelerating additional mutation accumulation and leading to extinction. Because

  9. Mutations in the gene region of hepatitis B virus genotype in Turkish patients

    Indian Academy of Sciences (India)

    Mehmet Özaslan; Ersan Özaslan; Arzu Barsgan; Mehmet Koruk

    2007-12-01

    The gene region of the hepatitis B virus (HBV) is responsible for the expression of surface antigens and includes the ‘a’-determinant region. Thus, mutation(s) in this region would afford HBV variants a distinct survival advantage, permitting the mutant virus to escape from the immune system. The aim of this study was to search for mutations of the gene region in different patient groups infected with genotype variants of HBV, and to analyse the biological significance of these mutations. Moreover, we investigated gene mutation inductance among family members. Forty HBV-DNA-positive patients were determined among 132 hepatitis B surface antigen (HbsAg) carriers by the first stage of seminested PCR. Genotypes and subtypes were established by sequencing of the amplified S gene regions. Variants were compared with original sequences of these serotypes, and mutations were identified. All variants were designated as genotype and subtype ayw3. Ten kinds of point mutations were identified within the region. The highest rates of mutation were found in chronic hepatitis patients and their family members. The amino acid mutations 125 (M → T) and 127 (T → P) were found on the first loop of ‘a’-determinant. The other consequence was mutation inductance in a family member. We found some mutations in the S gene region known to be stable and observed that some of these mutations affected gene expression.

  10. A Unique Profile of Adenomatous Polyposis Coli Gene Mutations in Iranian Patients Suffering Sporadic Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    Mojtaba Hasanpour

    2014-03-01

    Full Text Available Objective: Colorectal cancer (CRC is one of the most common and aggressive cancers worldwide. The majority of CRC cases are sporadic that caused by somatic mutations. The Adenomatous Polyposis Coli (APC; OMIM 611731 is a tumor suppressor gene of Wnt pathway and is frequently mutated in CRC cases. This study was designed to investigate the spectrum of APC gene mutations in Iranian patients with sporadic colorectal cancer. Materials and Methods: In this descriptive study, Tumor and normal tissue samples were obtained from thirty randomly selected and unrelated sporadic CRC patients. We examined the hotspot region of the APC gene in all patients. Our mutation detection method was direct DNA sequencing. Results: We found a total of 8 different APC mutations, including two nonsense mutations (c.4099C>T and c.4348C>T, two missense mutations (c.3236C>G and c.3527C>T and four frame shift mutations (c.2804dupA, c.4317delT, c.4464_4471delATTACATT and c.4468_4469dupCA. The c.3236C>G and c.4468_4469dupCA are novel mutations. The overall frequency of APC mutation was 26.7% (8 of 30 patients. Conclusion: This mutation rate is lower in comparison with previous studies from other countries. The findings of present study demonstrate a different APC mutation spectrum in CRC patients of Iranian origin compared with other populations.

  11. Comprehensive screening for a complete set of Japanese-population-specific filaggrin gene mutations.

    Science.gov (United States)

    Kono, M; Nomura, T; Ohguchi, Y; Mizuno, O; Suzuki, S; Tsujiuchi, H; Hamajima, N; McLean, W H I; Shimizu, H; Akiyama, M

    2014-04-01

    Mutations in FLG coding profilaggrin cause ichthyosis vulgaris and are an important predisposing factor for atopic dermatitis. Until now, most case-control studies and population-based screenings have been performed only for prevalent mutations. In this study, we established a high-throughput FLG mutation detection system by real-time PCR with a set of two double-dye probes and conducted comprehensive screening for almost all of the Japanese-population-specific FLG mutations (ten FLG mutations). The present comprehensive screening for all ten FLG mutations provided a more precise prevalence rate for FLG mutations (11.1%, n = 820), which seemed high compared with data of previous reports based on screening for limited numbers of FLG mutations. Our comprehensive screening suggested that population-specific FLG mutations may be a significant predisposing factor for hay fever (odds ratio = 2.01 [95% CI: 1.027-3.936, P < 0.05]), although the sample sizes of this study were too small for reliable subphenotype analysis on the association between FLG mutations and hay fever in the eczema patients and the noneczema individuals, and it is not clear whether the association between FLG mutations and hay fever is due to the close association between FLG mutations and hay fever patients with eczema.

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

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    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.

  13. TERT promoter mutations in skin cancer: the effects of sun exposure and X-irradiation.

    Science.gov (United States)

    Pópulo, Helena; Boaventura, Paula; Vinagre, João; Batista, Rui; Mendes, Adélia; Caldas, Regina; Pardal, Joana; Azevedo, Filomena; Honavar, Mrinalini; Guimarães, Isabel; Manuel Lopes, José; Sobrinho-Simões, Manuel; Soares, Paula

    2014-08-01

    The reactivation or reexpression of telomerase (TERT) is a widespread feature of neoplasms. TERT promoter mutations were recently reported that were hypothesized to result from UV radiation. In this retrospective study, we assessed TERT promoter mutations in 196 cutaneous basal cell carcinomas (BCCs), including 102 tumors from X-irradiated patients, 94 tumors from patients never exposed to ionizing radiation treatment, and 116 melanomas. We sought to evaluate the effects of UV and X-ray irradiation on TERT mutation frequency. TERT mutations were detected in 27% of BCCs from X-irradiated patients, 51% of BCCs from nonirradiated patients, and 22% of melanoma patients. TERT mutations were significantly increased in non-X-irradiated BCC patients compared with X-irradiated BCC patients; the mutations also presented a different mutation signature. In nonirradiated patients, TERT mutations were more frequent in BCCs of sun-exposed skin, supporting a possible causative role of UV radiation. In melanoma, TERT promoter mutations were generally restricted to intermittent sun-exposed areas and were associated with nodular and superficial spreading subtypes, increased thickness, ulceration, increased mitotic rate, and BRAFV600E mutations. Our results suggest that various carcinogenic factors may cause distinct TERT promoter mutations in BCC and that TERT promoter mutations might be associated with a poorer prognosis in melanoma.

  14. Telomerase reverse transcriptase promoter mutations in hepatitis B virus-associated hepatocellular carcinoma

    Science.gov (United States)

    Yang, Xunjun; Guo, Xiuchan; Chen, Yao; Chen, Guorong; Ma, Yin; Huang, Kate; Zhang, Yuning; Zhao, Qiongya; Winkler, Cheryl A.; An, Ping; Lyu, Jianxin

    2016-01-01

    Telomerase reverse transcriptase (TERT) promoter mutations are among the most frequent noncoding somatic mutations in multiple cancers, including hepatocellular carcinoma (HCC). The clinical and pathological implications of TERT promoter mutations in hepatitis B virus (HBV)-associated HCC have not been resolved. To investigate TERT promoter mutations, protein expression, and their clinical-pathological implications, we sequenced the TERT promoter region for hotspot mutations in HCC tissues and performed immunostaining for TERT protein expression from HBV-associated HCC in Chinese patients. Of 276 HCC tumor DNA samples sequenced, 85 (31%) carried TERT promoter mutations. TERT promoter mutations were more frequent in those with low α-fetoprotein (AFP) serum levels (p = 0.03), advanced age (p = 0.04), and in those lacking HCC family history (p = 0.02), but were not correlated with HCC stages and grades. TERT protein levels were higher in HCC (n = 28) compared to normal liver tissues (n = 8) (p =0.001), but did not differ between mutated and non-mutated tumor tissues. In conclusion, TERT promoter mutations are common somatic mutations in HCC of Han Chinese with HBV infection. Detection of TERT promoter mutations in those with low levels of AFP may aid diagnosis of HCC with atypical presentation. PMID:27056898

  15. Relationship between mutations of mitochondrial DNA ND1 gene and type 2 diabetes

    Institute of Scientific and Technical Information of China (English)

    于珮; 于德民; 刘德敏; 王琨; 汤新之

    2004-01-01

    Background Recent studies have indicated that many mutations in mitochondrial (mt)DNA NDI gene region are related to diabetes mellitus. In this study we explored the relationship between various mtDNA ND1 gene mutations and type 2 diabetes mellitus (DM) among Chinese. Methods Using PCR restriction fragment length polymorphism (PCR-RFLP) analysis and gene sequencing, 4 spots of mtDNA (nt3243, nt3316, nt3394, nt3426) were screened in 478 diabetics and 430 non-diabetic subjects.Results In diabetic group, there were 13 carriers (2.72%)of 3316 G→A mutation,12 (2.51%) of 3394 T→C mutation and 2 (0.42%) of 3426A→G mutation. In controls, only 3394 T→C mutation was observed in 2 subjects (0.47%). There was significant difference in the frequency of 3316 and 3394 mutation between two groups (P<0.05, respectively). More subjects with mitochondrial DNA ND1 gene mutations had DM family history and greater tendency of maternal inheritance when compared to those patients without mutation in diabetic group(P<0.01). A 3426 mutation diabetic pedigree was studied, and we found 12 maternal members in the family had the same mutation. Conclusion mtDNA ND1 gene mutations at nt3316 (G→A), nt3394 (T→C) and 3426 (A→G) might contribute to the pathogenesis of DM with other genetic factors and environment factors.

  16. Identification of anaplastic lymphoma kinase break points and oncogenic mutation profiles in acral/mucosal melanomas.

    Science.gov (United States)

    Niu, Hai-Tao; Zhou, Qi-Ming; Wang, Fang; Shao, Qiong; Guan, Yuan-Xiang; Wen, Xi-Zhi; Chen, Li-Zhen; Feng, Qi-Sheng; Li, Wei; Zeng, Yi-Xin; Zhang, Xiao-Shi

    2013-09-01

    Acral and mucosal melanomas, the two most common subtypes of melanoma in China, exhibit different genetic alterations and biologic behavior compared with other subtypes of melanomas. The purpose of this study was to identify the genetic alterations in patients with acral or mucosal melanomas in southern China. Fluorescence in situ hybridization (FISH), immunohistochemistry (IHC) analysis, polymerase chain reaction (PCR), and quantitative real-time reverse transcriptase PCR (qRT-PCR) were used to assess the anaplastic lymphoma kinase (ALK) break points. Furthermore, a mass spectrometry-based genotyping platform was used to analyze 30 acral melanomas and 28 mucosal melanomas to profile 238 known somatic mutations in 19 oncogenes. ALK break points were identified in four acral cases (6.9%). Eight (13.8%) cases harbored BRAF mutations, six (10.3%) had NRAS mutations, four (6.9%) had KIT mutations, two (3.5%) had EGFR mutations, two (3.5%) had KRAS mutations, two (3.5%) had MET mutations, one (1.7%) had an HRAS mutation, and one (1.7%) had a PIK3CA mutation. Two cases exhibited co-occurring mutations, and one case with a BRAF mutation had a translocation in ALK. This study represents a comprehensive and concurrent analysis of the major recurrent oncogenic mutations involved in melanoma cases from southern China. These data have implications for both clinical trial designs and therapeutic strategies.

  17. The Frequency and clinical significance of IDH1 mutations in Chinese acute myeloid leukemia patients.

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    Lixun Guan

    Full Text Available OBJECTIVE: Mutations in the gene encoding isocitrate dehydrogenease 1 (IDH1 occur in various hematopoietic tumors including acute myeloid leukemia (AML, myeloproliferative neoplasms and myelodysplastic syndromes. IDH1 mutations are significant in both diagnosis and prognosis of these conditions. In the present study we determined the prevalence and clinical significance of IDH1 mutations in 349 samples from newly diagnosed AML patients. RESULTS: Of the 349 AML patient specimens analyzed, 35 (10.03% were found to have IDH1 mutations including 4 IDH1 R132 mutations and 31 non-R132 mutations. IDH1 non-R132 mutations were largely concentrated within AML-M1 (35.72%, pA, p.R100Q; (2 c.311G>T, p.G104V; (3 c.322T>C, p.F108L; (4 c.356G>A, p.R119Q; and (5 c.388A>G, p.I130V. In addition, we identified three IDH1 mutations that were previously described in AML. The frequency of IDH1 mutations in AML patients with normal karyotype was 9.9%. IDH1 non-R132 mutations were concurrent with mutations in FLT3-ITD (p<0.01, CEBPA (p<0.01, and NRAS (p<0.01, as well as the overexpression of MN1 (p<0.01 and WT1(p<0.01. The overall survival (OS in the patients with IDH1 non-R132 mutations compared to patients without IDH1 mutations don't reach statistically significance (median 521 days vs median: not reached; n.s.. CONCLUSION: IDH1 non-R132 mutations occurred frequently in newly diagnosed adult Chinese AML patients, and these mutations were associated with genetic alterations. The OS was not influenced by IDH1 non-R132 mutations in the present study.

  18. Variation in RNA virus mutation rates across host cells.

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    Marine Combe

    2014-01-01

    Full Text Available It is well established that RNA viruses exhibit higher rates of spontaneous mutation than DNA viruses and microorganisms. However, their mutation rates vary amply, from 10(-6 to 10(-4 substitutions per nucleotide per round of copying (s/n/r and the causes of this variability remain poorly understood. In addition to differences in intrinsic fidelity or error correction capability, viral mutation rates may be dependent on host factors. Here, we assessed the effect of the cellular environment on the rate of spontaneous mutation of the vesicular stomatitis virus (VSV, which has a broad host range and cell tropism. Luria-Delbrück fluctuation tests and sequencing showed that VSV mutated similarly in baby hamster kidney, murine embryonic fibroblasts, colon cancer, and neuroblastoma cells (approx. 10(-5 s/n/r. Cell immortalization through p53 inactivation and oxygen levels (1-21% did not have a significant impact on viral replication fidelity. This shows that previously published mutation rates can be considered reliable despite being based on a narrow and artificial set of laboratory conditions. Interestingly, we also found that VSV mutated approximately four times more slowly in various insect cells compared with mammalian cells. This may contribute to explaining the relatively slow evolution of VSV and other arthropod-borne viruses in nature.

  19. Pyrosequencing for EGFR mutation detection: diagnostic accuracy and clinical implications.

    Science.gov (United States)

    Sahnane, Nora; Gueli, Rossana; Tibiletti, Maria G; Bernasconi, Barbara; Stefanoli, Michele; Franzi, Francesca; Pinotti, Graziella; Capella, Carlo; Furlan, Daniela

    2013-12-01

    EGFR-activating mutations predict responsiveness to EGFR tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC) patients. Mutation screening is crucial to support therapeutic decisions and is commonly conducted using dideoxy sequencing, although its sensitivity is suboptimal in clinical settings. To evaluate the diagnostic performance of pyrosequencing and dideoxy sequencing, we examined EGFR mutation status in a retrospective cohort of 53 patients with NSCLCs clinically selected for TKI therapy and whose clinical outcome was available. Moreover, pyrosequencing quantitative results were compared with EGFR amplification data. EGFR mutations were investigated by pyrosequencing and by dideoxy sequencing. Detection rates of both methods were determined by titration assays using NCI-H1975 and HCC-827 cell lines. Increased EGFR copy number was assessed by fluorescence in situ hybridization (FISH). Pyrosequencing showed a higher detection rate than dideoxy sequencing. Tumor control rate of cases with mutant and wild-type EGFR was 86% and 29%, respectively. EGFR amplification was significantly associated with EGFR mutation and a positive correlation between high percentages of mutant alleles and clinical response to TKI was observed. We concluded that pyrosequencing is more sensitive than dideoxy sequencing in mutation screening for EGFR mutations. Detection rate of dideoxy sequencing was suboptimal when low frequencies of mutant alleles or low tumor cell contents were observed. Pyrosequencing enables quantification of mutant alleles that correlates well with increased EGFR copy number assessed by FISH. Pyrosequencing should be used in molecular diagnostic of NSCLC to appropriately select patients who are likely to benefit from TKI therapy.

  20. A Fast Determination of DNA Mutation Induced by Ultraviolet Radiation

    Institute of Scientific and Technical Information of China (English)

    LuFeng; LiuLili; ZhangXiaofang; WuYutian

    2001-01-01

    Electrophoresis, chromatography, immunoassay, sequencing and other time consuming ap-proaches have been developed to determine DNA base mismatching, oxidative lesion or strand breaks. Sometimes,however, only qualitative information is enough to decide whether mutation has happened to DNA and its extent.Convolution spectrometry (CS), a new technique to discover ultrafme difference on ultraviolet (UV) absorption ofdifferent substances, is originally employed to find out any subtle mutation of DNA induced by UV radiation. Muta-tive DNA is compared with ego criteria based on the spectra of the former DNA, any difference is quantitatively ex-pressed by dispersion (5). Visible changes cannot be observed on second -derivative spectra until the mutation gets 5up to 11.48%. Dimethyl sulfoxide is an intensifier of UV 254 nm induced DNA mutation and protector at 365 nm,which is simply confirmed by increasing and decreasing 5. Every convolution procedure takes less than 1 min. Convolution spectrometry provides a fast, simple, sensitive and inexpensive alternative to determine DNA mutation, andto screen anti-mutational medicines.

  1. Mutation-selection balance and mixed mating with asexual reproduction.

    Science.gov (United States)

    Marriage, Tara N; Orive, Maria E

    2012-09-07

    The effects of asexual reproduction on both the number of deleterious mutations per gamete and the mean fitness under mutation-selection balance are investigated. We use two simulation models, considering both finite and infinite populations. The two models incorporate asexual reproduction with varying levels of outcrossing and selfing, degrees of dominance and selection coefficients. The values for mean fitness and number of deleterious mutations per gamete are compared within and among finite and infinite populations to identify the effect of asexual reproduction on levels of load, and how asexual reproduction may interact with genetic drift (population size). Increasing asexual reproduction resulted in an increase in mean fitness and a decrease in the average number of deleterious mutations per gamete for both nearly recessive and additive alleles in both the infinite and finite simulations. Increased mean fitness with increasing asexuality is possibly due to two interacting forces: a greater opportunity for selection to act on heterozygous versus homozygous mutations and the shielding of a proportion of the population from meiotic mutations due to asexual reproduction. The results found here highlight the need to consider asexual reproduction along with mixed mating in models of genetic load and mutation-selection balance.

  2. Deleterious mutation accumulation in asexual Timema stick insects.

    Science.gov (United States)

    Henry, Lee; Schwander, Tanja; Crespi, Bernard J

    2012-01-01

    Sexual reproduction is extremely widespread in spite of its presumed costs relative to asexual reproduction, indicating that it must provide significant advantages. One postulated benefit of sex and recombination is that they facilitate the purging of mildly deleterious mutations, which would accumulate in asexual lineages and contribute to their short evolutionary life span. To test this prediction, we estimated the accumulation rate of coding (nonsynonymous) mutations, which are expected to be deleterious, in parts of one mitochondrial (COI) and two nuclear (Actin and Hsp70) genes in six independently derived asexual lineages and related sexual species of Timema stick insects. We found signatures of increased coding mutation accumulation in all six asexual Timema and for each of the three analyzed genes, with 3.6- to 13.4-fold higher rates in the asexuals as compared with the sexuals. In addition, because coding mutations in the asexuals often resulted in considerable hydrophobicity changes at the concerned amino acid positions, coding mutations in the asexuals are likely associated with more strongly deleterious effects than in the sexuals. Our results demonstrate that deleterious mutation accumulation can differentially affect sexual and asexual lineages and support the idea that deleterious mutation accumulation plays an important role in limiting the long-term persistence of all-female lineages.

  3. 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.

  4. Novel mutations in the NRL gene and associated clinical findings in patients with dominant retinitis pigmentosa.

    Science.gov (United States)

    DeAngelis, Margaret M; Grimsby, Jonna L; Sandberg, Michael A; Berson, Eliot L; Dryja, Thaddeus P

    2002-03-01

    To search for mutations in the neural retina leucine zipper (NRL) gene in patients with dominant retinitis pigmentosa and to compare the severity of disease in these patients with that observed previously in patients with dominant rhodopsin mutations. Single-strand conformation analysis was used to survey 189 unrelated patients for mutations. The available relatives of index patients with mutations were also evaluated. In our clinical examination of patients, we measured visual acuity, final dark-adaptation threshold equivalent visual field diameter, and electroretinogram amplitudes among other parameters of visual function. We compared the clinical findings with those obtained earlier from similar evaluations of a group of 39 patients with the dominant rhodopsin mutation Pro23His and a group of 25 patients with the dominant rhodopsin mutation Pro347Leu. We identified 3 novel missense mutations in a total of 4 unrelated patients with dominant retinitis pigmentosa: Ser50Pro, Ser50Leu (2 patients), and Pro51Thr. Each mutation cosegregated with dominant retinitis pigmentosa. None of these mutations were found among 91 unrelated control individuals. The visual acuities among the 4 index patients and 3 relatives with NRL mutations who were clinically evaluated ranged from 20/20 (in a 9-year-old patient) to 20/200 (in a 73-year-old patient). All patients had bone-spicule pigment deposits in their fundi. Average rod-plus-cone and cone-isolated electroretinogram amplitudes were both decreased by 99% or more compared with normal amplitudes. The dark-adaptation thresholds, equivalent visual field diameters, and electroretinogram amplitudes (all corrected for age and refractive error) indicated that the disease caused by the NRL mutations was more severe than that caused by the dominant rhodopsin mutation Pro23His and was similar in severity to that produced by the rhodopsin mutation Pro347Leu. The 3 novel NRL mutations we discovered bring the total number of reported

  5. Timing constraints of in vivo gag mutations during primary HIV-1 subtype C infection.

    Directory of Open Access Journals (Sweden)

    Vladimir Novitsky

    Full Text Available BACKGROUND: Aiming to answer the broad question "When does mutation occur?" this study examined the time of appearance, dominance, and completeness of in vivo Gag mutations in primary HIV-1 subtype C infection. METHODS: A primary HIV-1C infection cohort comprised of 8 acutely and 34 recently infected subjects were followed frequently up to 500 days post-seroconversion (p/s. Gag mutations were analyzed by employing single-genome amplification and direct sequencing. Gag mutations were determined in relation to the estimated time of seroconversion. Time of appearance, dominance, and completeness was compared for different types of in vivo Gag mutations. RESULTS: Reverse mutations to the wild type appeared at a median (IQR of 62 (44;139 days p/s, while escape mutations from the wild type appeared at 234 (169;326 days p/s (p<0.001. Within the subset of mutations that became dominant, reverse and escape mutations appeared at 54 (30;78 days p/s and 104 (47;198 days p/s, respectively (p<0.001. Among the mutations that reached completeness, reverse and escape mutations appeared at 54 (30;78 days p/s and 90 (44;196 days p/s, respectively (p=0.006. Time of dominance for reverse mutations to and escape mutations from the wild type was 58 (44;105 days p/s and 219 (90;326 days p/s, respectively (p<0.001. Time of completeness for reverse and escape mutations was 152 (100;176 days p/s and 243 (101;370 days p/s, respectively (p=0.001. Fitting a Cox proportional hazards model with frailties confirmed a significantly earlier time of appearance (hazard ratio (HR: 2.6; 95% CI: 2.3-3.0, dominance (4.8 (3.4-6.8, and completeness (3.6 (2.3-5.5 of reverse mutations to the wild type Gag than escape mutations from the wild type. Some complex mutational pathways in Gag included sequential series of reversions and escapes. CONCLUSIONS: The study identified the timing of different types of in vivo Gag mutations in primary HIV-1 subtype C infection in relation to the

  6. Mutations induced by ultraviolet light

    Energy Technology Data Exchange (ETDEWEB)

    Pfeifer, Gerd P. [Department of Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010 (United States)]. E-mail: gpfeifer@coh.org; You, Young-Hyun [Department of Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010 (United States); Besaratinia, Ahmad [Department of Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010 (United States)

    2005-04-01

    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

  7. Epidermal growth factor receptor exon 20 p.S768I mutation in non-small cell lung carcinoma

    DEFF Research Database (Denmark)

    Improta, Giuseppina; Pettinato, Angela; Gieri, Stefania;

    2016-01-01

    mutations may be used to identify tumors sensitive to the effects of small-molecule EGFR-TKIs (gefitinib and erlotinib), and alternative, less frequently observed mutations, including the majority of mutations identified within exon 20, may be associated with a lack of response to TKIs. However, due...... to the comparative rarity of EGFR exon 20 mutations, clinical information concerning the association between EGFR exon 20 mutations and responsiveness to TKIs has been limited within the relevant literature, particularly for certain rare mutations, including p.S768I. The current study reports the case of a patient...... with NSCLC harboring a p.S768I mutation in the EGFR gene [a substitution at codon 768 of exon 20 (c.2303G>T, p.S768I)], as well as a mutation at codon 719, exon 18 (p.G719A). The relevant literature concerning this rare EGFR somatic mutation is also reviewed....

  8. Number of RUNX1 mutations, wild-type allele loss and additional mutations impact on prognosis in adult RUNX1-mutated AML.

    Science.gov (United States)

    Stengel, A; Kern, W; Meggendorfer, M; Nadarajah, N; Perglerovà, K; Haferlach, T; Haferlach, C

    2017-07-28

    RUNX1-mutated acute myeloid leukemia (AML) show a distinct pattern of genetic abnormalities and an adverse prognosis. We analyzed the impact of multiple RUNX1 mutations and RUNX1 wild-type (WT) loss in 467 AML with RUNX1 mutations (mut): (1) RUNX1 WT loss (n=53), (2) >1 RUNX1mut (n=94) and (3) 1 RUNX1mut (n=323). In 1 RUNX1mut, +8 was most frequent, whereas in WT loss +13 was the most abundant trisomy (+8: 66% vs 31%, P=0.022; +13: 15% vs 62%, P1 RUNX1mut (14 months) showed an adverse impact on prognosis compared with 1 RUNX1mut (22 months; P=0.002 and 0.048, respectively). Mutations in ASXL1 and ⩾2 additional mutations correlated with shorter OS (10 vs 18 months, P=0.028; 12 vs 20 months, P=0.017). Thus, the number of RUNX1mut, RUNX1 WT loss and the number and type of additional mutations is biologically and clinically relevant.Leukemia advance online publication, 15 August 2017; doi:10.1038/leu.2017.239.

  9. Mutational profiling reveals PIK3CA mutations in gallbladder carcinoma

    Directory of Open Access Journals (Sweden)

    Bardeesy Nabeel

    2011-02-01

    Full Text Available Abstract Background The genetics of advanced biliary tract cancers (BTC, which encompass intra- and extra-hepatic cholangiocarcinomas as well as gallbladder carcinomas, are heterogeneous and remain to be fully defined. Methods To better characterize mutations in established known oncogenes and tumor suppressor genes we tested a mass spectrometric based platform to interrogate common cancer associated mutations across a panel of 77 formalin fixed paraffin embedded archived BTC cases. Results Mutations among three genes, KRAS, NRAS and PIK3CA were confirmed in this cohort. Activating mutations in PIK3CA were identified exclusively in GBC (4/32, 12.5%. KRAS mutations were identified in 3 (13% intra-hepatic cholangiocarcinomas and 1 (33% perihillar cholangiocarcinoma but were not identified in gallbladder carcinomas and extra-hepatic cholangiocarcinoma. Conclusions The presence of activating mutations in PIK3CA specifically in GBC has clinical implications in both the diagnosis of this cancer type, as well as the potential utility of targeted therapies such as PI3 kinase inhibitors.

  10. A comparative study of pyrosequencing method and Sanger sequencing method for detecting the drug resistance mutation loci in hepatitis B virus%乙型肝炎病毒耐药突变的焦磷酸测序与Sanger双脱氧链终止法检测试剂的比对及临床应用

    Institute of Scientific and Technical Information of China (English)

    叶佩燕; 夏前林; 张建良

    2016-01-01

    Objective: To compare the pyrosequencing method and sanger sequencing method for detection of HBV drug resistance mutation loci. Methods: A total of 415 serum samples from hepatitis patients were collected, While 30 control serum samples were served as controls. HBV drug resistance mutation loci in the serum sample were detected in par allel with the pyrosequencing method and Sanger sequencing method. Using Sanger sequencing method as reference, the specificity, sensitivity and the total coincidence rate of pyrosequencing method were calculated. Kappa value was cal-culated for agreement analysis. Results:Taking Sanger sequencing method as reference, the specificity, sensitivity and the total coincidence rate of pyrosequencing method were 100%, 99.82% and 99.86%, respectively. Moreover, a high degree of agreement was observed (Kappa value, 0.997). Conclusions: Pyrosequencing method is a rapid, sensitive and specific method for the detection of HBV drug resistance mutation loci, and has a good prospect to be applied in clinical laboratory.%目的:将检测乙型肝炎病毒(hepatitis B virus,HBV)耐药突变位点的焦磷酸测序检测试剂与Sanger双脱氧链终止法(Sanger测序法,简称Sanger法)检测试剂进行临床比对,为临床诊断和个体化治疗提供参考。方法:分别用研制的焦磷酸测序检测试剂与Sanger法检测试剂检测415份临床慢性乙型肝炎(乙肝)患者的血清样本及30例对照血清样本,并与Sanger法检测试剂比对,计算焦磷酸测序检测试剂的特异度、灵敏度及总符合率,计算Kappa值,比较2种试剂检测结果的一致性。结果:与经典的Sanger法检测试剂比对,焦磷酸测序检测试剂的特异度为100%,灵敏度为99.82%,一致率为99.86%,受试者工作特征曲线下面积为0.9994,两者间具有较强的一致性。结论:焦磷酸测序检测试剂适合于临床对HBV样本进行耐药性诊断,其特异度、灵

  11. Livedoid vasculopathy and its association with factor V Leiden mutation.

    Science.gov (United States)

    Yong, Angeline Anning; Tan, Audrey Wei Hsia; Giam, Yoke Chin; Tang, Mark Boon Yang

    2012-12-01

    Livedoid vasculopathy is a rare chronic relapsing disorder characterised by recurrent painful thrombotic and vasculitic ulcers on the legs. We present the cases of two Indian women with livedoid vasculopathy that were found to be associated with an underlying factor V Leiden heterozygous mutation. There were no other thrombotic manifestations, and livedoid vasculopathy was the sole presenting feature of the factor V Leiden mutation, although this could also be coincidental. Initial treatment with high-dose immunosuppressive therapy was suboptimal, and the addition of pentoxifylline and antiplatelet therapy was crucial in achieving disease control and remission. These cases highlight the possible association with an underlying prothrombotic disorder, such as factor V Leiden mutation, in patients with livedoid vasculopathy. Although this association is relatively uncommon, it is more relevant to Indian patients, as the presence of factor V Leiden mutation is highest in this ethnicity as compared to the local Malay and Chinese populations.

  12. 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.

  13. Highly Multiplexed Profiling of Low Abundance Tumor Mutations in Plasma

    Science.gov (United States)

    Wiggin, Matthew; Pel, Joel; Vysotskaia, Valentina; Broemeling, David; Marziali, Andre; Hanson, Dan

    2013-01-01

    We have demonstrated a novel somatic mutation enrichment methodology demonstrating multiplexed detection of tumor mutations in plasma with sensitivity as low as 0.01% compared to normal DNA. This highly sensitive detection of low abundance mutations is achieved using electrophoretic separation and enrichment of DNA fragments containing point mutations over their wild-type counterparts. Commercialized as the OnTarget platform by Boreal Genomics, the system enriches nucleic acid samples for specific targets prior to amplification and detection, enabling the use of next-generation sequencing (NGS) or other detection assays for plasma or FFPE-based mutation detection and profiling. We present data demonstrating highly sensitive and multiplexed detection of panels of up to 100 mutations in plasma samples, improving the sensitivity of NGS assays to below 0.01% mutant content. We also report on concordance studies comparing low tumor content FFPE tissue and matched plasma in human samples demonstrating that OnTarget represents a robust, highly sensitive and multiplexed platform for non-invasive tumor monitoring.

  14. Colorectal carcinomas with KRAS mutation are associated with distinctive morphological and molecular features.

    Science.gov (United States)

    Rosty, Christophe; Young, Joanne P; Walsh, Michael D; Clendenning, Mark; Walters, Rhiannon J; Pearson, Sally; Pavluk, Erika; Nagler, Belinda; Pakenas, David; Jass, Jeremy R; Jenkins, Mark A; Win, Aung Ko; Southey, Melissa C; Parry, Susan; Hopper, John L; Giles, Graham G; Williamson, Elizabeth; English, Dallas R; Buchanan, Daniel D

    2013-06-01

    KRAS-mutated carcinomas comprise 35-40% of all colorectal carcinomas but little is known about their characteristics. The aim of this study was to examine the pathological and molecular features of KRAS-mutated colorectal carcinomas and to compare them with other carcinoma subgroups. KRAS mutation testing was performed in 776 incident tumors from the Melbourne Collaborative Cohort Study. O(6)-methylguanine DNA methyltransferase (MGMT) status was assessed using both immunohistochemistry and MethyLight techniques. Microsatellite instability (MSI) phenotype and BRAF V600E mutation status were derived from earlier studies. Mutation in KRAS codon 12 or codon 13 was present in 28% of colorectal carcinomas. Compared with KRAS wild-type carcinomas, KRAS-mutated carcinomas were more frequently observed in contiguity with a residual polyp (38 vs 21%; Pcarcinomas showed more frequent location in the proximal colon (41 vs 27%; P=0.001), mucinous differentiation (46 vs 25%; Pcarcinomas were distributed in a bimodal pattern along the proximal-distal axis of the colorectum. Compared with male subjects, female subjects were more likely to have KRAS-mutated carcinoma in the transverse colon and descending colon (39 vs 15%; P=0.02). No difference in overall survival was observed in patients according to their tumor KRAS mutation status. In summary, KRAS-mutated carcinomas frequently develop in contiguity with a residual polyp and show molecular features distinct from other colorectal carcinomas, in particular from tumors with neither BRAF nor KRAS mutation.

  15. Birth prevalence and mutation spectrum in danish patients with autosomal recessive albinism

    DEFF Research Database (Denmark)

    Grønskov, Karen; Ek, Jakob; Sand, Annie;

    2009-01-01

    PURPOSE: The study was initiated to investigate the mutation spectrum of four OCA genes and to calculate the birth prevalence in patients with autosomal recessive albinism. METHODS: Mutation analysis using dHPLC or direct DNA sequencing of TYR, OCA2, TYRP1, and MATP was performed in 62 patients....... Two mutations in one OCA gene explained oculocutaneous albinism (OCA) in 44% of the patients. Mutations in TYR were found in 26% of patients, while OCA2 and MATP caused OCA in 15% and 3%, respectively. No mutations were found in TYRP1. Of the remaining 56% of patients, 29% were heterozygous...... recessive ocular albinism (AROA) based on clinical findings was 55 to 45. CONCLUSIONS: TYR is the major OCA gene in Denmark, but several patients do not have mutations in the investigated genes. A relatively large fraction of patients were observed with AROA, and of those 52% had no mutations compared...

  16. Mutational dynamics of murine angiogenin duplicates

    Directory of Open Access Journals (Sweden)

    Fares Mario A

    2010-10-01

    Full Text Available Abstract Background Angiogenin (Ang is a protein involved in angiogenesis by inducing the formation of blood vessels. The biomedical importance of this protein has come from findings linking mutations in Ang to cancer progression and neurodegenerative diseases. These findings highlight the evolutionary constrain on Ang amino acid sequence. However, previous studies comparing human Angiogenin with homologs from other phylogenetically related organisms have led to the conclusion that Ang presents a striking variability. Whether this variability has an adaptive value per se remains elusive. Understanding why many functional Ang paralogs have been preserved in mouse and rat and identifying functional divergence mutations at these copies may explain the relationship between mutations and function. In spite of the importance of testing this hypothesis from the evolutionarily and biomedical perspectives, this remains yet unaccomplished. Here we test the main mutational dynamics driving the evolution and function of Ang paralogs in mammals. Results We analysed the phylogenetic asymmetries between the different Ang gene copies in mouse and rat in the context of vertebrate Ang phylogeny. This analysis shows strong evidence in support of accelerated evolution in some Ang murine copies (mAng. This acceleration is not due to non-functionalisation because constraints on amino acid replacements remain strong. We identify many of the amino acid sites involved in signal localization and nucleotide binding by Ang to have evolved under diversifying selection. Compensatory effects of many of the mutations at these paralogs and their key structural location in or nearby important functional regions support a possible functional shift (functional divergence in many Ang copies. Similarities between 3D-structural models for mAng copies suggest that their divergence is mainly functional. Conclusions We identify the main evolutionary dynamics shaping the variability of

  17. Genome profiling of chronic myelomonocytic leukemia: frequent alterations of RAS and RUNX1 genes

    Directory of Open Access Journals (Sweden)

    Olschwang Sylviane

    2008-10-01

    Full Text Available Abstract Background Chronic myelomonocytic leukemia (CMML is a hematological disease close to, but separate from both myeloproliferative disorders (MPD and myelodysplastic syndromes and may show either myeloproliferative (MP-CMML or myelodysplastic (MD-CMML features. Not much is known about the molecular biology of this disease. Methods We studied a series of 30 CMML samples (13 MP- and 11 MD-CMMLs, and 6 acutely transformed cases from 29 patients by using Agilent high density array-comparative genomic hybridization (aCGH and sequencing of 12 candidate genes. Results Two-thirds of samples did not show any obvious alteration of aCGH profiles. In one-third we observed chromosome abnormalities (e.g. trisomy 8, del20q and gain or loss of genes (e.g. NF1, RB1 and CDK6. RAS mutations were detected in 4 cases (including an uncommon codon 146 mutation in KRAS and PTPN11 mutations in 3 cases. We detected 11 RUNX1 alterations (9 mutations and 2 rearrangements. The rearrangements were a new, cryptic inversion of chromosomal region 21q21-22 leading to break and fusion of RUNX1 to USP16. RAS and RUNX1 alterations were not mutually exclusive. RAS pathway mutations occurred in MP-CMMLs (~46% but not in MD-CMMLs. RUNX1 alterations (mutations and cryptic rearrangement occurred in both MP and MD classes (~38%. Conclusion We detected RAS pathway mutations and RUNX1 alterations. The latter included a new cryptic USP16-RUNX1 fusion. In some samples, two alterations coexisted already at this early chronic stage.

  18. Markov models for accumulating mutations

    CERN Document Server

    Beerenwinkel, Niko

    2007-01-01

    We introduce and analyze a waiting time model for the accumulation of genetic changes. The continuous time conjunctive Bayesian network is defined by a partially ordered set of mutations and by the rate of fixation of each mutation. The partial order encodes constraints on the order in which mutations can fixate in the population, shedding light on the mutational pathways underlying the evolutionary process. We study a censored version of the model and derive equations for an EM algorithm to perform maximum likelihood estimation of the model parameters. We also show how to select the maximum likelihood poset. The model is applied to genetic data from different cancers and from drug resistant HIV samples, indicating implications for diagnosis and treatment.

  19. Dynamical Mutation of Dark Energy

    CERN Document Server

    Abramo, L R; Liberato, L; Rosenfeld, R

    2007-01-01

    We discuss the intriguing possibility that dark energy may change its equation of state in situations where large dark energy fluctuations are present. We show indications of this dynamical mutation in some generic models of dark energy.

  20. PPARγ mutations, lipodystrophy and diabetes.

    Science.gov (United States)

    Astapova, Olga; Leff, Todd

    2014-11-01

    The focus of this review is the lipodystrophy syndrome caused by mutation in the PPARγ nuclear receptor - partial familial lipodystrophy FPLD3. To provide a broader context for how these mutations act to generate the clinical features of partial lipodystrophy we will review the basic biology of PPARγ and also survey the set PPARγ genetic variants that do not cause lipodystrophy, but are nonetheless associated with clinically related syndromes, specifically type 2 diabetes.

  1. Gene mutations in hepatocellular adenomas

    DEFF Research Database (Denmark)

    Raft, Marie B; Jørgensen, Ernö N; Vainer, Ben

    2015-01-01

    is associated with bi-allelic mutations in the TCF1 gene and morphologically has marked steatosis. β-catenin activating HCA has increased activity of the Wnt/β-catenin pathway and is associated with possible malignant transformation. Inflammatory HCA is characterized by an oncogene-induced inflammation due....... This review offers an overview of the reported gene mutations associated with hepatocellular adenomas together with a discussion of the diagnostic and prognostic value....

  2. Stickler syndrome caused by COL2A1 mutations: genotype-phenotype correlation in a series of 100 patients

    DEFF Research Database (Denmark)

    Hoornaert, Kristien P; Vereecke, Inge; Dewinter, Chantal

    2010-01-01

    found more frequently in patients with a COL2A1 mutation compared with the mutation-negative group (P90% of the mutations were predicted to result in nonsense-mediated decay. On the basis of binary regression analysis, we developed a scoring system that may be useful when evaluating patients...

  3. Novel CNGA3 mutations in Chinese patients with achromatopsia.

    Science.gov (United States)

    Liang, Xiaofang; Dong, Fangtian; Li, Hui; Li, Huajin; Yang, Lizhu; Sui, Ruifang

    2015-04-01

    To study the clinical features and to identify the pathogenic mutations in Chinese patients with achromatopsia (ACHM). Fifteen patients from 10 unrelated families were included in this study. Detailed ocular examinations were performed for the affected subjects, including best-corrected visual acuity (BCVA), colour vision, slit lamp, fundus, electroretinography, perimetry, and spectral domain optical coherent topography (SD-OCT). Peripheral blood samples were obtained from all of the patients and their family members for genomic DNA extraction. All exons of CNGA3, CNGB3, GNAT2, PDE6C and PDE6H were amplified by a PCR and screened for mutation by direct Sanger sequencing. The sequences were analysed using the Blat tool and then compared with the gene transcript. A segregation test was conducted in the patients' parents if they were available. The variants were compared with the database of the 1000 Genomes Project to exclude polymorphism. Nystagmus, photophobia, and impaired colour discrimination were observed in all patients. The BCVA of the affected subjects ranged from 0.05-0.2. Severely depressed and non-recordable cone electroretinograms were observed. Noticeable structural changes including disruption or loss of the macular inner/outer segments (IS/OS) junction of the photoreceptors were observed with SD-OCT. CNGA3 mutations were identified in 13 patients from eight families. Sequencing revealed seven novel missense mutations, three novel deletion mutations, and four previously reported mutations among those patients. CNGA3 mutation is the most frequent cause of ACHM in this cohort of patients. Ten novel mutations were identified in CNGA3. Genetic characterisation of patients with ACHM is important for genetic counselling and future gene therapies. This study reports the comprehensive clinical and genetic features of Chinese patients with ACHM. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence

  4. Frequent heterogeneous missense mutations of GGAP2 in prostate cancer: implications for tumor biology, clonality and mutation analysis.

    Directory of Open Access Journals (Sweden)

    Yi Cai

    Full Text Available Prostate cancer is the most common visceral malignancy in Western men and a major cause of cancer deaths. Increased activation of the AKT and NFkB pathways have been identified as critical steps in prostate cancer initiation and progression. GGAP2 (GTP-binding and GTPase activating protein 2 is a multidomain protein that contains an N-terminal Ras homology domain (GTPase, followed by a PH domain, a C-terminal GAP domain and an ankyrin repeat domain. GGAP2 can directly activate signaling via both the AKT and NFkB pathways and acts as a node of crosstalk between these pathways. Increased GGAP2 expression is present in three quarters of prostate cancers. Mutations of GGAP2 have been reported in cell lines from other malignancies. We therefore analyzed 84 prostate cancer tissues and 43 benign prostate tissues for somatic mutations in GGAP2 by direct sequencing of individual clones derived from the GAP and GTPase domains of normal and tumor tissue. Overall, half of cancers contained mutant GAP domain clones and in 20% of cancers, 30% or more of clones were mutant in the GAP domain. Surprisingly, the mutations were heterogeneous and nonclonal, with multiple different mutations being present in many tumors. Similar findings were observed in the analysis of the GTPase domain. Mutant GGAP2 proteins had significantly higher transcriptional activity using AP-1 responsive reporter constructs when compared to wild-type protein. Furthermore, the presence of these mutations was associated with aggressive clinical behavior. The presence of high frequency nonclonal mutations of a single gene is novel and represents a new mode of genetic alteration that can promote tumor progression. Analysis of mutations in cancer has been used to predict outcome and guide therapeutic target identification but such analysis has focused on clonal mutations. Our studies indicate that in some cases high frequency nonclonal mutations may need to be assessed as well.

  5. Frequent heterogeneous missense mutations of GGAP2 in prostate cancer: implications for tumor biology, clonality and mutation analysis.

    Science.gov (United States)

    Cai, Yi; Wang, Jianghua; Ren, Chengxi; Ittmann, Michael

    2012-01-01

    Prostate cancer is the most common visceral malignancy in Western men and a major cause of cancer deaths. Increased activation of the AKT and NFkB pathways have been identified as critical steps in prostate cancer initiation and progression. GGAP2 (GTP-binding and GTPase activating protein 2) is a multidomain protein that contains an N-terminal Ras homology domain (GTPase), followed by a PH domain, a C-terminal GAP domain and an ankyrin repeat domain. GGAP2 can directly activate signaling via both the AKT and NFkB pathways and acts as a node of crosstalk between these pathways. Increased GGAP2 expression is present in three quarters of prostate cancers. Mutations of GGAP2 have been reported in cell lines from other malignancies. We therefore analyzed 84 prostate cancer tissues and 43 benign prostate tissues for somatic mutations in GGAP2 by direct sequencing of individual clones derived from the GAP and GTPase domains of normal and tumor tissue. Overall, half of cancers contained mutant GAP domain clones and in 20% of cancers, 30% or more of clones were mutant in the GAP domain. Surprisingly, the mutations were heterogeneous and nonclonal, with multiple different mutations being present in many tumors. Similar findings were observed in the analysis of the GTPase domain. Mutant GGAP2 proteins had significantly higher transcriptional activity using AP-1 responsive reporter constructs when compared to wild-type protein. Furthermore, the presence of these mutations was associated with aggressive clinical behavior. The presence of high frequency nonclonal mutations of a single gene is novel and represents a new mode of genetic alteration that can promote tumor progression. Analysis of mutations in cancer has been used to predict outcome and guide therapeutic target identification but such analysis has focused on clonal mutations. Our studies indicate that in some cases high frequency nonclonal mutations may need to be assessed as well.

  6. Mutations causative of familial hypercholesterolaemia

    DEFF Research Database (Denmark)

    Benn, Marianne; Watts, Gerald F; Tybjærg-Hansen, Anne

    2016-01-01

    AIMS: Ideally, familial hypercholesterolaemia (FH) is diagnosed by testing for mutations that decrease the catabolism of low-density lipoprotein (LDL) cholesterol; however, genetic testing is not universally available. The aim of the present study was to assess the frequency and predictors of FH....... The prevalence of the four FH mutations was 0.18% (1:565), suggesting a total prevalence of FH mutations of 0.46% (1:217). Using the Dutch Lipid Clinic Network (DLCN) criteria, odds ratios for an FH mutation were 439 (95% CI: 170-1 138) for definite FH, 90 (53-152) for probable FH, and 18 (13-25) for possible FH......-cholesterol concentration to discriminate between mutation carriers and non-carriers was 4.4 mmol/L. CONCLUSION: Familial hypercholesterolaemia-causing mutations are estimated to occur in 1:217 in the general population and are best identified by a definite or probable phenotypic diagnosis of FH based on the DLCN criteria...

  7. p53 Mutations and Protein Overexpression in Primary Colorectal Cancer and its Liver Metastasis

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    To compare p53 status in primary and hepatic metastatic colorectal cancer in 34 patients. Methods: p53 gene status (exons 5- 9) was examined by PCR, denaturing gradient gel electrophoresis (DGGE) and automated sequencing. P53 protein was detected by immunohistochemistry using monoclonal antibody DO-7. Results: p53 mutations were found in exons 5 through 9 in 21 of 34 patients (61.8%). Among them, 5 patients had mutation in liver metastasis but not in their primary tumors while in the other patients the same mutations were found in both primary and metastatic colorectal cancers. In no patients was p53 mutation exclusively found in the primary colorectal tumors. Moreover, additional mutation was detected in the metastatic lesions in two cases. Of the 37 mutations within the exons examined, 73% was missense mutation and 16% was nonsense mutation. There were 4 microinsertions. P53 protein was overexpressed in both primary and metastatic colorectal cancers with p53 gene mutations. The presence of p53 mutation significantly correlated with p53 protein accumulation (r=0.96, p< 0.001). However, in 4 patients with p53 nonsense mutation, immunohistochemical staining was negative. In three patients who showed no p53 mutation of the primary tumor, p53 protein was consistently overexpressed. Conclusion: In colorectal cancers, p53 gene mutation usually appears first in the primary tumor and maintains as such but is more prominent when metastasized to the liver. However, p53 gene mutation may occur only after being metastasized.Although p53 gene mutation and p53 protein overexpression correlate with each other, either parameter examined alone may lead to false positive or negative results.

  8. Spectrum of mutations and phenotypic expression in patients with autosomal dominant hypercholesterolemia identified in Italy.

    Science.gov (United States)

    Bertolini, Stefano; Pisciotta, Livia; Rabacchi, Claudio; Cefalù, Angelo B; Noto, Davide; Fasano, Tommaso; Signori, Alessio; Fresa, Raffaele; Averna, Maurizio; Calandra, Sebastiano

    2013-04-01

    To determine the spectrum of gene mutations and the genotype-phenotype correlations in patients with Autosomal Dominant Hypercholesterolemia (ADH) identified in Italy. The resequencing of LDLR, PCSK9 genes and a selected region of APOB gene were conducted in 1018 index subjects clinically heterozygous ADH and in 52 patients clinically homozygous ADH. The analysis was also extended to 1008 family members of mutation positive subjects. Mutations were detected in 832 individuals: 97.4% with LDLR mutations, 2.2% with APOB mutations and 0.36% with PCSK9 mutations. Among the patients with homozygous ADH, 51 were carriers of LDLR mutations and one was an LDLR/PCSK9 double heterozygote. We identified 237 LDLR mutations (45 not previously reported), 4 APOB and 3 PCSK9 mutations. The phenotypic characterization of 1769 LDLR mutation carriers (ADH-1) revealed that in both sexes independent predictors of the presence of tendon xanthomas were age, the quintiles of LDL cholesterol, the presence of coronary heart disease (CHD) and of receptor negative mutations. Independent predictors of CHD were male gender, age, the presence of arterial hypertension, smoking, tendon xanthomas, the scalar increase of LDL cholesterol and the scalar decrease of HDL cholesterol. We identified 13 LDLR mutation clusters, which allowed us to compare the phenotypic impact of different mutations. The LDL cholesterol raising potential of these mutations was found to vary over a wide range. This study confirms the genetic and allelic heterogeneity of ADH and underscores that the variability in phenotypic expression of ADH-1 is greatly affected by the type of LDLR mutation. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  9. Incidence and Outcome of BRCA Mutations in Unselected Patients with Triple Receptor-Negative Breast Cancer.

    LENUS (Irish Health Repository)

    Gonzalez-Angulo, Ana M

    2011-03-01

    To investigate the incidence of germline and somatic BRCA1\\/2 mutations in unselected patients with triple-negative breast cancer (TNBC) and determine the prognostic significance of carrying a mutation. Methods: DNA was obtained from 77 TNBC and normal tissues. BRCA1\\/2 exons\\/flanking regions were sequenced from tumor and patients classified as mutant or wild type (WT). Sequencing was repeated from normal tissue to identify germline and somatic mutations. Patient characteristics were compared with chi-square. Survival was estimated by Kaplan-Meier method and compared with log-rank. Cox proportional hazards models were fit to determine the independent association of mutation status with outcome.

  10. CCR4 frameshift mutation identifies a distinct group of adult T cell leukaemia/lymphoma with poor prognosis.

    Science.gov (United States)

    Yoshida, Noriaki; Miyoshi, Hiroaki; Kato, Takeharu; Sakata-Yanagimoto, Mamiko; Niino, Daisuke; Taniguchi, Hiroaki; Moriuchi, Yukiyoshi; Miyahara, Masaharu; Kurita, Daisuke; Sasaki, Yuya; Shimono, Joji; Kawamoto, Keisuke; Utsunomiya, Atae; Imaizumi, Yoshitaka; Seto, Masao; Ohshima, Koichi

    2016-04-01

    Adult T cell leukaemia/lymphoma (ATLL) is an intractable T cell neoplasm caused by human T cell leukaemia virus type 1. Next-generation sequencing-based comprehensive mutation studies have revealed recurrent somatic CCR4 mutations in ATLL, although clinicopathological findings associated with CCR4 mutations remain to be delineated. In the current study, 184 cases of peripheral T cell lymphoma, including 113 cases of ATLL, were subjected to CCR4 mutation analysis. This sequence analysis identified mutations in 27% (30/113) of cases of ATLL and 9% (4/44) of cases of peripheral T cell lymphoma not otherwise specified. Identified mutations included nonsense (NS) and frameshift (FS) mutations. No significant differences in clinicopathological findings were observed between ATLL cases stratified by presence of CCR4 mutation. All ATLL cases with CCR4 mutations exhibited cell-surface CCR4 positivity. Semi-quantitative CCR4 protein analysis of immunohistochemical sections revealed higher CCR4 expression in cases with NS mutations of CCR4 than in cases with wild-type (WT) CCR4. Furthermore, among ATLL cases, FS mutation was significantly associated with a poor prognosis, compared with NS mutation and WT CCR4. These results suggest that CCR4 mutation is an important determinant of the clinical course in ATLL cases, and that NS and FS mutations of CCR4 behave differently with respect to ATLL pathophysiology.

  11. Functional characterization of human cancer-derived TRKB mutations.

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    Thomas R Geiger

    Full Text Available Cancer originates from cells that have acquired mutations in genes critical for controlling cell proliferation, survival and differentiation. Often, tumors continue to depend on these so-called driver mutations, providing the rationale for targeted anticancer therapies. To date, large-scale sequencing analyses have revealed hundreds of mutations in human tumors. However, without their functional validation it remains unclear which mutations correspond to driver, or rather bystander, mutations and, therefore, whether the mutated gene represents a target for therapeutic intervention. In human colorectal tumors, the neurotrophic receptor TRKB has been found mutated on two different sites in its kinase domain (TRKB(T695I and TRKB(D751N. Another site, in the extracellular part of TRKB, is mutated in a human lung adenocarcinoma cell line (TRKB(L138F. Lastly, our own analysis has identified one additional TRKB point mutation proximal to the kinase domain (TRKB(P507L in a human melanoma cell line. The functional consequences of all these point mutations, however, have so far remained elusive. Previously, we have shown that TRKB is a potent suppressor of anoikis and that TRKB-expressing cells form highly invasive and metastatic tumors in nude mice. To assess the functional consequences of these four TRKB mutations, we determined their potential to suppress anoikis and to form tumors in nude mice. Unexpectedly, both colon cancer-derived mutants, TRKB(T695I and TRKB(D751N, displayed reduced activity compared to that of wild-type TRKB. Consistently, upon stimulation with the TRKB ligand BDNF, these mutants were impaired in activating TRKB and its downstream effectors AKT and ERK. The two mutants derived from human tumor cell lines (TRKB(L138F and TRKB(P507L were functionally indistinguishable from wild-type TRKB in both in-vitro and in-vivo assays. In conclusion, we fail to detect any gain-of-function of four cancer-derived TRKB point mutations.

  12. Mutation Analysis of the LH Receptor Gene in Leydig Cell Adenoma and Hyperplasia and Functional and Biochemical Studies of Activating Mutations of the LH Receptor Gene

    NARCIS (Netherlands)

    Boot, Annemieke M.; Lumbroso, Serge; Verhoef-Post, Miriam; Richter-Unruh, Annette; Looijenga, Leendert H. J.; Funaro, Ada; Beishuizen, Auke; van Marle, Andre; Drop, Stenvert L. S.; Themmen, Axel P. N.

    2011-01-01

    Context: Germline and somatic activating mutations in the LH receptor (LHR) gene have been reported. Objective: Our objective was to perform mutation analysis of the LHR gene of patients with Leydig cell adenoma or hyperplasia. Functional studies were conducted to compare the D578H-LHR mutant with t

  13. High resolution melting analysis: a rapid and accurate method to detect CALR mutations.

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    Cristina Bilbao-Sieyro

    Full Text Available The recent discovery of CALR mutations in essential thrombocythemia (ET and primary myelofibrosis (PMF patients without JAK2/MPL mutations has emerged as a relevant finding for the molecular diagnosis of these myeloproliferative neoplasms (MPN. We tested the feasibility of high-resolution melting (HRM as a screening method for rapid detection of CALR mutations.CALR was studied in wild-type JAK2/MPL patients including 34 ET, 21 persistent thrombocytosis suggestive of MPN and 98 suspected secondary thrombocytosis. CALR mutation analysis was performed through HRM and Sanger sequencing. We compared clinical features of CALR-mutated versus 45 JAK2/MPL-mutated subjects in ET.Nineteen samples showed distinct HRM patterns from wild-type. Of them, 18 were mutations and one a polymorphism as confirmed by direct sequencing. CALR mutations were present in 44% of ET (15/34, 14% of persistent thrombocytosis suggestive of MPN (3/21 and none of the secondary thrombocytosis (0/98. Of the 18 mutants, 9 were 52 bp deletions, 8 were 5 bp insertions and other was a complex mutation with insertion/deletion. No mutations were found after sequencing analysis of 45 samples displaying wild-type HRM curves. HRM technique was reproducible, no false positive or negative were detected and the limit of detection was of 3%.This study establishes a sensitive, reliable and rapid HRM method to screen for the presence of CALR mutations.

  14. High Resolution Melting Analysis: A Rapid and Accurate Method to Detect CALR Mutations

    Science.gov (United States)

    Moreno, Melania; Torres, Laura; Santana-Lopez, Gonzalo; Rodriguez-Medina, Carlos; Perera, María; Bellosillo, Beatriz; de la Iglesia, Silvia; Molero, Teresa; Gomez-Casares, Maria Teresa

    2014-01-01

    Background The recent discovery of CALR mutations in essential thrombocythemia (ET) and primary myelofibrosis (PMF) patients without JAK2/MPL mutations has emerged as a relevant finding for the molecular diagnosis of these myeloproliferative neoplasms (MPN). We tested the feasibility of high-resolution melting (HRM) as a screening method for rapid detection of CALR mutations. Methods CALR was studied in wild-type JAK2/MPL patients including 34 ET, 21 persistent thrombocytosis suggestive of MPN and 98 suspected secondary thrombocytosis. CALR mutation analysis was performed through HRM and Sanger sequencing. We compared clinical features of CALR-mutated versus 45 JAK2/MPL-mutated subjects in ET. Results Nineteen samples showed distinct HRM patterns from wild-type. Of them, 18 were mutations and one a polymorphism as confirmed by direct sequencing. CALR mutations were present in 44% of ET (15/34), 14% of persistent thrombocytosis suggestive of MPN (3/21) and none of the secondary thrombocytosis (0/98). Of the 18 mutants, 9 were 52 bp deletions, 8 were 5 bp insertions and other was a complex mutation with insertion/deletion. No mutations were found after sequencing analysis of 45 samples displaying wild-type HRM curves. HRM technique was reproducible, no false positive or negative were detected and the limit of detection was of 3%. Conclusions This study establishes a sensitive, reliable and rapid HRM method to screen for the presence of CALR mutations. PMID:25068507

  15. The Mutation Profile of Calreticulin in Patients with Myeloproliferative Neoplasms and Acute Leukemia

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    Jingyi Wang

    2016-08-01

    Full Text Available Objective: Calreticulin (CALR plays important roles in cell proliferation, apoptosis, and immune responses. CALR mutations were described recently in Janus kinase 2 gene (JAK2-negative or MPLnegative primary myelofibrosis (PMF and essential thrombocythemia (ET patients. CALR trails JAK2 as the second most mutated gene in myeloproliferative neoplasms (MPNs. However, little is known about CALR mutation in Chinese patients with leukemia. In the present study, a cohort of 305 Chinese patients with hematopoietic neoplasms was screened for CALR mutations, with the aim of uncovering the frequency of CALR mutations in leukemia and MPNs. Materials and Methods: Polymerase chain reaction and direct sequencing were performed to analyze mutations of CALR in 305 patients with hematopoietic malignancies, including 135 acute myeloid leukemia patients, 57 acute lymphoblastic leukemia patients, and 113 MPN patients. Results: CALR mutations were found in 10.6% (12 of 113 of samples from patients with MPNs. CALR mutations were determined in 11.3% (6 of 53, 21.7% (5 of 23, and 9.1% (1/11 of patients with ET, PMF, and unclassifiable MPN, respectively. Conclusion: We showed that MPN patients carrying CALR mutations presented with higher platelet counts and lower hemoglobin levels compared to those with mutated JAK2. However, all of the leukemia patients had negative results for CALR mutations.

  16. Analysis of HBV genotype, drug resistant mutations, and pre-core/basal core promoter mutations in Korean patients with acute hepatitis B.

    Science.gov (United States)

    Lee, Jong Ho; Hong, Sun Pyo; Jang, Eun Sun; Park, Sang Jong; Hwang, Seong Gyu; Kang, Sook-Kyoung; Jeong, Sook-Hyang

    2015-06-01

    Acute hepatitis B, caused by hepatitis B virus (HBV) strains with drug resistant mutations or pre-core/basal core promoter (PC/BCP) mutations, is a public health concern, because this infection is often associated with poor disease outcome or difficulty in therapeutic choice. The HBV genotype, the prevalence of drug resistant mutations, and PC/BCP mutations in Korean patients with acute hepatitis B were studied. From 2006 to 2008, 36 patients with acute hepatitis B were enrolled prospectively in four general hospitals. Among them, 20 showed detectable HBV DNA (median value was 4.8 log copies/mL). HBV genotyping and analysis of HBV mutations that conferred resistance against lamivudine, adefovir, or entecavir and of PC/BCP mutations were performed using highly sensitive restriction fragment mass polymorphism (RFMP) analysis. All 20 patients were infected with HBV genotype C, which causes almost all cases of chronic hepatitis B in Korea. No patient showed mutations that conferred resistance against lamivudine (L180M, M204V/I), adefovir (A181T, N236S), or entecavir (I169M, A184T/V, S202I/G, M250V/I/L). However, four patients had BCP mutations, and two had PC mutations. Platelet counts were significantly lower in the four patients with PC/BCP mutations compared to those with wild type. In this study, all acute hepatitis B patients had genotype C HBV strains with no drug resistant mutations. However, 20% showed PC/BCP mutations. This highlights the need for further study on the significance of PC/BCP mutations.

  17. Prognostic impact of mismatch repair genes germline defects in colorectal cancer patients: are all mutations equal?

    Science.gov (United States)

    Maccaroni, Elena; Bracci, Raffaella; Giampieri, Riccardo; Bianchi, Francesca; Belvederesi, Laura; Brugiati, Cristiana; Pagliaretta, Silvia; Del Prete, Michela; Scartozzi, Mario; Cascinu, Stefano

    2015-01-01

    Background Lynch syndrome (LS) is the most common hereditary colorectal cancer (CRC) syndrome, caused by germline mutations in MisMatch Repair (MMR) genes, particularly in MLH1, MSH2 and MSH6. Patients with LS seem to have a more favourable prognosis than those with sporadic CRC, although the prognostic impact of different mutation types is unknown. Aim of our study is to compare survival outcomes of different types of MMR mutations in patients with LS-related CRC. Methods 302 CRC patients were prospectively selected on the basis of Amsterdam or Revised Bethesda criteria to undergo genetic testing: direct sequencing of DNA and MLPA were used to examine the entire MLH1, MSH2 and MSH6 coding sequence. Patients were classified as mutation-positive or negative according to the genetic testing result. Results A deleterious MMR mutation was found in 38/302 patients. Median overall survival (OS) was significantly higher in mutation-positive vs mutation-negative patients (102.6 vs 77.7 months, HR:0.63, 95%CI:0.46–0.89, p = 0.0083). Different types of mutation were significantly related with OS: missense or splicing-site mutations were associated with better OS compared with rearrangement, frameshift or non-sense mutations (132.5 vs 82.5 months, HR:0.46, 95%CI:0.16–0.82, p = 0.0153). Conclusions Our study confirms improved OS for LS-patients compared with mutation-negative CRC patients. In addition, not all mutations could be considered equal: the better prognosis in CRC patients with MMR pathogenic missense or splicing site mutation could be due to different functional activity of the encoded MMR protein. This matter should be investigated by use of functional assays in the future. PMID:26485756

  18. BRCA1/2 mutation analysis in 41 ovarian cell lines reveals only one functionally deleterious BRCA1 mutation.

    LENUS (Irish Health Repository)

    Stordal, Britta

    2013-06-01

    Mutations in BRCA1\\/2 increase the risk of developing breast and ovarian cancer. Germline BRCA1\\/2 mutations occur in 8.6-13.7% of unselected epithelial ovarian cancers, somatic mutations are also frequent. BRCA1\\/2 mutated or dysfunctional cells may be sensitive to PARP inhibition by synthetic lethality. The aim of this study is to comprehensively characterise the BRCA1\\/2 status of a large panel of ovarian cancer cell lines available to the research community to assist in biomarker studies of novel drugs and in particular of PARP inhibitors. The BRCA1\\/2 genes were sequenced in 41 ovarian cell lines, mRNA expression of BRCA1\\/2 and gene methylation status of BRCA1 was also examined. The cytotoxicity of PARP inhibitors olaparib and veliparib was examined in 20 cell lines. The cell line SNU-251 has a deleterious BRCA1 mutation at 5564G > A, and is the only deleterious BRCA1\\/2 mutant in the panel. Two cell lines (UPN-251 and PEO1) had deleterious mutations as well as additional reversion mutations that restored the protein functionality. Heterozygous mutations in BRCA1\\/2 were relatively common, found in 14.6% of cell lines. BRCA1 was methylated in two cell lines (OVCAR8, A1847) and there was a corresponding decrease in gene expression. The BRCA1 methylated cell lines were more sensitive to PARP inhibition than wild-type cells. The SNU-251 deleterious mutant was more sensitive to PARP inhibition, but only in a long-term exposure to correct for its slow growth rate. Cell lines derived from metastatic disease are significantly more resistant to veliparib (2.0 fold p = 0.03) compared to those derived from primary tumours. Resistance to olaparib and veliparib was correlated Pearsons-R 0.5393, p = 0.0311. The incidence of BRCA1\\/2 deleterious mutations 1\\/41 cell lines derived from 33 different patients (3.0%) is much lower than the population incidence. The reversion mutations and high frequency of heterozygous mutations suggest that there is a selective

  19. OGG1 Mutations and Risk of Female Breast Cancer: Meta-Analysis and Experimental Data

    Directory of Open Access Journals (Sweden)

    Kashif Ali

    2015-01-01

    Full Text Available In first part of this study association between OGG1 polymorphisms and breast cancer susceptibility was explored by meta-analysis. Second part of the study involved 925 subjects, used for mutational analysis of OGG1 gene using PCR-SSCP and sequencing. Fifteen mutations were observed, which included five intronic mutations, four splice site mutations, two 3′UTR mutations, three missense mutations, and a nonsense mutation. Significantly (pG and 3′UTR variant g.9798848G>A. Among intronic mutations, highest (~15 fold increase in breast cancer risk was associated with g.9793680G>A (p<0.009. Similarly ~14-fold increased risk was associated with Val159Gly (p<0.01, ~17-fold with Gly221Arg (p<0.005, and ~18-fold with Ser326Cys (p<0.004 in breast cancer patients compared with controls, whereas analysis of nonsense mutation showed that ~13-fold (p<0.01 increased breast cancer risk was associated with Trp375STOP in patients compared to controls. In conclusion, a significant association was observed between OGG1 germ line mutations and breast cancer risk. These findings provide evidence that OGG1 may prove to be a good candidate of better diagnosis, treatment, and prevention of breast cancer.

  20. Sex enhances adaptation by unlinking beneficial from detrimental mutations in experimental yeast populations

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    Gray Jeremy C

    2012-03-01

    Full Text Available Abstract Background The maintenance of sexuality is a classic problem in evolutionary biology because it is a less efficient mode of reproduction compared with asexuality; however, many organisms are sexual. Theoretical work suggests sex facilitates natural selection, and experimental data support this. However, there are fewer experimental studies that have attempted to determine the mechanisms underlying the advantage of sex. Two main classes of hypotheses have been proposed to explain its advantage: detrimental mutation clearance and beneficial mutation accumulation. Here we attempt to experimentally differentiate between these two classes by evolving Saccharomyces cerevisiae populations that differ only in their ability to undergo sex, and also manipulate mutation rate. We cannot manipulate the types of mutation that occur, but instead propagate populations in both stressful and permissive environments and assume that the extent of detrimental mutation clearance and beneficial mutation incorporation differs between them. Results After 300 mitotic generations interspersed with 11 rounds of sex we found there was no change or difference in fitness between sexuals and asexuals propagated in the permissive environment, regardless of mutation rate. Sex conferred a greater extent of adaptation in the stressful environment, and wild-type and elevated mutation rate sexual populations adapted equivalently. However, the asexual populations with an elevated mutation rate appeared more retarded in their extent of adaptation compared to asexual wild-type populations. Conclusions Sex provided no advantage in the permissive environment where beneficial mutations were rare. We could not evaluate if sex functioned to clear detrimental mutations more effectively or not here as no additional fitness load was observed in the mutator populations. However, in the stressful environment, where detrimental mutations were likely of more consequence, and where

  1. Studies on mutation breeding of hibiscus syriacuse

    Energy Technology Data Exchange (ETDEWEB)

    Song, Hee Sub; Kim, Jin Kyu; Lee, Ki Un; Lim, Yong Taek [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-12-01

    Hibiscus has been known as a national flower of Korea. Hibiscus has ahch a characteristic of self-incompatibility that all the plants exist as natural hybrids and have heterogeneous genes. Thirth two domestic varieties were propagated. Radiosensitivity of H. syriacus irradiated with gamma ray was investigated in plant cuttings. The plant height was reduced by 45 percent in 5 kR irradiated group compared to control group. The radiation dose of 5 kR could be rrecommended for mutation breeding of Hibiscus cuttings. Promising mutant lines were selected form the varieties of Hwarang Wolsan 176, I1pyondansim and Emille. 6 tabs., 2 figs., 13 refs., 4 ills. (Author).

  2. Heavy ion induced mutation in arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Tano, Shigemitsu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    Heavy ions, He, C, Ar and Ne were irradiated to the seeds of Arabidopsis thaliana for inducing the new mutants. In the irradiated generation (M{sub 1}), germination and survival rate were observed to estimate the relative biological effectiveness in relation to the LET including the inactivation cross section. Mutation frequencies were compared by using three kinds of genetic loci after irradiation with C ions and electrons. Several interesting new mutants were selected in the selfed progenies of heavy ion irradiated seeds. (author)

  3. Oxidative Stress in Dilated Cardiomyopathy Caused by MYBPC3 Mutation

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    Thomas L. Lynch

    2015-01-01

    Full Text Available Cardiomyopathies can result from mutations in genes encoding sarcomere proteins including MYBPC3, which encodes cardiac myosin binding protein-C (cMyBP-C. However, whether oxidative stress is augmented due to contractile dysfunction and cardiomyocyte damage in MYBPC3-mutated cardiomyopathies has not been elucidated. To determine whether oxidative stress markers were elevated in MYBPC3-mutated cardiomyopathies, a previously characterized 3-month-old mouse model of dilated cardiomyopathy (DCM expressing a homozygous MYBPC3 mutation (cMyBP-C(t/t was used, compared to wild-type (WT mice. Echocardiography confirmed decreased percentage of fractional shortening in DCM versus WT hearts. Histopathological analysis indicated a significant increase in myocardial disarray and fibrosis while the second harmonic generation imaging revealed disorganized sarcomeric structure and myocyte damage in DCM hearts when compared to WT hearts. Intriguingly, DCM mouse heart homogenates had decreased glutathione (GSH/GSSG ratio and increased protein carbonyl and lipid malondialdehyde content compared to WT heart homogenates, consistent with elevated oxidative stress. Importantly, a similar result was observed in human cardiomyopathy heart homogenate samples. These results were further supported by reduced signals for mitochondrial semiquinone radicals and Fe-S clusters in DCM mouse hearts measured using electron paramagnetic resonance spectroscopy. In conclusion, we demonstrate elevated oxidative stress in MYPBC3-mutated DCM mice, which may exacerbate the development of heart failure.

  4. Large-scale mapping of mutations affecting zebrafish development

    Directory of Open Access Journals (Sweden)

    Neuhauss Stephan C

    2007-01-01

    Full Text Available Abstract Background Large-scale mutagenesis screens in the zebrafish employing the mutagen ENU have isolated several hundred mutant loci that represent putative developmental control genes. In order to realize the potential of such screens, systematic genetic mapping of the mutations is necessary. Here we report on a large-scale effort to map the mutations generated in mutagenesis screening at the Max Planck Institute for Developmental Biology by genome scanning with microsatellite markers. Results We have selected a set of microsatellite markers and developed methods and scoring criteria suitable for efficient, high-throughput genome scanning. We have used these methods to successfully obtain a rough map position for 319 mutant loci from the Tübingen I mutagenesis screen and subsequent screening of the mutant collection. For 277 of these the corresponding gene is not yet identified. Mapping was successful for 80 % of the tested loci. By comparing 21 mutation and gene positions of cloned mutations we have validated the correctness of our linkage group assignments and estimated the standard error of our map positions to be approximately 6 cM. Conclusion By obtaining rough map positions for over 300 zebrafish loci with developmental phenotypes, we have generated a dataset that will be useful not only for cloning of the affected genes, but also to suggest allelism of mutations with similar phenotypes that will be identified in future screens. Furthermore this work validates the usefulness of our methodology for rapid, systematic and inexpensive microsatellite mapping of zebrafish mutations.

  5. Severe neonatal epileptic encephalopathy and KCNQ2 mutation: neuropathological substrate?

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    Charlotte eDalen Meurs-Van Der Schoor

    2014-12-01

    Full Text Available Background:Neonatal convulsions are clinical manifestations in a heterogeneous group of disorders with different etiology and outcome. They are attributed to several genetic causes. Methods:We describe a patient with intractable neonatal seizures who died from respiratory compromise during a status epilepticus. Results:This case report provides EEG, MRI, genetic analysis and neuropathological data. Genetic analysis revealed a de novo heterozygous missense mutation in the KCNQ2 gene, which encodes a subunit of a voltage-gated potassium channel. KCNQ2 gene mutation is associated with intractable neonatal seizures. EEG, MRI data as well as mutation analysis have been described in other KCNQ2 cases. Postmortem neuropathologic investigation revealed mild malformation of cortical development with increased heterotopic neurons in the deep white matter compared to an age-matched control subject. The new finding of this study is the combination of a KCNQ2 mutation and the cortical abnormalities. Conclusions:KCNQ2 mutations should be considered in neonates with refractory epilepsy of unknown cause. The mild cortical malformation is an important new finding, though it remains unknown whether these cortical abnormalities are due to the KCNQ2 mutation or are secondary to the refractory seizures.

  6. Exome sequencing identifies recurrent somatic RAC1 mutations in melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Krauthammer, Michael; Kong, Yong; Ha, Byung Hak; Evans, Perry; Bacchiocchi, Antonella; McCusker, James P.; Cheng, Elaine; Davis, Matthew J.; Goh, Gerald; Choi, Murim; Ariyan, Stephan; Narayan, Deepak; Dutton-Regester, Ken; Capatana, Ana; Holman, Edna C.; Bosenberg, Marcus; Sznol, Mario; Kluger, Harriet M.; Brash, Douglas E.; Stern, David F.; Materin, Miguel A.; Lo, Roger S.; Mane, Shrikant; Ma, Shuangge; Kidd, Kenneth K.; Hayward, Nicholas K.; Lifton, Richard P.; Schlessinger, Joseph; Boggon, Titus J.; Halaban, Ruth (Yale-MED); (UCLA); (Queens)

    2012-10-11

    We characterized the mutational landscape of melanoma, the form of skin cancer with the highest mortality rate, by sequencing the exomes of 147 melanomas. Sun-exposed melanomas had markedly more ultraviolet (UV)-like C>T somatic mutations compared to sun-shielded acral, mucosal and uveal melanomas. Among the newly identified cancer genes was PPP6C, encoding a serine/threonine phosphatase, which harbored mutations that clustered in the active site in 12% of sun-exposed melanomas, exclusively in tumors with mutations in BRAF or NRAS. Notably, we identified a recurrent UV-signature, an activating mutation in RAC1 in 9.2% of sun-exposed melanomas. This activating mutation, the third most frequent in our cohort of sun-exposed melanoma after those of BRAF and NRAS, changes Pro29 to serine (RAC1{sup P29S}) in the highly conserved switch I domain. Crystal structures, and biochemical and functional studies of RAC1{sup P29S} showed that the alteration releases the conformational restraint conferred by the conserved proline, causes an increased binding of the protein to downstream effectors, and promotes melanocyte proliferation and migration. These findings raise the possibility that pharmacological inhibition of downstream effectors of RAC1 signaling could be of therapeutic benefit.

  7. Drosophila chem mutations disrupt epithelial polarity in Drosophila embryos

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    José M. Zamudio-Arroyo

    2016-12-01

    Full Text Available Drosophila embryogenesis has proven to be an extremely powerful system for developmental gene discovery and characterization. We isolated five new EMS-induced alleles that do not complement the l(3R5G83 lethal line isolated in the Nüsslein-Volhard and Wieschaus screens. We have named this locus chem. Lethality of the new alleles as homozygous zygotic mutants is not completely penetrant, and they have an extended phenocritical period. Like the original allele, a fraction of mutant embryos die with cuticular defects, notably head involution and dorsal closure defects. Embryonic defects are much more extreme in germline clones, where the majority of mutant embryos die during embryogenesis and do not form cuticle, implying a strong chem maternal contribution. chem mutations genetically interact with mutations in cytoskeletal genes (arm and with mutations in the epithelial polarity genes coracle, crumbs, and yurt. chem mutants dorsal open defects are similar to those present in yurt mutants, and, likewise, they have epithelial polarity defects. chem1 and chem3 mutations suppress yurt3, and chem3 mutants suppress crumbs1 mutations. In contrast, chem1 and coracle2 mutations enhance each other. Compared to controls, in chem mutants in embryonic lateral epithelia Crumbs expression is mislocalized and reduced, Coracle is increased and mislocalized basally at embryonic stages 13–14, then reduced at stage 16. Arm expression has a similar pattern but levels are reduced.

  8. Homozygosity for dominant mutations increases severity of muscle channelopathies.

    Science.gov (United States)

    Arzel-Hézode, Marianne; Sternberg, Damien; Tabti, Nacira; Vicart, Savine; Goizet, Cyril; Eymard, Bruno; Fontaine, Bertrand; Fournier, Emmanuel

    2010-04-01

    Muscle channelopathies caused by mutations in the SCN4A gene that encodes the muscle sodium channel are transmitted by autosomal-dominant inheritance. We report herein the first cases of homozygous patients for sodium channel mutations responsible for paramyotonia congenita (I1393T) or hypokalemic periodic paralysis (R1132Q). A parallel was drawn between this unprecedented situation and that of myotonia congenita by including patients homozygous or heterozygous for the CLCN1 I556N channel mutation, which is known for incomplete dominance and penetrance. Standardized electromyographic (EMG) protocols combining exercise and cold served as provocative tests to compare homozygotes with heterozygotes for each of the three mutations. Surface-recorded compound muscle action potentials (CMAPs) were used to monitor muscle electrical activity, and myotonic discharges were evaluated by needle EMG. In heterozygous patients, exercise tests disclosed abnormal patterns of CMAP changes, which matched those previously described for similar dominant sodium and chloride channel mutations. Homozygotes showed much more severe clinical features and CMAP changes. We hypothesized that the presence of 100% defective ion channels in the homozygotes could account for the most severe phenotype. This suggests that the severity of muscle channelopathies depends both on the degree of channel impairment caused by the mutation and on the number of mutant channels engaged in the pathophysiological process. Overall, this study has practical consequences for the diagnosis of muscle channelopathies and raises new questions about their pathophysiology.

  9. 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

  10. KRAS mutation analysis by PCR: a comparison of two methods.

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    Louise Bolton

    Full Text Available KRAS mutation assays are important companion diagnostic tests to guide anti-EGFR antibody treatment of metastatic colorectal cancer. Direct comparison of newer diagnostic methods with existing methods is an important part of validation of any new technique. In this this study, we have compared the Therascreen (Qiagen ARMS assay with Competitive Allele-Specific TaqMan PCR (castPCR, Life Technologies to determine equivalence for KRAS mutation analysis.DNA was extracted by Maxwell (Promega from 99 colorectal cancers. The ARMS-based Therascreen and a customized castPCR assay were performed according to the manufacturer's instructions. All assays were performed on either an Applied Biosystems 7500 Fast Dx or a ViiA7 real-time PCR machine (both from Life Technologies. The data were collected and discrepant results re-tested with newly extracted DNA from the same blocks in both assay types.Of the 99 tumors included, Therascreen showed 62 tumors to be wild-type (WT for KRAS, while 37 had KRAS mutations on initial testing. CastPCR showed 61 tumors to be wild-type (WT for KRAS, while 38 had KRAS mutations. Thirteen tumors showed BRAF mutation in castPCR and in one of these there was also a KRAS mutation. The custom castPCR plate included several other KRAS mutations and BRAF V600E, not included in Therascreen, explaining the higher number of mutations detected by castPCR. Re-testing of discrepant results was required in three tumors, all of which then achieved concordance for KRAS. CastPCR assay Ct values were on average 2 cycles lower than Therascreen.There was excellent correlation between the two methods. Although castPCR assay shows lower Ct values than Therascreen, this is unlikely to be clinically significant.

  11. Evolutionary Comparison Provides Evidence for Pathogenicity of RMRP Mutations.

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    2005-10-01

    Full Text Available Cartilage-hair hypoplasia (CHH is a pleiotropic disease caused by recessive mutations in the RMRP gene that result in a wide spectrum of manifestations including short stature, sparse hair, metaphyseal dysplasia, anemia, immune deficiency, and increased incidence of cancer. Molecular diagnosis of CHH has implications for management, prognosis, follow-up, and genetic counseling of affected patients and their families. We report 20 novel mutations in 36 patients with CHH and describe the associated phenotypic spectrum. Given the high mutational heterogeneity (62 mutations reported to date, the high frequency of variations in the region (eight single nucleotide polymorphisms in and around RMRP, and the fact that RMRP is not translated into protein, prediction of mutation pathogenicity is difficult. We addressed this issue by a comparative genomic approach and aligned the genomic sequences of RMRP gene in the entire class of mammals. We found that putative pathogenic mutations are located in highly conserved nucleotides, whereas polymorphisms are located in non-conserved positions. We conclude that the abundance of variations in this small gene is remarkable and at odds with its high conservation through species; it is unclear whether these variations are caused by a high local mutation rate, a failure of repair mechanisms, or a relaxed selective pressure. The marked diversity of mutations in RMRP and the low homozygosity rate in our patient population indicate that CHH is more common than previously estimated, but may go unrecognized because of its variable clinical presentation. Thus, RMRP molecular testing may be indicated in individuals with isolated metaphyseal dysplasia, anemia, or immune dysregulation.

  12. [Founder mutation in Lynch syndrome].

    Science.gov (United States)

    Cajal, Andrea R; Piñero, Tamara A; Verzura, Alicia; Santino, Juan Pablo; Solano, Angela R; Kalfayan, Pablo G; Ferro, Alejandra; Vaccaro, Carlos

    2016-01-01

    Lynch syndrome is the most frequent syndrome in hereditary colorectal cancer, a family-specific deleterious mutations in genes encoding DNA reparation proteins: MLH1 (mutL homolog 1), MSH2, MSH6 (mutS homolog 2 y 6, respectively), PMS2 (PMS1 homolog 2, mismatch repair system component) y MUTYH (mutY DNA glycosylase). The c.2252_2253delAA, p.Lys751Serfs*3 mutation in MLH1 gene segregates with a haplotype reported in the northern region of Italy and whose origin was attributed to a founder effect. This mutation co-segregates with typical characteristics of Lynch syndrome, including early age at onset and multiple primary tumors in the same individual, a high frequency of pancreatic cancer, high microsatellite instability and lack of PMS2 expression. This report describes a mutation in an Argentinian patient with endometrioid adenocarcinoma of uterus. Her first-degree relatives had a history of colon cancer diagnosed before 50 years, fulfilling the Amsterdam Criteria I and Lynch syndrome II. The high pathogenicity associated to this mutation makes necessary the study of all members from families with hereditary cancer, allowing pre-symptomatic genetic diagnosis, early assessment and the instauration of preventive treatments.

  13. SQSTM1 Mutations and Glaucoma.

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    Todd E Scheetz

    Full Text Available Glaucoma is the most common cause of irreversible blindness worldwide. One subset of glaucoma, normal tension glaucoma (NTG occurs in the absence of high intraocular pressure. Mutations in two genes, optineurin (OPTN and TANK binding kinase 1 (TBK1, cause familial NTG and have known roles in the catabolic cellular process autophagy. TKB1 encodes a kinase that phosphorylates OPTN, an autophagy receptor, which ultimately activates autophagy. The sequestosome (SQSTM1 gene also encodes an autophagy receptor and also is a target of TBK1 phosphorylation. Consequently, we hypothesized that mutations in SQSTM1 may also cause NTG. We tested this hypothesis by searching for glaucoma-causing mutations in a cohort of NTG patients (n = 308 and matched controls (n = 157 using Sanger sequencing. An additional 1098 population control samples were also analyzed using whole exome sequencing. A total of 17 non-synonymous mutations were detected which were not significantly skewed between cases and controls when analyzed separately, or as a group (p > 0.05. These data suggest that SQSTM1 mutations are not a common cause of NTG.

  14. Driven by Mutations: The Predictive Value of Mutation Subtype in EGFR-Mutated Non-Small Cell Lung Cancer.

    Science.gov (United States)

    Castellanos, Emily; Feld, Emily; Horn, Leora

    2016-12-23

    EGFR-mutated NSCLC is a genetically heterogeneous disease that includes more than 200 distinct mutations. The implications of mutational subtype for both prognostic and predictive value are being increasingly understood. Although the most common EGFR mutations-exon 19 deletions or L858R mutations-predict sensitivity to EGFR tyrosine kinase inhibitors (TKIs), it is now being recognized that outcomes may be improved in patients with exon 19 deletions. Additionally, 10% of patients will have an uncommon EGFR mutation, and response to EGFR TKI therapy is highly variable depending on the mutation. Given the growing recognition of the genetic and clinical variation seen in this disease, the development of comprehensive bioinformatics-driven tools to both analyze response in uncommon mutation subtypes and inform clinical decision making will be increasingly important. Clinical trials of novel EGFR TKIs should prospectively account for the presence of uncommon mutation subtypes in study design.

  15. cDNA sequencing improves the detection of P53 missense mutations in colorectal cancer

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    Jesionek-Kupnicka Dorota

    2009-08-01

    Full Text Available Abstract Background Recently published data showed discrepancies beteween P53 cDNA and DNA sequencing in glioblastomas. We hypothesised that similar discrepancies may be observed in other human cancers. Methods To this end, we analyzed 23 colorectal cancers for P53 mutations and gene expression using both DNA and cDNA sequencing, real-time PCR and immunohistochemistry. Results We found P53 gene mutations in 16 cases (15 missense and 1 nonsense. Two of the 15 cases with missense mutations showed alterations based only on cDNA, and not DNA sequencing. Moreover, in 6 of the 15 cases with a cDNA mutation those mutations were difficult to detect in the DNA sequencing, so the results of DNA analysis alone could be misinterpreted if the cDNA sequencing results had not also been available. In all those 15 cases, we observed a higher ratio of the mutated to the wild type template by cDNA analysis, but not by the DNA analysis. Interestingly, a similar overexpression of P53 mRNA was present in samples with and without P53 mutations. Conclusion In terms of colorectal cancer, those discrepancies might be explained under three conditions: 1, overexpression of mutated P53 mRNA in cancer cells as compared with normal cells; 2, a higher content of cells without P53 mutation (normal cells and cells showing K-RAS and/or APC but not P53 mutation in samples presenting P53 mutation; 3, heterozygous or hemizygous mutations of P53 gene. Additionally, for heterozygous mutations unknown mechanism(s causing selective overproduction of mutated allele should also be considered. Our data offer new clues for studying discrepancy in P53 cDNA and DNA sequencing analysis.

  16. Quantitative and sensitive detection of GNAS mutations causing mccune-albright syndrome with next generation sequencing.

    Science.gov (United States)

    Narumi, Satoshi; Matsuo, Kumihiro; Ishii, Tomohiro; Tanahashi, Yusuke; Hasegawa, Tomonobu

    2013-01-01

    Somatic activating GNAS mutations cause McCune-Albright syndrome (MAS). Owing to low mutation abundance, mutant-specific enrichment procedures, such as the peptide nucleic acid (PNA) method, are required to detect mutations in peripheral blood. Next generation sequencing (NGS) can analyze millions of PCR amplicons independently, thus it is expected to detect low-abundance GNAS mutations quantitatively. In the present study, we aimed to develop an NGS-based method to detect low-abundance somatic GNAS mutations. PCR amplicons encompassing exons 8 and 9 of GNAS, in which most activating mutations occur, were sequenced on the MiSeq instrument. As expected, our NGS-based method could sequence the GNAS locus with very high read depth (approximately 100,000) and low error rate. A serial dilution study with use of cloned mutant and wildtype DNA samples showed a linear correlation between dilution and measured mutation abundance, indicating the reliability of quantification of the mutation. Using the serially diluted samples, the detection limits of three mutation detection methods (the PNA method, NGS, and combinatory use of PNA and NGS [PNA-NGS]) were determined. The lowest detectable mutation abundance was 1% for the PNA method, 0.03% for NGS and 0.01% for PNA-NGS. Finally, we analyzed 16 MAS patient-derived leukocytic DNA samples with the three methods, and compared the mutation detection rate of them. Mutation detection rate of the PNA method, NGS and PNA-NGS in 16 patient-derived peripheral blood samples were 56%, 63% and 75%, respectively. In conclusion, NGS can detect somatic activating GNAS mutations quantitatively and sensitively from peripheral blood samples. At present, the PNA-NGS method is likely the most sensitive method to detect low-abundance GNAS mutation.

  17. Quantitative and sensitive detection of GNAS mutations causing mccune-albright syndrome with next generation sequencing.

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    Satoshi Narumi

    Full Text Available Somatic activating GNAS mutations cause McCune-Albright syndrome (MAS. Owing to low mutation abundance, mutant-specific enrichment procedures, such as the peptide nucleic acid (PNA method, are required to detect mutations in peripheral blood. Next generation sequencing (NGS can analyze millions of PCR amplicons independently, thus it is expected to detect low-abundance GNAS mutations quantitatively. In the present study, we aimed to develop an NGS-based method to detect low-abundance somatic GNAS mutations. PCR amplicons encompassing exons 8 and 9 of GNAS, in which most activating mutations occur, were sequenced on the MiSeq instrument. As expected, our NGS-based method could sequence the GNAS locus with very high read depth (approximately 100,000 and low error rate. A serial dilution study with use of cloned mutant and wildtype DNA samples showed a linear correlation between dilution and measured mutation abundance, indicating the reliability of quantification of the mutation. Using the serially diluted samples, the detection limits of three mutation detection methods (the PNA method, NGS, and combinatory use of PNA and NGS [PNA-NGS] were determined. The lowest detectable mutation abundance was 1% for the PNA method, 0.03% for NGS and 0.01% for PNA-NGS. Finally, we analyzed 16 MAS patient-derived leukocytic DNA samples with the three methods, and compared the mutation detection rate of them. Mutation detection rate of the PNA method, NGS and PNA-NGS in 16 patient-derived peripheral blood samples were 56%, 63% and 75%, respectively. In conclusion, NGS can detect somatic activating GNAS mutations quantitatively and sensitively from peripheral blood samples. At present, the PNA-NGS method is likely the most sensitive method to detect low-abundance GNAS mutation.

  18. Clinical characterization and the mutation spectrum in Swedish adenomatous polyposis families

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    Meuller Johan

    2008-04-01

    Full Text Available Abstract Background The dominantly inherited condition familial adenomatous polyposis (FAP is caused by germline mutations in the APC gene. Finding the causative mutations has great implications for the families. Correlating the genotypes to the phenotypes could help to improve the diagnosis and follow-up of patients. Methods Mutation screening of APC and the clinical characterization of 96 unrelated FAP patients from the Swedish Polyposis Registry was performed. In addition to generally used mutation screening methods, analyses of splicing-affecting mutations and investigations of the presence of low-frequency mutation alleles, indicating mosaics, have been performed, as well as quantitative real-time polymerase chain reaction to detect lowered expression of APC. Results Sixty-one different APC mutations in 81 of the 96 families were identified and 27 of those are novel. We have previously shown that 6 of the 96 patients carried biallelic MUTYH mutations. The 9 mutation-negative cases all display an attenuated or atypical phenotype. Probands with a genotype (codon 1250–1464 predicting a severe phenotype had a median age at diagnosis of 21.8 (range, 11–49 years compared with 34.4 (range, 14–57 years among those with mutations outside this region (P 1000 occurred in 75% of the probands with a severe phenotype compared with 30% in those with mutations outside this region. The morbidity in colorectal cancer among probands was 25% at a mean age of 37.5 years and 29% at a mean age of 46.6 years. Conclusion Using a variety of mutation-detection techniques, we have achieved a 100% detection frequency in classical FAP. Probands with APC mutations outside codon 1250–1464, although exhibiting a less-severe phenotype, are at high risk of having a colorectal cancer at diagnosis indicating that age at diagnosis is as important as the severity of the disease for colorectal cancer morbidity.

  19. GALNS mutations in Indian patients with mucopolysaccharidosis IVA.

    Science.gov (United States)

    Bidchol, Abdul Mueed; Dalal, Ashwin; Shah, Hitesh; S, Suryanarayana; Nampoothiri, Sheela; Kabra, Madhulika; Gupta, Neerja; Danda, Sumita; Gowrishankar, Kalpana; Phadke, Shubha R; Kapoor, Seema; Kamate, Mahesh; Verma, I C; Puri, Ratna Dua; Sankar, V H; Devi, A Radha Rama; Patil, S J; Ranganath, Prajnya; Jain, S Jamal Md Nurul; Agarwal, Meenal; Singh, Ankur; Mishra, Pallavi; Tamhankar, Parag M; Gopinath, Puthiya Mundyat; Nagarajaram, H A; Satyamoorthy, Kapaettu; Girisha, Katta Mohan

    2014-11-01

    Mucopolysaccharidosis IV A (Morquio syndrome A, MPS IVA) is a lysosomal storage disease caused by the deficiency of N-acetylgalactosamine-6-sulfatase (GALNS). The mutation spectrum in this condition is yet to be determined in Indians. We aimed to analyze the mutations in the GALNS gene in Asian Indians with MPS IVA. All the exons and the adjacent intronic regions of the gene were amplified and sequenced in sixty-eight unrelated Indian families. We identified 136 mutant alleles comprising of 40 different mutations. We report twenty-two novel mutations that comprise of seventeen missense (p.Asn32Thr, p.Leu36Arg, p.Pro52Leu, p.Pro77Ser, p.Cys79Arg, p.His142Pro, p.Tyr191Asp, p.Asn204Thr, p.Gly188Ser, p.Phe216Ser, p.Trp230Cys, p.Ala291Ser, p.Gly317Arg, p.His329Pro, p.Arg386Ser, p.Glu450Gly, p.Cys501Ser), three splice-site variants (c.120+1G>C, c.1003-3C>G, c.1139+1G>A), one nonsense mutation (p.Gln414*) and one frameshift mutation (p.Pro420Leufs*440). Eighteen mutations have been reported earlier. Among these p.Ser287Leu (8.82%), p.Phe216Ser (7.35%), p.Asn32Thr (6.61%) and p.Ala291Ser (5.88%) were the most frequent mutations in Indian patients but were rare in the mutational profiles reported in other populations. These results indicate that the Indian patients may have a distinct mutation spectrum compared to those of other populations. Mutant alleles in exon 1, 7 and 8 accounted for 44.8% of the mutations, and sequencing of these exons initially may be a cost-effective approach in Asian Indian patients. This is the largest study on molecular analysis of patients with MPS IVA reported in the literature, and the first report from India. © 2014 Wiley Periodicals, Inc.

  20. Rapid generation of hypomorphic mutations

    Science.gov (United States)

    Arthur, Laura L.; Chung, Joyce J.; Jankirama, Preetam; Keefer, Kathryn M.; Kolotilin, Igor; Pavlovic-Djuranovic, Slavica; Chalker, Douglas L.; Grbic, Vojislava; Green, Rachel; Menassa, Rima; True, Heather L.; Skeath, James B.; Djuranovic, Sergej

    2017-01-01

    Hypomorphic mutations are a valuable tool for both genetic analysis of gene function and for synthetic biology applications. However, current methods to generate hypomorphic mutations are limited to a specific organism, change gene expression unpredictably, or depend on changes in spatial-temporal expression of the targeted gene. Here we present a simple and predictable method to generate hypomorphic mutations in model organisms by targeting translation elongation. Adding consecutive adenosine nucleotides, so-called polyA tracks, to the gene coding sequence of interest will decrease translation elongation efficiency, and in all tested cell cultures and model organisms, this decreases mRNA stability and protein expression. We show that protein expression is adjustable independent of promoter strength and can be further modulated by changing sequence features of the polyA tracks. These characteristics make this method highly predictable and tractable for generation of programmable allelic series with a range of expression levels. PMID:28106166

  1. Neutral Evolution of Mutational Robustness

    CERN Document Server

    Van Nimwegen, E; Huynen, M; Nimwegen, Erik van; Crutchfield, James P.; Huynen, Martijn

    1999-01-01

    We introduce and analyze a general model of a population evolving over a network of selectively neutral genotypes. We show that the population's limit distribution on the neutral network is solely determined by the network topology and given by the principal eigenvector of the network's adjacency matrix. Moreover, the average number of neutral mutant neighbors per individual is given by the matrix spectral radius. This quantifies the extent to which populations evolve mutational robustness: the insensitivity of the phenotype to mutations. Since the average neutrality is independent of evolutionary parameters---such as, mutation rate, population size, and selective advantage---one can infer global statistics of neutral network topology using simple population data available from {\\it in vitro} or {\\it in vivo} evolution. Populations evolving on neutral networks of RNA secondary structures show excellent agreement with our theoretical predictions.

  2. Glucocerebrosidase activity in Parkinson's disease with and without GBA mutations.

    Science.gov (United States)

    Alcalay, Roy N; Levy, Oren A; Waters, Cheryl C; Fahn, Stanley; Ford, Blair; Kuo, Sheng-Han; Mazzoni, Pietro; Pauciulo, Michael W; Nichols, William C; Gan-Or, Ziv; Rouleau, Guy A; Chung, Wendy K; Wolf, Pavlina; Oliva, Petra; Keutzer, Joan; Marder, Karen; Zhang, Xiaokui

    2015-09-01

    Glucocerebrosidase (GBA) mutations have been associated with Parkinson's disease in numerous studies. However, it is unknown whether the increased risk of Parkinson's disease in GBA carriers is due to a loss of glucocerebrosidase enzymatic activity. We measured glucocerebrosidase enzymatic activity in dried blood spots in patients with Parkinson's disease (n = 517) and controls (n = 252) with and without GBA mutations. Participants were recruited from Columbia University, New York, and fully sequenced for GBA mutations and genotyped for the LRRK2 G2019S mutation, the most common autosomal dominant mutation in the Ashkenazi Jewish population. Glucocerebrosidase enzymatic activity in dried blood spots was measured by a mass spectrometry-based assay and compared among participants categorized by GBA mutation status and Parkinson's disease diagnosis. Parkinson's disease patients were more likely than controls to carry the LRRK2 G2019S mutation (n = 39, 7.5% versus n = 2, 0.8%, P Parkinson's risk but not with Gaucher disease (E326K, P = 0.009; T369M, P Parkinson's disease were considered, they had lower mean glucocerebrosidase enzymatic activity than controls (11.14 µmol/l/h versus 11.85 µmol/l/h, P = 0.011). Difference compared to controls persisted in patients with idiopathic Parkinson's disease (after exclusion of all GBA and LRRK2 carriers; 11.53 µmol/l/h, versus 12.11 µmol/l/h, P = 0.036) and after adjustment for age and gender (P = 0.012). Interestingly, LRRK2 G2019S carriers (n = 36), most of whom had Parkinson's disease, had higher enzymatic activity than non-carriers (13.69 µmol/l/h versus 11.93 µmol/l/h, P = 0.002). In patients with idiopathic Parkinson's, higher glucocerebrosidase enzymatic activity was associated with longer disease duration (P = 0.002) in adjusted models, suggesting a milder disease course. We conclude that lower glucocerebrosidase enzymatic activity is strongly associated with GBA mutations, and modestly with idiopathic Parkinson

  3. Mutations in ANKH cause chondrocalcinosis.

    Science.gov (United States)

    Pendleton, Adrian; Johnson, Michelle D; Hughes, Anne; Gurley, Kyle A; Ho, Andrew M; Doherty, Michael; Dixey, Josh; Gillet, Pierre; Loeuille, Damien; McGrath, Rodney; Reginato, Antonio; Shiang, Rita; Wright, Gary; Netter, Patrick; Williams, Charlene; Kingsley, David M

    2002-10-01

    Chondrocalcinosis (CC) is a common cause of joint pain and arthritis that is caused by the deposition of calcium-containing crystals within articular cartilage. Although most cases are sporadic, rare familial forms have been linked to human chromosomes 8 (CCAL1) or 5p (CCAL2) (Baldwin et al. 1995; Hughes et al. 1995; Andrew et al. 1999). Here, we show that two previously described families with CCAL2 have mutations in the human homolog of the mouse progressive ankylosis gene (ANKH). One of the human mutations results in the substitution of a highly conserved amino acid residue within a predicted transmembrane segment. The other creates a new ATG start site that adds four additional residues to the ANKH protein. Both mutations segregate completely with disease status and are not found in control subjects. In addition, 1 of 95 U.K. patients with sporadic CC showed a deletion of a single codon in the ANKH gene. The same change was found in a sister who had bilateral knee replacement for osteoarthritis. Each of the three human mutations was reconstructed in a full-length ANK expression construct previously shown to regulate pyrophosphate levels in cultured cells in vitro. All three of the human mutations showed significantly more activity than a previously described nonsense mutation that causes severe hydroxyapatite mineral deposition and widespread joint ankylosis in mice. These results suggest that small sequence changes in ANKH are one cause of CC and joint disease in humans. Increased ANK activity may explain the different types of crystals commonly deposited in human CCAL2 families and mutant mice and may provide a useful pharmacological target for treating some forms of human CC.

  4. Mutations determining mitomycin resistance in Bacillus subtilis.

    Science.gov (United States)

    Iyer, V N

    1966-12-01

    Iyer, V. N. (Microbiology Research Institute, Canada Department of Agriculture, Ottawa, Canada). Mutations determining mitomycin resistance in Bacillus subtilis. J. Bacteriol. 92:1663-1669. 1966.-The pattern of development of genetic resistance in Bacillus subtilis to mitomycin C was studied, and spontaneous single and multistep mutants were obtained. The transmission and expression of these mutations in sensitive strains proved possible by means of genetic transformation. The mutations were genetically studied in relation to a chromosomal mutation, mac-1, which confers resistance to the macrolide antibiotic erythromycin and which has been previously localized in the early-replicating segment of the B. subtilis chromosome. The results indicate that all of three primary mutations studied in this manner, as well as a secondary and tertiary mutation derived from one of the primary mutations, are clustered in this early-replicating segment. It appears that the secondary and tertiary mutations enhance the resistance conferred by the primary mutation, apparently without themselves conferring any resistance.

  5. Chaotic Particle Swarm Optimization with Mutation for Classification

    Science.gov (United States)

    Assarzadeh, Zahra; Naghsh-Nilchi, Ahmad Reza

    2015-01-01

    In this paper, a chaotic particle swarm optimization with mutation-based classifier particle swarm optimization is proposed to classify patterns of different classes in the feature space. The introduced mutation operators and chaotic sequences allows us to overcome the problem of early convergence into a local minima associated with particle swarm optimization algorithms. That is, the mutation operator sharpens the convergence and it tunes the best possible solution. Furthermore, to remove the irrelevant data and reduce the dimensionality of medical datasets, a feature selection approach using binary version of the proposed particle swarm optimization is introduced. In order to demonstrate the effectiveness of our proposed classifier, mutation-based classifier particle swarm optimization, it is checked out with three sets of data classifications namely, Wisconsin diagnostic breast cancer, Wisconsin breast cancer and heart-statlog, with different feature vector dimensions. The proposed algorithm is compared with different classifier algorithms including k-nearest neighbor, as a conventional classifier, particle swarm-classifier, genetic algorithm, and Imperialist competitive algorithm-classifier, as more sophisticated ones. The performance of each classifier was evaluated by calculating the accuracy, sensitivity, specificity and Matthews's correlation coefficient. The experimental results show that the mutation-based classifier particle swarm optimization unequivocally performs better than all the compared algorithms. PMID:25709937

  6. Chaotic particle swarm optimization with mutation for classification.

    Science.gov (United States)

    Assarzadeh, Zahra; Naghsh-Nilchi, Ahmad Reza

    2015-01-01

    In this paper, a chaotic particle swarm optimization with mutation-based classifier particle swarm optimization is proposed to classify patterns of different classes in the feature space. The introduced mutation operators and chaotic sequences allows us to overcome the problem of early convergence into a local minima associated with particle swarm optimization algorithms. That is, the mutation operator sharpens the convergence and it tunes the best possible solution. Furthermore, to remove the irrelevant data and reduce the dimensionality of medical datasets, a feature selection approach using binary version of the proposed particle swarm optimization is introduced. In order to demonstrate the effectiveness of our proposed classifier, mutation-based classifier particle swarm optimization, it is checked out with three sets of data classifications namely, Wisconsin diagnostic breast cancer, Wisconsin breast cancer and heart-statlog, with different feature vector dimensions. The proposed algorithm is compared with different classifier algorithms including k-nearest neighbor, as a conventional classifier, particle swarm-classifier, genetic algorithm, and Imperialist competitive algorithm-classifier, as more sophisticated ones. The performance of each classifier was evaluated by calculating the accuracy, sensitivity, specificity and Matthews's correlation coefficient. The experimental results show that the mutation-based classifier particle swarm optimization unequivocally performs better than all the compared algorithms.

  7. Survival in Norwegian BRCA1 mutation carriers with breast cancer

    Directory of Open Access Journals (Sweden)

    Hagen Anne

    2009-04-01

    Full Text Available Abstract Several studies of survival in women with BRCA1 mutations have shown either reduced survival or no difference compared to controls. Programmes for early detection and treatment of inherited breast cancer, have failed to demonstrate a significant improvement in survival in BRCA1 mutation carriers. One hundred and sixty-seven women with disease-associated germline BRCA1 mutations and breast cancer from 1980 to 2001 were identified. Tumour characteristics, treatment given and survival were recorded. A control group comprising three hundred and four women matched for age, time of diagnosis and stage were used to compare survival. BRCA1 mutation carriers were found to have a poorer prognosis, which could be explained by neither the mode of surgical treatment nor the use of adjuvant chemotherapy. BRCA1 mutation carriers with node negative breast cancer had worse overall survival than controls. Our findings confirm the serious prognosis of BRCA1-associated breast cancer even when diagnosed at an early stage, and that type of treatment does not influence prognosis.

  8. Optimization of Mutation Pressure in Relation to Properties of Protein-Coding Sequences in Bacterial Genomes.

    Science.gov (United States)

    Błażej, Paweł; Miasojedow, Błażej; Grabińska, Małgorzata; Mackiewicz, Paweł

    2015-01-01

    Most mutations are deleterious and require energetically costly repairs. Therefore, it seems that any minimization of mutation rate is beneficial. On the other hand, mutations generate genetic diversity indispensable for evolution and adaptation of organisms to changing environmental conditions. Thus, it is expected that a spontaneous mutational pressure should be an optimal compromise between these two extremes. In order to study the optimization of the pressure, we compared mutational transition probability matrices from bacterial genomes with artificial matrices fulfilling the same general features as the real ones, e.g., the stationary distribution and the speed of convergence to the stationarity. The artificial matrices were optimized on real protein-coding sequences based on Evolutionary Strategies approach to minimize or maximize the probability of non-synonymous substitutions and costs of amino acid replacements depending on their physicochemical properties. The results show that the empirical matrices have a tendency to minimize the effects of mutations rather than maximize their costs on the amino acid level. They were also similar to the optimized artificial matrices in the nucleotide substitution pattern, especially the high transitions/transversions ratio. We observed no substantial differences between the effects of mutational matrices on protein-coding sequences in genomes under study in respect of differently replicated DNA strands, mutational cost types and properties of the referenced artificial matrices. The findings indicate that the empirical mutational matrices are rather adapted to minimize mutational costs in the studied organisms in comparison to other matrices with similar mathematical constraints.

  9. Mitochondrial DNA deletion mutations in adult mouse cardiac side population cells

    Energy Technology Data Exchange (ETDEWEB)

    Lushaj, Entela B., E-mail: lushaj@surgery.wisc.edu [Division of Cardiothoracic Surgery, Department of Surgery, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53792 (United States); Lozonschi, Lucian; Barnes, Maria; Anstadt, Emily; Kohmoto, Takushi [Division of Cardiothoracic Surgery, Department of Surgery, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53792 (United States)

    2012-06-01

    We investigated the presence and potential role of mitochondrial DNA (mtDNA) deletion mutations in adult cardiac stem cells. Cardiac side population (SP) cells were isolated from 12-week-old mice. Standard polymerase chain reaction (PCR) was used to screen for the presence of mtDNA deletion mutations in (a) freshly isolated SP cells and (b) SP cells cultured to passage 10. When present, the abundance of mtDNA deletion mutation was analyzed in single cell colonies. The effect of different levels of deletion mutations on SP cell growth and differentiation was determined. MtDNA deletion mutations were found in both freshly isolated and cultured cells from 12-week-old mice. While there was no significant difference in the number of single cell colonies with mtDNA deletion mutations from any of the groups mentioned above, the abundance of mtDNA deletion mutations was significantly higher in the cultured cells, as determined by quantitative PCR. Within a single clonal cell population, the detectable mtDNA deletion mutations were the same in all cells and unique when compared to deletions of other colonies. We also found that cells harboring high levels of mtDNA deletion mutations (i.e. where deleted mtDNA comprised more than 60% of total mtDNA) had slower proliferation rates and decreased differentiation capacities. Screening cultured adult stem cells for mtDNA deletion mutations as a routine assessment will benefit the biomedical application of adult stem cells.

  10. Rates and genomic consequences of spontaneous mutational events in Drosophila melanogaster.

    Science.gov (United States)

    Schrider, Daniel R; Houle, David; Lynch, Michael; Hahn, Matthew W

    2013-08-01

    Because spontaneous mutation is the source of all genetic diversity, measuring mutation rates can reveal how natural selection drives patterns of variation within and between species. We sequenced eight genomes produced by a mutation-accumulation experiment in Drosophila melanogaster. Our analysis reveals that point mutation and small indel rates vary significantly between the two different genetic backgrounds examined. We also find evidence that ∼2% of mutational events affect multiple closely spaced nucleotides. Unlike previous similar experiments, we were able to estimate genome-wide rates of large deletions and tandem duplications. These results suggest that, at least in inbred lines like those examined here, mutational pressures may result in net growth rather than contraction of the Drosophila genome. By comparing our mutation rate estimates to polymorphism data, we are able to estimate the fraction of new mutations that are eliminated by purifying selection. These results suggest that ∼99% of duplications and deletions are deleterious--making them 10 times more likely to be removed by selection than nonsynonymous mutations. Our results illuminate not only the rates of new small- and large-scale mutations, but also the selective forces that they encounter once they arise.

  11. Three families with 'de novo' m.3243A > G mutation.

    Science.gov (United States)

    de Laat, Paul; Janssen, Mirian C H; Alston, Charlotte L; Taylor, Robert W; Rodenburg, Richard J T; Smeitink, Jan A M

    2016-12-01

    The m.3243A > G mutation is the most prevalent, disease-causing mitochondrial DNA (mtDNA) mutation. In a national cohort study of 48 families harbouring the m.3243A > G mutation, we identified three families in which the mutation appeared to occur sporadically within these families. In this report we describe these three families. Based on detailed mtDNA analysis of three different tissues using two different quantitative pyrosequencing assays with sensitivity to a level of 1% mutated mtDNA, we conclude that the m.3243A > G mutation has arisen de novo in each of these families. The symptomatic carriers presented with a variety of symptoms frequently observed in patients harbouring the m.3243A > G mutation. A more severe phenotype is seen in the de novo families compared to recent cohort studies, which might be due to reporting bias. The observation that de novo m.3243A > G mutations exist is of relevance for both diagnostic investigations and genetic counselling. Firstly, even where there is no significant (maternal) family history in patients with stroke-like episodes, diabetes and deafness or other unexplained organ dysfunction, the m.3243A > G mutation should be screened as a possible cause of the disease. Second, analysis of maternally-related family members is highly recommended to provide reliable counselling for these families, given that the m.3243A > G mutation may have arisen de novo.

  12. Optimization of Mutation Pressure in Relation to Properties of Protein-Coding Sequences in Bacterial Genomes.

    Directory of Open Access Journals (Sweden)

    Paweł Błażej

    Full Text Available Most mutations are deleterious and require energetically costly repairs. Therefore, it seems that any minimization of mutation rate is beneficial. On the other hand, mutations generate genetic diversity indispensable for evolution and adaptation of organisms to changing environmental conditions. Thus, it is expected that a spontaneous mutational pressure should be an optimal compromise between these two extremes. In order to study the optimization of the pressure, we compared mutational transition probability matrices from bacterial genomes with artificial matrices fulfilling the same general features as the real ones, e.g., the stationary distribution and the speed of convergence to the stationarity. The artificial matrices were optimized on real protein-coding sequences based on Evolutionary Strategies approach to minimize or maximize the probability of non-synonymous substitutions and costs of amino acid replacements depending on their physicochemical properties. The results show that the empirical matrices have a tendency to minimize the effects of mutations rather than maximize their costs on the amino acid level. They were also similar to the optimized artificial matrices in the nucleotide substitution pattern, especially the high transitions/transversions ratio. We observed no substantial differences between the effects of mutational matrices on protein-coding sequences in genomes under study in respect of differently replicated DNA strands, mutational cost types and properties of the referenced artificial matrices. The findings indicate that the empirical mutational matrices are rather adapted to minimize mutational costs in the studied organisms in comparison to other matrices with similar mathematical constraints.

  13. Unique spectrum of MEFV mutations in Iranian Jewish FMF patients--clinical and demographic significance.

    Science.gov (United States)

    Shinar, Y; Kuchuk, I; Menasherow, S; Kolet, M; Lidar, M; Langevitz, P; Livneh, A

    2007-11-01

    To determine the spectrum of mutations in the Mediterranean fever gene (MEFV) of Iranian Jews with familial Mediterranean fever (FMF) and to analyse their clinical manifestations. FMF patients with both parents of Iranian-Jewish (IJ) extraction or with one IJ parent (IJ-other, 10 of each) were characterized for clinical manifestations, and the B30.2 (PRYSPRY) domain of their MEFV was sequenced for mutations. Only one rare mutation, R653H, and one new mutation, G632S were present in the IJ group (in 2/10 patients), whereas the new, and common mutations were present in the IJ-other patients (8/10 patients). The new mutation was traced thrice to an IJ ancestor, and although carried asymptomatically by family members, it was over-represented in the patients (3/28 unrelated IJ alleles) compared non-affected IJ subjects (1/126 alleles, P = 0.03) or with non-Jewish Iranians (0/108 alleles, P = 0.001). The mutation was associated with a distinct phenotype regarding sites involved in the attack (P = 0.001), mild severity, sole expression of febrile episodes (P = 0.01) and a male bias (P = 0.01). In two 3D PRYSPRY models the G632S mutation was localized to a surface loop and close to a putative binding site. Iranian Jews with FMF have a unique spectrum of mutations including a newly described mutation with a non-typical phenotype.

  14. pncA mutations in clinical Mycobacterium tuberculosis isolates from Korea

    Directory of Open Access Journals (Sweden)

    Kim Cheol Min

    2001-06-01

    Full Text Available Abstract Background Pyrazinamide (PZA is among the first-line drugs for the treatment of tuberculosis. In vitro, it kills semidormant mycobacteria only at low pH. The purpose of this study was to compare PZA resistance with pyrazinamidase (PZase activity and the genotype to better understand the molecular basis of PZA resistance and to expand the profile of pncA mutations worldwide. Results Of the 28 tested strains of Mycobacterium tuberculosis, 6 were susceptible to PZA and positive for PZase activity and had no pncA mutations. Twenty-one strains were resistant to PZA and negative for PZase activity and had mutations in the pncA gene, including 15 point mutations, 5 insertions, and 2 deletions. One strain had no mutation in the pncA gene, even though it was resistant to PZA and negative for PZase activity. Three isolates had adenine to guanine point mutations in the -11 upstream region, making this the most common type of pncA mutations in this study, with at least two different RFLP patterns. Conclusion These data help in the understanding of the molecular basis of PZA resistance. An adenine to guanine point mutation in the -11 upstream region was the most common type of pncA mutation in our isolates. The results of pncA mutation analyses should be carefully interpreted for epidemiologic purposes.

  15. Mutations in the dihydropteroate synthase gene of Pneumocystis jiroveci isolates from Portuguese patients with Pneumocystis pneumonia

    DEFF Research Database (Denmark)

    Costa, M C; Helweg-Larsen, J; Lundgren, Bettina

    2003-01-01

    The aim of this study was to evaluate the frequency of mutations of the P. jiroveci dihydropteroate synthase (DHPS) gene in an immunocompromised Portuguese population and to investigate the possible association between DHPS mutations and sulpha exposure. In the studied population, DHPS gene...... mutations were not significantly more frequent in patients exposed to sulpha drugs compared with patients not exposed (P=0.390). The results of this study suggest that DHPS gene mutations are frequent in the Portuguese immunocompromised population but do not seem associated with previous sulpha exposure...

  16. Detection of EGFR and KRAS Mutation by Pyrosequencing Analysis in Cytologic Samples of Non-Small Cell Lung Cancer.

    Science.gov (United States)

    Lee, Seung Eun; Lee, So-Young; Park, Hyung-Kyu; Oh, Seo-Young; Kim, Hee-Joung; Lee, Kye-Young; Kim, Wan-Seop

    2016-08-01

    EGFR and KRAS mutations are two of the most common mutations that are present in lung cancer. Screening and detecting these mutations are of issue these days, and many different methods and tissue samples are currently used to effectively detect these two mutations. In this study, we aimed to evaluate the testing for EGFR and KRAS mutations by pyrosequencing method, and compared the yield of cytology versus histology specimens in a consecutive series of patients with lung cancer. We retrospectively reviewed EGFR and KRAS mutation results of 399 (patients with EGFR mutation test) and 323 patients (patients with KRAS mutation test) diagnosed with lung cancer in Konkuk University Medical Center from 2008 to 2014. Among them, 60 patients had received both EGFR and KRAS mutation studies. We compared the detection rate of EGFR and KRAS tests in cytology, biopsy, and resection specimens. EGFR and KRAS mutations were detected in 29.8% and 8.7% of total patients, and the positive mutation results of EGFR and KRAS were mutually exclusive. The detection rate of EGFR mutation in cytology was higher than non-cytology (biopsy or resection) materials (cytology: 48.5%, non-cytology: 26.1%), and the detection rate of KRAS mutation in cytology specimens was comparable to non-cytology specimens (cytology: 8.3%, non-cytology: 8.7%). We suggest that cytology specimens are good alternatives that can readily substitute tissue samples for testing both EGFR and KRAS mutations. Moreover, pyrosequencing method is highly sensitive in detecting EGFR and KRAS mutations in lung cancer patients.

  17. ANALYSIS OF C-HA-RAS GENE AMPLIFICATION AND MUTATION IN LARYNGEAL CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    刘世喜; 林代诚; 洪邦泰; 黄光琦

    1995-01-01

    In order to study the ahered molecular events during laryngeal carcinogenesis and elucidate the role of Ha-ras oncogene amplification and mutation, we have examined their profile by polymerase chain reaction (PCR) and selective oligonucleoride hybridization. We analyzed the mutational status of codon 12 of Ha-ras in 22 laryngeal carcinomas and 10 normal tissues, and found that 7 of 22 laryngeal carcinomas con-tained a Ha-ras mutation at codon 12. The frequency of mutation was 32%. None of the normal tissues re-vealed mutation. Moreover, no amplification was found in cancers when compared to the normal. Our findings indicated that the aefivmed Ha-ras gene existed in laryngeal carcinoma, and activation of the Ha-ras gene by mutation at codon 12 might play a key role in laryngeal carcinogenesis.

  18. Wilson disease: Identification of two novel mutations and clinical correlation in Eastern Chinese patients

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To study mutations in the P-type ATPase (ATP7B)gene responsible for Wilson disease (WD) in the Eastern Chinese population, and the possible correlation of specific mutations with clinical characteristics.METHODS: Mutations of the ATP7B gene were sought by means of direct sequencing in 50 Eastern Chinese WD patients of Han ethnic origin.RESULTS: Two novel mutations, Asp96Gly and Asp196Glu, were first identified. We also compared the characterization of mutations in ATP7B with the clinical findings, and a significant correlation with hepatic manifestations between patients carrying the Arg778Leu mutation and those without was found.CONCLUSION: Gene sequencing analysis was shown to have a high detection rate and accuracy. It may become the first priority in screening of WD patients.

  19. Gene-specific function prediction for non-synonymous mutations in monogenic diabetes genes.

    Directory of Open Access Journals (Sweden)

    Quan Li

    Full Text Available The rapid progress of genomic technologies has been providing new opportunities to address the need of maturity-onset diabetes of the young (MODY molecular diagnosis. However, whether a new mutation causes MODY can be questionable. A number of in silico methods have been developed to predict functional effects of rare human mutations. The purpose of this study is to compare the performance of different bioinformatics methods in the functional prediction of nonsynonymous mutations in each MODY gene, and provides reference matrices to assist the molecular diagnosis of MODY. Our study showed that the prediction scores by different methods of the diabetes mutations were highly correlated, but were more complimentary than replacement to each other. The available in silico methods for the prediction of diabetes mutations had varied performances across different genes. Applying gene-specific thresholds defined by this study may be able to increase the performance of in silico prediction of disease-causing mutations.

  20. Haplotype structure in Ashkenazi Jewish BRCA1 and BRCA2 mutation carriers

    DEFF Research Database (Denmark)

    Im, Kate M; Kirchhoff, Tomas; Wang, Xianshu

    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 fre...

  1. Prevalence and phenotypes of APC and MUTYH mutations in patients with multiple colorectal adenomas

    NARCIS (Netherlands)

    S. Grover (Shilpa); F. Kastrinos (Fay); E.W. Steyerberg (Ewout); E.F. Cook (E. Francis); A. Dewanwala (Akriti); L.A. Burbidge; R.J. Wenstrup (Richard); S. Syngal (Sapna)

    2012-01-01

    textabstractContext: Patients with multiple colorectal adenomas may carry germline mutations in the APC or MUTYH genes. Objectives: To determine the prevalence of pathogenic APC and MUTYH mutations in patients with multiple colorectal adenomas who had undergone genetic testing and to compare the pre

  2. 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; Pankratz, V. Shane; 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.; Collee, 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, Pawel; Nevanlinna, Heli; Aittomaki, 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; Duran, 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

    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 freque

  3. Not only emerging technologies are at risk: The case of mutation breeding

    DEFF Research Database (Denmark)

    Hagemann, Kit S.; Scholderer, Joachim

    2007-01-01

    plants. Unlike crop cultivars developed by newer techniques such as genetic engineering, mutation-bred cultivars are not subject to special types of horizontal regulation in any UN country. Based on representative survey data (N = 1000), public attitudes towards mutation breeding were compared...

  4. Reference genome-independent assessment of mutation density using restriction enzyme-phased sequencing

    Science.gov (United States)

    Determining the mutation rates in single individuals is a significant challenge requiring a substantial amount of sequencing and analysis. We have developed a simple method based on restriction enzyme-phased sequencing to measure the mutation density by comparing a wild type to mutagenized individua...

  5. Loss-of-function mutations in filaggrin gene and malignant melanoma

    DEFF Research Database (Denmark)

    Thyssen, J P; Andersen, Y M F; Balslev, E

    2017-01-01

    aimed to investigate the association between FLG mutation status and the occurrence of malignant melanoma (MM) in Danish adults. METHODS: The prevalence of FLG mutations in a sample of MM biopsies was compared with a FLG-genotyped cohort from two general population studies. Pearson's chi...

  6. Isocitrate dehydrogenase mutations in gliomas.

    Science.gov (United States)

    Waitkus, Matthew S; Diplas, Bill H; Yan, Hai

    2016-01-01

    Over the last decade, extraordinary progress has been made in elucidating the underlying genetic causes of gliomas. In 2008, our understanding of glioma genetics was revolutionized when mutations in isocitrate dehydrogenase 1 and 2 (IDH1/2) were identified in the vast majority of progressive gliomas and secondary glioblastomas (GBMs). IDH enzymes normally catalyze the decarboxylation of isocitrate to generate α-ketoglutarate (αKG), but recurrent mutations at Arg(132) of IDH1 and Arg(172) of IDH2 confer a neomorphic enzyme activity that catalyzes reduction of αKG into the putative oncometabolite D-2-hydroxyglutate (D2HG). D2HG inhibits αKG-dependent dioxygenases and is thought to create a cellular state permissive to malignant transformation by altering cellular epigenetics and blocking normal differentiation processes. Herein, we discuss the relevant literature on mechanistic studies of IDH1/2 mutations in gliomas, and we review the potential impact of IDH1/2 mutations on molecular classification and glioma therapy.

  7. Mutations in RARS cause hypomyelination

    NARCIS (Netherlands)

    Wolf, Nicole I.; Salomons, Gajja S.; Rodenburg, Richard J.; Pouwels, Petra J. W.; Schieving, Jolanda H.; Derks, Terry G. J.; Fock, Johanna M.; Rump, Patrick; van Beek, Daphne M.; van der Knaap, Marjo S.; Waisfisz, Quinten

    2014-01-01

    Hypomyelinating disorders of the central nervous system are still a diagnostic challenge, as many patients remain without genetic diagnosis. Using magnetic resonance imaging (MRI) pattern recognition and whole exome sequencing, we could ascertain compound heterozygous mutations in RARS in 4 patients

  8. Mutations in RARS cause hypomyelination

    NARCIS (Netherlands)

    Wolf, Nicole I.; Salomons, Gajja S.; Rodenburg, Richard J.; Pouwels, Petra J. W.; Schieving, Jolanda H.; Derks, Terry G. J.; Fock, Johanna M.; Rump, Patrick; van Beek, Daphne M.; van der Knaap, Marjo S.; Waisfisz, Quinten

    Hypomyelinating disorders of the central nervous system are still a diagnostic challenge, as many patients remain without genetic diagnosis. Using magnetic resonance imaging (MRI) pattern recognition and whole exome sequencing, we could ascertain compound heterozygous mutations in RARS in 4 patients

  9. Mutations in RARS cause hypomyelination

    NARCIS (Netherlands)

    Wolf, N.I.; Salomons, G.S.; Rodenburg, R.J.; Pouwels, P.J.; Schieving, J.H.; Derks, T.G.; Fock, J.M.; Rump, P.; Beek, D.M. van; Knaap, M.S. van der; Waisfisz, Q.

    2014-01-01

    Hypomyelinating disorders of the central nervous system are still a diagnostic challenge, as many patients remain without genetic diagnosis. Using magnetic resonance imaging (MRI) pattern recognition and whole exome sequencing, we could ascertain compound heterozygous mutations in RARS in 4 patients

  10. Clinical and biological characteristics of cervical neoplasias with FGFR3 mutation

    Directory of Open Access Journals (Sweden)

    Thiery Jean

    2005-05-01

    Full Text Available Abstract Background We have previously reported activating mutations of the gene coding for the fibroblast growth factor receptor 3 (FGFR3 in invasive cervical carcinoma. To further analyze the role of FGFR3 in cervical tumor progression, we extended our study to screen a total of 75 invasive tumors and 80 cervical intraepithelial neoplasias (40 low-grade and 40 high-grade lesions. Results Using single strand conformation polymorphism (SSCP followed by DNA sequencing, we found FGFR3 mutation (S249C in all cases in 5% of invasive cervical carcinomas and no mutation in intraepithelial lesions. These results suggest that, unlike in bladder carcinoma, FGFR3 mutation does not or rarely occur in non invasive lesions. Compared to patients with wildtype FGFR3 tumor, patients with S249C FGFR3 mutated tumors were older (mean age 64 vs. 49.4 years, P = 0.02, and were more likely to be associated with a non-16/18 HPV type in their tumor. Gene expression analysis demonstrated that FGFR3 mutated tumors were associated with higher FGFR3b mRNA expression levels compared to wildtype FGFR3 tumors. Supervised analysis of Affymetrix expression data identified a significant number of genes specifically differentially expressed in tumors with respect to FGFR3 mutation status. Conclusion This study suggest that tumors with FGFR3 mutation appear to have distinctive clinical and biological characteristics that may help in defining a population of patients for FGFR3 mutation screening.

  11. Glucocerebrosidase gene L444P mutation is a risk factor for Parkinson's disease in Chinese population.

    Science.gov (United States)

    Sun, Qi-Ying; Guo, Ji-Feng; Wang, Lei; Yu, Ren-He; Zuo, Xing; Yao, Ling-Yan; Pan, Qian; Xia, Kun; Tang, Bei-Sha

    2010-06-15

    An association between mutations in the glucocerebrosidase (GBA) gene and Parkinson's disease (PD) has been reported in several populations. We searched for four common GBA mutations (L444P, F213I, R353W, and N370S) in 402 Chinese PD patients and 413 age- and sex-matched controls. In the PD cohort, 11 patients were found carrying a heterozygous GBA mutation and all of them had the L444P mutation. Heterozygous GBA mutations were detected none in controls. The GBA gene L444P mutation was detected at a significantly higher frequency among PD patients (11/402 = 2.74%), when compared with the control group (0/413): P = 0.0007. To evaluate the possible role of the GBA gene L444P mutation in PD in Ashkenazi Jewish and non-Jewish populations, we conducted a meta-analysis on the topic. In the Chinese population, the GBA gene L444P mutation was detected at a significantly higher frequency among PD patients, when compared with the control group: Z = 3.83, P = 0.0001, OR = 8.42, confidence interval = 95%, 2.83-25.06. In the non-Jewish populations, the difference was obviously significant: Z = 5.76, P < 0.00001, OR = 8.82, confidence interval = 95%, 4.21-18.48. The results suggest that the GBA gene L444P mutation appears to be a risk factor for PD in Chinese population.

  12. IDH mutations in acute myeloid leukemia.

    Science.gov (United States)

    Rakheja, Dinesh; Konoplev, Sergej; Medeiros, L Jeffrey; Chen, Weina

    2012-10-01

    Acute myeloid leukemia is a heterogeneous group of diseases. Mutations of the isocitrate dehydrogenase (IDH) genes represent a novel class of point mutations in acute myeloid leukemia. These mutations prevent oxidative decarboxylation of isocitrate to α-ketoglutarate and confer novel enzymatic activity, facilitating the reduction of α-ketoglutarate to d-2-hydroxyglutarate, a putative oncometabolite. IDH1/IDH2 mutations are heterozygous, and their combined frequency is approximately 17% in unselected acute myeloid leukemia cases, 27% in cytogenetically normal acute myeloid leukemia cases, and up to 67% in acute myeloid leukemia cases with cuplike nuclei. These mutations are largely mutually exclusive. Despite many similarities of IDH1 and IDH2 mutations, it is possible that they represent distinct molecular or clinical subgroups of acute myeloid leukemia. All known mutations involve arginine (R), in codon 132 of IDH1 or codon 140 or 172 of IDH2. IDH1(R132) and IDH2(R140) mutations are frequently accompanied by normal cytogenetics and NPM1 mutation, whereas IDH2(R172) is frequently the only mutation detected in acute myeloid leukemia. There is increasing evidence that the prognostic impact of IDH1/2 mutations varies according to the specific mutation and also depends on the context of concurrent mutations of other genes. IDH1(R132) mutation may predict poor outcome in a subset of patients with molecular low-risk acute myeloid leukemia, whereas IDH2(R172) mutations confer a poor prognosis in patients with acute myeloid leukemia. Expression of IDH1/2 mutants induces an increase in global DNA hypermethylation and inhibits TET2-induced cytosine 5-hydroxymethylation, DNA demethylation. These data suggest that IDH1/2 mutations constitute a distinct mutational class in acute myeloid leukemia, which affects the epigenetic state, an important consideration for the development of therapeutic agents.

  13. FLT3 and NPM1 mutations in Chinese patients with acute myeloid leukemia and normal cytogenetics.

    Science.gov (United States)

    Wang, Lei; Xu, Wei-lai; Meng, Hai-tao; Qian, Wen-bin; Mai, Wen-yuan; Tong, Hong-yan; Mao, Li-ping; Tong, Yin; Qian, Jie-jing; Lou, Yin-jun; Chen, Zhi-mei; Wang, Yun-gui; Jin, Jie

    2010-10-01

    Mutations of fms-like tyrosine kinase 3 (FLT3) and nucleophosmin (NPM1) exon 12 genes are the most common abnormalities in adult acute myeloid leukemia (AML) with normal cytogenetics. To assess the prognostic impact of the two gene mutations in Chinese AML patients, we used multiplex polymerase chain reaction (PCR) and capillary electrophoresis to screen 76 AML patients with normal cytogenetics for mutations in FLT3 internal tandem duplication (FLT3/ITD) and exon 12 of the NPM1 gene. FLT3/ITD mutation was detected in 15 (19.7%) of 76 subjects, and NPM1 mutation in 20 (26.3%) subjects. Seven (9.2%) cases were positive for both FLT3/ITD and NPM1 mutations. Significantly more FLT3/ITD aberration was detected in subjects with French-American-British (FAB) M1 (42.8%). NPM1 mutation was frequently detected in subjects with M5 (47.1%) and infrequently in subjects with M2 (11.1%). FLT3 and NPM1 mutations were significantly associated with a higher white blood cell count in peripheral blood and a lower CD34 antigen expression, but not age, sex, or platelet count. Statistical analysis revealed that the FLT3/ITD-positive group had a lower complete remission (CR) rate (53.3% vs. 83.6%). Survival analysis showed that the FLT3/ITD-positive/NPM1 mutation-negative group had worse overall survival (OS) and relapse-free survival (RFS). The FLT3/ITD-positive/NPM1 mutation-positive group showed a trend towards favorable survival compared with the FLT3/ITD-positive/NPM1 mutation-negative group (P=0.069). Our results indicate that the FLT3/ITD mutation might be a prognostic factor for an unfavorable outcome in Chinese AML subjects with normal cytogenetics, while NPM1 mutation may be a favorable prognostic factor for OS and RFS in the presence of FLT3/ITD.

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

    KAUST Repository

    Ghiotto, Fabio

    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.

  15. Identification of High-Impact cis-Regulatory Mutations Using Transcription Factor Specific Random Forest Models.

    Directory of Open Access Journals (Sweden)

    Dmitry Svetlichnyy

    2015-11-01

    Full Text Available Cancer genomes contain vast amounts of somatic mutations, many of which are passenger mutations not involved in oncogenesis. Whereas driver mutations in protein-coding genes can be distinguished from passenger mutations based on their recurrence, non-coding mutations are usually not recurrent at the same position. Therefore, it is still unclear how to identify cis-regulatory driver mutations, particularly when chromatin data from the same patient is not available, thus relying only on sequence and expression information. Here we use machine-learning methods to predict functional regulatory regions using sequence information alone, and compare the predicted activity of the mutated region with the reference sequence. This way we define the Predicted Regulatory Impact of a Mutation in an Enhancer (PRIME. We find that the recently identified driver mutation in the TAL1 enhancer has a high PRIME score, representing a "gain-of-target" for MYB, whereas the highly recurrent TERT promoter mutation has a surprisingly low PRIME score. We trained Random Forest models for 45 cancer-related transcription factors, and used these to score variations in the HeLa genome and somatic mutations across more than five hundred cancer genomes. Each model predicts only a small fraction of non-coding mutations with a potential impact on the function of the encompassing regulatory region. Nevertheless, as these few candidate driver mutations are often linked to gains in chromatin activity and gene expression, they may contribute to the oncogenic program by altering the expression levels of specific oncogenes and tumor suppressor genes.

  16. Efficient algorithms for probing the RNA mutation landscape.

    Directory of Open Access Journals (Sweden)

    Jérôme Waldispühl

    Full Text Available The diversity and importance of the role played by RNAs in the regulation and development of the cell are now well-known and well-documented. This broad range of functions is achieved through specific structures that have been (presumably optimized through evolution. State-of-the-art methods, such as McCaskill's algorithm, use a statistical mechanics framework based on the computation of the partition function over the canonical ensemble of all possible secondary structures on a given sequence. Although secondary structure predictions from thermodynamics-based algorithms are not as accurate as methods employing comparative genomics, the former methods are the only available tools to investigate novel RNAs, such as the many RNAs of unknown function recently reported by the ENCODE consortium. In this paper, we generalize the McCaskill partition function algorithm to sum over the grand canonical ensemble of all secondary structures of all mutants of the given sequence. Specifically, our new program, RNAmutants, simultaneously computes for each integer k the minimum free energy structure MFE(k and the partition function Z(k over all secondary structures of all k-point mutants, even allowing the user to specify certain positions required not to mutate and certain positions required to base-pair or remain unpaired. This technically important extension allows us to study the resilience of an RNA molecule to pointwise mutations. By computing the mutation profile of a sequence, a novel graphical representation of the mutational tendency of nucleotide positions, we analyze the deleterious nature of mutating specific nucleotide positions or groups of positions. We have successfully applied RNAmutants to investigate deleterious mutations (mutations that radically modify the secondary structure in the Hepatitis C virus cis-acting replication element and to evaluate the evolutionary pressure applied on different regions of the HIV trans-activation response

  17. Identification of Germline Genetic Mutations in Pancreatic Cancer Patients

    Science.gov (United States)

    Salo-Mullen, Erin E.; O’Reilly, Eileen; Kelsen, David; Ashraf, Asad M.; Lowery, Maeve; Yu, Kenneth; Reidy, Diane; Epstein, Andrew S.; Lincoln, Anne; Saldia, Amethyst; Jacobs, Lauren M.; Rau-Murthy, Rohini; Zhang, Liying; Kurtz, Robert; Saltz, Leonard; Offit, Kenneth; Robson, Mark; Stadler, Zsofia K.

    2016-01-01

    Background Pancreatic adenocarcinoma (PAC) is part of several cancer predisposition syndromes; however, indications for genetic counseling/testing are not well-defined. We sought to determine mutation prevalence and characteristics that predict for inherited predisposition to PAC. Methods We identified 175 consecutive PAC patients who underwent clinical genetics assessment at Memorial Sloan Kettering between 2011–2014. Clinical data, family history, and germline results were evaluated. Results Among 159 PAC patients who pursued genetic testing, 24 pathogenic mutations were identified (15.1%; 95%CI, 9.5%–20.7%), including BRCA2(n=13), BRCA1(n=4), p16(n=2), PALB2(n=1), and Lynch syndrome(n=4). BRCA1/BRCA2 prevalence was 13.7% in Ashkenazi Jewish(AJ) (n=95) and 7.1% in non-AJ(n=56) patients. In AJ patients with strong, weak, or absent family history of BRCA-associated cancers, mutation prevalence was 16.7%, 15.8%, and 7.4%, respectively. Mean age at diagnosis in all mutation carriers was 58.5y(range 45–75y) compared to 64y(range 27–87y) in non-mutation carriers(P=0.02). Although BRCA2 was the most common mutation identified, no patients with early-onset PAC(≤50y) harbored a BRCA2 mutation and the mean age at diagnosis in BRCA2 carriers was equivalent to non-mutation carriers(P=0.34). Mutation prevalence in early-onset patients(n=21) was 28.6%, including BRCA1(n=2), p16(n=2), MSH2(n=1) and MLH1(n=1). Conclusion Mutations in BRCA2 account for over 50% of PAC patients with an identified susceptibility syndrome. AJ patients had high BRCA1/BRCA2 prevalence regardless of personal/family history, suggesting that ancestry alone indicates a need for genetic evaluation. With the exception of BRCA2-associated PAC, inherited predisposition to PAC is associated with earlier age at PAC diagnosis suggesting that this subset of patients may also represent a population warranting further evaluation. PMID:26440929

  18. Environmental carcinogens and mutational pathways in atherosclerosis.

    Science.gov (United States)

    Pulliero, A; Godschalk, R; Andreassi, M G; Curfs, D; Van Schooten, F J; Izzotti, A

    2015-05-01

    Atherosclerosis is associated with DNA damage in both circulating and vessel-wall cells and DNA adducts derived from exposure to environmental mutagens are abundant in atherosclerotic vessels. Environmental chemical carcinogens identified as risk factor for atherosclerosis include polycyclic aromatic hydrocarbons (benzo(a)pyrene, dimethylbenz(a)anthracene, beta-naphthoflavone, pyrene, 3-methylcolanthrene), arsenic, cadmium, 1,3-butadiene, cigarette smoke. Accordingly, polymorphisms of genes encoding for phase I/II metabolic reaction and DNA repair are risk factor for cardiovascular diseases, although their role is negligible as compared to other risk factors. The pathogenic relevance of mutation-related molecular damage in atherosclerosis has been demonstrated in experimental animal models involving the exposure to chemical mutagens. The relevance of mutation-related events in worsening atherosclerosis prognosis has been demonstrated in human clinical studies mainly as referred to mitochondrial DNA damage. Atherosclerosis is characterized by the occurrence of high level of oxidative damage in blood vessel resulting from both endogenous and exogenous sources. Mitochondrial damage is a main endogenous source of oxidative stress whose accumulation causes activation of intrinsic apoptosis through BIRC2 inhibition and cell loss contributing to plaque development and instability. Environmental physical mutagens, including ionizing radiation, are a risk factor for atherosclerosis even at the low exposure dose occurring in case of occupational exposure or the high exposure doses occurring during radiotherapy. Conversely, the role of exciting UV radiation in atherosclerosis is still uncertain. This review summarizes the experimental and clinical evidence supporting the pathogenic role of mutation-related pathway in atherosclerosis examining the underlying molecular mechanisms.

  19. The fate of BRCA1-related germline mutations in triple-negative breast tumors

    Science.gov (United States)

    Kotoula, Vassiliki; Fostira, Florentia; Papadopoulou, Kyriaki; Apostolou, Paraskevi; Tsolaki, Eleftheria; Lazaridis, Georgios; Manoussou, Kyriaki; Zagouri, Flora; Pectasides, Dimitrios; Vlachos, Ioannis; Tikas, Ioannis; Lakis, Sotiris; Konstantopoulou, Irene; Pentheroudakis, George; Gogas, Helen; Papakostas, Pavlos; Christodoulou, Christos; Bafaloukos, Dimitrios; Razis, Evangelia; Karavasilis, Vasilios; Bamias, Christina; Yannoukakos, Drakoulis; Fountzilas, George

    2017-01-01

    The preservation of pathogenic BRCA1/2 germline mutations in tumor tissues is usually not questioned, while it remains unknown whether these interact with somatic genotypes for patient outcome. Herein we compared germline and tumor genotypes in operable triple-negative breast cancer (TNBC) and evaluated their combined effects on prognosis. We analyzed baseline germline and primary tumor genotype data obtained by Sanger and Next Generation Sequencing in 194 TNBC patients. We also performed multiple tests interrogating the preservation of germline mutations in matched tumors and breast tissue from carriers with available material. Patients had been treated within clinical trials with adjuvant anthracyclines-taxanes based chemotherapy. We identified 50 (26%) germline mutation carriers (78% in BRCA1) and 136 (71%) tumors with somatic mutations (83% in TP53). Tumor mutation patterns differed between carriers and non-carriers (P<0.001); PIK3CA mutations were exclusively present in non-carriers (P=0.007). Germline BRCA1/2 mutations were not detected in matched tumors and breast tissues from 14 out of 33 (42%) evaluable carriers. Microsatellite markers revealed tumor loss of the germline mutant allele in one case only. Tumors that had lost the germline mutation demonstrated a higher incidence of somatic TP53 mutations as compared to tumors with preserved germline mutations (P=0.036). Germline mutation status significantly interacted with tumor TP53 mutations for patient disease-free survival (interaction P=0.026): In non-carriers, tumor TP53 mutations did not affect outcome; In carriers, those with mutated TP53 tumors experienced more relapses compared to those with wild-type TP53 tumors (36% vs. 9% relapse rate, respectively). In conclusion, we show that loss of germline BRCA1/2 mutations is not a rare event in TNBC. This finding, the observed differences in tumor genotypes with respect to germline status and the prognostic interaction between germline BRCA1-related and

  20. DNA damage and mutations induced by arachidonic acid peroxidation.

    Science.gov (United States)

    Lim, Punnajit; Sadre-Bazzaz, Kianoush; Shurter, Jesse; Sarasin, Alain; Termini, John

    2003-12-30

    Endogenous cellular oxidation of omega6-polyunsaturated fatty acids (PUFAs) has long been recognized as a contributing factor in the development of various cancers. The accrual of DNA damage as a result of reaction with free radical and electrophilic aldehyde products of lipid peroxidation is believed to be involved; however, the genotoxic and mutation-inducing potential of specific membrane PUFAs remains poorly defined. In the present study we have examined the ability of peroxidizing arachidonic acid (AA, 20:4omega6) to induce DNA strand breaks, base modifications, and mutations. The time-dependent induction of single-strand breaks and oxidative base modifications by AA in genomic DNA was quantified using denaturing glyoxal gel electrophoresis. Mutation spectra were determined in XP-G fibroblasts and a repair-proficient line corrected for this defect by c-DNA complementation (XP-G(+)). Mutation frequencies were elevated from approximately 5- to 30-fold over the background following reaction of DNA with AA for various times. The XPG gene product was found to be involved in the suppression of mutations after extended reaction of DNA with AA. Arachidonic acid-induced base substitutions were consistent with the presence of both oxidized and aldehyde base adducts in DNA. The frequency of multiple-base substitutions induced by AA was significantly reduced upon correction for the XPG defect (14% vs 2%, P = 0.0015). Evidence is also presented which suggests that the induced frequency of multiple mutations is lesion dependent. These results are compared to published data for mutations stimulated by alpha,beta-unsaturated aldehydes identified as products of lipid peroxidation.

  1. The effect of deleterious mutations on neutral molecular variation

    Energy Technology Data Exchange (ETDEWEB)

    Charlesworth, B.; Morgan, M.T.; Charlesworth, D. (Univ. of Chicago, IL (United States))

    1993-08-01

    Selection against deleterious alleles maintained by mutation may cause a reduction in the amount of genetic variability at linked neutral sites. This is because a new neutral variant can remain in a large population for a long period of time only if it is maintained in gametes that are free of deleterious alleles, and hence are not destined for rapid elimination from the population by selection. Approximate formulas are derived for the reduction below classical neutral values resulting from such background selection against deleterious mutations, for the mean times of fixation and loss of new mutations, nucleotide site diversity, and number of segregating sites. These formulas apply to random-mating populations with no genetic recombination, and to populations reproducing exclusively asexually or by self-fertilization. For a given selection regime and mating system, the reduction is an exponential function of the total mutation rate to deleterious mutations for the section of the genome involved. Simulations show that the effect decreases rapidly with increasing recombination frequency or rate of outcrossing. The mean time to loss of new neutral mutations and the total number of segregating neutral sites are less sensitive to background selection than the other statistics, unless the population size is of the order of a hundred thousand or more. The stationary distribution of allele frequencies at the neutral sites is correspondingly skewed in favor of rare alleles, compared with the classical neutral result. Observed reductions in molecular variation in low recombination genomic regions of sufficiently large size, for instance in the centromere-proximal regions of Drosophila autosomes or in highly selfing plant populations, may be partly due to background selection against deleterious mutations. 58 refs., 3 figs., 6 tabs.

  2. Tilting mutation of Brauer tree algebras

    CERN Document Server

    Aihara, T

    2010-01-01

    We define tilting mutations of symmetric algebras as the endomorphism algebras of Okuyama-Rickard complexes. For Brauer tree algebras, we give an explicit description of the change of Brauer trees under mutation.

  3. Identifying driver mutations in sequenced cancer genomes

    DEFF Research Database (Denmark)

    Raphael, Benjamin J; Dobson, Jason R; Oesper, Layla

    2014-01-01

    High-throughput DNA sequencing is revolutionizing the study of cancer and enabling the measurement of the somatic mutations that drive cancer development. However, the resulting sequencing datasets are large and complex, obscuring the clinically important mutations in a background of errors, noise......, and random mutations. Here, we review computational approaches to identify somatic mutations in cancer genome sequences and to distinguish the driver mutations that are responsible for cancer from random, passenger mutations. First, we describe approaches to detect somatic mutations from high-throughput DNA...... sequencing data, particularly for tumor samples that comprise heterogeneous populations of cells. Next, we review computational approaches that aim to predict driver mutations according to their frequency of occurrence in a cohort of samples, or according to their predicted functional impact on protein...

  4. Hospital Compare

    Data.gov (United States)

    U.S. Department of Health & Human Services — Hospital Compare has information about the quality of care at over 4,000 Medicare-certified hospitals across the country. You can use Hospital Compare to find...

  5. Inactivating CUX1 mutations promote tumorigenesis

    OpenAIRE

    2013-01-01

    A major challenge for cancer genetics is to determine which low frequency somatic mutations are drivers of tumorigenesis. Here we interrogate the genomes of 7,651 diverse human cancers to identify novel drivers and find inactivating mutations in the homeodomain transcription factor CUX1 (cut-like homeobox 1) in ~1-5% of tumors. Meta-analysis of CUX1 mutational status in 2,519 cases of myeloid malignancies reveals disruptive mutations associated with poor survival, highlighting the clinical si...

  6. The influence of TP53 mutations on the prognosis of patients with early stage non-small cell lung cancer may depend on the intratumor heterogeneity of the mutations.

    Science.gov (United States)

    Lee, Shin Yup; Jeon, Hyo-Sung; Hwangbo, Yup; Jeong, Ji Yun; Park, Ji Young; Lee, Eun Jin; Jin, Guang; Shin, Kyung Min; Yoo, Seung Soo; Lee, Jaehee; Lee, Eung Bae; Cha, Seung Ick; Kim, Chang Ho; Park, Jae Yong

    2015-02-01

    A large number of studies have evaluated the impact of TP53 mutations on the prognosis of patients with non-small cell lung cancer (NSCLC); however, the results of these studies are still controversial. Recently, considerable intratumor heterogeneity for genetic alterations has been demonstrated in various human cancers, including lung cancer. In the present study, we evaluated TP53 mutations in NSCLCs by direct sequencing and observed remarkable variation in the values of relative intensity (RI, the height of the peak of mutated allele/the height of the peak of non-mutated allele) of the mutations. We also examined whether the RI values were associated with intratumor heterogeneity of TP53 mutations. In addition, we evaluated the relationship between TP53 mutations and survival outcome. The patients with a TP53 mutation did not have significantly worse survival compared to those without the mutation. However, when tumors with a TP53 mutation were categorized into two groups, those with a low and those with a high RI, the latter group had significantly worse survival compared to those with wild-type TP53 (adjusted hazard ratio = 2.58, 95% confidence interval = 1.21-5.48, P = 0.01), whereas the former group did not. These results suggest that intratumor genetic heterogeneity may be an important factor in determining the role of TP53 mutations on the prognosis of NSCLC patients.

  7. Hypothesizing an ancient Greek origin of the GJB2 35delG mutation: can science meet history?

    Science.gov (United States)

    Kokotas, Haris; Grigoriadou, Maria; Villamar, Manuela; Giannoulia-Karantana, Aglaia; del Castillo, Ignacio; Petersen, Michael B

    2010-04-01

    One specific mutation of the GJB2 gene that encodes the connexin 26 protein, the 35delG mutation, has become a major interest among scientists who focus on the genetics of nonsyndromic hearing loss. The mutation accounts for the majority of GJB2 mutations detected in Caucasian populations and represents one of the most frequent disease mutations identified so far. The debate was so far between the arguments whether or not the 35delG mutation constitutes a mutational hot-spot or a founder effect; however, it was recently clarified that the latter seems the most likely. In an attempt to explore the origin and propagation of the 35delG mutation, several groups have reported the prevalence of the mutation and the carrier rates in different populations worldwide. It is now certain that the theory of a common founder prevails and that the highest carrier frequencies of the 35delG mutation are observed in southern European populations, giving rise to a discussion regarding the origin of the 35delG mutation. In this study, we discuss data previously published by our and other groups and also compare the haplotype distribution of the mutation in southern Europe, trying to understand the pathways of science and history and the conflict between them.

  8. Sodium ion channel mutations in glioblastoma patients correlate with shorter survival

    Directory of Open Access Journals (Sweden)

    Velculescu Victor E

    2011-02-01

    Full Text Available Abstract Background Glioblastoma Multiforme (GBM is the most common and invasive astrocytic tumor associated with dismal prognosis. Treatment for GBM patients has advanced, but the median survival remains a meager 15 months. In a recent study, 20,000 genes from 21 GBM patients were sequenced that identified frequent mutations in ion channel genes. The goal of this study was to determine whether ion channel mutations have a role in disease progression and whether molecular targeting of ion channels is a promising therapeutic strategy for GBM patients. Therefore, we compared GBM patient survival on the basis of presence or absence of mutations in calcium, potassium and sodium ion transport genes. Cardiac glycosides, known sodium channel inhibitors, were then tested for their ability to inhibit GBM cell proliferation. Results Nearly 90% of patients showed at least one mutation in ion transport genes. GBM patients with mutations in sodium channels showed a significantly shorter survival compared to patients with no sodium channel mutations, whereas a similar comparison based on mutational status of calcium or potassium ion channel mutations showed no survival differences. Experimentally, targeting GBM cells with cardiac glycosides such as digoxin and ouabain demonstrated preferential cytotoxicity against U-87 and D54 GBM cells compared to non-tumor astrocytes (NTAs. Conclusions These pilot studies of GBM patients with sodium channel mutations indicate an association with a more aggressive disease and significantly shorter survival. Moreover, inhibition of GBM cells by ion channel inhibitors such as cardiac glycosides suggest a therapeutic strategy with relatively safe drugs for targeting GBM ion channel mutations. Key Words: glioblastoma multiforme, ion channels, mutations, small molecule inhibitors, cardiac glycosides.

  9. K-ras genetic mutation and influencing factor analysis for Han and Uygur nationality colorectal cancer patients.

    Science.gov (United States)

    Eli, Mayinur; Mollayup, Ablikim; Muattar; Liu, Chao; Zheng, Chao; Bao, Yong-Xing

    2015-01-01

    To investigate the K-ras genetic mutation status in colorectal cancer patients, compare the difference of K-ras genetic mutation rate in Han and Uygur nationality and analyze the influencing factor. 91 cases (52 cases of Han nationality and 39 cases of Uygur nationality) of colorectal biopsy or surgical ablation pathology specimen from the first affiliated hospital of Xinjiang Medical University during January, 2010 to March, 2013 were collected to detect the 12th and 13th code mutation status of K-ras gene exon 2 with pyrosequencing method and compare the difference of K-ras gene mutation rate between Han and Uygur nationality patients. Single factor analysis and multiple factor logistic regression analysis were utilized to analyze the influencing factor for K-ras genetic mutation. 33 cases of patients with K-ras genetic mutation were found from the 91 cases colorectal cancer patients and the total mutation rate was 36.3%. Among them, 24 cases (72.7%) were found with mutation only in the 12th code, 9 cases (27.3%) were found with mutation only in the 13th code and no one case was found with mutation in both the two codes. Mutation rate of the 12th code in the Uygur nationality was significantly higher than that in the Han nationality (P0.05). There were no associativity (P>0.05) between the K-ras genetic mutation and sex, age, smoking history, drinking history, tumor location, macropathology type, differentiation level, staging, invasive depth, lymph nodes transferring and metastasis in colorectal cancer patients (P>0.05). K-ras genetic mutation rate is high in colorectal cancer patients. The mutation rate of 12th code in Uygur nationality is higher than that in Han nationality. There is no significant associativity between K-ras genetic mutation rate and patients' clinical pathology characteristic.

  10. Solving TSP Using Advanced Crossover & Mutating Operators of Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Shruti Sharma

    2013-07-01

    Full Text Available In this paper we develops a new crossover and mutating operator, Round crossover (RX and Round mutating (RM operator, for a genetic algorithm that generates high quality solutions to the Traveling Salesman Problem (TSP. The round crossover operator constructs an offspring from a pair of parents in a circular way using better edges on the basis of their values that may be present in the parents’ structure maintaining the sequence of nodes in the parent chromosomes. The round mutation applied to the resultant chromosome after crossover by selecting a random cut point and then joining the remaining substring to first substring in circular way. The efficiency of the RX is compared as against some existing crossover operators; namely, edge recombination crossover (ERX, Order crossover (OX and partially Matched crossover (PMX for some benchmark TSPLIB instances. Experimental results show that the new crossover operator is better than the PMX, ERX and OX

  11. Annealing Ant Colony Optimization with Mutation Operator for Solving TSP

    Directory of Open Access Journals (Sweden)

    Abdulqader M. Mohsen

    2016-01-01

    Full Text Available Ant Colony Optimization (ACO has been successfully applied to solve a wide range of combinatorial optimization problems such as minimum spanning tree, traveling salesman problem, and quadratic assignment problem. Basic ACO has drawbacks of trapping into local minimum and low convergence rate. Simulated annealing (SA and mutation operator have the jumping ability and global convergence; and local search has the ability to speed up the convergence. Therefore, this paper proposed a hybrid ACO algorithm integrating the advantages of ACO, SA, mutation operator, and local search procedure to solve the traveling salesman problem. The core of algorithm is based on the ACO. SA and mutation operator were used to increase the ants population diversity from time to time and the local search was used to exploit the current search area efficiently. The comparative experiments, using 24 TSP instances from TSPLIB, show that the proposed algorithm outperformed some well-known algorithms in the literature in terms of solution quality.

  12. Annealing Ant Colony Optimization with Mutation Operator for Solving TSP.

    Science.gov (United States)

    Mohsen, Abdulqader M

    2016-01-01

    Ant Colony Optimization (ACO) has been successfully applied to solve a wide range of combinatorial optimization problems such as minimum spanning tree, traveling salesman problem, and quadratic assignment problem. Basic ACO has drawbacks of trapping into local minimum and low convergence rate. Simulated annealing (SA) and mutation operator have the jumping ability and global convergence; and local search has the ability to speed up the convergence. Therefore, this paper proposed a hybrid ACO algorithm integrating the advantages of ACO, SA, mutation operator, and local search procedure to solve the traveling salesman problem. The core of algorithm is based on the ACO. SA and mutation operator were used to increase the ants population diversity from time to time and the local search was used to exploit the current search area efficiently. The comparative experiments, using 24 TSP instances from TSPLIB, show that the proposed algorithm outperformed some well-known algorithms in the literature in terms of solution quality.

  13. Neomycin is more efficient than streptomycin in suppressing frameshift mutations.

    Science.gov (United States)

    Phoenix, P; Gravel, M; Herrington, M B; Brakier-Gingras, L

    1985-12-01

    The effects of streptomycin and neomycin on the phenotypic suppression of frameshift mutations in the lacZ gene of Escherichia coli and on the efficiency of suppression of amber mutations in T4 phage by the informational supE tRNA nonsense suppressor were compared. Neomycin stimulated much more efficiently than streptomycin the phenotypic suppression of frameshift mutations. Because neomycin favors mismatches of the central codon base whereas streptomycin favors mismatches of the first codon base, this result suggests that mismatching of the central codon base pair and shifting of the reading frame are two correlated phenomena. In contrast, both streptomycin and neomycin stimulated about equally the efficiency of the tRNA nonsense suppressor, an effect probably related to their interference with the proofreading control in tRNA selection.

  14. Plastome Mutations and Recombination Events in Barley Chloroplast Mutator Seedlings.

    Science.gov (United States)

    Landau, Alejandra; Lencina, Franco; Pacheco, María G; Prina, Alberto R

    2016-05-01

    The barley chloroplast mutator (cpm) is an allele of a nuclear gene that when homozygous induces several types of cytoplasmically inherited chlorophyll deficiencies. In this work, a plastome Targeting Induced Local Lesions in Genomes (TILLING) strategy based on mismatch digestion was used on families that carried the cpm genotype through many generations. Extensive scanning of 33 plastome genes and a few intergenic regions was conducted. Numerous polymorphisms were detected on both genic and intergenic regions. The detected polymorphisms can be accounted for by at least 61 independent mutational events. The vast majority of the polymorphisms originated in substitutions and small indels (insertions/deletions) in microsatellites. The rpl23 and the rps16 genes were the most polymorphic. Interestingly, the variation observed in the rpl23 gene consisted of several combinations of 5 different one nucleotide polymorphisms. Besides, 4 large indels that have direct repeats at both ends were also observed, which appear to be originated from recombinational events. The cpm mutation spectrum suggests that the CPM gene product is probably involved in plastome mismatch repair. The numerous subtle molecular changes that were localized in a wide range of plastome sites show the cpm as a valuable source of plastome variability for plant research and/or plant breeding. Moreover, the cpm mutant appears to be an interesting experimental material for investigating the mechanisms responsible for maintaining the stability of plant organelle DNA.

  15. Rater reliability of fragile X mutation size estimates: A multilaboratory analysis

    Energy Technology Data Exchange (ETDEWEB)

    Fisch, G.S. [Kings County Hospital Center and SUNY/Health Science Center, Brooklyn, NY (United States); Carpenter, N. [Chapman Institute of Medical Genetics, Tulsa, OK (United States); Maddalena, A. [Medical College of Virginia, Richmond, VA (United States)] [and others

    1996-08-09

    Notwithstanding the use of comparable molecular protocols, description and measurement of the fra(X) (fragile X) mutation may vary according to its appearance as a discrete band, smear, multiple bands, or mosaic. Estimation of mutation size may also differ from one laboratory to another. We report on the description of a mutation size estimate for a large sample of individuals tested for the fra(X) pre- or full mutation. Of 63 DNA samples evaluated, 45 were identified previously as fra(X) pre- or full mutations. DNA from 18 unaffected individuals was used as control. Genomic DNA was extracted from peripheral blood, and DNA fragments from each of four laboratories were sent to a single center where Southern blots were prepared and hybridized with the pE5.1 probe. Photographs from autoradiographs were returned to each site, and raters blind to the identity of the specimens were asked to evaluate them. Raters` estimates of mutation size compared favorably with a reference test. Intrarater reliability was good to excellent. Variability in mutation size estimates was comparable across band types. Variability in estimates was moderate, and was significantly correlated with absolute mutation size and band type. 9 refs., 1 fig., 3 tabs.

  16. Treatment burden in patients with at least one class IV or V CFTR mutation.

    Science.gov (United States)

    Dewulf, Jonas; Vermeulen, François; Wanyama, Simeon; Thomas, Muriel; Proesmans, Marijke; Dupont, Lieven; De Boeck, Kris

    2015-12-01

    CFTR mutations are grouped according to disease-causing mechanism. Several studies demonstrated that patients having at least one mutation of class IV/V, present with a milder phenotype, but little is known about their relative treatment burden. We compared treatment burden between patients with two class I, II, or III mutations and patients with at least one mutation of class IV/V in the 2010 database of the Belgian CF Registry. We calculated a "Treatment Burden Index" (TBI) by assigning long term therapies to categories low, medium and high intensity, for differential weighing in the total score. There were 779 patients with two known class I/II/III mutations and 94 patients with at least one class IV/V mutation. Compared to class I/II/III, class IV/V patients had a lower median number of clinic visits (4 vs. 5; P 50.8%; P intravenous antibiotic treatment (23.5% vs. 46.0%; P IV/V patients with pancreatic insufficiency (n = 31) were considered. This study clearly demonstrates the significantly lower treatment burden in patients with CF and at least one class IV/V mutation compared to patients with two class I/II/III mutations and contributes to providing better individual counseling at time of diagnosis. © 2015 Wiley Periodicals, Inc.

  17. Biological evolution model with conditional mutation rates

    Science.gov (United States)

    Saakian, David B.; Ghazaryan, Makar; Bratus, Alexander; Hu, Chin-Kun

    2017-05-01

    We consider an evolution model, in which the mutation rates depend on the structure of population: the mutation rates from lower populated sequences to higher populated sequences are reduced. We have applied the Hamilton-Jacobi equation method to solve the model and calculate the mean fitness. We have found that the modulated mutation rates, directed to increase the mean fitness.

  18. 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.

  19. A Mutation Model from First Principles of the Genetic Code.

    Science.gov (United States)

    Thorvaldsen, Steinar

    2016-01-01

    The paper presents a neutral Codons Probability Mutations (CPM) model of molecular evolution and genetic decay of an organism. The CPM model uses a Markov process with a 20-dimensional state space of probability distributions over amino acids. The transition matrix of the Markov process includes the mutation rate and those single point mutations compatible with the genetic code. This is an alternative to the standard Point Accepted Mutation (PAM) and BLOcks of amino acid SUbstitution Matrix (BLOSUM). Genetic decay is quantified as a similarity between the amino acid distribution of proteins from a (group of) species on one hand, and the equilibrium distribution of the Markov chain on the other. Amino acid data for the eukaryote, bacterium, and archaea families are used to illustrate how both the CPM and PAM models predict their genetic decay towards the equilibrium value of 1. A family of bacteria is studied in more detail. It is found that warm environment organisms on average have a higher degree of genetic decay compared to those species that live in cold environments. The paper addresses a new codon-based approach to quantify genetic decay due to single point mutations compatible with the genetic code. The present work may be seen as a first approach to use codon-based Markov models to study how genetic entropy increases with time in an effectively neutral biological regime. Various extensions of the model are also discussed.

  20. Mutation induction in human lymphoid cells by energetic heavy ions

    Science.gov (United States)

    Kronenberg, A.

    1994-10-01

    One of the concerns for extended space flight outside the magnetosphere is exposure to galactic cosmic radiation. In the series of studies presented herein, the mutagenic effectiveness of high energy heavy ions is examined using human B-lymphoblastoid cells across an LET range from 32keV/μm to 190 keV/μm. Mutations were scored for an autosomal locus, thymidine kinase (tk), and for an X-linked locus, hypoxanthine phosphoribosyltransferase (hprt). For each of the radiations studied, the autosomal locus is more sensitive to mutation induction than is the X-linked locus. When mutational yields are expressed in terms of particle fluence, the two loci respond quite differently across the range of LET. The action cross section for mutation induction peaks at 61 keV/μm for the tk locus and then declines for particles of higher LET, including Fe ions. For the hprt locus, the action cross section for mutation is maximal at 95 keV/μm but is relatively constant across the range from 61 keV/μm to 190 keV/gmm. The yields of hprt-deficient mutants obtained after HZE exposure to TK6 lymphoblasts may be compared directly with published data on the induction of hprt-deficient mutants in human neonatal fibroblasts exposed to similar ions. The action cross section for induction of hprt-deficient mutants by energetic Fe ions is more than 10-fold lower for lymphoblastoid cells than for fibroblasts.

  1. Abnormal retinal development associated with FRMD7 mutations.

    Science.gov (United States)

    Thomas, Mervyn G; Crosier, Moira; Lindsay, Susan; Kumar, Anil; Araki, Masasuke; Leroy, Bart P; McLean, Rebecca J; Sheth, Viral; Maconachie, Gail; Thomas, Shery; Moore, Anthony T; Gottlob, Irene

    2014-08-01

    Idiopathic infantile nystagmus (IIN) is a genetically heterogeneous disorder, often associated with FRMD7 mutations. As the appearance of the retina is reported to be normal based on conventional fundus photography, IIN is postulated to arise from abnormal cortical development. To determine whether the afferent visual system is involved in FRMD7 mutations, we performed in situ hybridization studies in human embryonic and fetal stages (35 days post-ovulation to 9 weeks post-conception). We show a dynamic retinal expression pattern of FRMD7 during development. We observe expression within the outer neuroblastic layer, then in the inner neuroblastic layer and at 9 weeks post-conception a bilaminar expression pattern. Expression was also noted within the developing optic stalk and optic disk. We identified a large cohort of IIN patients (n = 100), and performed sequence analysis which revealed 45 patients with FRMD7 mutations. Patients with FRMD7 mutations underwent detailed retinal imaging studies using ultrahigh-resolution optical coherence tomography. The tomograms were compared with a control cohort (n = 60). The foveal pit was significantly shallower in FRMD7 patients (P < 0.0001). The optic nerve head morphology was abnormal with significantly decreased optic disk area, retinal nerve fiber layer thickness, cup area and cup depth in FRMD7 patients (P < 0.0001). This study shows for the first time that abnormal afferent system development is associated with FRMD7 mutations and could be an important etiological factor in the development of nystagmus.

  2. Absence of pathogenic mitochondrial DNA mutations in mouse brain tumors

    Directory of Open Access Journals (Sweden)

    Seyfried Thomas N

    2005-08-01

    Full Text Available Abstract Background Somatic mutations in the mitochondrial genome occur in numerous tumor types including brain tumors. These mutations are generally found in the hypervariable regions I and II of the displacement loop and unlikely alter mitochondrial function. Two hypervariable regions of mononucleotide repeats occur in the mouse mitochondrial genome, i.e., the origin of replication of the light strand (OL and the Arg tRNA. Methods In this study we examined the entire mitochondrial genome in a series of chemically induced brain tumors in the C57BL/6J strain and spontaneous brain tumors in the VM mouse strain. The tumor mtDNA was compared to that of mtDNA in brain mitochondrial populations from the corresponding syngeneic mouse host strain. Results Direct sequencing revealed a few homoplasmic base pair insertions, deletions, and substitutions in the tumor cells mainly in regions of mononucleotide repeats. A heteroplasmic mutation in the 16srRNA gene was detected in a spontaneous metastatic VM brain tumor. Conclusion None of the mutations were considered pathogenic, indicating that mtDNA somatic mutations do not likely contribute to the initiation or progression of these diverse mouse brain tumors.

  3. Combined Immunodeficiency Associated with DOCK8 Mutations

    Science.gov (United States)

    Zhang, Qian; Davis, Jeremiah C.; Lamborn, Ian T.; Freeman, Alexandra F.; Jing, Huie; Favreau, Amanda J.; Matthews, Helen F.; Davis, Joie; Turner, Maria L.; Uzel, Gulbu; Holland, Steven M.; Su, Helen C.

    2010-01-01

    BACKGROUND Recurrent sinopulmonary and cutaneous viral infections with elevated serum levels of IgE are features of some variants of combined immunodeficiency. The genetic causes of these variants are unknown. METHODS We collected longitudinal clinical data on 11 patients from eight families who had recurrent sinopulmonary and cutaneous viral infections. We performed comparative genomic hybridization arrays and targeted gene sequencing. Variants with predicted loss-of-expression mutations were confirmed by means of a quantitative reverse-transcriptase –polymerase-chain-reaction assay and immunoblotting. We evaluated the number and function of lymphocytes with the use of in vitro assays and flow cytometry. RESULTS Patients had recurrent otitis media, sinusitis, and pneumonias; recurrent Staphylococcus aureus skin infections with otitis externa; recurrent, severe herpes simplex virus or herpes zoster infections; extensive and persistent infections with molluscum contagiosum; and human papillomavirus infections. Most patients had severe atopy with anaphylaxis; several had squamous-cell carcinomas, and one had T-cell lymphoma –leukemia. Elevated serum IgE levels, hypereosinophilia, low numbers of T cells and B cells, low serum IgM levels, and variable IgG antibody responses were common. Expansion in vitro of activated CD8 T cells was impaired. Novel homozygous or compound heterozygous deletions and point mutations in the gene encoding the dedicator of cytokinesis 8 protein (DOCK8) led to the absence of DOCK8 protein in lymphocytes. CONCLUSIONS Autosomal recessive DOCK8 deficiency is associated with a novel variant of combined immunodeficiency. PMID:19776401

  4. Consistent mutational paths predict eukaryotic thermostability

    Directory of Open Access Journals (Sweden)

    van Noort Vera

    2013-01-01

    Full Text Available Abstract Background Proteomes of thermophilic prokaryotes have been instrumental in structural biology and successfully exploited in biotechnology, however many proteins required for eukaryotic cell function are absent from bacteria or archaea. With Chaetomium thermophilum, Thielavia terrestris and Thielavia heterothallica three genome sequences of thermophilic eukaryotes have been published. Results Studying the genomes and proteomes of these thermophilic fungi, we found common strategies of thermal adaptation across the different kingdoms of Life, including amino acid biases and a reduced genome size. A phylogenetics-guided comparison of thermophilic proteomes with those of other, mesophilic Sordariomycetes revealed consistent amino acid substitutions associated to thermophily that were also present in an independent lineage of thermophilic fungi. The most consistent pattern is the substitution of lysine by arginine, which we could find in almost all lineages but has not been extensively used in protein stability engineering. By exploiting mutational paths towards the thermophiles, we could predict particular amino acid residues in individual proteins that contribute to thermostability and validated some of them experimentally. By determining the three-dimensional structure of an exemplar protein from C. thermophilum (Arx1, we could also characterise the molecular consequences of some of these mutations. Conclusions The comparative analysis of these three genomes not only enhances our understanding of the evolution of thermophily, but also provides new ways to engineer protein stability.

  5. Efficiency of BRCAPRO and Myriad II mutation probability thresholds versus cancer history criteria alone for BRCA1/2 mutation detection.

    Science.gov (United States)

    van Harssel, J J T; van Roozendaal, C E P; Detisch, Y; Brandão, R D; Paulussen, A D C; Zeegers, M; Blok, M J; Gómez García, E B

    2010-06-01

    Considerable differences exist amongst countries in the mutation probability methods and thresholds used to select patients for BRCA1/2 genetic screening. In order to assess the added value of mutation probability methods, we have retrospectively calculated the BRCAPRO and Myriad II probabilities in 306 probands who had previously been selected for DNA-analysis according to criteria based on familial history of cancer. DNA-analysis identified 52 mutations (16.9%) and 11 unclassified variants (UVs, 3.6%). Compared to cancer history, a threshold > or = 10% with BRCAPRO or with Myriad II excluded about 40% of the patients from analysis, including four with a mutation and probabilities 20% with BRCAPRO and Myriad II. In summary, BRCAPRO and Myriad II are more efficient than cancer history alone to exclude patients without a mutation. BRCAPRO performs better for the detection of BRCA1 mutations than of BRCA2 mutations. The Myriad II scores provided no additional information than the BRCAPRO scores alone for the detection of patients with a mutation. The use of thresholds excluded from analysis the majority of patients carrying an UV.

  6. TCOF1 mutation database: novel mutation in the alternatively spliced exon 6A and update in mutation nomenclature.

    Science.gov (United States)

    Splendore, Alessandra; Fanganiello, Roberto D; Masotti, Cibele; Morganti, Lucas S C; Passos-Bueno, M Rita

    2005-05-01

    Recently, a novel exon was described in TCOF1 that, although alternatively spliced, is included in the major protein isoform. In addition, most published mutations in this gene do not conform to current mutation nomenclature guidelines. Given these observations, we developed an online database of TCOF1 mutations in which all the reported mutations are renamed according to standard recommendations and in reference to the genomic and novel cDNA reference sequences (www.genoma.ib.usp.br/TCOF1_database). We also report in this work: 1) results of the first screening for large deletions in TCOF1 by Southern blot in patients without mutation detected by direct sequencing; 2) the identification of the first pathogenic mutation in the newly described exon 6A; and 3) statistical analysis of pathogenic mutations and polymorphism distribution throughout the gene.

  7. Anaerobically Grown Escherichia coli Has an Enhanced Mutation Rate and Distinct Mutational Spectra

    Science.gov (United States)

    Shewaramani, Sonal; Finn, Thomas J.; Kassen, Rees; Rainey, Paul B.

    2017-01-01

    Oxidative stress is a major cause of mutation but little is known about how growth in the absence of oxygen impacts the rate and spectrum of mutations. We employed long-term mutation accumulation experiments to directly measure the rates and spectra of spontaneous mutation events in Escherichia coli populations propagated under aerobic and anaerobic conditions. To detect mutations, whole genome sequencing was coupled with methods of analysis sufficient to identify a broad range of mutational classes, including structural variants (SVs) generated by movement of repetitive elements. The anaerobically grown populations displayed a mutation rate nearly twice that of the aerobic populations, showed distinct asymmetric mutational strand biases, and greater insertion element activity. Consistent with mutation rate and spectra observations, genes for transposition and recombination repair associated with SVs were up-regulated during anaerobic growth. Together, these results define differences in mutational spectra affecting the evolution of facultative anaerobes. PMID:28103245

  8. Immunodeficiency in ataxia telangiectasia is correlated strongly with the presence of two null mutations in the ataxia telangiectasia mutated gene

    Science.gov (United States)

    Staples, E R; McDermott, E M; Reiman, A; Byrd, P J; Ritchie, S; Taylor, A M R; Davies, E G

    2008-01-01

    Immunodeficiency affects over half of all patients with ataxia telangiectasia (A-T) and when present can contribute significantly to morbidity and mortality. A retrospective review of clinical history, immunological findings, ataxia telangiectasia mutated (ATM) enzyme activity and ATM mutation type was conducted on 80 consecutive patients attending the National Clinic for Ataxia Telangiectasia, Nottingham, UK between 1994 and 2006. The aim was to characterize the immunodeficiency in A-T and determine its relationship to the ATM mutations present. Sixty-one patients had mutations resulting in complete loss of ATM kinase activity (group A) and 19 patients had leaky splice or missense mutations resulting in residual kinase activity (group B). There was a significantly higher proportion of patients with recurrent sinopulmonary infections in group A compared with group B (31 of 61 versus four of 19 P = 0·03) and a greater need for prophylactic antibiotics (30 of 61 versus one of 19 P = 0·001). Comparing group A with group B patients, 25 of 46 had undetectable/low immunoglobulin A (IgA) levels compared with none of 19; T cell lymphopenia was found in 28 of 56 compared with one of 18 and B cell lymphopenia in 35 of 55 compared with four of 18 patients (P = 0·00004, 0·001 and 0·003 respectively). Low IgG2 subclass levels and low levels of antibodies to pneumococcal polysaccharide were more common in group A than group B (16 of 27 versus one of 11 P = 0·01; 34/43 versus six of 17 P = 0·002) patients. Ig replacement therapy was required in 10 (12·5%) of the whole cohort, all in group A. In conclusion, A-T patients with no ATM kinase activity had a markedly more severe immunological phenotype than those expressing low levels of ATM activity. PMID:18505428

  9. PAX6 mutations: genotype-phenotype correlations

    Directory of Open Access Journals (Sweden)

    Hanson Isabel M

    2005-05-01

    Full Text Available Abstract Background The PAX6 protein is a highly conserved transcriptional regulator that is important for normal ocular and neural development. In humans, heterozygous mutations of the PAX6 gene cause aniridia (absence of the iris and related developmental eye diseases. PAX6 mutations are archived in the Human PAX6 Allelic Variant Database, which currently contains 309 records, 286 of which are mutations in patients with eye malformations. Results We examined the records in the Human PAX6 Allelic Variant Database and documented the frequency of different mutation types, the phenotypes associated with different mutation types, the contribution of CpG transitions to the PAX6 mutation spectrum, and the distribution of chain-terminating mutations in the open reading frame. Mutations that introduce a premature termination codon into the open reading frame are predominantly associated with aniridia; in contrast, non-aniridia phenotypes are typically associated with missense mutations. Four CpG dinucleotides in exons 8, 9, 10 and 11 are major mutation hotspots, and transitions at these CpG's account for over half of all nonsense mutations in the database. Truncating mutations are distributed throughout the PAX6 coding region, except for the last half of exon 12 and the coding part of exon 13, where they are completely absent. The absence of truncating mutations in the 3' part of the coding region is statistically significant and is consistent with the idea that nonsense-mediated decay acts on PAX6 mutant alleles. Conclusion The PAX6 Allelic Variant Database is a valuable resource for studying genotype-phenotype correlations. The consistent association of truncating mutations with the aniridia phenotype, and the distribution of truncating mutations in the PAX6 open reading frame, suggests that nonsense-mediated decay acts on PAX6 mutant alleles.

  10. Mutation Clusters from Cancer Exome.

    Science.gov (United States)

    Kakushadze, Zura; Yu, Willie

    2017-08-15

    We apply our statistically deterministic machine learning/clustering algorithm *K-means (recently developed in https://ssrn.com/abstract=2908286) to 10,656 published exome samples for 32 cancer types. A majority of cancer types exhibit a mutation clustering structure. Our results are in-sample stable. They are also out-of-sample stable when applied to 1389 published genome samples across 14 cancer types. In contrast, we find in- and out-of-sample instabilities in cancer signatures extracted from exome samples via nonnegative matrix factorization (NMF), a computationally-costly and non-deterministic method. Extracting stable mutation structures from exome data could have important implications for speed and cost, which are critical for early-stage cancer diagnostics, such as novel blood-test methods currently in development.

  11. Amelogenin signal peptide mutation: Correlation between mutations in the amelogenin gene (AMGX) and manifestations of X-linked amelogenesis imperfecta

    Energy Technology Data Exchange (ETDEWEB)

    Lagerstroem-Fermer, M.; Nilsson, M.; Pettersson, U. [Univ. of Uppsala (Sweden)] [and others

    1995-03-01

    Formation of tooth enamel is a poorly understood biological process. In this study the authors describe a 9-bp deletion in exon 2 of the amelogenin gene (AMGX) causing X-linked hypoplastic amelogenesis imperfecta, a disease characterized by defective enamel. The mutation results in the loss of 3 amino acids and exchange of 1 in the signal peptide of the amelogenin protein. This deletion in the signal peptide probably interferes with translocation of the amelogenin protein during synthesis, resulting in the thin enamel observed in affected members of the family. The authors compare this mutation to a previously reported mutation in the amelogenin gene that causes a different disease phenotype. The study illustrates that molecular analysis can help explain the various manifestations of a tooth disorder and thereby provide insights into the mechanisms of tooth enamel formation. 16 refs., 2 figs., 1 tab.

  12. Tailoring the metabolism against mutations

    Science.gov (United States)

    Gulbahce, Natali; Motter, Adilson E.; Almaas, Eivind; Barabasi, Albert Laszlo

    2008-03-01

    In the post-genomic era, organisms can be modelled at the whole-cell level in silico via steady state methods to describe their metabolic capabilities. We use two such methods, Flux Balance Analysis and Minimization of Metabolic Adjustment to explore the behavior of cells (of E. coli and S. cerevisiae) after severe mutations. We propose experimentally feasible ways of modifying the underlying biochemical reaction network of a mutant cell such that cell functionality, in particular growth rate, is significantly improved.

  13. Recessive mutations in the INS gene result in neonatal diabetes through reduced insulin biosynthesis.

    Science.gov (United States)

    Garin, Intza; Edghill, Emma L; Akerman, Ildem; Rubio-Cabezas, Oscar; Rica, Itxaso; Locke, Jonathan M; Maestro, Miguel Angel; Alshaikh, Adnan; Bundak, Ruveyde; del Castillo, Gabriel; Deeb, Asma; Deiss, Dorothee; Fernandez, Juan M; Godbole, Koumudi; Hussain, Khalid; O'Connell, Michele; Klupa, Thomasz; Kolouskova, Stanislava; Mohsin, Fauzia; Perlman, Kusiel; Sumnik, Zdenek; Rial, Jose M; Ugarte, Estibaliz; Vasanthi, Thiruvengadam; Johnstone, Karen; Flanagan, Sarah E; Martínez, Rosa; Castaño, Carlos; Patch, Ann-Marie; Fernández-Rebollo, Eduardo; Raile, Klemens; Morgan, Noel; Harries, Lorna W; Castaño, Luis; Ellard, Sian; Ferrer, Jorge; Perez de Nanclares, Guiomar; Hattersley, Andrew T

    2010-02-16

    Heterozygous coding mutations in the INS gene that encodes preproinsulin were recently shown to be an important cause of permanent neonatal diabetes. These dominantly acting mutations prevent normal folding of proinsulin, which leads to beta-cell death through endoplasmic reticulum stress and apoptosis. We now report 10 different recessive INS mutations in 15 probands with neonatal diabetes. Functional studies showed that recessive mutations resulted in diabetes because of decreased insulin biosynthesis through distinct mechanisms, including gene deletion, lack of the translation initiation signal, and altered mRNA stability because of the disruption of a polyadenylation signal. A subset of recessive mutations caused abnormal INS transcription, including the deletion of the C1 and E1 cis regulatory elements, or three different single base-pair substitutions in a CC dinucleotide sequence located between E1 and A1 elements. In keeping with an earlier and more severe beta-cell defect, patients with recessive INS mutations had a lower birth weight (-3.2 SD score vs. -2.0 SD score) and were diagnosed earlier (median 1 week vs. 10 weeks) compared to those with dominant INS mutations. Mutations in the insulin gene can therefore result in neonatal diabetes as a result of two contrasting pathogenic mechanisms. Moreover, the recessively inherited mutations provide a genetic demonstration of the essential role of multiple sequence elements that regulate the biosynthesis of insulin in man.

  14. Impact of RAS and BRAF mutations on carcinoembryonicantigen production and pattern of colorectal metastases

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    AIM To investigate the impact of RAS and BRAFmutations on the pattern of metastatic disease andcarcinoembryonic antigen (CEA) production.METHODS: In this retrospective study, we investigatedthe impact of RAS and BRAF mutational status on patternof metastatic disease and CEA production. Only patientspresenting with a newly diagnosed metastatic colorectalcancer (CRC) were included. Patients' characteristics,primary tumor location, site of metastatic disease andCEA at presentation were compared between those withand without RAS and BRAF mutations.RESULTS: Among 174 patients, mutations in KRAS ,NRAS and BRAF were detected in 47%, 3% and 6%respectively. RAS mutations (KRAS and NRAS ) weremore likely to be found in African American patients(87% vs 13%; P value = 0.0158). RAS mutations wereassociated with a higher likelihood of a normal CEA (〈5 ng/mL) at presentation. BRAF mutations were morelikely to occur in females. We were not able to confirm any association between mutational status and site ofmetastatic disease at initial diagnosis.CONCLUSION: No association was found between RASand BRAF mutations and sites of metastatic disease atthe time of initial diagnosis in our cohort. Patients withRAS mutations were more likely to present with CEAlevels 〈 5 ng/mL. These findings may have clinical implicationson surveillance strategies for RAS mutant patientswith earlier stages of CRC.

  15. Oncogene Mutations in Colorectal Polyps Identified in the Norwegian Colorectal Cancer Prevention (NORCCAP) Screening Study

    Science.gov (United States)

    Lorentzen, Jon A.; Grzyb, Krzysztof; De Angelis, Paula M.; Hoff, Geir; Eide, Tor J.; Andresen, Per Arne

    2016-01-01

    Data are limited on oncogene mutation frequencies in polyps from principally asymptomatic participants of population-based colorectal cancer screening studies. In this study, DNA from 204 polyps, 5 mm or larger, were collected from 176 participants of the NORCCAP screening study and analyzed for mutations in KRAS, BRAF, and PIK3CA including the rarely studied KRAS exons 3 and 4 mutations. KRAS mutations were identified in 23.0% of the lesions and were significantly associated with tubulovillous adenomas and large size. A significantly higher frequency of KRAS mutations in females was associated with mutations in codon 12. The KRAS exon 3 and 4 mutations constituted 23.4% of the KRAS positive lesions, which is a larger proportion compared to previous observations in colorectal cancer. BRAF mutations were identified in 11.3% and were associated with serrated polyps. None of the individuals were diagnosed with de novo or recurrent colorectal cancer during the follow-up time (median 11.2 years). Revealing differences in mutation-spectra according to gender and stages in tumorigenesis might be important for optimal use of oncogenes as therapeutic targets and biomarkers. PMID:27656095

  16. Serum ferritin concentration is affected by ferroportin Q248H mutation in Africans.

    Science.gov (United States)

    Kasvosve, Ishmael; Tshwenyego, Uyapo; Phuthego, Thato; Koto, Garesego; Zachariah, Matshediso; Nyepetsi, Naledi G; Motswaledi, Modisa S

    2015-04-15

    Ferroportin Q248H mutation is common in populations with African ancestry. Studies have reported that the mutation does not alter the ferroportin-hepcidin axis, but there is evidence suggesting that the mutation may lead to hyperferritinemia. We report on the relationship of ferroportin Q248H mutation on serum ferritin (SF) in health adults. A total of 174 apparently healthy adults from Botswana were studied. SF was measured using an enzyme immunoassay and ferroportin Q248H mutation was identified by polymerase chain reaction and restriction enzyme digestion. Independent sample Mann-Whitney U test was used to correlate the presence of the mutation with SF. Ferroportin Q248H mutation was identified in 30 individuals (17.2%) (one homozygote, 29 heterozygotes) and was absent in 144 individuals (82.8%), with Q248H allele frequency of 8.9%. In males, SF was significantly higher in ferroportin Q248H heterozygotes compared to wild types, p=0.029, but the relationship between ferroportin Q248H mutation and iron stores was blunted in females. Our study of healthy adults provides further evidence that ferroportin Q248H mutation affects SF concentration in Africans. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Identification of a common mutation in mucopolysaccharidosis IVA: correlation among genotype, phenotype, and keratan sulfate.

    Science.gov (United States)

    Tomatsu, Shunji; Dieter, Tatiana; Schwartz, Ida V; Sarmient, Piedad; Giugliani, Roberto; Barrera, Luis A; Guelbert, Norberto; Kremer, Raquel; Repetto, Gabriela M; Gutierrez, Monica A; Nishioka, Tatsuo; Serrato, Olga Peña; Montaño, Adriana Maria; Yamaguchi, Seiji; Noguchi, Akihiko

    2004-01-01

    Mucopolysaccharidosis IVA (MPS IVA) is a lysosomal storage disorder caused by the deficiency of N-acetylgalactosamine-6-sulfate sulfatase (GALNS). Mutation screening of the GALNS was performed by genomic PCR and direct sequence analyses in 20 MPS IVA patients from Latin America. In this study, 12 different gene mutations including nine unreported ones were identified in 16 severe and four attenuated patients and accounted for 90.0% of the unrelated mutant alleles. The gene alterations were missense mutations except one insertion. Six recurrent mutations, p.A75G, p.G116S, p.G139S, p.N164T, p.R380S, and p.R386C, accounted for 5.0, 10.0, 5.0, 7.5, 5.0, and 32.5% of the unrelated mutant alleles, respectively. The p.R386C mutation was identified in all Latin American populations studied. Eleven mutations correlated with a severe form, while one mutation, p.R380S, was associated with an attenuated form. MPS IVA patients had an elevation of urine and plasma keratan sulfate (KS) concentrations compared with those of the age-matched control. KS concentrations in severe patients were higher than those in attenuated patients. These data provide evidence for extensive allelic heterogeneity and presence of a common mutation in Latin American patients. Accumulation of mutations with clinical description and KS concentration will lead us to predict clinical severity of the patient more precisely.

  18. Intra-organ variation in age-related mutation accumulation in the mouse.

    Directory of Open Access Journals (Sweden)

    Rita A Busuttil

    Full Text Available Using a transgenic mouse model harboring chromosomally integrated lacZ mutational target genes, we previously demonstrated that mutations accumulate with age much more rapidly in the small intestine than in the brain. Here it is shown that in the small intestine point mutations preferentially accumulate in epithelial cells of the mucosa scraped off the underlying serosa. The mucosal cells are the differentiated villus cells that have undergone multiple cell divisions. A smaller age-related increase, also involving genome rearrangements, was observed in the serosa, which consists mainly of the remaining crypts and non-dividing smooth muscle cells. In the brain we observed an accumulation of only point mutations in no other areas than hypothalamus and hippocampus. To directly test for cell division as the determining factor in the generation of point mutations we compared mutation induction between mitotically active and quiescent embryonic fibroblasts from the same lacZ mice, treated with either UV (a point mutagen or hydrogen peroxide (a clastogen. The results indicate that while point mutations are highly replication-dependent, genome rearrangements are as easily induced in non-dividing cells as in mitotically active ones. This strongly suggests that the point mutations found to have accumulated in the mucosal part of the small intestine are the consequence of replication errors. The same is likely true for point mutations accumulating in hippocampus and hypothalamus of the brain since neurogenesis in these two areas continues throughout life. The observed intra-organ variation in mutation susceptibility as well as the variation in replication dependency of different types of mutations indicates the need to not only extend observations made on whole organs to their sub-structures but also take the type of mutations and mitotic activity of the cells into consideration. This should help elucidating the impact of genome instability and its

  19. AIRE gene mutations and autoantibodies to interferon omega in patients with chronic hypoparathyroidism without APECED.

    Science.gov (United States)

    Cervato, Sara; Morlin, Luca; Albergoni, Maria Paola; Masiero, Stefano; Greggio, Nella; Meossi, Cristiano; Chen, Shu; del Pilar Larosa, Maria; Furmaniak, Jadwiga; Rees Smith, Bernard; Alimohammadi, Mohammad; Kämpe, Olle; Valenzise, Mariella; Betterle, Corrado

    2010-11-01

    To assess autoimmune regulator (AIRE) gene mutations, class II HLA haplotypes, and organ- or non-organ-specific autoantibodies in patients with chronic hypoparathyroidism (CH) without associated Addison's disease (AD) or chronic candidiasis (CC). Twenty-four patients who had CH without AD or CC were included in the study. AIRE gene mutations in all 14 exons were studied using PCR in 24 patients, 105 healthy controls and 15 first-degree relatives of CH patients with AIRE mutations. Human leucocyte antigens (HLA) were determined for all 24 patients and 105 healthy controls. Autoantibodies to a range of antigens including NACHT leucine-rich-repeat protein-5 (NALP5) and interferon omega (IFNω) were tested in all 24 patients. AIRE gene mutations were found in 6 of 24 (25%) patients, all females, and this was significantly higher (P AIRE mutations found in healthy controls (2/105). Three patients (12·5%) had homozygous AIRE mutations characteristic of Autoimmune-Poly-Endocrinopathy-Candidiasis-Ectodermal-Dystrophy and all three were also positive for IFNω-autoantibodies. Three patients (12·5%) had heterozygous AIRE mutations; two of these were novel mutations. One of the patients with heterozygous AIRE mutations was positive for both NACHT leucine-rich-repeat protein 5 and IFNω autoantibodies. Heterozygous AIRE mutations were found in 10 of 15 first-degree relatives of CH patients with AIRE mutations, although none was affected by CH. Class II HLA haplotypes were not statistically different in patients with CH compared to healthy controls. Analysis of AIRE gene mutations together with serum autoantibody profile should be helpful in the assessment of patients with CH, in particular young women with associated autoimmune diseases. © 2010 Blackwell Publishing Ltd.

  20. 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.

  1. Profiling of somatic mutations in acute myeloid leukemia with FLT3-ITD at diagnosis and relapse.

    Science.gov (United States)

    Garg, Manoj; Nagata, Yasunobu; Kanojia, Deepika; Mayakonda, Anand; Yoshida, Kenichi; Haridas Keloth, Sreya; Zang, Zhi Jiang; Okuno, Yusuke; Shiraishi, Yuichi; Chiba, Kenichi; Tanaka, Hiroko; Miyano, Satoru; Ding, Ling-Wen; Alpermann, Tamara; Sun, Qiao-Yang; Lin, De-Chen; Chien, Wenwen; Madan, Vikas; Liu, Li-Zhen; Tan, Kar-Tong; Sampath, Abhishek; Venkatesan, Subhashree; Inokuchi, Koiti; Wakita, Satoshi; Yamaguchi, Hiroki; Chng, Wee Joo; Kham, Shirley-Kow Yin; Yeoh, Allen Eng-Juh; Sanada, Masashi; Schiller, Joanna; Kreuzer, Karl-Anton; Kornblau, Steven M; Kantarjian, Hagop M; Haferlach, Torsten; Lill, Michael; Kuo, Ming-Chung; Shih, Lee-Yung; Blau, Igor-Wolfgang; Blau, Olga; Yang, Henry; Ogawa, Seishi; Koeffler, H Phillip

    2015-11-26

    Acute myeloid leukemia (AML) with an FLT3 internal tandem duplication (FLT3-ITD) mutation is an aggressive hematologic malignancy with a grave prognosis. To identify the mutational spectrum associated with relapse, whole-exome sequencing was performed on 13 matched diagnosis, relapse, and remission trios followed by targeted sequencing of 299 genes in 67 FLT3-ITD patients. The FLT3-ITD genome has an average of 13 mutations per sample, similar to other AML subtypes, which is a low mutation rate compared with that in solid tumors. Recurrent mutations occur in genes related to DNA methylation, chromatin, histone methylation, myeloid transcription factors, signaling, adhesion, cohesin complex, and the spliceosome. Their pattern of mutual exclusivity and cooperation among mutated genes suggests that these genes have a strong biological relationship. In addition, we identified mutations in previously unappreciated genes such as MLL3, NSD1, FAT1, FAT4, and IDH3B. Mutations in 9 genes were observed in the relapse-specific phase. DNMT3A mutations are the most stable mutations, and this DNMT3A-transformed clone can be present even in morphologic complete remissions. Of note, all AML matched trio samples shared at least 1 genomic alteration at diagnosis and relapse, suggesting common ancestral clones. Two types of clonal evolution occur at relapse: either the founder clone recurs or a subclone of the founder clone escapes from induction chemotherapy and expands at relapse by acquiring new mutations. Relapse-specific mutations displayed an increase in transversions. Functional assays demonstrated that both MLL3 and FAT1 exert tumor-suppressor activity in the FLT3-ITD subtype. An inhibitor of XPO1 synergized with standard AML induction chemotherapy to inhibit FLT3-ITD growth. This study clearly shows that FLT3-ITD AML requires additional driver genetic alterations in addition to FLT3-ITD alone.

  2. Founding BRCA1 mutations in hereditary breast and ovarian cancer in southern Sweden.

    Science.gov (United States)

    Johannsson, O; Ostermeyer, E A; Håkansson, S; Friedman, L S; Johansson, U; Sellberg, G; Brøndum-Nielsen, K; Sele, V; Olsson, H; King, M C; Borg, A

    1996-03-01

    Nine different germ-line mutations in the BRCA1 breast and ovarian cancer susceptibility gene were identified in 15 of 47 kindreds from southern Sweden, by use of SSCP and heteroduplex analysis of all exons and flanking intron region and by a protein-truncation test for exon 11, followed by direct sequencing. All but one of the mutations are predicted to give rise to premature translation termination and include seven frameshift insertions or deletions, a nonsense mutation, and a splice acceptor site mutation. The remaining mutation is a missense mutation (Cys61Gly) in the zinc-binding motif. Four novel Swedish founding mutations were identified: the nucleotide 2595 deletion A was found in five families, the C 1806 T nonsense mutation in three families, the 3166 insertion TGAGA in three families, and the nucleotide 1201 deletion 11 in two families. Analysis of the intragenic polymorphism D17S855 supports common origins of the mutations. Eleven of the 15 kindreds manifesting BRCA1 mutations were breast-ovarian cancer families, several of them with a predominant ovarian cancer phenotype. The set of 32 families in which no BRCA1 alterations were detected included 1 breast-ovarian cancer kindred manifesting clear linkage to the BRCA1 region and loss of the wild-type chromosome in associated tumors. Other tumor types found in BRCA1 mutation/haplotype carriers included prostatic, pancreas, skin, and lung cancer, a malignant melanoma, an oligodendroglioma, and a carcinosarcoma. In all, 12 of 16 kindreds manifesting BRCA1 mutation or linkage contained ovarian cancer, as compared with only 6 of the remaining 31 families (P<.001). The present study confirms the involvement of BRCA1 in disease predisposition for a subset of hereditary breast cancer families often characterized by ovarian cancers.

  3. Founding BRCA1 mutations in hereditary breast and ovarian cancer in southern Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Johannsson, O.; Hakansson, S.; Johannson, U. [Univ. Hospital, Lund (Sweden)] [and others

    1996-03-01

    Nine different germ-line mutations in the BRCA1 breast and ovarian cancer susceptibility gene were identified in 15 of 47 kindreds from southern Sweden, by use of SSCP and heteroduplex analysis of all exons and flanking intron region and by a protein-truncation test for exon 11, followed by direct sequencing. All but one of the mutations are predicted to give rise to premature translation termination and include seven frameshift insertions or deletions, a nonsense mutation, and a splice acceptor site mutation. The remaining mutation is a missense mutation (Cys61Gly) in the zinc-binding motif. Four novel Swedish founding mutations were identified: the nucleotide 2595 deletion A was found in five families, the C 1806 T nonsense mutation in three families, the 3166 insertion TGAGA in three families, and the nucleotide 1201 deletion 11 in two families. Analysis of the intragenic polymorphism D17S855 supports common origins of the mutations. Eleven of the 15 kindreds manifesting BRCA1 mutations were breast-ovarian cancer families, several of them with a predominant ovarian cancer phenotype. The set of 32 families in which no BRCA1 alterations were detected included 1 breast-ovarian cancer kindred manifesting clear linkage to the BRCA1 region and loss of the wild-type chromosome in associated tumors. Other tumor types found in BRCA1 mutation/haplotype carriers included prostatic, pancreas, skin, and lung cancer, a malignant melanoma, an oligodendroglioma, and a carcinosarcoma. In all, 12 of 16 kindreds manifesting BRCA1 mutation or linkage contained ovarian cancer, as compared with only 6 of the remaining 31 families (P < .001). The present study confirms the involvement of BRCA1 in disease predisposition for a subset of hereditary breast cancer families often characterized by ovarian cancers. 28 refs., 3 figs., 4 tabs.

  4. Impact of smoking status and pathologic type on epidermal growth factor receptor mutations in lung cancer

    Institute of Scientific and Technical Information of China (English)

    HUANG Yi-sheng; WU Yi-long; YANG Jin-ji; ZHANG Xu-chao; YANG Xue-ning; HUANG Yu-juan; XU Chong-rui; ZHOU Qing; WANG Zhen; SU Jian

    2011-01-01

    Background Epidermal growth factor receptor (EGFR) mutations in lung carcinomas can make the disease more responsive to the treatment with tyrosine kinase inhibitors. We aimed to evaluate the prevalence of EGFR mutations in a large series of lung carcinomas.Methods We examined 1195 consecutive lung cancer patients for EGFR mutations in exons 18, 19, and 21 using direct sequencing of polymerase chain reaction products. A detailed smoking history was obtained. Patients were categorized as never smokers (<100 lifetime cigarettes), former smokers (quit >1 year ago), or current smokers (quit <1 year ago).Results There were EGFR mutations in 9 (4.5%) of 201 squamous carcinomas, in 1 (2%) of 50 large cell carcinomas,and in 1 (2.3%) of 44 small cell carcinomas that were investigated. Three hundred and twenty-seven mutations were found in the series of 858 adenocarcinomas (38.1%). Among 858 lung adenocarcinomas, we detected EGFR mutations in 250 (48.6%) of 514 never smokers, 39 (33.9%) of 115 former smokers, and 38 (16.6%) of 229 current smokers.Significantly fewer EGFR mutations were found in people who smoked for more than 15 pack-years (P=0.0002) or stopped smoking less than 15 years ago (P=0.033) compared with individuals who never smoked.Conclusions Adenocarcinoma is the most frequent EGFR mutation pathologic type in lung cancer. The likelihood of EGFR mutations in exons 18, 19 and 21 decreases as the number of pack-years increases. Mutations were less common in people who smoked for more than 15 pack-years or who stopped smoking cigarettes less than 15 years ago. These data can assist clinicians in assessing the likelihood of exons 18, 19, or 21 EGFR mutations in Chinese patients with lung cancer when mutational analysis is not feasible.

  5. Pathogenic mutations in Parkinson disease.

    Science.gov (United States)

    Tan, Eng-King; Skipper, Lisa M

    2007-07-01

    Parkinson disease (PD; Parkinson's) is the second most common neurodegenerative disease, characterized by the progressive loss of dopamine neurons and the accumulation of Lewy bodies. Increasing evidence suggests that deficits in mitochondrial function, oxidative and nitrosative stress, the accumulation of aberrant or misfolded proteins, and ubiquitin-proteasome system (UPS) dysfunction may represent the principal molecular pathways that commonly underlie the pathogenesis. The relative role of genetic and environmental factors has been the focus of research and debate. The recent discovery of a number of disease-causing genes (SNCA, Parkin/PARK2, UCHL1, PINK1, DJ1/PARK7, and LRRK2) in familial and sporadic forms of PD has provided considerable insights into the pathophysiology of this complex disorder. The frequency of these gene mutations may vary according to ethnicity and to the specific gene. A gene dosage effect is observed in some cases, and the phenotype of some of the mutation carriers closely resembles typical PD. Penetrance of some of the recurrent mutations is incomplete and may vary with age. Further research to unravel the etiopathology could identify biochemical or genetic markers for potential neuroprotective trials. (c) 2007 Wiley-Liss, Inc.

  6. LHON: Mitochondrial Mutations and More.

    Science.gov (United States)

    Kirches, E

    2011-03-01

    Leber's hereditary optic neuropathy (LHON) is a mitochondrial disorder leading to severe visual impairment or even blindness by death of retinal ganglion cells (RGCs). The primary cause of the disease is usually a mutation of the mitochondrial genome (mtDNA) causing a single amino acid exchange in one of the mtDNA-encoded subunits of NADH:ubiquinone oxidoreductase, the first complex of the electron transport chain. It was thus obvious to accuse neuronal energy depletion as the most probable mediator of neuronal death. The group of Valerio Carelli and other authors have nicely shown that energy depletion shapes the cell fate in a LHON cybrid cell model. However, the cybrids used were osteosarcoma cells, which do not fully model neuronal energy metabolism. Although complex I mutations may cause oxidative stress, a potential pathogenetic role of the latter was less taken into focus. The hypothesis of bioenergetic failure does not provide a simple explanation for the relatively late disease onset and for the incomplete penetrance, which differs remarkably between genders. It is assumed that other genetic and environmental factors are needed in addition to the 'primary LHON mutations' to elicit RGC death. Relevant nuclear modifier genes have not been identified so far. The review discusses the unresolved problems of a pathogenetic hypothesis based on ATP decline and/or ROS-induced apoptosis in RGCs.

  7. Detecting selection needs comparative data

    DEFF Research Database (Denmark)

    Nielsen, Rasmus; Hubisz, Melissa J.

    2005-01-01

    Positive selection at the molecular level is usually indicated by an increase in the ratio of non-synonymous to synonymous substitutions (dN/dS) in comparative data. However, Plotkin et al. 1 describe a new method for detecting positive selection based on a single nucleotide sequence. We show here...... that this method is particularly sensitive to assumptions regarding the underlying mutational processes and does not provide a reliable way to identify positive selection....

  8. Quantum dots immunofluorescence histochemical detection of EGFR gene mutations in the non-small cell lung cancers using mutation-specific antibodies

    Directory of Open Access Journals (Sweden)

    Qu YG

    2014-12-01

    Full Text Available Yan-Gang Qu,1 Qian Zhang,2 Qi Pan,3 Xian-Da Zhao,4 Yan-Hua Huang,2 Fu-Chun Chen,3 Hong-Lei Chen41Department of Pathology, The Central Hospital of Enshi Autonomous Prefecture, Enshi, 2Department of Molecular Pathology, Wuhan Nano Tumor Diagnosis Engineering Research Center, Wuhan, Hubei, People’s Republic of China; 3Department of Thoracosurgery, Traditional Chinese Medical Hospital of Wenling, Wenling, Zhejiang, People’s Republic of China; 4Department of Pathology, School of Basic Medical Science, Wuhan University, Wuhan, Hubei, People’s Republic of ChinaBackground: Epidermal growth factor receptor (EGFR mutation status plays an important role in therapeutic decision making for non-small cell lung cancer (NSCLC patients. Since EGFR mutation-specific antibodies (E746-A750del and L858R have been developed, EGFR mutation detection by immunohistochemistry (IHC is a suitable screening test. On this basis, we want to establish a new screening test, quantum dots immunofluorescence histochemistry (QDs-IHC, to assess EGFR gene mutation in NSCLC tissues, and we compared it to traditional IHC and amplification refractory mutation system (ARMS.Materials and methods: EGFR gene mutations were detected by QDs-IHC, IHC, and ADx-ARMS in 65 cases of NSCLC composed of 55 formalin-fixed, paraffin-embedded specimens and ten pleural effusion cell blocks, including 13 squamous cell carcinomas, two adenosquamous carcinomas, and 50 adenocarcinomas.Results: Positive rates of EGFR gene mutations detected by QDs-IHC, IHC, and ADx-ARMS were 40.0%, 36.9%, and 46.2%, respectively, in 65 cases of NSCLC patients. The sensitivity of QDs-IHC when detecting EGFR mutations, as compared to ADx-ARMS, was 86.7% (26/30; the specificity for both antibodies was 100.0% (26/26. IHC sensitivity was 80.0% (24/30 and the specificity was 92.31% (24/26. When detecting EGFR mutations, QDs-IHC and ADx-ARMS had perfect consistency (κ=0.882; P<0.01. Excellent agreement was observed

  9. Germline Mutations in Predisposition Genes in Pediatric Cancer

    Science.gov (United States)

    Edmonson, Michael N.; Gruber, Tanja A.; Easton, John; Hedges, Dale; Ma, Xiaotu; Zhou, Xin; Yergeau, Donald A.; Wilkinson, Mark R.; Vadodaria, Bhavin; Chen, Xiang; McGee, Rose B.; Hines-Dowell, Stacy; Nuccio, Regina; Quinn, Emily; Shurtleff, Sheila A.; Rusch, Michael; Patel, Aman; Becksfort, Jared B.; Wang, Shuoguo; Weaver, Meaghann S.; Ding, Li; Mardis, Elaine R.; Wilson, Richard K.; Gajjar, Amar; Ellison, David W.; Pappo, Alberto S.; Pui, Ching-Hon; Downing, James R.

    2016-01-01

    BACKGROUND The prevalence and spectrum of predisposing mutations among children and adolescents with cancer are largely unknown. Knowledge of such mutations may improve the understanding of tumorigenesis, direct patient care, and enable genetic counseling of patients and families. METHODS In 1120 patients younger than 20 years of age, we sequenced the whole genomes (in 595 patients), whole exomes (in 456), or both (in 69). We analyzed the DNA sequences of 565 genes, including 60 that have been associated with autosomal dominant cancer-predisposition syndromes, for the presence of germline mutations. The pathogenicity of the mutations was determined by a panel of medical experts with the use of cancer-specific and locus-specific genetic databases, the medical literature, computational predictions, and second hits identified in the tumor genome. The same approach was used to analyze data from 966 persons who did not have known cancer in the 1000 Genomes Project, and a similar approach was used to analyze data from an autism study (from 515 persons with autism and 208 persons without autism). RESULTS Mutations that were deemed to be pathogenic or probably pathogenic were identified in 95 patients with cancer (8.5%), as compared with 1.1% of the persons in the 1000 Genomes Project and 0.6% of the participants in the autism study. The most commonly mutated genes in the affected patients were TP53 (in 50 patients), APC (in 6), BRCA2 (in 6), NF1 (in 4), PMS2 (in 4), RB1 (in 3), and RUNX1 (in 3). A total of 18 additional patients had protein-truncating mutations in tumor-suppressor genes. Of the 58 patients with a predisposing mutation and available information on family history, 23 (40%) had a family history of cancer. CONCLUSIONS Germline mutations in cancer-predisposing genes were identified in 8.5% of the children and adolescents with cancer. Family history did not predict the presence of an underlying predisposition syndrome in most patients. (Funded by the American

  10. Relating the disease mutation spectrum to the evolution of the cystic fibrosis transmembrane conductance regulator (CFTR.

    Directory of Open Access Journals (Sweden)

    Lavanya Rishishwar

    Full Text Available Cystic fibrosis (CF is the most common genetic disease among Caucasians, and accordingly the cystic fibrosis transmembrane conductance regulator (CFTR protein has perhaps the best characterized disease mutation spectrum with more than 1,500 causative mutations having been identified. In this study, we took advantage of that wealth of mutational information in an effort to relate site-specific evolutionary parameters with the propensity and severity of CFTR disease-causing mutations. To do this, we devised a scoring scheme for known CFTR disease-causing mutations based on the Grantham amino acid chemical difference matrix. CFTR site-specific evolutionary constraint values were then computed for seven different evolutionary metrics across a range of increasing evolutionary depths. The CFTR mutational scores and the various site-specific evolutionary constraint values were compared in order to evaluate which evolutionary measures best reflect the disease-causing mutation spectrum. Site-specific evolutionary constraint values from the widely used comparative method PolyPhen2 show the best correlation with the CFTR mutation score spectrum, whereas more straightforward conservation based measures (ConSurf and ScoreCons show the greatest ability to predict individual CFTR disease-causing mutations. While far greater than could be expected by chance alone, the fraction of the variability in mutation scores explained by the PolyPhen2 metric (3.6%, along with the best set of paired sensitivity (58% and specificity (60% values for the prediction of disease-causing residues, were marginal. These data indicate that evolutionary constraint levels are informative but far from determinant with respect to disease-causing mutations in CFTR. Nevertheless, this work shows that, when combined with additional lines of evidence, information on site-specific evolutionary conservation can and should be used to guide site-directed mutagenesis experiments by more narrowly

  11. Association of FMF-related (MEFV) point mutations with secondary and FMF amyloidosis.

    Science.gov (United States)

    Atagunduz, M Pamir; Tuglular, Serhan; Kantarci, Gulcin; Akoglu, Emel; Direskeneli, Haner

    2004-01-01

    Familial Mediterranean fever (FMF) is the major cause of AA amyloidosis in Turkey. M694V mutation in MEFV gene was suggested to be associated with severe clinical features and amyloidosis of FMF. In this study, the frequencies of three FMF-related MEFV mutations (M694V, M680I and V726A) were investigated in FMF patients with (AA-FMF, n = 37) and without amyloidosis (non-AA-FMF, n = 35), in patients with secondary amyloidosis related to non-FMF inflammatory conditions (S-AA, n = 19) and in a non-inflammatory control group (n = 185) by molecular genetic studies using polymerase chain reaction with the ARMS (amplification refractory mutation system) method. Both AA and non-AA-FMF patients had significantly higher MEFV mutations compared to non-inflammatory controls (81 and 62.7% respectively vs. 4.2%, p = 0.0001). AA-FMF patients carried significantly more MEFV mutations than non-AA-FMF patients (p = 0.01). M694V was the most common mutation in both FMF groups (63.5 vs. 51.4%), however allele frequency (p = 0.17) and the number of homozygous patients for this mutation did not differ between the groups (p = 0.77). Although lower compared to FMF patients, S-AA patients also had a significantly higher incidence of MEFV mutations than non-inflammatory controls (21 vs. 4.2%) (p = 0.0002). M694V was the only MEFV mutation in this group. MEFV mutations are found to be increased both in FMF and non-FMF associated secondary amyloidosis in our study; however, no clear association between M694V and amyloidosis is observed, except in the non-FMF group. Our results suggest that MEVF mutations may also serve as a severity marker for other inflammatory conditions. Copyright 2004 S. Karger AG, Basel

  12. Correlation of Primary Hepatocellular Carcinoma with HBV Genotypes, Subgenotypes and Gene Mutations in Gansu Province

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    Objective To investigate the occurrence of basal core promoter (BCP) and pre-C mutations in patients with hepatitis B virus (HBV) infection in Gansu Province, China, and to analyze the correlation of HBV mutation and HBV genotype with primary hepatocellular carcinoma (HCC). Methods PCR-RFLP was applied to detect HBV subgenotypes, and the presence of the pre-C and BCP mutations in 62 patients with HCC, 70 patients with hepatitis B induced liver cirrhosis (LC) and 90 patients with chronic hepatitis B (CHB). Results In HCC patients, genotype C was the major genotype (70.97%). The pre-C mutation was found in 59.68%, 31.43% and 16.67% patients with HCC, LC and CHB, respectively. The frequency of BCP mutations was signiifcantly different between patients with HCC, LC and CHB (74.19%, 51.43% and 37.78%, respectively;χ2=30.727, 19.540, respectively,P < 0.01). Patients in HCC group had a higher incidence of pre-C as well as BCP mutations compared to the other groups. The prevalence of pre-C and BCP mutations was signiifcantly higher in patients with genotype C1 (44.32% and 69.32%, respectively) compared to patients with other subgenotypes (P < 0.05). Conclusions The incidence of pre-C and BCP mutations increases with disease progression. Pre-C and BCP mutations frequently occur in patients with genotype C1. HBV genotype C, pre-C mutations and BCP mutations are closely related to the occurrence of HCC.

  13. 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)

  14. Detection of EGFR Mutations by TaqMan Mutation Detection Assays Powered by Competitive Allele-Specific TaqMan PCR Technology

    Directory of Open Access Journals (Sweden)

    Cristin Roma

    2013-01-01

    Full Text Available Epidermal growth factor receptor (EGFR mutations in non-small-cell lung cancer (NSCLC are predictive of response to treatment with tyrosine kinase inhibitors. Competitive Allele-Specific TaqMan PCR (castPCR is a highly sensitive and specific technology. EGFR mutations were assessed by TaqMan Mutation Detection Assays (TMDA based on castPCR technology in 64 tumor samples: a training set of 30 NSCLC and 6 colorectal carcinoma (CRC samples and a validation set of 28 NSCLC cases. The sensitivity and specificity of this method were compared with routine diagnostic techniques including direct sequencing and the EGFR Therascreen RGQ kit. Analysis of the training set allowed the identification of the threshold value for data analysis (0.2; the maximum cycle threshold (Ct=37; and the cut-off ΔCt value (7 for the EGFR TMDA. By using these parameters, castPCR technology identified both training and validation set EGFR mutations with similar frequency as compared with the Therascreen kit. Sequencing detected rare mutations that are not identified by either castPCR or Therascreen, but in samples with low tumor cell content it failed to detect common mutations that were revealed by real-time PCR based methods. In conclusion, our data suggest that castPCR is highly sensitive and specific to detect EGFR mutations in NSCLC clinical samples.

  15. Oncogene mutational profile in nasopharyngeal carcinoma

    Directory of Open Access Journals (Sweden)

    Zhang ZC

    2014-03-01

    Full Text Available Zi-Chen Zhang,1,* Sha Fu,1,* Fang Wang,1 Hai-Yun Wang,1 Yi-Xin Zeng,2 Jian-Yong Shao11Department of Molecular Diagnostics, 2Department of Experimental Research, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou, People's Republic of China *These authors contributed equally to this work Abstract: Nasopharyngeal carcinoma (NPC is a common tumor in Southern China, but the oncogene mutational status of NPC patients has not been clarified. Using time-of-flight mass spectrometry, 238 mutation hotspots in 19 oncogenes were examined in 123 NPC patients. The relationships between mutational status and clinical data were assessed with a χ2 or Fisher's exact test. Survival analysis was performed using the Kaplan–Meier method with the log-rank test. In 123 patients, 21 (17.1% NPC tumors were positive for mutations in eight oncogenes: six patients had PIK3CA mutations (4.9%, five NRAS mutations (4.1%, four KIT mutations (3.3%, two PDGFRA mutations (1.6%, two ABL mutations (1.6%, and one with simultaneous mutations in HRAS, EGFR, and BRAF (1%. Patients with mutations were more likely to relapse or develop metastasis than those with wild-type alleles (P=0.019. No differences or correlations were found in other clinical characteristics or in patient survival. No mutations were detected in oncogenes AKT1, AKT2, CDK, ERBB2, FGFR1, FGFR3, FLT3, JAK2, KRAS, MET, and RET. These results demonstrate an association between NPC and mutations in NRAS, KIT, PIK3CA, PDGFRA, and ABL, which are associated with patient relapse and metastasis. Keywords: NPC, oncogene, mutation

  16. Grb2-associated binder 1 polymorphism was associated with the risk of Helicobactor pylori infection and gastric atrophy

    Directory of Open Access Journals (Sweden)

    Yasuyuki Goto, Takafumi Ando, Kazuko Nishio, Sayo Kawai, Yoshiko Ishida, Mariko Naito, Hidemi Goto, Nobuyuki Hamajima

    2007-01-01

    Full Text Available Background: Various single nucleotide polymorphisms (SNPs have explained the association between Helicobacter pylori (H. pylori and gastric atrophy and cancer. This study investigated the associations of Grb2 associated binder 1 (Gab1 polymorphism and the combination of PTPN11 gene encoding src homology 2 domain-containing protein tyrosine phosphatase-2 (SHP2 and Gab1 gene with gastric cancer and gastric atrophy among H. pylori seropositive subjects. Methods: A single nucleotide polymorphism at intron 2 of Gab1 (JST164345 was examined for 454 Japanese health checkup examinees (126 males and 328 females aged 35 to 85 without a history of gastric cancer and 202 gastric cancer patients (134 males and 68 females aged 33 to 94 with pathologically confirmed diagnosis of gastric adenocarcinoma. Results: The decreased OR of the Gab1 A/A for H. pylori seropositivity was 0.25 (95% confidence interval (CI: 0.08-0.71. Among seropositive healthy controls, the OR of the Gab1 G/A+A/A for gastric atrophy was significant (OR=1.95, 95% CI: 1.12 -3.40. Seropositive individuals with PTPN11 G/G and Gab1 G/A+A/A demonstrated the highest risk of gastric atrophy with significance (OR=3.49, 95% CI: 1.54-7.90 relative to PTPN11 G/A+A/A and Gab1 G/G, the lowest risk combination, as a reference. However, the gene-gene interaction between PTPN11 and Gab1 was not observed (OR=1.39, 95% CI: 0.41-4.66. Compared to gastric cancer case, the Gab1 did not influence the step of atrophy/metaplasia-gastric cancer sequence. Conclusions: This study represents that the Gab1 polymorphism was associated with the low risk of H. pylori infection and the high risk of gastric atrophy among seropositive healthy controls, and that seropositive individuals with PTPN11 G/G and Gab1 G/A+G/G were associated with the greatest risk of gastric atrophy. These findings require confirmation in much larger studies.

  17. BRAF mutation testing with a rapid, fully integrated molecular diagnostics system

    OpenAIRE

    Janku, Filip; Claes, Bart; Huang, Helen J.; Falchook, Gerald S.; Devogelaere, Benoit; Kockx, Mark; Bempt, Isabelle Vanden; Reijans, Martin; Naing, Aung; Fu, Siqing; Piha-Paul, Sarina A.; Hong, David S.; Holley, Veronica R.; Tsimberidou, Apostolia M.; Stepanek, Vanda M.

    2015-01-01

    Fast and accurate diagnostic systems are needed for further implementation of precision therapy of BRAF-mutant and other cancers. The novel IdyllaTM BRAF Mutation Test has high sensitivity and shorter turnaround times compared to other methods. We used Idylla to detect BRAF V600 mutations in archived formalin-fixed paraffin-embedded (FFPE) tumor samples and compared these results with those obtained using the cobas 4800 BRAF V600 Mutation Test or MiSeq deep sequencing system and with those ob...

  18. Detecting the spectrum of multigene mutations in non-small cell lung cancer by Snapshot assay

    Institute of Scientific and Technical Information of China (English)

    Jian Su; Xiao-Sui Huang; Yi-Long Wu; Xu-Chao Zhang; She-Juan An; Wen-Zhao Zhong; Ying Huang; Shi-Liang Chen; Hong-Hong Yan; Zhi-Hong Chen; Wei-Bang Guo

    2014-01-01

    As molecular targets continue to be identified and more targeted inhibitors are developed for personalized treatment of non-small cell lung cancer (NSCLC), multigene mutation determination will be needed for routine oncology practice and for clinical trials. In this study, we evaluated the sensitivity and specificity of multigene mutation testing by using the Snapshot assay in NSCLC. We retrospectively reviewed a cohort of 110 consecutive NSCLC specimens for which epidermal growth factor receptor (EGFR) mutation testing was performed between November 2011 and December 2011 using Sanger sequencing. Using the Snapshot assay, mutation statuses were detected forEGFR, Kirsten rate sarcoma viral oncogene homolog (KRAS), phosphoinositide-3-kinase catalytic alpha polypeptide (PIK3CA), v-Raf murine sarcoma viral oncogene homolog B1 (BRAF), v-ras neuroblastoma viral oncogene homolog (NRAS), dual specificity mitogen activated protein kinase kinase 1 (MEK1), phosphatase and tensin homolog (PTEN), and human epidermal growth factor receptor 2 (HER2) in patient specimens and cellline DNA. Snapshot data were compared to Sanger sequencing data. Of the 110 samples, 51 (46.4%) harbored at least one mutation. The mutation frequency in adenocarcinoma specimens was 55.6%, and the frequencies ofEGFR, KRAS, PIK3CA, PTEN, andMEK1 mutations were 35.5%, 9.1%, 3.6%, 0.9%, and 0.9%, respectively. No mutation was found in theHER2, NRAS, orBRAF genes. Three of the 51 mutant samples harbored double mutations: twoPIK3CA mutations coexisted withKRAS orEGFR mutations, and another KRAS mutation coexisted with aPTEN mutation. Among the 110 samples, 47 were surgical specimens, 60 were biopsy specimens, and 3 were cytological specimens; the corresponding mutation frequencies were 51.1%, 41.7%, and 66.7%, respectively (P = 0.532). Compared to Sanger sequencing, Snapshot specificity was 98.4% and sensitivity was 100% (positive predictive value, 97.9%; negative predictive value, 100%). The Snapshot assay

  19. A mutational analysis of Caenorhabditis elegans in space

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Yang [Department of Medical Genetics, University of British Columbia, Life Sciences Centre, Room 1364-2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3 (Canada); Lai, Kenneth [Department of Medical Genetics, University of British Columbia, Life Sciences Centre, Room 1364-2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3 (Canada); Cheung, Iris [Department of Medical Genetics, University of British Columbia, Life Sciences Centre, Room 1364-2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3 (Canada); Youds, Jillian [Department of Medical Genetics, University of British Columbia, Life Sciences Centre, Room 1364-2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3 (Canada); Tarailo, Maja [Department of Medical Genetics, University of British Columbia, Life Sciences Centre, Room 1364-2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3 (Canada); Tarailo, Sanja [Department of Medical Genetics, University of British Columbia, Life Sciences Centre, Room 1364-2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3 (Canada); Rose, Ann [Department of Medical Genetics, University of British Columbia, Life Sciences Centre, Room 1364-2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3 (Canada)]. E-mail: arose@gene.nce.ubc.ca

    2006-10-10

    The International Caenorhabditis elegans Experiment First Flight (ICE-First) was a project using C. elegans as a model organism to study the biological effects of short duration spaceflight (11 days in the International Space Station). As a member of the ICE-First research team, our group focused on the mutational effects of spaceflight. Several approaches were taken to measure mutational changes that occurred during the spaceflight including measurement of the integrity of poly-G/poly-C tracts, determination of the mutation frequency in the unc-22 gene, analysis of lethal mutations captured by the genetic balancer eT1(III;V), and identification of alterations in telomere length. By comparing the efficiency, sensitivity, and convenience of these methods, we deduced that the eT1 balancer system is well-suited for capturing, maintaining and recovering mutational events that occur over several generations during spaceflight. In the course of this experiment, we have extended the usefulness of the eT1 balancer system by identifying the physical breakpoints of the eT1 translocation and have developed a PCR assay to follow the eT1 chromosomes. C. elegans animals were grown in a defined liquid media during the spaceflight. This is the first analysis of genetic changes in C. elegans grown in the defined media. Although no significant difference in mutation rate was detected between spaceflight and control samples, which is not surprising given the short duration of the spaceflight, we demonstrate here the utility of worms as an integrating biological dosimeter for spaceflight.

  20. IDH1 mutation detection by droplet digital PCR in glioma.

    Science.gov (United States)

    Wang, Jing; Zhao, Yi-ying; Li, Jian-feng; Guo, Cheng-cheng; Chen, Fu-rong; Su, Hong-kai; Zhao, Hua-fu; Long, Ya-kang; Shao, Jian-yong; To, Shing shun Tony; Chen, Zhong-ping

    2015-11-24

    Glioma is the most frequent central nervous system tumor in adults. The overall survival of glioma patients is disappointing, mostly due to the poor prognosis of glioblastoma (Grade IV glioma). Isocitrate dehydrogenase (IDH) is a key factor in metabolism and catalyzes the oxidative decarboxylation of isocitrate. Mutations in IDH genes are observed in over 70% of low-grade gliomas and some cases of glioblastoma. As the most frequent mutation, IDH1(R132H) has been served as a predictive marker of glioma patients. The recently developed droplet digital PCR (ddPCR) technique generates a large amount of nanoliter-sized droplets, each of which carries out a PCR reaction on one template. Therefore, ddPCR provides high precision and absolute quantification of the nucleic acid target, with wide applications for both research and clinical diagnosis. In the current study, we collected 62 glioma tissue samples (Grade II to IV) and detected IDH1 mutations by Sanger direct sequencing, ddPCR, and quantitative real-time PCR (qRT-PCR). With the results from Sanger direct sequencing as the standard, the characteristics of ddPCR were compared with qRT-PCR. The data indicated that ddPCR was much more sensitive and much easier to interpret than qRT-PCR. Thus, we demonstrated that ddPCR is a reliable and sensitive method for screening the IDH mutation. Therefore, ddPCR is able to applied clinically in predicting patient prognosis and selecting effective therapeutic strategies. Our data also supported that the prognosis of Grade II and III glioma was better in patients with an IDH mutation than in those without mutation.

  1. Physician Compare

    Data.gov (United States)

    U.S. Department of Health & Human Services — Physician Compare, which meets Affordable Care Act of 2010 requirements, helps you search for and select physicians and other healthcare professionals enrolled in...

  2. [TP53 mutations and molecular epidemiology].

    Science.gov (United States)

    Otsuka, Kazunori; Ishioka, Chikashi

    2007-05-01

    Tumor suppressor p53 protein is activated by a variety of cellular stresses through several pathways and transactivates its downstream genes, including regulators of cell cycle, apoptosis and DNA repair. The loss of p53 function by TP53 gene mutations therefore fails to activate these genes and is thought to be a critical cause of carcinogenesis and/or tumor progression. TP53 is one of the most frequently mutated genes in human cancer. TP53 mutations are found in about 50% of human cancers, although the frequency of TP53 mutations differs among tumor types. However, the degree of functional disorder of mutant p53 varies according to the type of TP53 mutation. And the effects of p53 on cancer formation and/or progression are influenced by the degree of p53 dysfunction. So it is important to analyze the effects of TP53 mutations carefully according to the oncogenicity of each mutation from the molecular epidemiological point of view. Here, together with some cautions needed for analyzing and interpreting the significance of TP53 gene mutations, we present some examples of the identified specific mutation spectrum and the correlation between the prognosis and TP53 mutation in some cancers.

  3. Evaluation of CFTR gene mutations in Adana

    Directory of Open Access Journals (Sweden)

    Ozlem Goruroglu Ozturk

    2013-04-01

    Full Text Available ABSTRACT Objective: Cystic fibrosis is the most common autosomal recessive inherited disorder seen in the white populations. It develops in result of mutations of cystic fibrosis transmembrane regulator (CFTR gene. Rate of these mutations vary in different geographical regions. In this study, we aimed to determine the frequency of CFTR gene mutations in Adana. Methods: DNA samples of 63 subjects (21 women, 42 men who were diagnosed as cystic fibrosis at Balcali Hospital of Cukurova University, were studied for 19 different CFTR mutations by the strip assay method which is based on reverse hybridization. Results: In cystic fibrosis diagnosed patients, 19 mutations were observed of which 9 were homozygous and 10 were heterozygous. ∆F508 frequency was found as 11.9%, and rate of homozygous was found as 66.7%. Mutation frequencies of W1282X and N1303K were found as 2.40% and 4.80% respectively and rate of homozygous mutations were 50% for both. I148T mutation frequency was found as 3.20% and all were heterozygous. For the whole 19 mutations, frequency of mutation in 63 subjects was 22.3%. Conclusion: Detection of CFTR gene mutations by the strip assay method by reverse hybridization is an easy, fast and informative method. However, due to improvability of the common mutations in probable cystic fibrosis patients because of heterogenity in this region, it is still a major problem and does not exclude cystic fibrosis diagnosis. But this problematic issue can be overcome by evaluating the whole exons of CFTR mutations by advanced molecular tecniques. Key words: CFTR, cystic fibrosis, molecular diagnosis, reverse hibridisation [Cukurova Med J 2013; 38(2.000: 202-208

  4. Impact of two myostatin (MSTN mutations on weight gain and lamb carcass classification in Norwegian White Sheep (Ovis aries

    Directory of Open Access Journals (Sweden)

    Blichfeldt Thor

    2010-01-01

    Full Text Available Abstract Background Our aim was to estimate the effect of two myostatin (MSTN mutations in Norwegian White Sheep, one of which is close to fixation in the Texel breed. Methods The impact of two known MSTN mutations was examined in a field experiment with Norwegian White Sheep. The joint effect of the two MSTN mutations on live weight gain and weaning weight was studied on 644 lambs. Carcass weight gain from birth to slaughter, carcass weight, carcass conformation and carcass fat classes were calculated in a subset of 508 lambs. All analyses were carried out with a univariate linear animal model. Results The most significant impact of both mutations was on conformation and fat classes. The largest difference between the genotype groups was between the wild type for both mutations and the homozygotes for the c.960delG mutation. Compared to the wild types, these mutants obtained a conformation score 5.1 classes higher and a fat score 3.0 classes lower, both on a 15-point scale. Conclusions Both mutations reduced fatness and increased muscle mass, although the effect of the frameshift mutation (c.960delG was more important as compared to the 3'-UTR mutation (c.2360G>A. Lambs homozygous for the c.960delG mutation grew more slowly than those with other MSTN genotypes, but had the least fat and the largest muscle mass. Only c.960delG showed dominance effects.

  5. Lattices, graphs, and Conway mutation

    CERN Document Server

    Greene, Joshua Evan

    2011-01-01

    The d-invariant of an integral, positive definite lattice L records the minimal norm of a characteristic covector in each equivalence class mod 2L. We prove that the 2-isomorphism type of a connected graph is determined by the d-invariant of its lattice of integral cuts (or flows). As an application, we prove that a reduced, alternating link diagram is determined up to mutation by the Heegaard Floer homology of the link's branched double-cover. Thus, alternating links with homeomorphic branched double-covers are mutants.

  6. Stratum corneum lipids, skin barrier function and filaggrin mutations in patients with atopic eczema

    DEFF Research Database (Denmark)

    Høgh, Julie Kaae; Hellgren, Lars; Jungersted, JM

    2010-01-01

    Background: Prior to the discovery of filaggrin (FLG) mutations, evidence for an impaired skin barrier in atopic dermatitis (AD) has been documented, and changes in ceramide profile, altered skin pH and increased trans-epidermal water loss (TEWL) in patients with AD have been reported. Until now......, no studies have analysed stratum corneum (SC) lipids combined with skin barrier parameters in subjects of known FLG genotype. Methods: A cohort of 49 German individuals genotyped for the most common FLG mutations (R501X, 2282del4) had SC samples taken for lipid analysis by high-performance thin layer...... differences were observed for ceramide 2, 3, 5 and 6. FLGmut individuals had significantly higher skin pH values than individuals not carrying FLG mutations. Patients with AD with FLG mutations had significantly higher erythema compared to patients with AD without FLG mutations. Conclusion: Our results...

  7. Familial adenomatous polyposis patients without an identified APC germline mutation have a severe phenotype

    DEFF Research Database (Denmark)

    Bisgaard, M L; Ripa, R; Knudsen, Anne Louise;

    2004-01-01

    BACKGROUND: Development of more than 100 colorectal adenomas is diagnostic of the dominantly inherited autosomal disease familial adenomatous polyposis (FAP). Germline mutations can be identified in the adenomatous polyposis coli (APC) gene in approximately 80% of patients. The APC protein...... comprises several regions and domains for interaction with other proteins, and specific clinical manifestations are associated with the mutation assignment to one of these regions or domains. AIMS: The phenotype in patients without an identified causative APC mutation was compared with the phenotype...... in patients with a known APC mutation and with the phenotypes characteristic of patients with mutations in specific APC regions and domains. PATIENTS: Data on 121 FAP probands and 149 call up patients from 70 different families were extracted from the Danish Polyposis register. METHODS: Differences in 16...

  8. Not only emerging technologies are at risk: The case of mutation breeding

    DEFF Research Database (Denmark)

    Hagemann, Kit S.; Scholderer, Joachim

    2007-01-01

    plants. Unlike crop cultivars developed by newer techniques such as genetic engineering, mutation-bred cultivars are not subject to special types of horizontal regulation in any UN country. Based on representative survey data (N = 1000), public attitudes towards mutation breeding were compared....... One technology where such a latent crisis potential has often been suspected is mutation breeding. Mutation breeding is a standard technique in the development of new crop cultivars, known since the 1930s, typically involving the use of ionizing radiation to induce alterations in the genomes of crop...... with attitudes towards several other agricultural and food biotechnologies in terms of evaluative extremity, strength, and structure. Among the technologies included in the survey, mutation breeding was by far the most negatively evaluated one (substantially more so than genetic engineering). At the same time...

  9. Analysis of mitochondrial DNA somatic mutations in OXYS and Wistar strain rats.

    Science.gov (United States)

    Rotskaya, U N; Rogozin, I B; Vasyunina, E A; Kolosova, N G; Malyarchuk, B A; Nevinsky, G A; Sinitsyna, O I

    2009-04-01

    Rats of the OXYS strain are sensitive to oxidative stress and serve as a biological model of premature aging. We have compared spectra of somatic mutations in a control region of mtDNA from the liver of the OXYS rat strain and of Wistar rats as a control. The majority of nucleotide substitutions in the mutation spectra were represented by transitions: 94 and 97% in the OXYS and Wistar rats, respectively. It was shown that 40% of somatic mutations in the control region of mtDNA from Wistar rats were significantly consistent with the model of dislocation mutagenesis. No statistical support for this model was found for mutations in the control region of mtDNA from OXYS rats. The mutation frequency in the ETAS section was higher in the OXYS strain rats than in Wistar rats. These results suggest different mechanisms of mutagenesis in the two rat strains under study.

  10. Novel FAM126A mutations in hypomyelination and congenital cataract disease.

    Science.gov (United States)

    Traverso, M; Assereto, S; Gazzerro, E; Savasta, S; Abdalla, E M; Rossi, A; Baldassari, S; Fruscione, F; Ruffinazzi, G; Fassad, M R; El Beheiry, A; Minetti, C; Zara, F; Biancheri, R

    2013-09-27

    Hypomyelination and congenital cataract (HCC, OMIM #610532) is a rare autosomal recessive disorder due to FAM126A mutations characterized by congenital cataract, progressive neurologic impairment, and myelin deficiency in the central and peripheral nervous system. We have identified two novel mutations in three affected members of two unrelated families. Two sibs harbouring a microdeletion causing a premature stop in the protein showed the classical clinical and neuroradiologic HCC picture. The third patient carrying a missense mutation showed a relatively mild clinical picture without peripheral neuropathy. A residual amount of hyccin protein in primary fibroblasts was demonstrated by functional studies indicating that missense mutations are likely to have less detrimental effects if compared with splice-site mutations or deletions that cause the full-blown HCC phenotype, including peripheral nervous system involvement.

  11. Nocturnal frontal lobe epilepsy caused by a mutation in the GATOR1 complex gene NPRL3.

    Science.gov (United States)

    Korenke, Georg-Christoph; Eggert, Marlene; Thiele, Holger; Nürnberg, Peter; Sander, Thomas; Steinlein, Ortrud K

    2016-03-01

    Mutations in NPRL3, one of three genes that encode proteins of the mTORC1-regulating GATOR1 complex, have recently been reported to cause cortical dysplasia with focal epilepsy. We have now analyzed a multiplex epilepsy family by whole exome sequencing and identified a frameshift mutation (NM_001077350.2; c.1522delG; p.E508Rfs*46) within exon 13 of NPRL3. This truncating mutation causes an epilepsy phenotype characterized by early childhood onset of mainly nocturnal frontal lobe epilepsy. The penetrance in our family was low (three affected out of six mutation carriers), compared to families with either ion channel- or DEPDC5-associated familial nocturnal frontal lobe epilepsy. The absence of apparent structural brain abnormalities suggests that mutations in NPRL3 are not necessarily associated with focal cortical dysplasia but might be able to cause epilepsy by different, yet unknown pathomechanisms.

  12. Limited diagnostic value of enzyme analysis in patients with mitochondrial tRNA mutations

    DEFF Research Database (Denmark)

    Wibrand, Flemming; Jeppesen, Tina Dysgaard; Frederiksen, Anja L

    2010-01-01

    We evaluated the diagnostic value of respiratory chain (RC) enzyme analysis of muscle in adult patients with mitochondrial myopathy (MM). RC enzyme activity was measured in muscle biopsies from 39 patients who carry either the 3243A>G mutation, other tRNA point mutations, or single, large....... Only 10% of patients with the 3243A>G point mutation had decreased enzyme activity of one or more RC complexes, whereas this was the case for 83% of patients with other point mutations and 62% of patients with deletions. Abnormal muscle histochemistry was found in 65%, 100%, and 85% of patients......-scale deletions of mtDNA. Findings were compared with those obtained from asymptomatic relatives with the 3243A>G mutation, myotonic dystrophy patients, and healthy subjects. Plasma lactate concentration, maximal oxygen uptake, and ragged-red fibers/cytochrome c-negative fibers in muscle were also determined...

  13. The application of asymmetric PCR-SSCP in gene mutation detecting

    Institute of Scientific and Technical Information of China (English)

    Xiaohui ZHANG; Shangzhong XU; Xue GAO; Lupei ZHANG; Hongyan REN; Jinbao CHEN

    2008-01-01

    The advantages and disadvantages of asymmetric PCR-SSCP and the traditional PCR-SSCP were compared in this study.The mutations in 3'UTR of Smad4 gene of Luxi cattle and the Holstein cow were analyzed by asymmetric PCR-SSCP and one insert "T" mutation and one G/A mutation in this region were found.The G/A mutation created a HhaI restriction enzyme digestion position and the frequencies studied by asymmetric PCR-SSCP and HhaI-RFLP in 116 Luxi cattle and 75 Holstein cows were all the same.The asymmetric PCR-SSCP had fewer,clearer and more stabile bands than traditional PCR-SSCP.This indicates that the asymmetric PCR-SSCP is suited for mutation detection.

  14. Targeting EGFR T790M mutation in NSCLC: From biology to evaluation and treatment.

    Science.gov (United States)

    Passaro, Antonio; Guerini-Rocco, Elena; Pochesci, Alessia; Vacirca, Davide; Spitaleri, Gianluca; Catania, Chiara Matilde; Rappa, Alessandra; Barberis, Massimo; de Marinis, Filippo

    2017-03-01

    The identification of EGFR mutations and their respectively tyrosine kinase inhibitors (TKIs), changed dramatically treatment and survival of patients with EGFR-positive lung cancer. Nowadays, different EGFR TKIs as afatinib, erlotinib and gefitinib are approved worldwide for the treatment of NSCLC harbouring EGFR mutations, in particular exon 19 deletions or exon 21 (Leu858Arg) substitution EGFR mutations. In first-line setting, when comparing with platinum-based chemotherapy, these target drugs improves progression-free survival, response rate and quality of life. Unfortunately, the development of different mechanism of resistance, limits the long term efficacy of these agents. The most clear mechanism of resistance is the development of EGFR Thr790Met mutation. Against this new target, different third-generation EGFR-mutant-selective TKIs, such as osimertinib, rociletinib and olmutinib, showed a great activity. In this review, we summarize the scientific evidences about biology, evaluation and treatment on NSCLC with EGFR T790M mutation.

  15. Breast cancer risk in Chinese women with BRCA1 or BRCA2 mutations.

    Science.gov (United States)

    Yao, Lu; Sun, Jie; Zhang, Juan; He, Yingjian; Ouyang, Tao; Li, Jinfeng; Wang, Tianfeng; Fan, Zhaoqing; Fan, Tie; Lin, Benyao; Xie, Yuntao

    2016-04-01

    BRCA1/2 mutations represent approximately 5 % of unselected Chinese women with breast cancer. However, the breast cancer risk of Chinese women with BRCA1/2 mutations is unknown. Therefore, the aim of this study was to estimate the age-specific cumulative risk of breast cancer in Chinese women who carry a BRCA1 or BRCA2 mutation. Our study included 1816 unselected Chinese women with breast cancer and 5549 female first-degree relatives of these probands. All probands were screened for BRCA1/2 mutation. The age-specific cumulative risks of BRCA1/2 carriers were estimated using the kin-cohort study by comparing the history of breast cancer in first-degree female relatives of BRCA1/2 carriers and non-carriers. Among the 1816 probands, 125 BRCA1/2 pathogenic mutations were identified (70 in the BRCA1 gene and 55 in the BRCA2 gene). The incidence of breast cancer in the first-degree female relatives of BRCA1/2 mutation carriers was significantly higher (3.7-fold and 4.4-fold for BRCA1 and BRCA2 mutation carriers, respectively) than in non-carriers. The estimated cumulative risks of breast cancer by age 70 years were 37.9 % [95 % confidence interval (CI) 24.1-54.4 %] for BRCA1 mutation carriers and 36.5 % (95 % CI 26.7-51.8 %) for BRCA2 mutation carriers, respectively. Our study suggests that the breast cancer risk of Chinese women with BRCA1/2 mutations appears to be relatively high by the age of 70. Therefore, genetic counseling, enhanced surveillance, and individual preventive strategies should be provided for Chinese women who carry a BRCA1/2 mutation.

  16. Clinical features of chronic hepatitis B patients with YMDD mutation after lamivudine therapy

    Institute of Scientific and Technical Information of China (English)

    LIU Ke-zhou; HOU Wei; ZUMBIKA Edward; NI Qin

    2005-01-01

    Objective: To study the clinical features of chronic hepatitis B (CHB) patients with tyrosine-methionine-aspartateaspartate (YMDD) mutation after lamivudine therapy. Methods: This investigation was a retrospective study of 63 CHB patients with YMDD mutation during lamivudine therapy. Clinical data, including period and types of YMDD mutation; hepatitis B virus (HBV) DNA levels and alanine aminotransferase (ALT) levels before and after YMDD mutation were measured. YMDD mutation in the HBV DNA polymerase gene was determined using polymerase chain reaction (PCR) and direct sequencing. HBV DNA quantification was determined using real-time PCR. Relevant serum markers of HBV were measured. The follow-up period was 12 months after YMDD mutation. Results: YMDD mutation occurred 7~44 months (median, 21.5 months) after the start of lamivudine therapy. The majority of the cases (42/63, 66.6%) had YMDD mutants detected between 12 and 24 months. Four types of YMDD mutation were observed in this study, rtL180M/M204V mutation was the predominant type (26/63, 41.3%). A proportion of patients (16/63, 25.4%; 12/63, 19.1%) had higher HBV DNA levels and ALT levels (after mutation vs before mutation),respectively. Conclusion: The majority of patients with YMDD mutants had similar or lower HBV DNA levels and ALT levels compared with baseline values. This subset of patients might have benefited from the continued lamivudine therapy. The patients with increased ALT and HBV DNA levels (breakthrough hepatitis) should benefit from the addition of a newer nucleotide analogue (e.g. adefovir).

  17. Functional analysis of 'a' determinant mutations associated with occult HBV in HIV-positive South Africans.

    Science.gov (United States)

    Powell, Eleanor A; Boyce, Ceejay L; Gededzha, Maemu P; Selabe, Selokela G; Mphahlele, M Jeffrey; Blackard, Jason T

    2016-07-01

    Occult hepatitis B is defined by the presence of hepatitis B virus (HBV) DNA in the absence of hepatitis B surface antigen (HBsAg). Occult HBV is associated with the development of hepatocellular carcinoma, reactivation during immune suppression, and virus transmission. Viral mutations contribute significantly to the occult HBV phenotype. Mutations in the 'a' determinant of HBsAg are of particular interest, as these mutations are associated with immune escape, vaccine escape and diagnostic failure. We examined the effects of selected occult HBV-associated mutations identified in a population of HIV-positive South Africans on HBsAg production in vitro. Mutations were inserted into two different chronic HBV backbones and transfected into a hepatocyte-derived cell line. HBsAg levels were quantified by enzyme-linked immunosorbent assay (ELISA), while the detectability of mutant HBsAg was determined using an HA-tagged HBsAg expression system. Of the seven mutations analysed, four (S132P, C138Y, N146D and C147Y) resulted in decreased HBsAg expression in one viral background but not in the second viral background. One mutation (N146D) led to a decrease in HBsAg detected as compared to HA-tag, indicating that this mutation compromises the ability of the ELISA to detect HBsAg. The contribution of occult-associated mutations to the HBsAg-negative phenotype of occult HBV cannot be determined adequately by testing the effect of the mutation in a single viral background, and rigorous analysis of these mutations is required.

  18. Spectrum of mutations in CRM-positive and CRM-reduced hemophilia A

    Energy Technology Data Exchange (ETDEWEB)

    McGinniss, M.J.; Kazazian, H.H. Jr.; Bi, L.; Antonarakis, S.E. (John Hopkins Univ., Baltimore, MD (United States)); Hoyer, L.W. (American Red Cross Blood Services, Rockville, MD (United States)); Inaba, H. (Tokyo Medical College (Japan))

    1993-02-01

    Hemophilia A is due to the functional deficiency of factor VIII (FVIII, gene locus F8C). Although half the patients have no detectable FVIII protein in their plasma, the more rare patients ([approximately]5%) have normal levels of a dysfunctional FVIII and are termed cross-reacting material (CRM)-positive. More commonly ([approximately]45%), patients have plasma FVIII protein reduced to an extent roughly comparable to the level of FVIII activity and are designated CRM-reduced. We used denaturing gradient gel electrophoresis to screen for mutations within the F8C gene of 11 patients (6CRM-positive, 5 CRM-reduced) and identified 9 different mutations in 9 patients after analyses of all 26 exons, the promoter region, and the polyadenylation site. Six mutations have not been described previously. Five weree missense (Ser289Leu, Ser558Phe, Val634Ala, Val634Met, Asn1441Lys), and the sixth was a 3-bp deletion ([Delta]Phe652). A review of the literature and the assay of FVIII antigen in 5 hemophilia A patients with previously identified missense mutations from this laboratory yielded a total of 20 other unique CRM-reduced and CRM-positive mutations. Almost all CRM-positive/reduced mutations (24/26) were missense, and many (12/26) occurred at CpG dinucleotides. We examined 19 missense mutation for evolutionary conservation using the portions of the porcine and murine F8C sequences that are known, and 18/19 amino acid residue altered by mutation in these patients wer conserved. Almost 50% of mutations (11/26) clustered in the A2 domain, suggesting that this region is critical for the function of FVIII. The results indicate a nonrandom distribution of mutations and suggest that mutations in a limited number of FVIII regions may cause CRM-positive and CRM-reduced heomphilia A. 48 refs., 1 fig., 1 tab.

  19. Mutation, Witten Index, and Quiver Invariant

    CERN Document Server

    Kim, Heeyeon; Yi, Piljin

    2015-01-01

    We explore Seiberg-like dualities, or mutations, for ${\\cal N}=4$ 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.

  20. Somatic mutations in aging, cancer and neurodegeneration.

    Science.gov (United States)

    Kennedy, Scott R; Loeb, Lawrence A; Herr, Alan J

    2012-04-01

    The somatic mutation theory of aging posits that the accumulation of mutations in the genetic material of somatic cells as a function of time results in a decrease in cellular function. In particular, the accumulation of random mutations may inactivate genes that are important for the functioning of the somatic cells of various organ systems of the adult, result in a decrease in organ function. When the organ function decreases below a critical level, death occurs. A significant amount of research has shown that somatic mutations play an important role in aging and a number of age related pathologies. In this review, we explore evidence for increases in somatic nuclear mutation burden with age and the consequences for aging, cancer, and neurodegeneration. We then review evidence for increases in mitochondrial mutation burden and the consequences for dysfunction in the disease processes.

  1. Identification of six new Gaucher disease mutations

    Energy Technology Data Exchange (ETDEWEB)

    Beutler, E.; Gelbart, T.; West, C. (Scripps Research Institute, La Jolla, CA (United States))

    1993-01-01

    The four most common mutations account for 97% of the Gaucher disease-producing alleles in Jewish patients and 75% of the alleles in non-Jewish patients. Although at least 15 other mutations and some examples of gene conversion and/or fusion genes have been described, a number of mutations remain unidentified. We have now identified six new mutations, a deletion of a C at the 72 position of the cDNA, a 481C[yields]T mutation (122p[sup Gly[yields]Ser]), a 751T [yields] C (212 [sup Tyr[yields]His]), a 1549G [yields] A (478[sup Gly[yields]Ser]), a 1604G [yields] A (496 [sup Arg[yields]His]), and a 55-bp deletion. All but one of these were found in single families. The 1604A mutation, however, was observed in four unrelated individuals. 7 refs., 2 tabs.

  2. How mutation affects evolutionary games on graphs.

    Science.gov (United States)

    Allen, Benjamin; Traulsen, Arne; Tarnita, Corina E; Nowak, Martin A

    2012-04-21

    Evolutionary dynamics are affected by population structure, mutation rates and update rules. Spatial or network structure facilitates the clustering of strategies, which represents a mechanism for the evolution of cooperation. Mutation dilutes this effect. Here we analyze how mutation influences evolutionary clustering on graphs. We introduce new mathematical methods to evolutionary game theory, specifically the analysis of coalescing random walks via generating functions. These techniques allow us to derive exact identity-by-descent (IBD) probabilities, which characterize spatial assortment on lattices and Cayley trees. From these IBD probabilities we obtain exact conditions for the evolution of cooperation and other game strategies, showing the dual effects of graph topology and mutation rate. High mutation rates diminish the clustering of cooperators, hindering their evolutionary success. Our model can represent either genetic evolution with mutation, or social imitation processes with random strategy exploration.

  3. Somatic mutational analysis of FAK in breast cancer: A novel gain-of-function mutation due to deletion of exon 33

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Xu-Qian [Department of Clinical Laboratory, Ruijin Hospital, Shanghai JiaoTong University School of Medicine, Shanghai (China); Liu, Xiang-Fan [Faculty of Medical Laboratory Science, Shanghai JiaoTong University School of Medicine, Shanghai (China); Yao, Ling [Department of Biochemistry and Molecular Biology, Shanghai JiaoTong University School of Medicine, Shanghai (China); Chen, Chang-Qiang; Gu, Zhi-Dong [Department of Clinical Laboratory, Ruijin Hospital, Shanghai JiaoTong University School of Medicine, Shanghai (China); Ni, Pei-Hua [Faculty of Medical Laboratory Science, Shanghai JiaoTong University School of Medicine, Shanghai (China); Zheng, Xin-Min [Department of Biochemistry and Molecular Biology, Shanghai JiaoTong University School of Medicine, Shanghai (China); Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY (United States); Fan, Qi-Shi, E-mail: qishifan@126.com [Department of Clinical Laboratory, Ruijin Hospital, Shanghai JiaoTong University School of Medicine, Shanghai (China)

    2014-01-10

    Highlights: •A novel FAK splicing mutation identified in breast tumor. •FAK-Del33 mutation promotes cell migration and invasion. •FAK-Del33 mutation regulates FAK/Src signal pathway. -- Abstract: Focal adhesion kinase (FAK) regulates cell adhesion, migration, proliferation, and survival. We identified a novel splicing mutant, FAK-Del33 (exon 33 deletion, KF437463), in both breast and thyroid cancers through colony sequencing. Considering the low proportion of mutant transcripts in samples, this mutation was detected by TaqMan-MGB probes based qPCR. In total, three in 21 paired breast tissues were identified with the FAK-Del33 mutation, and no mutations were found in the corresponding normal tissues. When introduced into a breast cell line through lentivirus infection, FAK-Del33 regulated cell motility and migration based on a wound healing assay. We demonstrated that the expression of Tyr397 (main auto-phosphorylation of FAK) was strongly increased in FAK-Del33 overexpressed breast tumor cells compared to wild-type following FAK/Src RTK signaling activation. These results suggest a novel and unique role of the FAK-Del33 mutation in FAK/Src signaling in breast cancer with significant implications for metastatic potential.

  4. 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

  5. Evidence of a Mild Mutator Phenotype in Cambodian Plasmodium falciparum Malaria Parasites.

    Science.gov (United States)

    Lee, Andrew H; Fidock, David A

    2016-01-01

    Malaria control efforts have been continuously stymied by drug-resistant strains of Plasmodium falciparum, which typically originate in Southeast Asia prior to spreading into high-transmission settings in Africa. One earlier proposed explanation for Southeast Asia being a hotbed of resistance has been the hypermutability or "Accelerated Resistance to Multiple Drugs" (ARMD) phenotype, whereby multidrug-resistant Southeast Asian parasites were reported to exhibit 1,000-fold higher rates of resistance to unrelated antimalarial agents when compared to drug-sensitive parasites. However, three recent studies do not recapitulate this hypermutability phenotype. Intriguingly, genome sequencing of recently derived multidrug-resistant Cambodian isolates has identified a high proportion of DNA repair gene mutations in multidrug-resistant parasites, suggesting their potential role in shaping local parasite evolution. By adapting fluctuation assays for use in P. falciparum, we have examined the in vitro mutation rates of five recent Cambodian isolates and three reference laboratory strains. For these studies we also generated a knockout parasite line lacking the DNA repair factor Exonuclease I. In these assays, parasites were typed for their ability to acquire resistance to KAE609, currently in advanced clinical trials, yielding 13 novel mutations in the Na+/H+-ATPase PfATP4, the primary resistance determinant. We observed no evidence of hypermutability. Instead, we found evidence of a mild mutator (up to a 3.4-fold increase in mutation rate) phenotype in two artemisinin-resistant Cambodian isolates, which carry DNA repair gene mutations. We observed that one such mutation in the Mismatch Repair protein Mlh1 contributes to the mild mutator phenotype when modeled in yeast (scmlh1-P157S). Compared to basal rates of mutation, a mild mutator phenotype may provide a greater overall benefit for parasites in Southeast Asia in terms of generating drug resistance without incurring

  6. Distinct Clinicopathological Patterns of Mismatch Repair Status in Colorectal Cancer Stratified by KRAS Mutations.

    Directory of Open Access Journals (Sweden)

    Wenbin Li

    Full Text Available In sporadic colorectal cancer (CRC, the BRAFV600E mutation is associated with deficient mismatch repair (MMR status and inversely associated with to KRAS mutations. In contrast to deficient MMR (dMMR CRC, data on the presence of KRAS oncogenic mutations in proficient MMR (pMMR CRC and their relationship with tumor progression are scarce. We therefore examined the MMR status in combination with KRAS mutations in 913 Chinese patients and correlated the findings obtained with clinical and pathological features. The MMR status was determined based on detection of MLH1, MSH2, MSH6 and PMS2 expression. KRAS mutation and dMMR status were detected in 36.9% and 7.5% of cases, respectively. Four subtypes were determined by MMR and KRAS mutation status: KRAS (+/pMMR (34.0%, KRAS (+/dMMR (2.9%, KRAS (-/pMMR (58.5% and KRAS (-/dMMR (4.6%. A higher percentage of pMMR tumors with KRAS mutation were most likely to be female (49.0%, proximal located (45.5%, a mucinous histology (38.4%, and to have increased lymph node metastasis (60.3%, compared with pMMR tumors without BRAFV600E and KRAS mutations (36.0%, 29.3%, 29.4% and 50.7%, respectively; all P < 0.01. To the contrary, compared with those with KRAS(-/dMMR tumors, patients with KRAS(+/dMMR tumors demonstrated no statistically significant differences in gender, tumor location, pT depth of invasion, lymph node metastasis, pTNM stage, and histologic grade. This study revealed that specific epidemiologic and clinicopathologic characteristics are associated with MMR status stratified by KRAS mutation. Knowledge of MMR and KRAS mutation status may enhance molecular pathologic staging of CRC patients and metastatic progression in CRC can be estimated based on the combination of these biomarkers.

  7. Hemodynamic and clinical onset in patients with hereditary pulmonary arterial hypertension and BMPR2 mutations

    Directory of Open Access Journals (Sweden)

    Tiede Henning

    2011-07-01

    Full Text Available Abstract Background Mutations in the bone morphogenetic protein receptor 2 (BMPR2 gene can lead to idiopathic pulmonary arterial hypertension (IPAH. This study prospectively screened for BMPR2 mutations in a large cohort of PAH-patients and compared clinical features between BMPR2 mutation carriers and non-carriers. Methods Patients have been assessed by right heart catheterization and genetic testing. In all patients a detailed family history and pedigree analysis have been obtained. We compared age at diagnosis and hemodynamic parameters between carriers and non-carriers of BMPR2 mutations. In non-carriers with familial aggregation of PAH further genes/gene regions as the BMPR2 promoter region, the ACVRL1, Endoglin, and SMAD8 genes have been analysed. Results Of the 231 index patients 22 revealed a confirmed familial aggregation of the disease (HPAH, 209 patients had sporadic IPAH. In 49 patients (86.3% of patients with familial aggregation and 14.3% of sporadic IPAH mutations of the BMPR2 gene have been identified. Twelve BMPR2 mutations and 3 unclassified sequence variants have not yet been described before. Mutation carriers were significantly younger at diagnosis than non-carriers (38.53 ± 12.38 vs. 45.78 ± 11.32 years, p Conclusion This study identified in a large prospectively assessed cohort of PAH- patients new BMPR2 mutations, which have not been described before and confirmed previous findings that mutation carriers are younger at diagnosis with a more severe hemodynamic compromise. Thus, screening for BMPR2 mutations may be clinically useful.

  8. Spliceosome mutations exhibit specific associations with epigenetic modifiers and proto-oncogenes mutated in myelodysplastic syndrome.

    Science.gov (United States)

    Mian, Syed A; Smith, Alexander E; Kulasekararaj, Austin G; Kizilors, Aytug; Mohamedali, Azim M; Lea, Nicholas C; Mitsopoulos, Konstantinos; Ford, Kevin; Nasser, Erick; Seidl, Thomas; Mufti, Ghulam J

    2013-07-01

    The recent identification of acquired mutations in key components of the spliceosome machinery strongly implicates abnormalities of mRNA splicing in the pathogenesis of myelodysplastic syndromes. However, questions remain as to how these aberrations functionally combine with the growing list of mutations in genes involved in epigenetic modification and cell signaling/transcription regulation identified in these diseases. In this study, amplicon sequencing was used to perform a mutation screen in 154 myelodysplastic syndrome patients using a 22-gene panel, including commonly mutated spliceosome components (SF3B1, SRSF2, U2AF1, ZRSR2), and a further 18 genes known to be mutated in myeloid cancers. Sequencing of the 22-gene panel revealed that 76% (n=117) of the patients had mutations in at least one of the genes, with 38% (n=59) having splicing gene mutations and 49% (n=75) patients harboring more than one gene mutation. Interestingly, single and specific epigenetic modifier mutations tended to coexist with SF3B1 and SRSF2 mutations (P<0.03). Furthermore, mutations in SF3B1 and SRSF2 were mutually exclusive to TP53 mutations both at diagnosis and at the time of disease transformation. Moreover, mutations in FLT3, NRAS, RUNX1, CCBL and C-KIT were more likely to co-occur with splicing factor mutations generally (P<0.02), and SRSF2 mutants in particular (P<0.003) and were significantly associated with disease transformation (P<0.02). SF3B1 and TP53 mutations had varying impacts on overall survival with hazard ratios of 0.2 (P<0.03, 95% CI, 0.1-0.8) and 2.1 (P<0.04, 95% CI, 1.1-4.4), respectively. Moreover, patients with splicing factor mutations alone had a better overall survival than those with epigenetic modifier mutations, or cell signaling/transcription regulator mutations with and without coexisting mutations of splicing factor genes, with worsening prognosis (P<0.001). These findings suggest that splicing factor mutations are maintained throughout disease

  9. Comparative Advantage

    DEFF Research Database (Denmark)

    Zhang, Jie; Jensen, Camilla

    2007-01-01

    that are typically explained from the supply-side variables, the comparative advantage of the exporting countries. A simple model is proposed and tested. The results render strong support for the relevance of supply-side factors such as natural endowments, technology, and infrastructure in explaining international...

  10. Mutational analysis of Bloom helicase.

    Science.gov (United States)

    Xi, Xu Guang

    2010-01-01

    DNA helicases are biomolecular motors that convert the chemical energy derived from the hydrolysis of nucleotide triphosphate (usually ATP) into mechanical energy to unwind double-stranded DNA. The unwinding of double-stranded DNA is an essential process for DNA replication, repair, recombination, and transcription. Mutations in human RecQ helicases result in inherent human disease including Bloom's syndrome, Werner's syndrome, and Rothmund-Thomson syndrome. Bloom's syndrome (BS) is a rare human autosomal recessive disorder characterized by a strong predisposition to a wide range of cancers commonly affecting the general population. In order to understand the molecular basis of BS pathology and the mechanism underlying the function of Bloom helicase, we have analyzed BS-causing missense mutations by a combination of structural modeling, site-directed mutagenesis, and biochemical and biophysical approaches. Here, we describe the methods and protocols for measuring ATPase, ATP and DNA binding, DNA strand annealing, and DNA unwinding activities of Bloom protein and its mutant variants. These approaches should be applicable and useful for studying other helicases.

  11. Definition of mutations in polyautoimmunity.

    Science.gov (United States)

    Johar, Angad; Sarmiento-Monroy, Juan C; Rojas-Villarraga, Adriana; Silva-Lara, Maria F; Patel, Hardip R; Mantilla, Ruben D; Velez, Jorge I; Schulte, Klaus-Martin; Mastronardi, Claudio; Arcos-Burgos, Mauricio; Anaya, Juan-Manuel

    2016-08-01

    Familial autoimmunity and polyautoimmunity represent extreme phenotypes ideal for identifying major genomic variants contributing to autoimmunity. Whole exome sequencing (WES) and linkage analysis are well suited for this purpose due to its strong resolution upon familial segregation patterns of functional protein coding and splice variants. The primary objective of this study was to identify potentially autoimmune causative variants using WES data from extreme pedigrees segregating polyautoimmunity phenotypes. DNA of 47 individuals across 10 extreme pedigrees, ascertained from probands affected with polyautoimmunity and familial autoimmunity, were selected for WES. Variant calls were obtained through Genome Analysis Toolkit. Filtration and prioritization framework to identify mutation(s) were applied, and later implemented for genetic linkage analysis. Sanger sequencing corroborated variants with significant linkage. Novel and mostly rare variants harbored in SRA1, MLL4, ABCB8, DHX34 and PLAUR showed significant linkage (LOD scores are >3.0). The strongest signal was in SRA1, with a LOD score of 5.48. Network analyses indicated that SRA1, PLAUR and ABCB8 contribute to regulation of apoptotic processes. Novel and rare variants in genetic linkage with polyautoimmunity were identified throughout WES. Genes harboring these variants might be major players of autoimmunity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Mutation detection using Surveyor nuclease.

    Science.gov (United States)

    Qiu, Peter; Shandilya, Harini; D'Alessio, James M; O'Connor, Kevin; Durocher, Jeffrey; Gerard, Gary F

    2004-04-01

    We have developed a simple and flexible mutation detection technology for the discovery and mapping of both known and unknown mutations. This technology is based on a new mismatch-specific DNA endonuclease from celery, Surveyor nuclease, which is a member of the CEL nuclease family of plant DNA endonucleases. Surveyor nuclease cleaves with high specificity at the 3' side of any mismatch site in both DNA strands, including all base substitutions and insertion/deletions up to at least 12 nucleotides. Surveyor nuclease technology involves four steps: (i) PCR to amplify target DNA from both mutant and wild-type reference DNA; (ii) hybridization to form heteroduplexes between mutant and wild-type reference DNA; (iii) treatment of annealed DNA with Surveyor nuclease to cleave heteroduplexes; and (iv) analysis of digested DNA products using the detection/separation platform of choice. The technology is highly sensitive, detecting rare mutants present at as low as 1 in 32 copies. Unlabeled Surveyor nuclease digestion products can be analyzed using conventional gel electrophoresis or high-performance liquid chromatography (HPLC), while end labeled digestion products are suitable for analysis by automated gel or capillary electrophoresis. The entire protocol can be performed in less than a day and is suitable for automated and high-throughput procedures.

  13. Activating GNAS mutations in parosteal osteosarcoma.

    Science.gov (United States)

    Carter, Jodi M; Inwards, Carrie Y; Jin, Long; Evers, Barbara; Wenger, Doris E; Oliveira, Andre M; Fritchie, Karen J

    2014-03-01

    Parosteal osteosarcoma is a surface-based osteosarcoma that often exhibits deceptively bland cytologic features, hindering diagnosis in small biopsies or when correlative radiologic imaging is not readily available. A number of benign and malignant fibro-osseous lesions, including fibrous dysplasia (FD) and low-grade central osteosarcoma, fall within the morphologic differential diagnosis of parosteal osteosarcoma. Somatic mutations in GNAS, encoding the α-subunit of the heterotrimeric G protein complex (Gsα), occur in FD and McCune-Albright syndrome but have not been reported in parosteal osteosarcoma. We evaluated GNAS mutational status in parosteal osteosarcoma and several of its histologic mimics to determine its utility in differentiating these entities. Eleven of 14 (79%) FD cases had GNAS mutations within codon 201 (5 R201C and 6 R201H mutations). GNAS mutations were not detected in any cases of adamantinoma or osteofibrous dysplasia. Direct sequencing of 9 parosteal osteosarcomas, including 3 of low grade and 6 with dedifferentiation, revealed activating GNAS mutations in 5 cases (55%), distributed as 4 R201C-mutated tumors and 1 tumor with an R201H mutation. GNAS codon 227 mutations were not detected in any of the cases. There was no association between GNAS mutational status and patient demographics, histologic dedifferentiation, or clinical outcome. To our knowledge, we report the first series of parosteal osteosarcomas harboring activating GNAS mutations. Our data suggest that GNAS mutational status may have limited utility as an ancillary technique in differentiating benign and malignant fibro-osseous lesions of the bone.

  14. The Mutational Robustness of Influenza A Virus

    Science.gov (United States)

    McCrone, John T.; Lauring, Adam S.

    2016-01-01

    A virus’ mutational robustness is described in terms of the strength and distribution of the mutational fitness effects, or MFE. The distribution of MFE is central to many questions in evolutionary theory and is a key parameter in models of molecular evolution. Here we define the mutational fitness effects in influenza A virus by generating 128 viruses, each with a single nucleotide mutation. In contrast to mutational scanning approaches, this strategy allowed us to unambiguously assign fitness values to individual mutations. The presence of each desired mutation and the absence of additional mutations were verified by next generation sequencing of each stock. A mutation was considered lethal only after we failed to rescue virus in three independent transfections. We measured the fitness of each viable mutant relative to the wild type by quantitative RT-PCR following direct competition on A549 cells. We found that 31.6% of the mutations in the genome-wide dataset were lethal and that the lethal fraction did not differ appreciably between the HA- and NA-encoding segments and the rest of the genome. Of the viable mutants, the fitness mean and standard deviation were 0.80 and 0.22 in the genome-wide dataset and best modeled as a beta distribution. The fitness impact of mutation was marginally lower in the segments coding for HA and NA (0.88 ± 0.16) than in the other 6 segments (0.78 ± 0.24), and their respective beta distributions had slightly different shape parameters. The results for influenza A virus are remarkably similar to our own analysis of CirSeq-derived fitness values from poliovirus and previously published data from other small, single stranded DNA and RNA viruses. These data suggest that genome size, and not nucleic acid type or mode of replication, is the main determinant of viral mutational fitness effects. PMID:27571422

  15. The inheritance of pathogenic mitochondrial DNA mutations

    OpenAIRE

    Cree, L.M.; Samuels, D.C.; Chinnery, P F

    2009-01-01

    Abstract Mitochondrial DNA mutations cause disease in >1 in 5000 of the population, and ~1 in 200 of the population are asymptomatic carriers of a pathogenic mtDNA mutation. Many patients with these pathogenic mtDNA mutations present with a progressive, disabling neurological syndrome that leads to major disability and premature death. There is currently no effective treatment for mitochondrial disorders, placing great emphasis on preventing the transmission of these diseases. An e...

  16. The Mutational Robustness of Influenza A Virus.

    Directory of Open Access Journals (Sweden)

    Elisa Visher

    2016-08-01

    Full Text Available A virus' mutational robustness is described in terms of the strength and distribution of the mutational fitness effects, or MFE. The distribution of MFE is central to many questions in evolutionary theory and is a key parameter in models of molecular evolution. Here we define the mutational fitness effects in influenza A virus by generating 128 viruses, each with a single nucleotide mutation. In contrast to mutational scanning approaches, this strategy allowed us to unambiguously assign fitness values to individual mutations. The presence of each desired mutation and the absence of additional mutations were verified by next generation sequencing of each stock. A mutation was considered lethal only after we failed to rescue virus in three independent transfections. We measured the fitness of each viable mutant relative to the wild type by quantitative RT-PCR following direct competition on A549 cells. We found that 31.6% of the mutations in the genome-wide dataset were lethal and that the lethal fraction did not differ appreciably between the HA- and NA-encoding segments and the rest of the genome. Of the viable mutants, the fitness mean and standard deviation were 0.80 and 0.22 in the genome-wide dataset and best modeled as a beta distribution. The fitness impact of mutation was marginally lower in the segments coding for HA and NA (0.88 ± 0.16 than in the other 6 segments (0.78 ± 0.24, and their respective beta distributions had slightly different shape parameters. The results for influenza A virus are remarkably similar to our own analysis of CirSeq-derived fitness values from poliovirus and previously published data from other small, single stranded DNA and RNA viruses. These data suggest that genome size, and not nucleic acid type or mode of replication, is the main determinant of viral mutational fitness effects.

  17. Somatic mutations of calreticulin in myeloproliferative neoplasms.

    Science.gov (United States)

    Klampfl, Thorsten; Gisslinger, Heinz; Harutyunyan, Ashot S; Nivarthi, Harini; Rumi, Elisa; Milosevic, Jelena D; Them, Nicole C C; Berg, Tiina; Gisslinger, Bettina; Pietra, Daniela; Chen, Doris; Vladimer, Gregory I; Bagienski, Klaudia; Milanesi, Chiara; Casetti, Ilaria Carola; Sant'Antonio, Emanuela; Ferretti, Virginia; Elena, Chiara; Schischlik, Fiorella; Cleary, Ciara; Six, Melanie; Schalling, Martin; Schönegger, Andreas; Bock, Christoph; Malcovati, Luca; Pascutto, Cristiana; Superti-Furga, Giulio; Cazzola, Mario; Kralovics, Robert

    2013-12-19

    Approximately 50 to 60% of patients with essential thrombocythemia or primary myelofibrosis carry a mutation in the Janus kinase 2 gene (JAK2), and an additional 5 to 10% have activating mutations in the thrombopoietin receptor gene (MPL). So far, no specific molecular marker has been identified in the remaining 30 to 45% of patients. We performed whole-exome sequencing to identify somatically acquired mutations in six patients who had primary myelofibrosis without mutations in JAK2 or MPL. Resequencing of CALR, encoding calreticulin, was then performed in cohorts of patients with myeloid neoplasms. Somatic insertions or deletions in exon 9 of CALR were detected in all patients who underwent whole-exome sequencing. Resequencing in 1107 samples from patients with myeloproliferative neoplasms showed that CALR mutations were absent in polycythemia vera. In essential thrombocythemia and primary myelofibrosis, CALR mutations and JAK2 and MPL mutations were mutually exclusive. Among patients with essential thrombocythemia or primary myelofibrosis with nonmutated JAK2 or MPL, CALR mutations were detected in 67% of those with essential thrombocythemia and 88% of those with primary myelofibrosis. A total of 36 types of insertions or deletions were identified that all cause a frameshift to the same alternative reading frame and generate a novel C-terminal peptide in the mutant calreticulin. Overexpression of the most frequent CALR deletion caused cytokine-independent growth in vitro owing to the activation of signal transducer and activator of transcription 5 (STAT5) by means of an unknown mechanism. Patients with mutated CALR had a lower risk of thrombosis and longer overall survival than patients with mutated JAK2. Most patients with essential thrombocythemia or primary myelofibrosis that was not associated with a JAK2 or MPL alteration carried a somatic mutation in CALR. The clinical course in these patients was more indolent than that in patients with the JAK2 V617F

  18. Computational Analysis of PTEN Gene Mutation

    Directory of Open Access Journals (Sweden)

    Siew-Kien Mah

    2012-01-01

    Full Text Available Post-genomic data can be efficiently analyzed using computational tools. It has the advantage over the biochemical and biophysical methods in term of higher coverage. In this research, we adopted a computational analysis on PTEN gene mutation.  Mutation in PTEN is responsible for many human diseases. The results of this research provide insights into the protein domains of PTEN and the distribution of mutation.

  19. Clustering of Caucasian Leber hereditary optic neuropathy patients containing the 11778 or 14484 mutations on an mtDNA lineage

    Energy Technology Data Exchange (ETDEWEB)

    Brown, M.D.; Sun, F.; Wallace, D.C. [Emory Univ. School of Medicine, Atlanta, GA (United States)

    1997-02-01

    Leber hereditary optic neuropathy (LHON) is a type of blindness caused by mtDNA mutations. Three LHON mtDNA mutations at nucleotide positions 3460, 11778, and 14484 are specific for LHON and account for 90% of worldwide cases and are thus designated as {open_quotes}primary{close_quotes} LHON mutations. Fifteen other {open_quotes}secondary{close_quotes} LHON mtDNA mutations have been identified, but their pathogenicity is unclear. mtDNA haplotype and phylogenetic analysis of the primary LHON mutations in North American Caucasian patients and controls has shown that, unlike the 3460 and 11778 mutations, which are distributed throughout the European-derived (Caucasian) mtDNA phylogeny, patients containing the 14484 mutation tended to be associated with European mtDNA haplotype J. To investigate this apparent clustering, we performed {chi}{sup 2}-based statistical analyses to compare the distribution of LHON patients on the Caucasian phylogenetic tree. Our results indicate that, unlike the 3460 and 11778 mutations, the 14484 mutation was not distributed on the phylogeny in proportion to the frequencies of the major Caucasian mtDNA haplogroups found in North America. The 14484 mutation was next shown to occur on the haplogroup J background more frequently that expected, consistent with the observation that {approximately}75% of worldwide 14484-positive LHON patients occur in association with haplogroup J. The 11778 mutation also exhibited a moderate clustering on haplogroup J. These observations were supported by statistical analysis using all available mutation frequencies reported in the literature. This paper thus illustrates the potential importance of genetic background in certain mtDNA-based diseases, speculates on a pathogenic role for a subset of LHON secondary mutations and their interaction with primary mutations, and provides support for a polygenic model for LHON expression in some cases. 18 refs., 3 tabs.

  20. 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

    2015-01-01

    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

  1. nfxB as a novel target for analysis of mutation spectra in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Mariela R Monti

    Full Text Available nfxB encodes a negative regulator of the mexCD-oprJ genes for drug efflux in the opportunistic pathogen Pseudomonas aeruginosa. Inactivating mutations in this transcriptional regulator constitute one of the main mechanisms of resistance to ciprofloxacin (Cip(r. In this work, we evaluated the use of nfxB/Cip(r as a new test system to study mutation spectra in P. aeruginosa. The analysis of 240 mutations in nfxB occurring spontaneously in the wild-type and mutator backgrounds or induced by mutagens showed that nfxB/Cip(r offers several advantages compared with other mutation detection systems. Identification of nfxB mutations was easy since the entire open reading frame and its promoter region were sequenced from the chromosome using a single primer. Mutations detected in nfxB included all transitions and transversions, 1-bp deletions and insertions, >1-bp deletions and duplications. The broad mutation spectrum observed in nfxB relies on the selection of loss-of-function changes, as we confirmed by generating a structural model of the NfxB repressor and evaluating the significance of each detected mutation. The mutation spectra characterized in the mutS, mutT, mutY and mutM mutator backgrounds or induced by the mutagenic agents 2-aminopurine, cisplatin and hydrogen peroxide were in agreement with their predicted mutational specificities. Additionally, this system allowed the analysis of sequence context effects since point mutations occurred at 85 different sites distributed over the entire nfxB. Significant hotspots and preferred sequence contexts were observed for spontaneous and mutagen-induced mutation spectra. Finally, we demonstrated the utility of a luminescence-based reporter for identification of nfxB mutants previous to sequencing analysis. Thus, the nfxB/Cip(r system in combination with the luminescent reporter may be a valuable tool for studying mutational processes in Pseudomonas spp. wherein the genes encoding the NfxB repressor and

  2. CFTR mutations spectrum and the efficiency of molecular diagnostics in Polish cystic fibrosis patients.

    Science.gov (United States)

    Ziętkiewicz, Ewa; Rutkiewicz, Ewa; Pogorzelski, Andrzej; Klimek, Barbara; Voelkel, Katarzyna; Witt, Michał

    2014-01-01

    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 efficiency of

  3. Impact of glucocerebrosidase mutations on motor and nonmotor complications in Parkinson's disease.

    Science.gov (United States)

    Oeda, Tomoko; Umemura, Atsushi; Mori, Yuko; Tomita, Satoshi; Kohsaka, Masayuki; Park, Kwiyoung; Inoue, Kimiko; Fujimura, Harutoshi; Hasegawa, Hiroshi; Sugiyama, Hiroshi; Sawada, Hideyuki

    2015-12-01

    Homozygous mutations of the glucocerebrosidase gene (GBA) cause Gaucher disease (GD), and heterozygous mutations of GBA are a major risk factor for Parkinson's disease (PD). This study examined the impact of GBA mutations on the longitudinal clinical course of PD patients by retrospective cohort design. GBA-coding regions were fully sequenced in 215 PD patients and GD-associated GBA mutations were identified in 19 (8.8%) PD patients. In a retrospective cohort study, time to develop dementia, psychosis, wearing-off, and dyskinesia were examined. Survival time analysis followed a maximum 12-year observation (median 6.0 years), revealing that PD patients with GD-associated mutations developed dementia and psychosis significantly earlier than those without mutations (p < 0.001 and p = 0.017, respectively). Adjusted hazard ratios of GBA mutations were 8.3 for dementia (p < 0.001) and 3.1 for psychosis (p = 0.002). No statistically significant differences were observed for wearing-off and dyskinesia between the groups. N-isopropyl-p[(123)I] iodoamphetamine single-photon emission tomography pixel-by-pixel analysis revealed that regional cerebral blood flow was reduced in the bilateral parietal cortex, including the precuneus of GD-associated mutant PD patients, compared with matched PD controls without mutations.

  4. TP53 Mutations and Survival in Osteosarcoma Patients: A Meta-Analysis of Published Data

    Directory of Open Access Journals (Sweden)

    Zhe Chen

    2016-01-01

    Full Text Available Several research groups have examined the association between TP53 mutations and prognosis in human osteosarcoma. However, the results were controversial. The purpose of this study was to evaluate the prognostic value of TP53 mutations in osteosarcoma patients. A meta-analysis was conducted with all eligible studies which quantitatively evaluated the relationship between TP53 mutations and clinical outcome of osteosarcoma patients. Eight studies with a total of 210 patients with osteosarcoma were included in this meta-analysis. The risk ratio (RR with a 95% confidence interval (95% CI was calculated to assess the effect of TP53 mutations on 2-year overall survival. The quantitative synthesis of 8 published studies showed that TP53 mutations were associated with 2-year overall survival in osteosarcoma patients. These data suggested that TP53 mutations had an unfavorable impact on 2-year overall survival when compared to the counterparts with wild type (WT TP53 (RR: 1.79; 95% CI: 1.12 to 2.84; P=0.01; I2=0%. There was no between-study heterogeneity. TP53 mutations are an effective prognostic marker for survival of patients with osteosarcoma. However, further large-scale prospective trials should be performed to clarify the prognostic value of TP53 mutations on 3- or 5-year survival in osteosarcoma patients.

  5. TP53 Mutations and Survival in Osteosarcoma Patients: A Meta-Analysis of Published Data.

    Science.gov (United States)

    Chen, Zhe; Guo, Jiayi; Zhang, Kun; Guo, Yanxing

    2016-01-01

    Several research groups have examined the association between TP53 mutations and prognosis in human osteosarcoma. However, the results were controversial. The purpose of this study was to evaluate the prognostic value of TP53 mutations in osteosarcoma patients. A meta-analysis was conducted with all eligible studies which quantitatively evaluated the relationship between TP53 mutations and clinical outcome of osteosarcoma patients. Eight studies with a total of 210 patients with osteosarcoma were included in this meta-analysis. The risk ratio (RR) with a 95% confidence interval (95% CI) was calculated to assess the effect of TP53 mutations on 2-year overall survival. The quantitative synthesis of 8 published studies showed that TP53 mutations were associated with 2-year overall survival in osteosarcoma patients. These data suggested that TP53 mutations had an unfavorable impact on 2-year overall survival when compared to the counterparts with wild type (WT) TP53 (RR: 1.79; 95% CI: 1.12 to 2.84; P = 0.01; I (2) = 0%). There was no between-study heterogeneity. TP53 mutations are an effective prognostic marker for survival of patients with osteosarcoma. However, further large-scale prospective trials should be performed to clarify the prognostic value of TP53 mutations on 3- or 5-year survival in osteosarcoma patients.

  6. Further evidence for elevated human minisatellite mutation rate in Belarus eight years after the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Dubrova, Yuri E.; Buard, Jerome; Jeffreys, Alec J. [Department of Genetics, University of Leicester, Adrian Building, University Road, Leicester (United Kingdom); Nesterov, Valeri N.; Krouchinsky, Nicolay G.; Ostapenko, Vladislav A. [Research Institute for Radiation Medicine, Mogilev (Belarus); Vergnaud, Gilles; Giraudeau, Fabienne [Laboratoire de Recherche en Genetique des Especes, Institut de Biologie, Nantes (France)

    1997-11-28

    Analysis of germline mutation rate at human minisatellites among children born in areas of the Mogilev district of Belarus heavily polluted after the Chernobyl accident has been extended, both by recruiting more families from the affected region and by using five additional minisatellite probes, including multi-locus probe 33.6 and four hypervariable single-locus probes. These additional data confirmed a twofold higher mutation rate in exposed families compared with non-irradiated families from the United Kingdom. An elevated rate was seen at all three independent sets of minisatellites (detected separately by multi-locus probes 33.15, 33.6 and six single-locus probes), indicating a generalised increase in minisatellite germline mutation rate in the Belarus families. Within the Belarus cohort, mutation rate was significantly greater in families with higher parental radiation dose estimated for chronic external and internal exposure to caesium-137, consistent with radiation induction of germline mutation. The spectra of mutation seen in the unexposed and exposed families were indistinguishable, suggesting that increased mutation observed over multiple loci arises indirectly by some mechanism that enhances spontaneous minisatellite mutation.

  7. An adaptive genetic algorithm with diversity-guided mutation and its global convergence property

    Institute of Scientific and Technical Information of China (English)

    李枚毅; 蔡自兴; 孙国荣

    2004-01-01

    An adaptive genetic algorithm with diversity-guided mutation, which combines adaptive probabilities of crossover and mutation was proposed. By means of homogeneous finite Markov chains, it is proved that adaptive genetic algorithm with diversity-guided mutation and genetic algorithm with diversity-guided mutation converge to the global optimum if they maintain the best solutions, and the convergence of adaptive genetic algorithms with adaptive probabilities of crossover and mutation was studied. The performances of the above algorithms in optimizing several unimodal and multimodal functions were compared. The results show that for multimodal functions the average convergence generation of the adaptive genetic algorithm with diversity-guided mutation is about 900 less than that of adaptive genetic algorithm with adaptive probabilities and genetic algorithm with diversity-guided mutation, and the adaptive genetic algorithm with diversity-guided mutation does not lead to premature convergence. It is also shown that the better balance between overcoming premature convergence and quickening convergence speed can be gotten.

  8. Whole genome analysis of linezolid resistance in Streptococcus pneumoniae reveals resistance and compensatory mutations

    Directory of Open Access Journals (Sweden)

    Légaré Danielle

    2011-10-01

    Full Text Available Abstract Background Several mutations were present in the genome of Streptococcus pneumoniae linezolid-resistant strains but the role of several of these mutations had not been experimentally tested. To analyze the role of these mutations, we reconstituted resistance by serial whole genome transformation of a novel resistant isolate into two strains with sensitive background. We sequenced the parent mutant and two independent transformants exhibiting similar minimum inhibitory concentration to linezolid. Results Comparative genomic analyses revealed that transformants acquired G2576T transversions in every gene copy of 23S rRNA and that the number of altered copies correlated with the level of linezolid resistance and cross-resistance to florfenicol and chloramphenicol. One of the transformants also acquired a mutation present in the parent mutant leading to the overexpression of an ABC transporter (spr1021. The acquisition of these mutations conferred a fitness cost however, which was further enhanced by the acquisition of a mutation in a RNA methyltransferase implicated in resistance. Interestingly, the fitness of the transformants could be restored in part by the acquisition of altered copies of the L3 and L16 ribosomal proteins and by mutations leading to the overexpression of the spr1887 ABC transporter that were present in the original linezolid-resistant mutant. Conclusions Our results demonstrate the usefulness of whole genome approaches at detecting major determinants of resistance as well as compensatory mutations that alleviate the fitness cost associated with resistance.

  9. Specificity of mutations induced by carbon ions in budding yeast Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Matuo, Youichirou [Graduate School of Engineering, Osaka University, Yamada-oka 2-1, Suita, Osaka 565-0871 (Japan); Nishijima, Shigehiro [Graduate School of Engineering, Osaka University, Yamada-oka 2-1, Suita, Osaka 565-0871 (Japan); Hase, Yoshihiro [Radiation-Applied Biology Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), Watanuki-machi 1233, Takasaki, Gunma 370-1292 (Japan); Sakamoto, Ayako [Radiation-Applied Biology Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), Watanuki-machi 1233, Takasaki, Gunma 370-1292 (Japan); Tanaka, Atsushi [Radiation-Applied Biology Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), Watanuki-machi 1233, Takasaki, Gunma 370-1292 (Japan); Shimizu, Kikuo [Radioisotope Research Center, Osaka University, Yamada-oka 2-4, Suita, Osaka 565-0871 (Japan)]. E-mail: shimizu@rirc.osaka-u.ac.jp

    2006-12-01

    To investigate the nature of mutations induced by accelerated ions in eukaryotic cells, the effects of carbon-ion irradiation were compared with those of {gamma}-ray irradiation in the budding yeast Saccharomyces cerevisiae. The mutational effect and specificity of carbon-ion beams were studied in the URA3 gene of the yeast. Our experiments showed that the carbon ions generated more than 10 times the number of mutations induced by {gamma}-rays, and that the types of base changes induced by carbon ions include transversions (68.7%), transitions (13.7%) and deletions/insertions (17.6%). The transversions were mainly G:C {sup {yields}} T:A, and all the transitions were G:C {sup {yields}} A:T. In comparison with the surrounding sequence context of mutational base sites, the C residues in the 5'-AC(A/T)-3' sequence were found to be easily changed. Large deletions and duplications were not observed, whereas ion-induced mutations in Arabidopsis thaliana were mainly short deletions and rearrangements. The remarkable feature of yeast mutations induced by carbon ions was that the mutation sites were localized near the linker regions of nucleosomes, whereas mutations induced by {gamma}-ray irradiation were located uniformly throughout the gene.

  10. Absence of GABRA1 Ala322Asp mutation in juvenile myoclonic epilepsy families from India

    Indian Academy of Sciences (India)

    A. Kapoor; J. Vijai; H. M. Ravishankar; P. Satishchandra; K. Radhakrishnan; A. Anand

    2003-04-01

    An Ala322Asp mutation in the GABRA1 gene was recently reported to be responsible for causing the autosomal dominant (AD) form of juvenile myoclonic epilepsy (JME) in a French-Canadian family. To study if JME families from India exhibiting the AD mode of inheritance carry the Ala322Asp mutation, we examined 35 unrelated JME-affected individuals from such families for the Ala322Asp mutation in GABRA1. Ala322Asp mutation was not observed in any of these JME-affected individuals, suggesting that this mutation is unlikely to be a predominant mutation involved in causation of epilepsy. To evaluate the possibility of other mutation(s) in and around GABRA1 that may predispose to JME, we compared the allele frequencies at two marker loci, D5S2118 and D5S422, flanking GABRA1, in probands and 100 matched population controls. One of the allele frequencies at D5S422 shows a significant difference between the cases and controls (2 = 11.44, d.f. = 1, $P = 0.0007$), suggesting genetic association between JME and genes located in the proximity of the DNA marker.

  11. Empirical evaluation reveals best fit of a logistic mutation model for human Y-chromosomal microsatellites.

    Science.gov (United States)

    Jochens, Arne; Caliebe, Amke; Rösler, Uwe; Krawczak, Michael

    2011-12-01

    The rate of microsatellite mutation is dependent upon both the allele length and the repeat motif, but the exact nature of this relationship is still unknown. We analyzed data on the inheritance of human Y-chromosomal microsatellites in father-son duos, taken from 24 published reports and comprising 15,285 directly observable meioses. At the six microsatellites analyzed (DYS19, DYS389I, DYS390, DYS391, DYS392, and DYS393), a total of 162 mutations were observed. For each locus, we employed a maximum-likelihood approach to evaluate one of several single-step mutation models on the basis of the data. For five of the six loci considered, a novel logistic mutation model was found to provide the best fit according to Akaike's information criterion. This implies that the mutation probability at the loci increases (nonlinearly) with allele length at a rate that differs between upward and downward mutations. For DYS392, the best fit was provided by a linear model in which upward and downward mutation probabilities increase equally with allele length. This is the first study to empirically compare different microsatellite mutation models in a locus-specific fashion.

  12. Reliability of KRAS mutation testing in metastatic colorectal cancer patients across five laboratories

    Directory of Open Access Journals (Sweden)

    Feigelson Heather

    2012-04-01

    Full Text Available Abstract Background Mutations in the KRAS gene are associated with poor response to epidermal growth factor receptor inhibitors used in the treatment of metastatic colorectal cancer. Factors influencing KRAS test results in tumor specimens include: tumor heterogeneity, sample handling, slide preparation, techniques for tumor enrichment, DNA preparation, assay design and sensitivity. We evaluated comparability and consistency of KRAS test results among five laboratories currently being used to determine KRAS mutation status of metastatic colorectal cancer specimens in a large, multi-center observational study. Findings Twenty formalin-fixed paraffin-embedded human colorectal cancer samples from colon resections previously tested for KRAS mutations were selected based on mutation status (6 wild type, 8 codon 12 mutations, and 6 codon 13 mutations. We found good agreement across laboratories despite differences in mutation detection methods. Eighteen of twenty samples (90% were concordant across all five labs. Discordant results are likely not due to laboratory error, but instead to tumor heterogeneity, contamination of the tumor sample with normal tissue, or analytic factors affecting assay sensitivity. Conclusions Our results indicate commercial and academic laboratories provide reliable results for the common KRAS gene mutations at codons 12 and 13 when an adequate percentage of tumor cells is present in the sample.

  13. RDEL: Restart Differential Evolution algorithm with Local Search Mutation for global numerical optimization

    Directory of Open Access Journals (Sweden)

    Ali Wagdy Mohamed

    2014-11-01

    Full Text Available In this paper, a novel version of Differential Evolution (DE algorithm based on a couple of local search mutation and a restart mechanism for solving global numerical optimization problems over continuous space is presented. The proposed algorithm is named as Restart Differential Evolution algorithm with Local Search Mutation (RDEL. In RDEL, inspired by Particle Swarm Optimization (PSO, a novel local mutation rule based on the position of the best and the worst individuals among the entire population of a particular generation is introduced. The novel local mutation scheme is joined with the basic mutation rule through a linear decreasing function. The proposed local mutation scheme is proven to enhance local search tendency of the basic DE and speed up the convergence. Furthermore, a restart mechanism based on random mutation scheme and a modified Breeder Genetic Algorithm (BGA mutation scheme is combined to avoid stagnation and/or premature convergence. Additionally, an exponent increased crossover probability rule and a uniform scaling factors of DE are introduced to promote the diversity of the population and to improve the search process, respectively. The performance of RDEL is investigated and compared with basic differential evolution, and state-of-the-art parameter adaptive differential evolution variants. It is discovered that the proposed modifications significantly improve the performance of DE in terms of quality of solution, efficiency and robustness.

  14. Mutation in D-loop region of mitochondrial DNA in gastric cancer and its significance

    Institute of Scientific and Technical Information of China (English)

    Yi-Bing Zhao; Hong-Yu Yang; Xi-Wei Zhang; Guo-Yu Chen

    2005-01-01

    AIM: lo investigate the mutation in D-loop region of mitochondrial DNA in gastric cancer and its influence on the changes of reactive oxygen species (ROS) and cell cycle. METHODS: The D-loop region was amplified by PCR and sequenced. Reactive oxygen species and cell cycle were detected by flow cytometry in 20 specimens from gastriccancer and adjacent normal tissues. According to the sequence results, gastric cancer tissue was divided into mutation group and control group. Reactive oxygen species, apoptosis and proliferation in the two groups were compared.RESULTS: Among the 20 gastric cancer specimens, 18 mutations were identified in 7 patients, the mutation rate being 35%. There were four microsatellite instabilities in the mutations. No mutation was found in the adjacent tissues. Reactive oxygen species, apoptosis, and proliferation in the mutation group were all significantly higher than those in control group.CONCLUSION: Mutation in D-loop region plays a role in the genesis and development of gastric cancer.

  15. Pre-S deletion and complex mutations of hepatitis B virus related to young age hepatocellular carcinoma in Qidong, China.

    Directory of Open Access Journals (Sweden)

    Lishuai Qu

    Full Text Available BACKGROUND/AIM: To investigate the roles of biomedical factors, hepatitis B virus (HBV DNA levels, genotypes, and specific viral mutation patterns on the progression of hepatocellular carcinoma (HCC patients below 40 years of age in Qidong, China. METHODS: We conducted a case-control study within a cohort of 2387 male HBV carriers who were recruited from August, 1996. The HBV DNA sequence was determined in 49 HCC and 90 chronic hepatitis (CH patients below 40 years of age. Mutation exchanges during follow-up in 32 cases were compared with 65 controls with paired serum samples. In addition, a consecutive series of samples from 14 HCC cases were employed to compare the sequences before and after the occurrence of HCC. RESULTS: After adjustment for age, history of cigarette smoking and alcohol consumption, HBeAg positive, HBV DNA levels ≥4.00 log(10 copies/mL, pre-S deletion, T1762/A1764 double mutations, and T1766 and/or A1768 mutations were associated with risk of young age HCC. Moreover, the presence of an increasing number of HCC-related mutations (pre-S deletion, T1762/A1764, and T1766 and/or A1768 mutations was associated with an increased risk of young age HCC. Paired samples analysis indicated that the increased HCC risk for at-risk sequence mutations were attributable to the persistence of these mutations, but not a single time point mutation. The longitudinal observation demonstrated a gradual combination of pre-S deletion, T1762/A1764 double mutations, and T1766 and/or A1768 mutations during the development of HCC. CONCLUSION: High HBV DNA levels and pre-S deletion were independent risk factors of young age HCC. Combination of pre-S deletion and core promoter mutations increased the risk and persistence of at-risk sequence mutations is critical for HCC development.

  16. Additional prognostic role of EGFR activating mutations in lung adenocarcinoma patients with brain metastasis: integrating with lung specific GPA score.

    Science.gov (United States)

    Lee, Dae-Won; Shin, Dong-Yeop; Kim, Jin Wook; Keam, Bhumsuk; Kim, Tae Min; Kim, Hak Jae; Kim, Dong-Wan; Wu, Hong-Gyun; Paek, Sun Ha; Kim, Young Whan; Heo, Dae Seog; Kim, Dong Gyu; Lee, Se-Hoon

    2014-12-01

    While several prognostic models have been presented in NSCLC patients with brain metastasis, none of these models have included molecular markers as an index. The aim of our study was to evaluate the prognostic value of EGFR mutations and to integrate these EGFR mutations into the prognostic index in NSCLC patients with brain metastasis. We analyzed retrospectively 292 lung adenocarcinoma patients with brain metastasis. Clinico-pathological features and overall survival (OS) were compared between patients with EGFR mutations and patients with EGFR wild type. EGFR mutation status was integrated with lung specific graded prognostic assessment (GPA) score. Among 292 patients, EGFR mutation status was tested in 183 patients. One hundred and five patients (57.4%) had EGFR activating mutations, 14 (7.7%) had EGFR non-activating mutations and 64 (35.0%) had EGFR wild type. OS was significantly longer in patients with EGFR activating mutations than in those with EGFR wild type patients (20.4 vs. 10.1 months, p = 0.002). However, patients with EGFR non-activating mutations did not show superior OS compared with EGFR wild type patients (14.6 vs. 10.1 months, p = 0.83). Multivariate analysis revealed that the presence of EGFR activating mutation is an independent positive prognostic factor for OS (adjusted hazard ratio 0.56, p = 0.002). EGFR activating mutations have a prognostic role in lung adenocarcinoma patients with brain metastasis that is independent of other known prognostic factors. The frequency of EGFR mutation was higher than expected. The presence of EGFR activating mutations should be included as an index in the prognostic models for lung adenocarcinoma patients with brain metastasis. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  17. Methods for detection of ataxia telangiectasia mutations

    Energy Technology Data Exchange (ETDEWEB)

    Gatti, Richard A.

    2005-10-04

    The present invention is directed to a method of screening large, complex, polyexonic eukaryotic genes such as the ATM gene for mutations and polymorphisms by an improved version of single strand conformation polymorphism (SSCP) electrophoresis that allows electrophoresis of two or three amplified segments in a single lane. The present invention also is directed to new mutations and polymorphisms in the ATM gene that are useful in performing more accurate screening of human DNA samples for mutations and in distinguishing mutations from polymorphisms, thereby improving the efficiency of automated screening methods.

  18. Mutation rate analysis at 19 autosomal microsatellites.

    Science.gov (United States)

    Qian, Xiao-Qin; Yin, Cai-Yong; Ji, Qiang; Li, Kai; Fan, Han-Ting; Yu, Yan-Fang; Bu, Fan-Li; Hu, Ling-Li; Wang, Jian-Wen; Mu, Hao-Fang; Haigh, Steven; Chen, Feng

    2015-07-01

    Previous studies have demonstrated that a large sample size is needed to reliably estimate population- and locus-specific microsatellite mutation rates. Therefore, we conducted a long-term collaboration study and performed a comprehensive analysis on the mutation characteristics of 19 autosomal short tandem repeat (STR) loci. The STR loci located on 15 of 22 autosomal chromosomes were analyzed in a total of 21,106 samples (11,468 parent-child meioses) in a Chinese population. This provided 217,892 allele transfers at 19 STR loci. An overall mutation rate of 1.20 × 10(-3) (95% CI, 1.06-1.36 × 10(-3) ) was observed in the populations across 18 of 19 STR loci, except for the TH01 locus with no mutation found. Most STR mutations (97.7%) were single-step mutations, and only a few mutations (2.30%) comprised two and multiple steps. Interestingly, approximately 93% of mutation events occur in the male germline. The mutation ratios increased with the paternal age at child birth (r = 0.99, ptesting, kinship analysis, and population genetics.

  19. The mutational spectrum in Waardenburg syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Read, A.P.; Tassabehji, M.; Liu, X.Z. [and others

    1994-09-01

    101 individuals or families with Waardenburg syndrome (WS) or related abnormalities have been screened for mutations in the PAX3 gene. PAX3 mutations were seen in 19 of 35 individuals or families with features of Type I Waardenburg syndrome. None of the 47 Type 2 WS families showed any PAX3 mutation, nor did any of 19 individuals with other neural crest syndromes or pigmentary disturbances. PAX3 mutations included substitutions of highly conserved amino acids, splice site mutations, nonsense mutations and frameshifting deletions or insertions. One patient (with Type 1 WS, mental retardation and growth retardation) had a chromosomal deletion of 7-8 Mb encompassing the PAX3 gene. Mutations were seen in each of exons 2-6, with a concentration in the 5{prime} part of the paired box (exon 2) and the 3{prime} part of the homeobox (exon 6). There was no evident relation between the molecular change and the clinical manifestations in mutation carriers. We conclude that PAX3 dosage effects very specifically produce dystopia canthorum, the distinguishing feature of Type 1 WS, and variably produce the other features of Type 1 WS depending on genetic background or chance events. Two of the Type 2 families showed linkage to markers from 3p14, the location of the MITF gene. MITF encodes a basic helix-loop-helix-zipper protein which is the homologue of the mouse microphthalmia gene product. It is likely that mutations in MITF cause some but not all Type 2 WS.

  20. Strong effects of ionizing radiation from Chernobyl on mutation rates

    Science.gov (United States)

    Møller, Anders Pape; Mousseau, Timothy A.

    2015-02-01

    In this paper we use a meta-analysis to examine the relationship between radiation and mutation rates in Chernobyl across 45 published studies, covering 30 species. Overall effect size of radiation on mutation rates estimated as Pearson's product-moment correlation coefficient was very large (E = 0.67; 95% confidence intervals (CI) 0.59 to 0.73), accounting for 44.3% of the total variance in an unstructured random-effects model. Fail-safe calculations reflecting the number of unpublished null results needed to eliminate this average effect size showed the extreme robustness of this finding (Rosenberg's method: 4135 at p = 0.05). Indirect tests did not provide any evidence of publication bias. The effect of radiation on mutations varied among taxa, with plants showing a larger effect than animals. Humans were shown to have intermediate sensitivity of mutations to radiation compared to other species. Effect size did not decrease over time, providing no evidence for an improvement in environmental conditions. The surprisingly high mean effect size suggests a strong impact of radioactive contamination on individual fitness in current and future generations, with potentially significant population-level consequences, even beyond the area contaminated with radioactive material.

  1. Nasal Potential Difference in Cystic Fibrosis considering Severe CFTR Mutations

    Directory of Open Access Journals (Sweden)

    Ronny Tah Yen Ng

    2015-01-01

    Full Text Available The gold standard for diagnosing cystic fibrosis (CF is a sweat chloride value above 60 mEq/L. However, this historical and important tool has limitations; other techniques should be studied, including the nasal potential difference (NPD test. CFTR gene sequencing can identify CFTR mutations, but this method is time-consuming and too expensive to be used in all CF centers. The present study compared CF patients with two classes I-III CFTR mutations (10 patients (G1, CF patients with classes IV-VI CFTR mutations (five patients (G2, and 21 healthy subjects (G3. The CF patients and healthy subjects also underwent the NPD test. A statistical analysis was performed using the Mann-Whitney, Kruskal-Wallis, χ2, and Fisher’s exact tests, α=0.05. No differences were observed between the CF patients and healthy controls for the PDMax, Δamiloride, and Δchloride + free + amiloride markers from the NPD test. For the finger value, a difference between G2 and G3 was described. The Wilschanski index values were different between G1 and G3. In conclusion, our data showed that NPD is useful for CF diagnosis when classes I-III CFTR mutations are screened. However, if classes IV-VI are considered, the NPD test showed an overlap in values with healthy subjects.

  2. Sequence analysis of mutations and translocations across breast cancer subtypes

    Science.gov (United States)

    Banerji, Shantanu; Cibulskis, Kristian; Rangel-Escareno, Claudia; Brown, Kristin K.; Carter, Scott L.; Frederick, Abbie M.; Lawrence, Michael S.; Sivachenko, Andrey Y.; Sougnez, Carrie; Zou, Lihua; Cortes, Maria L.; Fernandez-Lopez, Juan C.; Peng, Shouyong; Ardlie, Kristin G.; Auclair, Daniel; Bautista-Piña, Veronica; Duke, Fujiko; Francis, Joshua; Jung, Joonil; Maffuz-Aziz, Antonio; Onofrio, Robert C.; Parkin, Melissa; Pho, Nam H.; Quintanar-Jurado, Valeria; Ramos, Alex H.; Rebollar-Vega, Rosa; Rodriguez-Cuevas, Sergio; Romero-Cordoba, Sandra L.; Schumacher, Steven E.; Stransky, Nicolas; Thompson, Kristin M.; Uribe-Figueroa, Laura; Baselga, Jose; Beroukhim, Rameen; Polyak, Kornelia; Sgroi, Dennis C.; Richardson, Andrea L.; Jimenez-Sanchez, Gerardo; Lander, Eric S.; Gabriel, Stacey B.; Garraway, Levi A.; Golub, Todd R.; Melendez-Zajgla, Jorge; Toker, Alex; Getz, Gad; Hidalgo-Miranda, Alfredo; Meyerson, Matthew

    2014-01-01

    Breast carcinoma is the leading cause of cancer-related mortality in women worldwide with an estimated 1.38 million new cases and 458,000 deaths in 2008 alone1. This malignancy represents a heterogeneous group of tumours with characteristic molecular features, prognosis, and responses to available therapy2–4. Recurrent somatic alterations in breast cancer have been described including mutations and copy number alterations, notably ERBB2 amplifications, the first successful therapy target defined by a genomic aberration5. Prior DNA sequencing studies of breast cancer genomes have revealed additional candidate mutations and gene rearrangements 6–10. Here we report the whole-exome sequences of DNA from 103 human breast cancers of diverse subtypes from patients in Mexico and Vietnam compared to matched-normal DNA, together with whole-genome sequences of 22 breast cancer/normal pairs. Beyond confirming recurrent somatic mutations in PIK3CA11, TP536, AKT112, GATA313, and MAP3K110, we discovered recurrent mutations in the CBFB transcription factor gene and deletions of its partner RUNX1. Furthermore, we have identified a recurrent MAGI3-AKT3 fusion enriched in triple-negative breast cancer lacking estrogen and progesterone receptors and ERBB2 expression. The Magi3-Akt3 fusion leads to constitutive activation of Akt kinase, which is abolished by treatment with an ATP-competitive Akt small-molecule inhibitor. PMID:22722202

  3. WRN mutations in Werner syndrome patients: genomic rearrangements, unusual intronic mutations and ethnic-specific alterations.

    Science.gov (United States)

    Friedrich, Katrin; Lee, Lin; Leistritz, Dru F; Nürnberg, Gudrun; Saha, Bidisha; Hisama, Fuki M; Eyman, Daniel K; Lessel, Davor; Nürnberg, Peter; Li, Chumei; Garcia-F-Villalta, María J; Kets, Carolien M; Schmidtke, Joerg; Cruz, Vítor Tedim; Van den Akker, Peter C; Boak, Joseph; Peter, Dincy; Compoginis, Goli; Cefle, Kivanc; Ozturk, Sukru; López, Norberto; Wessel, Theda; Poot, Martin; Ippel, P F; Groff-Kellermann, Birgit; Hoehn, Holger; Martin, George M; Kubisch, Christian; Oshima, Junko

    2010-07-01

    Werner syndrome (WS) is an autosomal recessive segmental progeroid syndrome caused by null mutations at the WRN locus, which codes for a member of the RecQ family of DNA helicases. Since 1988, the International Registry of Werner syndrome had enrolled 130 molecularly confirmed WS cases from among 110 worldwide pedigrees. We now report 18 new mutations, including two genomic rearrangements, a deep intronic mutation resulting in a novel exon, a splice consensus mutation leading to utilization of the nearby splice site, and two rare missense mutations. We also review evidence for founder mutations among various ethnic/geographic groups. Founder WRN mutations had been previously reported in Japan and Northern Sardinia. Our Registry now suggests characteristic mutations originated in Morocco, Turkey, The Netherlands and elsewhere.

  4. Comparative hemorheology

    OpenAIRE

    Başkurt, Oğuz K.; Meiselman, Herbert J.

    2013-01-01

    Comparative data on blood composition and blood flow properties indicate different levels of interspecies variation for several parameters. Hematocrit and hemoglobin levels have relatively low variability among mammals, while mean cell volume and red blood cell (RBC) count are more variable. There is also a difference of variability between high and low shear rate blood viscosity in mammals, with low shear rate viscosity having a higher degree of interspecies variation. This observation paral...

  5. 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

  6. Mutational Signatures Are Critical for Proper Estimation of Purifying Selection Pressures in Cancer Somatic Mutation Data When Using the dN/dS Metric.

    Science.gov (United States)

    Van den Eynden, Jimmy; Larsson, Erik

    2017-01-01

    Large cancer genome sequencing initiatives have led to the identification of cancer driver genes based on signals of positive selection in somatic mutation data. Additionally, the identification of purifying (negative) selection has the potential to identify essential genes that may be of therapeutic interest. The most widely used way of quantifying selection pressures in protein-coding genes is the dN/dS metric, which compares non-synonymous to synonymous substitution rates. In this study, we examine whether and how this metric is influenced by the mutational processes that have been active during tumor evolution. We use exome sequencing data from six different cancer types from The Cancer Genome Atlas (TCGA) and demonstrate that dN/dS in its basic form, where uniform base substitution probabilities are assumed, is in fact strongly biased by these mutational processes. This is particularly true in malignant melanoma, where the mutational signature is characterized by a high amount of UV-induced cytosine to thymine mutations at dipyrimidine dinucleotides. This increases the likelihood of random synonymous mutations occurring in hydrophobic amino acid codons, leading to reduced dN/dS ratios in genes encoding membrane proteins and falsely suggesting purifying selection in these genes. When this effect is corrected for by taking mutational signature-derived substitution probabilities into account, purifying selection was found to be limited and similar in all cancer types studied. Our results demonstrate that it is crucial to take mutational signatures into account when applying the dN/dS metric to cancer somatic mutation data.

  7. A frequent splicing mutation and novel missense mutations color the updated mutational spectrum of classic galactosemia in Portugal.

    Science.gov (United States)

    Coelho, Ana I; Ramos, Ruben; Gaspar, Ana; Costa, Cláudia; Oliveira, Anabela; Diogo, Luísa; Garcia, Paula; Paiva, Sandra; Martins, Esmeralda; Teles, Elisa Leão; Rodrigues, Esmeralda; Cardoso, M Teresa; Ferreira, Elena; Sequeira, Sílvia; Leite, Margarida; Silva, Maria João; de Almeida, Isabel Tavares; Vicente, João B; Rivera, Isabel

    2014-01-01

    Classic galactosemia is an autosomal recessive disorder caused by deficient galactose-1-phosphate uridylyltransferase (GALT) activity. Patients develop symptoms in the neonatal period, which can be ameliorated by dietary restriction of galactose. Many patients develop long-term complications, with a broad range of clinical symptoms whose pathophysiology is poorly understood. The high allelic heterogeneity of GALT gene that characterizes this disorder is thought to play a determinant role in biochemical and clinical phenotypes. We aimed to characterize the mutational spectrum of GALT deficiency in Portugal and to assess potential genotype-phenotype correlations. Direct sequencing of the GALT gene and in silico analyses were employed to evaluate the impact of uncharacterized mutations upon GALT functionality. Molecular characterization of 42 galactosemic Portuguese patients revealed a mutational spectrum comprising 14 nucleotide substitutions: ten missense, two nonsense and two putative splicing mutations. Sixteen different genotypic combinations were detected, half of the patients being p.Q188R homozygotes. Notably, the second most frequent variation is a splicing mutation. In silico predictions complemented by a close-up on the mutations in the protein structure suggest that uncharacterized missense mutations have cumulative point effects on protein stability, oligomeric state, or substrate binding. One splicing mutation is predicted to cause an alternative splicing event. This study reinforces the difficulty in establishing a genotype-phenotype correlation in classic galactosemia, a monogenic disease whose complex pathogenesis and clinical features emphasize the need to expand the knowledge on this "cloudy" disorder.

  8. Screening PCR Versus Sanger Sequencing: Detection of CALR Mutations in Patients With Thrombocytosis.

    Science.gov (United States)

    Jeong, Ji Hun; Lee, Hwan Tae; Seo, Ja Young; Seo, Yiel Hea; Kim, Kyung Hee; Kim, Moon Jin; Lee, Jae Hoon; Park, Jinny; Hong, Jun Shik; Park, Pil Whan; Ahn, Jeong Yeal

    2016-07-01

    Mutations in calreticulin (CALR) have been reported to be key markers in the molecular diagnosis of myeloid proliferative neoplasms. In most previous reports, CALR mutations were analyzed by using Sanger sequencing. Here, we report a new, rapid, and convenient system for screening CALR mutations without sequencing. Eighty-three bone marrow samples were obtained from 81 patients with thrombocytosis. PCR primers were designed to detect wild-type CALR (product: 357 bp) and CALR with type 1 (product: 302 bp) and type 2 mutations (product: 272 bp) in one reaction. The results were confirmed by Sanger sequencing and compared with results from fragment analysis. The minimum detection limit of the screening PCR was 10 ng for type 1, 1 ng for type 2, and 0.1 ng for cases with both mutations. CALR type 1 and type 2 mutants were detected with screening PCR with a maximal analytical sensitivity of 3.2% and <0.8%, respectively. The screening PCR detected 94.1% (16/17) of mutation cases and showed concordant results with sequencing in the cases of type 1 and type 2 mutations. Sanger sequencing identified one novel mutation (c.1123_1132delinsTGC). Compared with sequencing, the screening PCR showed 94.1% sensitivity, 100.0% specificity, 100.0% positive predictive value, and 98.5% negative predictive value. Compared with fragment analysis, the screening PCR presented 88.9% sensitivity and 100.0% specificity. This screening PCR is a rapid, sensitive, and cost-effective method for the detection of major CALR mutations.

  9. Mutation specific functions of EGFR result in a mutation-specific downstream pathway activation

    NARCIS (Netherlands)

    L. Eraslan-Erdem (Lale); Y. Gao; N.K. Kloosterhof (Nanne); Y. Atlasi (Yaser); J.A.A. Demmers (Jeroen); A. Sacchetti (Andrea); J.M. Kros (Johan); P.A.E. Sillevis Smitt (Peter); J.G.J.V. Aerts (Joachim); P.J. French (Pim)

    2015-01-01

    markdownabstractBackground: Epidermal growth factor receptor (EGFR) is frequently mutated in various types of cancer. Although all oncogenic mutations are considered activating, different tumour types have different mutation spectra. It is possible that functional differences underlie this tumour-ty

  10. Parental source effect of inherited mutations in the dystrophin gene of mice and men

    Energy Technology Data Exchange (ETDEWEB)

    Kress, W.; Grimm, T.; Mueller, C.R. [Institute of Human Genetics, Wuerburg (Germany); Bittner, R. [Institute of Anatomy, Wein (Australia)

    1994-09-01

    Skewed X-inactivation has been suspected the genetic cause for some manifesting female carriers of BMD and DMD. To test whether a parental source effect on the protein expression of the dystrophin gene exists, we have set up backcrosses of mdx mice to wild type strains, enabling us to study the effect of the well-defined origin of the mutation on the dystrophin expression. In skeletal muscle sections the immunohistological staining patterns of dystrophin antibodies were showing a significant difference in the proportion of dystrophin positive versus negative fibers, suggesting a lower expression of paternally inherited mdx mutations. These data are in concordance with the pyruvate kinase (PK) levels in the serum: PK levels were much higher when the mutation was of maternal origin as compared to PK levels in paternally derived mutations. In order to test this {open_quotes}paternal source effect{close_quotes} in humans, we checked obligatory carriers of Becker muscular dystrophy (BMD) for the origin of their mutations. Creatin kinase (CK) levels in 21 carriers with maternally derived mutations were compared to CK values from 8 heterozygotes with mutations of paternal origin: CK (mat) = 140.3 IU/1 versus CK (pat) = 48.6 IU/I. The difference is statistically significant at the 5% level. These observations suggest either a differential X-inactivation or an imprinting of the dystrophin gene in mice and men.

  11. Mutation screening of mismatch repair gene Mlh3 in familial esophageal cancer

    Institute of Scientific and Technical Information of China (English)

    Hong-Xu Liu; Yu Li; Xue-Dong Jiang; Hong-Nian Yin; Lin Zhang; Yu Wang; Jun Yang

    2006-01-01

    AIM: To shed light on the possible role of mismatch repair gene Mlh3 in familial esophageal cancer (FEC).METHODS: A total of 66 members from 10 families suggestive of a genetic predisposition to hereditary esophageal cancer were screened for germline mutations in Mlh3 with denaturing high performance liquid chromatography (DHPLC), a newly developed method of comparative sequencing based on heteroduplex detection. For all samples exhibiting abnormal DHPLC profiles,sequence changes were evaluated by cycle sequencing.For any mutation in family members, we conducted a segregation study to compare its prevalence in sporadic esophageal cancer patients and normal controls.RESULTS: Exons of Mlh3 in all samples were successfully examined. Overall, 4 missense mutations and 3 polymorphisms were identified in 4 families. Mlh3 missense mutations in families 9 and 10 might be pathogenic, but had a reduced penetrance. While in families 1 and 7,there was no sufficient evidence supporting the monogenic explanations of esophageal cancers in families.The mutations were found in 33% of high-risk families and 50% of low-risk families.CONCLUSION: Mlh3 is a high risk gene with a reduced penetrance in some families. However, it acts as a low risk gene for esophageal cancer in most families. Mutations of Mlh3 may work together with other genes in an accumulated manner and result in an increased risk of esophageal tumor. DHPLC is a robust and sensitive technique for screening gene mutations.

  12. Cartilage hair hypoplasia mutations that lead to RMRP promoter inefficiency or RNA transcript instability.

    Science.gov (United States)

    Nakashima, Eiji; Tran, Joseph R; Welting, Tim J M; Pruijn, Ger J M; Hirose, Yuichiro; Nishimura, Gen; Ohashi, Hirofumi; Schurman, Shepherd H; Cheng, Jun; Candotti, Fabio; Nagaraja, Ramaiah; Ikegawa, Shiro; Schlessinger, David

    2007-11-15

    Cartilage hair hypoplasia (CHH; MIM 250250) is an autosomal recessive disease with diverse clinical manifestations. It is caused by mutations in RMRP gene, the RNA component of the ribonucleoprotein complex RNase MRP. Mutations in RMRP have been found in patients in the core promoter region or in the transcribed region, but the pathogenetic effect of the mutations is unclear. Real-time PCR assays confirmed that both promoter (c.-16_-1 dup and c.-15_+2 dup) and transcribed mutations (c.168G > A and c.218A > G) lower the expression level of RMRP. Experiments with 5'RACE, showed that the reduced transcription in the promoter mutants was accompanied by shifting of the transcription initiation sites to nucleotides 5'-upstream of the authentic site. Low levels of RMRP expression levels with transcript mutations were also seen when constructs encoding the wild-type and mutant genes were transfected into cultured cells. The reduced transcription was correlated with greater instability of mutant RMRP transcripts compared to controls. A comparable reduction was seen when a mouse gene containing the c.70A > G mutation (the major mutation in humans with CHH) was introduced into ES cells in place of one of the wild-type alleles. The low expression level of the c.70A > G Rmrp RNA was confirmed by expression assays into cultured cells, and was again correlated with RNA instability. Our results indicate that a loss of mutant RNA transcripts is a critical feature of pathogenesis. (c) 2007 Wiley-Liss, Inc.

  13. TERT promoter mutations in thyroid cancer.

    Science.gov (United States)

    Liu, Rengyun; Xing, Mingzhao

    2016-03-01

    The 2013 discovery of Telomerase reverse transcriptase (TERT) promoter mutations chr5, 1,295,228 C>T (C228T) and 1,295,250 C>T (C250T) in thyroid cancer represents an important event in the thyroid cancer field and much progress has occurred since then. This article provides a comprehensive review of this exciting new thyroid cancer field. The oncogenic role of TERT promoter mutations involves their creation of consensus binding sites for E-twenty-six transcriptional factors. TERT C228T is far more common than TERT C250T and their collective prevalence is, on average, 0, 11.3, 17.1, 43.2 and 40.1% in benign thyroid tumors, papillary thyroid cancer (PTC), follicular thyroid cancer, poorly differentiated thyroid cancer and anaplastic thyroid cancer, respectively, displaying an association with aggressive types of thyroid cancer. TERT promoter mutations are associated with aggressive thyroid tumor characteristics, tumor recurrence and patient mortality as well as BRAF V600E mutation. Coexisting BRAF V600E and TERT promoter mutations have a robust synergistic impact on the aggressiveness of PTC, including a sharply increased tumor recurrence and patient mortality, while either mutation alone has a modest impact. Thus, TERT with promoter mutations represents a prominent new oncogene in thyroid cancer and the mutations are promising new diagnostic and prognostic genetic markers for thyroid cancer, which, in combination with BRAF V600E mutation or other genetic markers (e.g. RAS mutations), are proving to be clinically useful for the management of thyroid cancer. Future studies will specifically define such clinical utilities, elucidate the biological mechanisms and explore the potential as therapeutic targets of TERT promoter mutations in thyroid cancer.

  14. A new monoclonal antibody (CAL2) detects CALRETICULIN mutations in formalin-fixed and paraffin-embedded bone marrow biopsies.

    Science.gov (United States)

    Stein, H; Bob, R; Dürkop, H; Erck, C; Kämpfe, D; Kvasnicka, H-M; Martens, H; Roth, A; Streubel, A

    2016-01-01

    Recent advances in the diagnostic of myeloproliferative neoplasms (MPNs) discovered CALRETICULIN (CALR) mutations as a major driver in these disorders. In contrast to JAK2 mutations being mainly associated with polycythaemia vera, CALR mutations are only associated with primary myelofibrosis (PMF) and essential thrombocythaemia (ET). CALR mutations are present in the majority of PMF and ET patients lacking JAK2 and MPL mutations. As these CALR mutations are absent from reactive bone marrow (BM) lesions their presence indicates ET or PMF. So far these mutations are detectable only by molecular assays. Their molecular detection is cumbersome because of the great CALR mutation heterogeneity. Therefore, the availability of a simple assay would be of great help. All CALR mutations reported lead to a frameshift generating a new 36 amino-acid C-terminus. We generated a monoclonal antibody (CAL2) to this C-neoterminus by immunizing mice with a representative peptide and compared its performance with Sanger sequencing data in 173 MPNs and other BM diseases. There was a 100% correlation between the molecular and the CAL2 immunohistochemical (IHC) assays. Thus, the detection of CALR mutations by the CAL2 IHC is a specific, sensitive, rapid, simple and low-cost method.

  15. Epistasis as a determinant of the HIV-1 protease's robustness to mutation.

    Directory of Open Access Journals (Sweden)

    Elena Capel

    Full Text Available The robustness of phenotypes to mutation is critical to protein evolution; robustness may be an adaptive trait if it promotes evolution. We hypothesised that native proteins subjected to natural selection in vivo should be more robust than proteins generated in vitro in the absence of natural selection. We compared the mutational robustness of two human immunodeficiency virus type 1 (HIV-1 proteases with comparable catalytic efficiencies, one isolated from an infected individual and the second generated in vitro via random mutagenesis. Single mutations in the protease (82 and 60 in the wild-type and mutant backgrounds, respectively were randomly generated in vitro and the catalytic efficiency of each mutant was determined. No differences were observed between these two protease variants when lethal, neutral, and deleterious mutations were compared (P = 0.8025, chi-squared test. Similarly, average catalytic efficiency (-72.6% and -64.5%, respectively did not significantly differ between protease mutant libraries (P = 0.3414, Mann Whitney test. Overall, the two parental proteins displayed similar mutational robustness. Importantly, strong and widespread epistatic interactions were observed when the effect of the same mutation was compared in both proteases, suggesting that epistasis can be a key determinant of the robustness displayed by the in vitro generated protease.

  16. Muscle imaging in patients with tubular aggregate myopathy caused by mutations in STIM1

    DEFF Research Database (Denmark)

    Tasca, Giorgio; D'Amico, Adele; Monforte, Mauro;

    2015-01-01

    involvement in this disease, upper and lower girdles and lower limbs were imaged in five patients with mutations in STIM1, and the scans were compared with two patients with tubular aggregate myopathy not caused by mutations in STIM1. A common pattern of involvement was found in STIM1-mutated patients......, although with variable extent and severity of lesions. In the upper girdle, the subscapularis muscle was invariably affected. In the lower limbs, all the patients showed a consistent involvement of the flexor hallucis longus, which is very rarely affected in other muscle diseases, and a diffuse involvement...

  17. Studies on induction of chlorophyll mutations in soybean, Glycine max (L.) Merrill

    Institute of Scientific and Technical Information of China (English)

    Mudasir Hafiz KHAN; Sunil Dutt TYAGI

    2009-01-01

    The phenotypic response of two soybean cultivars to a chemical mutagen (ethyl methane sulphonate, EMS), physical mutagen (gamma rays) and their combinations were studied in M1 and M2 generations and the frequency and spectrum of chlorophyll mutations were worked out. Combined treatment was found to be more effective in inducing chlorophyll mutations compared to individual treatments of gamma rays and EMS in both the cultivars. As far as the spectrum of chlorophyll mutations is concerned, a wider spectrum in both the cultivars was observed in 45 kR + 0.2% EMS combined treatment.

  18. KRAS-mutated plasma DNA as predictor of outcome from irinotecan monotherapy in metastatic colorectal cancer

    DEFF Research Database (Denmark)

    Spindler, K G; Appelt, A L; Pallisgaard, N

    2013-01-01

    Background:We investigated the clinical implications of KRAS and BRAF mutations detected in both archival tumor tissue and plasma cell-free DNA in metastatic colorectal cancer patients treated with irinotecan monotherapy.Methods:Two hundred and eleven patients receiving second-line irinotecan (350...... with mutations detectable in plasma responded to therapy. Response rate and disease control rate in plasma KRAS wt patients were 19 and 66% compared with 0 and 37%, in patients with pKRAS mutations, (P=0.04 and 0.01). Tumor KRAS status was not associated with PFS but with OS in the validation cohort. Plasma BRAF...

  19. Adhesion of Escherichia coli under flow conditions reveals potential novel effects of FimH mutations

    DEFF Research Database (Denmark)

    Feenstra, T.; Schmidt Thøgersen, Mariane; Wieser, E.

    2017-01-01

    H mutations on bacterial adhesion using a novel adhesion assay, which models the physiological flow conditions bacteria are exposed to. We introduced 12 different point mutations in the mannose binding pocket of FimH in an E. coli strain expressing type 1 fimbriae only (MSC95-FimH). We compared the bacterial...... mutations abrogated adhesion. We demonstrated that FimH residues E50 and T53 are crucial for adhesion under flow conditions. The coating of endothelial cells on biochips and modelling of physiological flow conditions enabled us to identify FimH residues crucial for adhesion. These results provide novel...

  20. CYP1B1 Mutations in Individuals With Primary Congenital Glaucoma and Residing in Denmark

    DEFF Research Database (Denmark)

    Grønskov, Karen; Redó-Riveiro, Alba; Sandfeld, Lisbeth;

    2016-01-01

    Primary congenital glaucoma (PCG OMIM 231300) can be caused by pathogenic sequence variations in cytochrome P450, subfamily 1, polypeptide 1 (CYP1B1). The purpose of this study was to investigate the contribution of sequence variations in CYP1B1 in a cohort of individuals with PCG residing...... mutations, 5 of which were novel. The frequency of CYP1B1 mutations in this cohort was comparable with other populations. We also detected an individual heterozygous for p.(Tyr81Asn) mutation, previously suggested to cause autosomal dominant primary open-angle glaucoma....

  1. Polysaccharide storage myopathy phenotype in quarter horse-related breeds is modified by the presence of an RYR1 mutation.

    Science.gov (United States)

    McCue, M E; Valberg, S J; Jackson, M; Borgia, L; Lucio, M; Mickelson, J R

    2009-01-01

    In this study we examined a family of Quarter Horses with Polysaccharide Storage Myopathy (PSSM) with a dominant mutation in the skeletal muscle glycogen synthase (GYS1) gene. A subset of horses within this family had a more severe and occasionally fatal PSSM phenotype. The purpose of this study was to identify a modifying gene(s) for the severe clinical phenotype. A genetic association analysis was used to identify RYR1 as a candidate modifying gene. A rare, known equine RYR1 mutation, associated with malignant hyperthermia (MH), was found to segregate in this GYS1 PSSM family. Retrospective analysis of patient records (n=179) demonstrated that horses with both the GYS1 and RYR1 mutations had a more severe clinical phenotype than horses with the GYS1 mutation alone. A treadmill trial (n=8) showed that serum creatine kinase activity was higher and exercise intolerance greater in horses with both mutations compared to the GYS1 mutation alone.

  2. CALR exon 9 mutations are somatically acquired events in familial cases of essential thrombocythemia or primary myelofibrosis.

    Science.gov (United States)

    Rumi, Elisa; Harutyunyan, Ashot S; Pietra, Daniela; Milosevic, Jelena D; Casetti, Ilaria C; Bellini, Marta; Them, Nicole C C; Cavalloni, Chiara; Ferretti, Virginia V; Milanesi, Chiara; Berg, Tiina; Sant'Antonio, Emanuela; Boveri, Emanuela; Pascutto, Cristiana; Astori, Cesare; Kralovics, Robert; Cazzola, Mario

    2014-04-10

    Somatic mutations in the calreticulin (CALR) gene were recently discovered in patients with sporadic essential thrombocythemia (ET) and primary myelofibrosis (PMF) lacking JAK2 and MPL mutations. We studied CALR mutation status in familial cases of myeloproliferative neoplasm. In a cohort of 127 patients, CALR indels were identified in 6 of 55 (11%) subjects with ET and in 6 of 20 (30%) with PMF, whereas 52 cases of polycythemia vera had nonmutated CALR. All CALR mutations were somatic, found in granulocytes but not in T lymphocytes. Patients with CALR-mutated ET showed a higher platelet count (P = .017) and a lower cumulative incidence of thrombosis (P = .036) and of disease progression (P = .047) compared with those with JAK2 (V617F). In conclusion, a significant proportion of familial ET and PMF nonmutated for JAK2 carry a somatic mutation of CALR.

  3. Transforming activity of the c-Ha-ras oncogene having two point mutations in codons 12 and 61.

    Science.gov (United States)

    Sekiya, T; Prassolov, V S; Fushimi, M; Nishimura, S

    1985-09-01

    A recombinant plasmid carrying the human c-Ha-ras gene with two point mutations in codons 12 and 61 was constructed and its transforming activity on mouse NIH 3T3 cells was compared with those of genes with a single mutation in either codon 12 or 61. Quantitative analyses revealed that the gene with two mutations had essentially the same transforming activity as the genes with single mutations. These results indicate that a single mutation of the c-Ha-ras gene in either codon 12 or 61 is sufficient to activate the gene and that neither of the two mutation sites involved in activation of the gene needs to be intact for transforming activity.

  4. Finite mutation classes of coloured quivers

    CERN Document Server

    Torkildsen, Hermund André

    2010-01-01

    We consider the general notion of coloured quiver mutation and show that the mutation class of a coloured quiver $Q$, arising from an $m$-cluster tilting object associated with $H$, is finite if and only if $H$ is of finite or tame representation type, or it has at most 2 simples. This generalizes a result known for 1-cluster categories.

  5. Silting mutation for self-injective algebras

    CERN Document Server

    Aihara, Takuma

    2010-01-01

    We study `silting mutaion' for self-injective algebras. In particular we focus on `tilting mutation' and show that iterated irreducible `silting mutation' transitively act on the set of silting objects for representation-finite symmetric algebras. Moreover we give some sufficient conditions for `Bongartz-type Lemma' on silting objects.

  6. MT-CYB mutations in hypertrophic cardiomyopathy

    DEFF Research Database (Denmark)

    Hagen, Christian M; Aidt, Frederik H; Havndrup, Ole

    2013-01-01

    Mitochondrial dysfunction is a characteristic of heart failure. Mutations in mitochondrial DNA, particularly in MT-CYB coding for cytochrome B in complex III (CIII), have been associated with isolated hypertrophic cardiomyopathy (HCM). We hypothesized that MT-CYB mutations might play an important...

  7. Inverse PCR for Point Mutation Introduction.

    Science.gov (United States)

    Silva, Diogo; Santos, Gustavo; Barroca, Mário; Collins, Tony

    2017-01-01

    Inverse PCR is a powerful tool for the rapid introduction of desired mutations at desired positions in a circular double-stranded DNA sequence. Here, custom-designed mutant primers oriented in the inverse direction are used to amplify the entire circular template with incorporation of the required mutation(s). By careful primer design it can be used to perform such diverse modifications as the introduction of point mutations and multiple mutations, the insertion of new sequences, and even sequence deletions. Three primer formats are commonly used; nonoverlapping, partially overlapping and fully overlapping primers, and here we describe the use of nonoverlapping primers for introduction of a point mutation. Use of such a primer setup in the PCR reaction, with one of the primers containing the desired mismatch mutation, results in the amplification of a linear, double-stranded, mutated product. Methylated template DNA is removed from the nonmethylated PCR product by DpnI digestion and the PCR product is then phosphorylated by polynucleotide kinase treatment before being recircularized by ligation, and transformed to E. coli. This relatively simple site-directed mutagenesis procedure is of major importance in biology and biotechnology today where it is commonly employed for the study and engineering of DNA, RNA, and proteins.

  8. KRAS and BRAF mutations in anal carcinoma

    DEFF Research Database (Denmark)

    Serup-Hansen, Eva; Linnemann, Dorte; Høgdall, Estrid

    2015-01-01

    the frequency and the prognostic value of KRAS and BRAF mutations in a large cohort of patients with anal cancer. One hundred and ninety-three patients with T1-4N0-3M0-1 anal carcinoma were included in the study. Patients were treated with curative (92%) or palliative intent (8%) between January 2000...... and January 2010. KRAS mutations were detected using Therascreen(®)KRAS real-time PCR assay (Qiagen) and V600E or V600D/K BRAF mutations were uncovered using Pyrosequencing. The frequency of KRAS and BRAF mutations was low; KRAS mutations were detected in 1.6% and BRAF mutations in 4.7% of the biopsies....... No impact of KRAS or BRAF status on survival was found. In conclusion, both KRAS and BRAF mutations are rare in anal cancer. The low frequency of KRAS mutations support protocols exploring EGFR-targeted therapy in patients with metastatic anal cancer, while treatment with BRAF inhibitors might be relevant...

  9. KRAS mutation testing in metastatic colorectal cancer

    Institute of Scientific and Technical Information of China (English)

    Cong Tan; Xiang Du

    2012-01-01

    The KRAS oncogene is mutated in approximately 35%-45% of colorectal cancers,and KRAS mutational status testing has been highlighted in recent years.The most frequent mutations in this gene,point substitutions in codons 12 and 13,were validated as negative predictors of response to anti-epidermal growth factor receptor antibodies.Therefore,determining the KRAS mutational status of tumor samples has become an essential tool for managing patients with colorectal cancers.Currently,a variety of detection methods have been established to analyze the mutation status in the key regions of the KRAS gene; however,several challenges remain related to standardized and uniform testing,including the selection of tumor samples,tumor sample processing and optimal testing methods.Moreover,new testing strategies,in combination with the mutation analysis of BRAF,PIK3CA and loss of PTEN proposed by many researchers and pathologists,should be promoted.In addition,we recommend that microsatellite instability,a prognostic factor,be added to the abovementioned concomitant analysis.This review provides an overview of KRAS biology and the recent advances in KRAS mutation testing.This review also addresses other aspects of status testing for determining the appropriate treatment and offers insight into the potential drawbacks of mutational testing.

  10. Mutational analysis of TARDBP in Parkinson's disease

    NARCIS (Netherlands)

    Blitterswijk, M. van; Es, M.A. van; Verbaan, D.; Hilten, J.J. van; Scheffer, H.; Warrenburg, B.P.C. van de; Veldink, J.H.; Berg, L.H. van den

    2013-01-01

    Mutations in TAR DNA-binding protein (TARDBP) are associated with heterogenic phenotypes, including amyotrophic lateral sclerosis, frontotemporal dementia, and Parkinson's disease. In this study, we investigated the presence of TARDBP mutations in a cohort of 429 Dutch patients with Parkinson's dise

  11. Abetalipoproteinemia: A novel mutation of microsomal triglyceride ...

    African Journals Online (AJOL)

    Hager Barakizou

    2016-01-25

    Jan 25, 2016 ... molecular genetics in a Tunisian child having a novel mutation of MTP gene. 2. ... ABL is caused by MTP gene frameshift, non-sense and splice site mutations which ... and its variations could be associated with central obesity, ele- vated liver enzymes, and alcoholic fatty liver disease [5]. It has recently been ...

  12. Analyzing effects of naturally occurring missense mutations.

    Science.gov (United States)</