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Sample records for c677t del gen

  1. Trombosis venosa portal y mesentérica asociadas a hiperhomocisteinemia y anemia perniciosa en un paciente heterocigoto para la mutación C677T del gen de la MTHFR

    National Research Council Canada - National Science Library

    Fernández-Ruiz, Mario; Alonso-Navas, Félix; Muro, Eva; Pérez-Carreras, Mercedes

    2011-01-01

    ... del gen del factor ii , mutación V617F del gen JAK2 , síndrome antifosfolipídico o deficiencia de proteínas C y S 1–4 . La hiperhomocisteinemia, a través de un mecanismo de lesión y disfunc...

  2. Repercusión de los fármacos antiepilépticos en la edad pediátrica sobre los niveles plasmáticos de homocisteína, ácido fólico y vitamina B12 y su relación con la mutación C677T del gen para la metilentetrahidrofolato reductasa (MTHFR)

    OpenAIRE

    Gómez Lado, María del Carmen

    2016-01-01

    hiperhomocisteinemia. En adultos la hiperhomocisteinemia es más frecuente entre los portadores homocigotos de la mutación C677T de la metilentetrahidrofolatoreductasa (MTHFR). Se analiza la repercusión de los FAES sobre la concentración de homocisteína, ácido fólico y vitamina B12 así como la influencia del polimorfismo C677T de la MTHFR sobre las mismas en niños tratados con FAES. Se observa que los FAES se asocian con hiperhomocisteinemia en niños. El tratamiento con carbamazepina se asocia...

  3. Estudio del polimorfismo MTHFR C677T en recien nacidos con cardiopatias congenitas aisladas, en una poblacion colombiana

    National Research Council Canada - National Science Library

    Caicedo, Victor; Garcia-Robles, Reggie; Pachon, Sonia; Ayala-Ramirez, Paola Andrea; Nunez, Federico; Bernal, Jaime; Bermudez, Martha; Salazar, Marleny; Villegas, Victoria Eugenia; Ramirez, Sandra

    2011-01-01

    ...) se asocia con el desarrollo de cardiopatias congenitas aisladas. Metodos: Se compararon las frecuencias alelicas y genotipicas del polimorfismo en 34 recien nacidos con cardiopatias congenitas aisladas y en 102 individuos sanos...

  4. Methylenetetrahydrofolate Reductase C677T polymorphism and ...

    African Journals Online (AJOL)

    Background: Methylenetetrahydrofolate (MTHFR) enzyme plays an important role in folate metabolism which is involved in DNA methylation, repair, and synthesis. Objective: We investigated if the MTHFR C677T polymorphism modulates the risk of developing breast cancer in Moroccan women. Methods: Genotyping was ...

  5. Prevalence of methylenetetrahydrofolate reductase C677T and ...

    African Journals Online (AJOL)

    Naglaa Raafat AbdRaboh

    2012-11-03

    Nov 3, 2012 ... for homocysteine remethylation to methionine [15]. Two of the most investigated polymorphisms in the MTHFR gene are C677T and A1298C. The C677T polymorphism con- verts an alanine residue to a valine (ALA222VAL), leading to lower enzymatic activity [16]. Compared with the 677CC wild genotype ...

  6. Methylenetetrahydrofolate Reductase C677T: Hypoplastic Left Heart and Thrombosis.

    Science.gov (United States)

    Spronk, Kimberly J; Olivero, Anthony D; Haw, Marcus P; Vettukattil, Joseph J

    2015-10-01

    The incidence of congenital heart defects is higher in infants with mutation of methylenetetrahydrofolate reductase (MTHFR) gene. The MTHFR C677T gene decreases the bioavailability of folate and increases plasma homocysteine, a risk factor for thrombosis. There have been no reported cases in the literature on the clinical implications of this procoagulable state in the setting of cyanotic heart disease, which itself has prothrombotic predisposition. Two patients with hypoplastic left heart syndrome developed postoperative thrombotic complications, both were homozygous for MTHFR C677T. We present these cases and highlight the implications of MTHFR mutation in the management of complex congenital heart disease. © The Author(s) 2015.

  7. The methylenetetrahydrofolate reductase gene variant (C677T) in ...

    African Journals Online (AJOL)

    This unreeled study aimed to examine the relationship between the genetic polymorphisms C677T in MTHFR gene and mapped this figure with other ethnic populations. The present study examined 70 Saudi females (30 mothers with DS children plus 40 healthy mothers who gave birth only to healthy children) for C677T ...

  8. Prevalence of methylenetetrahydrofolate reductase C677T and ...

    African Journals Online (AJOL)

    Naglaa Raafat AbdRaboh

    2012-11-03

    Nov 3, 2012 ... b Oncology Diagnostic Unit, Faculty of Medicine, Ain Shams University, Cairo, Egypt c Internal Medicine Department, ... KEYWORDS. T2DM;. (MTHFR) gene;. Gene polymorphism;. Risk factor. Abstract Type 2 diabetes mellitus (T2DM) is a major public health problem around the world. The C677T and ...

  9. MTHFR Gene C677T Polymorphism in Autism Spectrum Disorders

    Directory of Open Access Journals (Sweden)

    Elif Funda Sener

    2014-01-01

    Full Text Available Aim. Autism is a subgroup of autism spectrum disorders, classified as a heterogeneous neurodevelopmental disorder and symptoms occur in the first three years of life. The etiology of autism is largely unknown, but it has been accepted that genetic and environmental factors may both be responsible for the disease. Recent studies have revealed that the genes involved in the folate/homocysteine pathway may be risk factors for autistic children. In particular, C677T polymorphism in the MTHFR gene as a possible risk factor for autism is still controversial. We aimed to investigate the possible effect of C677T polymorphism in a Turkish cohort. Methods. Autism patients were diagnosed by child psychiatrists according to DSM-IV and DSM-V criteria. A total of 98 children diagnosed as autistic and 70 age and sex-matched children who are nonautistic were tested for C677T polymorphism. This polymorphism was studied by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP methods. Results. MTHFR 677T-allele frequency was found to be higher in autistic children compared with nonautistic children (29% versus 24%, but it was not found statistically significant. Conclusions. We conclude that other MTHFR polymorphisms such as A1298C or other folate/homocysteine pathway genes may be studied to show their possible role in autism.

  10. MTHFR C677T polymorphism and osteoporotic fractures.

    Science.gov (United States)

    Valero, C; Alonso, M A; Zarrabeitia, M T; Viadero, C; Hernández, J L; Riancho, J A

    2007-08-01

    The C677T (rs1801133) polymorphism of MTHFR (methylenetetrahydrofolate reductase) has been associated with the risk of cardiovascular events, and also with osteoporosis in some studies. However, the results are controversial. Our objective was to determine the relationship of the polymorphism with osteoporotic fractures by means of a case-control study. C677T was analyzed in 823 subjects (365 controls, 136 with vertebral fractures and 322 with hip fracture) by using a Taqman assay. The distribution of MTHFR genotypes was similar in patients and controls. In comparison with TC/CC genotypes, the age-adjusted OR for hip fractures of the TT genotype was 1.0 (95% confidence interval 0.6-1.7) in women and 0.7 (0.3-1.8) in men. The OR for vertebral fractures was 0.8 (0.4-1.7) in women and 1.7 (0.4-6.7) in men. A meta-analysis combining these data with previous reports confirmed the lack of association between MTHFR and fractures, with an OR of 1.1 (0.7-1.9, p=0.65) for vertebral fractures and 1.2 (0.7-2.0; p=0.45) for peripheral fractures, but there was significant heterogeneity among the results of individual studies, particularly about peripheral fractures. In conclusion, the C677T polymorphism of the MTHFR gene does not appear to be associated with the overall risk of osteoporotic fractures. However, given the heterogeneity of the results of published studies, further investigations are needed to evaluate its influence in specific population subgroups.

  11. Interaction between the MTHFR C677T polymorphism and traumatic childhood events predicts depression

    NARCIS (Netherlands)

    Lok, A.; Bockting, C. L. H.; Koeter, M. W. J.; Snieder, H.; Assies, J.; Mocking, R. J. T.; Vinkers, C. H.; Kahn, R. S.; Boks, M. P.; Schene, A. H.

    2013-01-01

    Childhood trauma is associated with the onset and recurrence of major depressive disorder (MDD). The thermolabile T variant of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism (rs1801133) is associated with a limited (oxidative) stress defense. Therefore, C677T MTHFR could be a

  12. Interaction between the MTHFR C677T polymorphism and traumatic childhood events predicts depression

    NARCIS (Netherlands)

    Lok, A; Bockting, C L H; Koeter, M W J; Snieder, H; Assies, J; Mocking, R J T; Vinkers, C H; Kahn, R S; Boks, M P; Schene, A H

    Childhood trauma is associated with the onset and recurrence of major depressive disorder (MDD). The thermolabile T variant of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism (rs1801133) is associated with a limited (oxidative) stress defense. Therefore, C677T MTHFR could be a

  13. Methylenetetrahydrofolate C677T polymorphism and pre-eclamptic Egyptian women

    Directory of Open Access Journals (Sweden)

    Zakia Mahdy Ibrahim

    2012-06-01

    Conclusion: C677T polymorphism of MTHFR gene was found to be associated with the development of pre-eclampsia. Mutant T allele and TT genotypes of C677T may be considered genetic risk factors for the development of pre-eclampsia among Egyptian pregnant women.

  14. Association of MTHFR gene C677T mutation with diabetic peripheral neuropathy and diabetic retinopathy.

    Science.gov (United States)

    Yigit, Serbulent; Karakus, Nevin; Inanir, Ahmet

    2013-01-01

    Diabetic peripheral neuropathy (DPN) is one of the most common diabetic chronic complications. Methylenetetrahydrofolate reductase (MTHFR) gene variants have been associated with vasculopathy that has been linked to diabetic neuropathy. The aim of the present study was to investigate the possible association between MTHFR gene C677T mutation and DPN and evaluate if there is an association with clinical features in a relatively large cohort of Turkish patients. The study included 230 patients affected by DPN and 282 healthy controls. Genomic DNA was isolated and genotyped using the polymerase chain reaction-based restriction fragment length polymorphism assay for the MTHFR gene C677T mutation. The genotype and allele frequencies of the C677T mutation showed statistically significant differences between the patients with DPN and the controls (p=0.003 and p=0.002, respectively). After the patients with DPN were stratified according to clinical and demographic characteristics, a significant association was observed between the C677T mutation and history of retinopathy (p=0.039). A high association between the MTHFR gene C677T mutation and DPN was observed in the present study. In addition, history of retinopathy was associated with the MTHFR C677T mutation in patients with DPN.

  15. Lack of association between the MTHFR (C677T) polymorphism and atopic disease

    DEFF Research Database (Denmark)

    Thuesen, Betina Heinsbaek; Husemoen, Lise Lotte Nystrup; Fenger, Mogens

    2009-01-01

    -tetrahydrofolate reductase (MTHFR)-gene, a well-known marker of impaired folate metabolism. OBJECTIVES: The aim of this study was to investigate the association between the MTHFR (C677T) polymorphism and different outcome variables of asthma and atopic disease. METHODS: This study was a population-based study of 1189...... and symptoms of allergy and asthma. In addition, participants were genotyped for the MTHFR (C677T) polymorphism. RESULTS: None of the examined outcomes were significantly associated with the MTHFR (C677T) polymorphism. CONCLUSIONS: The results of this study using detailed objective markers of atopic disease do...... not support the hypothesis that impaired folate metabolism as reflected by the MTHFR genotype is involved in the development of atopic disease....

  16. Is the prevalence of MTHFR C677T polymorphism associated with ultraviolet radiation in Eurasia?

    Science.gov (United States)

    Yafei, Wang; Lijun, Pei; Jinfeng, Wang; Xiaoying, Zheng

    2012-12-01

    The methylenetetrahydrofolic acid reductase (MTHFR) C677T polymorphism causes an amino-acid change from alanine to valine and results in the enzyme becoming thermolabile and half decreased activity. Its prevalence varies among global population. We collected data about MTHFR C677T polymorphism prevalence from epidemiology studies, as well as ultraviolet (UV) radiations and some other climatological factors from the internet. The results of the correlation and quadric regression showed that there was inverse U-shape relationship between T allele frequency and UV radiation. The explanatory power of UV radiation was stronger than latitude and all climatological factors. Our results supported the hypothesis that the distribution pattern of MTFHR C677T polymorphism in Eurasia might be the result of interaction of genetic and environmental natural selection, especially the UV radiation.

  17. Association of the MTHFR Gene C677T Polymorphism with Breast Cancer in a Turkish Population.

    Science.gov (United States)

    Kaya, Emir F; Karakus, Nevin; Ulusoy, Ali N; Özaslan, Cihangir; Kara, Nurten

    2016-01-01

    Breast cancer is the most common cancer among women. 1 in every 8 women in the United States have a lifetime risk of getting breast cancer. MTHFR is a key enzyme that regulates the folate metabolism which has an important role in DNA synthesis, repair, and methylation. The aim of the current study was to analyze the association between the MTHFR gene C677T (Ala222Val, rs1801133) polymorphism and breast cancer. 199 breast cancer patients and 195 healthy controls were included in this study. The MTHFR gene C677T polymorphism was analyzed using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) methods. A meta-analysis including 707 breast cancer patients and 880 controls from Turkish populations was also carried out. Statistical analyses were performed using the χ2 test. No statistically significant differences in allele and genotype frequencies were observed between patients and controls (p > 0.05). Although not statistically significant, TT homozygous variants were encountered more frequently in patients than in controls. A statistically significant association was observed between the MTHFR gene C677T polymorphism and the tumor histology of breast cancer patients (p = 0.038). The results of the meta-analysis suggested that there was a high association between breast cancer and the MTHFR gene C677T polymorphism in Turkish populations (p association between the MTHFR gene C677T polymorphism and breast cancer. However, a meta-analysis of the 6 association studies carried out in Turkish populations with 707 patients and 880 controls showed a significant association between breast cancer and the MTHFR gene C677T polymorphism. © 2016 S. Karger GmbH, Freiburg.

  18. Association of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism with primary glaucoma in Saudi population.

    Science.gov (United States)

    Al-Shahrani, Hamoud; Al-Dabbagh, Najwa; Al-Dohayan, Nourah; Arfin, Misbahul; Al-Asmari, Mohammad; Rizvi, Sadaf; Al-Asmari, Abdulrahman

    2016-09-01

    Methylenetetrahydrofolate reductase (MTHFR), a critical enzyme in folate metabolism is involved in DNA synthesis, DNA repair and DNA methylation. The functional polymorphism of MTHFR gene, C677T has been shown to impact various diseases and implicated as a risk factor for the development of various neurodegenerative disorders including glaucoma. We investigated MTHFR C677T genotypes and alleles frequencies in primary glaucoma [primary open angle glaucoma (POAG) and primary angle closure glaucoma (PACG)] patients and matched healthy controls in a case-control study. Two hundred ten primary glaucoma cases were studied for MTHFR C677T polymorphism and compared with 280 controls taken from the healthy population, employing the polymerase chain reaction-restriction fragment length polymorphism technique (PCR-RFLP). The MTHFR gene was amplified using specific primers. The PCR products (294 bp) was subsequently digested with HinfI (New England Biolabs) at 37 °C for 12 h, separated by electrophoresis on 2 % agarose gels, and visualized with ethidium bromide staining. The restriction digestion yielded 168 and 126 bp fragments for TT, 294, 168 and 126 bp fragments for CT and undigested PCR product 294 bp indicating CC genotype. We found the frequency of the genotypes and alleles of MTHFR C677T differ significantly between cases and controls. The frequencies of allele T and genotype CT were significantly higher while the frequencies of allele C and genotype CC were lower in primary glaucoma patients as compared to controls (p MTHFR C677T polymorphism are significantly associated with POAG while allele C and CC genotype may be protective for it. We conclude that the MTHFR C677T polymorphism increases the risk for POAG development in Saudi population and can be a genetic marker however, further studies are needed with multiple-ethnic populations affected with POAG to strengthen these findings.

  19. MTHFR C677T polymorphism affects normotensive diastolic blood pressure independently of blood lipids.

    Science.gov (United States)

    Heifetz, Eliyahu M; Birk, Ruth Z

    2015-03-01

    Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism was found to be associated with hypertension. High blood pressure (BP) is a major risk factor for cardiovascular disease, gestational hypertension, and high-risk pregnancy. BP is a complex trait strongly associated with blood lipid parameters. However, studies of the effect of MTHFR C677T polymorphism on BP levels independently of blood lipids are scarce. Our objective was to analyze and quantify the effect of MTHFR C677T polymorphism on normotensive BP independently of blood lipids. MTHFR C677T genotyping was done for 151 Israeli women attending the genetics clinic at Soroka Medical Center. Biochemical (blood lipids) and BP data were extracted from Soroka Medical Center records. BP was regarded as a continuous parameter using analysis of covariance and post hoc Tukey's HSD (honestly significant difference) analysis. The frequencies of genotypes CC, TT, and CT were 41%, 12%, and 47%, respectively. A significant (P < 0.0001) association was found between genotype and diastolic BP (DBP) when adjusted to body mass index and age. Mean DBP was significantly lower for CC than for TT genotypes (71.2 vs. 78.7 mm Hg); however the difference between the heterozygotes (73.9 mm Hg) and the other 2 genotypes was not significant. Cholesterol, LDLcalc (LDLcalculaed), and homocysteine blood levels significantly contributed to the effect of MTHFR C677T polymorphism on the DBP trait. There was also significant association between genotype and folic acid levels. MTHFR C677T polymorphism significantly affects DBP in Israeli women, independently of blood lipids. Each C to T substitution is associated with a mean 3.4-mm Hg increase in DBP. © American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and age at onset of schizophrenia

    DEFF Research Database (Denmark)

    Saetre, Peter; Grove, Jakob; Børglum, Anders

    2012-01-01

    Methylenetetrahydrofolate reductase (MTHFR) is an enzyme involved in metabolic pathways of importance for nucleotide synthesis and methylation of DNA, membranes, proteins and lipids. The MTHFR gene includes a common polymorphism (rs1801133 or C677T), which is associated with enzyme activity. The T...... the original Scandinavian samples, there was no significant association between MTHFR C677T polymorphism and age at onset in schizophrenia. The present results do not suggest that the investigated MTHFR polymorphism has any significant influence on age at onset of schizophrenia in the Nordic population. © 2012...

  1. The 5,10-methylenetetrahydrofolate reductase C677T polymorphism interacts with smoking to increase homocysteine.

    NARCIS (Netherlands)

    Brown, K.S.; Kluijtmans, L.A.J.; Young, I.S.; Murray, L.; McMaster, D.; Woodside, J.; Yarnell, J.W.; Boreham, C.A.; McNulty, H.; Strain, J.J.; McPartlin, J.; Scott, J.M.; Mitchell, L.E.; Whitehead, A.S.

    2004-01-01

    Elevated homocysteine is a risk marker for several human pathologies. Risk factors for elevated homocysteine include low folate and homozygosity for the T allele of the 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism. Because nitric oxide may inhibit folate catabolism and

  2. Association of C677T transition of the human methylenetetrahydrofolate reductase (MTHFR) gene with male infertility.

    Science.gov (United States)

    Karimian, Mohammad; Colagar, Abasalt Hosseinzadeh

    2016-04-01

    The human methylenetetrahydrofolate reductase (MTHFR) gene encodes one of the key enzymes in folate metabolism. This gene is located on chromosome 1 (1p36.3), which has 12 exons. The aim of the present study was to investigate the possible association of the two (C677T and A1298C) polymorphisms of this gene with male infertility. In a case-control study, 250 blood samples were collected from IVF centres in Sari and Babol (Iran): 118 samples were from oligospermic men and 132 were from controls. Two single nucleotide polymorphisms of the MTHFR genotype were detected using polymerase chain reaction-restriction fragment length polymorphism. There was no association found between the A1298C variant and male infertility. However, carriers of the 677T allele (CT and TT genotypes) were at a higher risk of infertility than individuals with other genotypes (odds ratio 1.84; 95% confidence interval 1.11-3.04; P=0.0174). Structural analysis of human MTHFR flavoprotein showed that C677T transition played an important role in the change in affinity of the MTHFR-Flavin adenine dinucleotide binding site. Based on our results, we suggest that C677T transition in MTHFR may increase the risk of male infertility, and detection of the C677T polymorphism biomarker may be helpful in the screening of idiopathic male infertility.

  3. Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism in psoriasis in southern Turkey.

    Science.gov (United States)

    Izmirli, Muzeyyen; Sen, Bilge Bulbul; Rifaioglu, Eminenur; Gogebakan, Bulent; Aldemir, Ozgur; Sen, Tuba; Ekiz, Ozlem; Alptekin, Davut

    2016-01-01

    Psoriasis is a multigenic and multifactorial dermatological disease linked to cardiovascular diseases. Increased levels of homocysteine in patients with psoriasis have been demonstrated in many studies. The most frequently investigated genetic defect that plays a role in homocysteine metabolism is single point substitution (C to T) located on the 677th nucleotide of the methylenetetrahydrofolate reductase gene (MTHFR). In this study, we aimed to investigate methylenetetrahydrofolate C677T polymorphism in psoriasis patients in Turkey. The study included 96 patients with psoriasis and 77 controls from southern Turkey. Methylenetetrahydrofolate C677T polymorphism was analysed using the Polymerase Chain Reaction-Restriction Fragment Length Polymorphism methods. In the psoriasis group, 34 CC (35.4%), 46 CT (47.9%) and 16 TT (16.7%) genotypes were found, respectively; while in the control group, the figures were 39 (50.6%), 35 (45.5%), 3 (3.9%). Homozygote and heterozygote T alleles of methylenetetrahydrofolate C677T polymorphism were significantly higher in the psoriasis than in the control group (p=0.013). We firstly found a correlation between methylenetetrahydrofolate C677T polymorphism and psoriasis among the southern Turkish population.

  4. Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism: epidemiology, metabolism and the associated diseases.

    Science.gov (United States)

    Liew, Siaw-Cheok; Gupta, Esha Das

    2015-01-01

    The Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism is associated with various diseases (vascular, cancers, neurology, diabetes, psoriasis, etc) with the epidemiology of the polymorphism of the C677T that varies dependent on the geography and ethnicity. The 5,10-Methylenetetrahydrofolate reductase (MTHFR) locus is mapped on chromosome 1 at the end of the short arm (1p36.6). This enzyme is important for the folate metabolism which is an integral process for cell metabolism in the DNA, RNA and protein methylation. The mutation of the MTHFR gene which causes the C677T polymorphism is located at exon 4 which results in the conversion of valine to alanine at codon 222, a common polymorphism that reduces the activity of this enzyme. The homozygous mutated subjects have higher homocysteine levels while the heterozygous mutated subjects have mildly raised homocysteine levels compared with the normal, non-mutated controls. Hyperhomocysteinemia is an emerging risk factor for various cardiovascular diseases and with the increasing significance of this polymorphism in view of the morbidity and mortality impact on the patients, further prevention strategies and nutritional recommendations with the supplementation of vitamin B12 and folic acid which reduces plasma homocysteine level would be necessary as part of future health education. This literature review therefore focuses on the recent evidence-based reports on the associations of the MTHFR C677T polymorphism and the various diseases globally. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  5. Maternal MTHFR C677T genotype and septal defects in offspring ...

    African Journals Online (AJOL)

    Ghada M. Elsayed

    2013-10-09

    Oct 9, 2013 ... Abstract Background: While abnormal folate/homocysteine metabolism has been implicated as an etiology for the development of both CHD and DS, recent studies and meta-analyses did not consider MTHFR C677T genotype as a maternal risk factor for either of these conditions alone. Aim of work: To ...

  6. Maternal MTHFR C677T genotype and septal defects in offspring ...

    African Journals Online (AJOL)

    Abstract. Background: While abnormal folate/homocysteine metabolism has been implicated as an etiology for the development of both CHD and DS, recent studies and meta-analyses did not consider MTHFR C677T genotype as a maternal risk factor for either of these conditions alone. Aim of work: To investigate if ...

  7. Evaluation of High Resolution Melting for MTHFR C677T Genotyping in Congenital Heart Disease.

    Directory of Open Access Journals (Sweden)

    Ying Wang

    Full Text Available High resolution melting (HRM is a simple, flexible and low-cost mutation screening technique. The methylenetetrahydrofolate reductase (MTHFR gene encoding a critical enzyme, potentially affects susceptibility to some congenital defects like congenital heart disease (CHD. We evaluate the performance of HRM for genotyping of the MTHFR gene C677T locus in CHD cases and healthy controls of Chinese Han population.A total of 315 blood samples from 147 CHD patients (male72, female 75 and 168 healthy controls (male 92, female 76 were enrolled in the study. HRM was utilized to genotype MTHFR C677T locus of all the samples. The results were compared to that of PCR-RFLP and Sanger sequencing. The association of the MTHFR C677T genotypes and the risk of CHD was analyzed using odds ratio with their 95% confidence interval (CIs from unconditional logistic regression.All the samples were successfully genotyped by HRM within 1 hour and 30 minutes while at least 6 hours were needed for PCR-RFLP and sequencing. The genotypes of MTHFR C677T CC, CT, and TT were 9.52%, 49.66%, and 40.82% in CHD group but 29.17%, 50% and 20.83% in control group, which were identical using both methods of HRM and PCR-RFLP, demonstrating the sensitivity and specificity of HRM were all 100%.MTHFR C677T is a potential risk factor for CHD in our local residents of Shandong province in China. HRM is a fast, sensitive, specific and reliable method for clinical application of genotyping.

  8. Association of C677T polymorphism (rs1801133) in MTHFR gene with depression.

    Science.gov (United States)

    Rai, V

    2017-07-31

    Depression is one of the mental disorders with a state of low mood and aversion to activities that exerts a negative effect on a person's thoughts and behavior. Genetic association studies on MTHFR C677T polymorphism and depression have been repeatedly performed over the last two decades, but results are inconsistent. The aim of the present study was to assess the relationship between MTHFR C677T polymorphism and depression by literature review and meta-analysis. Four electronic databases, PubMed, Google Scholar, Science direct and Springer Link were searched for case control articles focusing on MTHFR C677T polymorphism and the risk of depression. A total of 30 studies including 4,802 cases and 17,362 controls were involved in present meta-analysis. When all the eligible studies were pooled into this meta-analysis,  significant association between depression risk and MTHFR C677T polymorphism was found in three genetic models (Additive model: OR T vs C= 1.20, 95 % CI= 1.00-1.34, p=0.0004; homozygote model: OR TT vs.CC=1.37, 95% CI= 1.13-1.65, p=0.0004; dominant model: OR TT+CT vs CC=1.13, 95 % CI= 0.99-1.28, p=0.04), while meta-analysis with other two genetic models did not show association with other two genetic models ( recessive model: OR TT vs CT+CC= 1.36, 95 % CI = 0.91-2.04, p=0.13; co-dominant model: OR CT vs CC=1.00, 95 % CI=0.93-1.08,p=0.84). Present meta-analysis supports that there is a meager significant association between MTHFR C677T polymorphism and depression risk.

  9. Methylenetetrahydrofolate reductase C677T polymorphism in patients with lung cancer in a Korean population

    Directory of Open Access Journals (Sweden)

    Yun Woo-Jun

    2011-02-01

    Full Text Available Abstract Background This study was designed to investigate an association between methylenetetrahydrofolate reductase (MTHFR C677T polymorphism and the risk of lung cancer in a Korean population. Methods We conducted a large-scale, case-control study involving 3938 patients with newly diagnosed lung cancer and 1700 healthy controls. Genotyping was performed with peripheral blood DNA for MTHFR C677T polymorphisms. Statistical significance was estimated by logistic regression analysis. Results The MTHFR C677T frequencies of CC, CT, and TT genotypes were 34.5%, 48.5%, and 17% among lung cancer patients, and 31.8%, 50.7%, and 17.5% in the controls, respectively. The MTHFR 677CT and TT genotype showed a weak protection against lung cancer compared with the homozygous CC genotype, although the results did not reach statistical significance. The age- and gender-adjusted odds ratio (OR of overall lung cancer was 0.90 (95% confidence interval (CI, 0.77-1.04 for MTHFR 677 CT and 0.88 (95% CI, 0.71-1.07 for MTHFR 677TT. However, after stratification analysis by histological type, the MTHFR 677CT genotype showed a significantly decreased risk for squamous cell carcinoma (age- and gender-adjusted OR, 0.78; 95% CI, 0.64-0.96. The combination of 677 TT homozygous with 677 CT heterozygous also appeared to have a protection effect on the risk of squamous cell carcinoma. We observed no significant interaction between the MTHFR C677T polymorphism and age and gender or smoking habit. Conclusions This is the first reported study focusing on the association between MTHFR C677T polymorphisms and the risk of lung cancer in a Korean population. The T allele was found to provide a weak protective association with lung squamous cell carcinoma.

  10. Methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and gastric cancer susceptibility.

    Science.gov (United States)

    Xia, Lei-Zhou; Liu, Yi; Xu, Xiao-Zhou; Jiang, Peng-Cheng; Ma, Gui; Bu, Xue-Feng; Zhang, Yong-Jun; Yu, Feng; Xu, Ke-Sen; Li, Hua

    2014-08-28

    To identify the association between methylenetetrahydrofolate reductase (MTHFR) polymorphisms and gastric cancer (GC) susceptibility. Systematic searches were performed on the electronic databases PubMed, ISI, Web of knowledge, CNKI and Wanfang, as well as manual searching of the references of the identified articles. A total of 26 papers were included in this meta-analysis. Overall and subgroup analyses were performed. Odds ratio (OR) and 95%CI were used to evaluate the associations between MTHFR polymorphisms and GC risk. The I (2) statistics were used to evaluate between-study heterogeneity. Sensitivity analysis was also performed. Increased risk was found for the MTHFR C677T polymorphism under four genetic models (TT + CT vs CC: OR = 1.23, P = 0.002; T vs C: OR = 1.15, P = 0.001; TT vs CC: OR = 1.37, P = 0.0005; TT vs CT + CC: OR = 1.17, P = 0.0008). Subgroup analysis by ethnicity suggested that C677T polymorphism conferred a risk of GC in eastern but not in western populations. Stratification by tumor site showed an association between the C677T polymorphism and gastric cardia cancer and non-cardia GC in the worldwide population and in eastern populations. Regardless of comparisons with controls or diffuse-type GC, a positive association was found for the C677T polymorphism and an increased risk of intestinal-type GC in the whole population and in western populations. With regard to the A1298C polymorphism, we found that genotype CC was significantly decreased and conferred protection against GC in eastern populations (CC vs AA: OR = 0.44, P = 0.03; CC vs AC + AA: OR = 0.46, P = 0.04). MTHFR C677T polymorphism is a risk factor for GC, and the A1298C polymorphism may be a protective factor against GC in eastern populations.

  11. Methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and gastric cancer susceptibility

    Science.gov (United States)

    Xia, Lei-Zhou; Liu, Yi; Xu, Xiao-Zhou; Jiang, Peng-Cheng; Ma, Gui; Bu, Xue-Feng; Zhang, Yong-Jun; Yu, Feng; Xu, Ke-Sen; Li, Hua

    2014-01-01

    AIM: To identify the association between methylenetetrahydrofolate reductase (MTHFR) polymorphisms and gastric cancer (GC) susceptibility. METHODS: Systematic searches were performed on the electronic databases PubMed, ISI, Web of knowledge, CNKI and Wanfang, as well as manual searching of the references of the identified articles. A total of 26 papers were included in this meta-analysis. Overall and subgroup analyses were performed. Odds ratio (OR) and 95%CI were used to evaluate the associations between MTHFR polymorphisms and GC risk. The I2 statistics were used to evaluate between-study heterogeneity. Sensitivity analysis was also performed. RESULTS: Increased risk was found for the MTHFR C677T polymorphism under four genetic models (TT + CT vs CC: OR = 1.23, P = 0.002; T vs C: OR = 1.15, P = 0.001; TT vs CC: OR = 1.37, P = 0.0005; TT vs CT + CC: OR = 1.17, P = 0.0008). Subgroup analysis by ethnicity suggested that C677T polymorphism conferred a risk of GC in eastern but not in western populations. Stratification by tumor site showed an association between the C677T polymorphism and gastric cardia cancer and non-cardia GC in the worldwide population and in eastern populations. Regardless of comparisons with controls or diffuse-type GC, a positive association was found for the C677T polymorphism and an increased risk of intestinal-type GC in the whole population and in western populations. With regard to the A1298C polymorphism, we found that genotype CC was significantly decreased and conferred protection against GC in eastern populations (CC vs AA: OR = 0.44, P = 0.03; CC vs AC + AA: OR = 0.46, P = 0.04). CONCLUSION: MTHFR C677T polymorphism is a risk factor for GC, and the A1298C polymorphism may be a protective factor against GC in eastern populations. PMID:25170232

  12. The methylenetetrahydrofolate reductase C677T genotype and the risk of obesity in three large population-based cohorts

    DEFF Research Database (Denmark)

    Lewis, S.J.; Lawlor, D.A.; Nordestgaard, B.G.

    2008-01-01

    of this relationship. The methylenetetrahydrofolate reductase (MTHFR) C677T TT genotype is associated with reduced folate availability and may be a surrogate for measuring folate levels. We sought to determine whether MTHFR C677T genotype was associated with obesity. Design: We carried out our study on four...

  13. Urinary tract anomalies associated with MTHFR gene polymorphism C677T in girls.

    Science.gov (United States)

    Behunova, Jana; Klimcakova, Lucia; Podracka, Ludmila

    2011-01-01

    Periconceptional folate has a preventive effect not only on neural tube defects, but possibly also on other birth defects such as urinary tract anomalies (UTA), orofacial clefts and conotruncal heart defects. Folate metabolism gene variants are therefore being investigated as potential susceptibility factors. We assessed the methylenetetrahydrofolate reductase (MTHFR) gene C677T and A1298C genotypes in 132 UTA patients and 290 controls, also with respect to sex. We found a significantly higher incidence of the T allele/TT genotype of the C677T polymorphism in UTA patients compared with controls (p = 0.019/p = 0.044). In the individual sexes, the T allele frequency in UTA girls versus control girls was 42.6 versus 21.7%, p methylation due to the lower activity of MTHFR in the system with the highest sexual dimorphism: the urogenital system. Naturally, this assumption should be further tested. Copyright © 2011 S. Karger AG, Basel.

  14. Prevalence of methylenetetrahydrofolate reductase C677T polymorphism in eastern Uttar Pradesh

    Science.gov (United States)

    Rai, Vandana; Yadav, Upendra; Kumar, Pradeep

    2012-01-01

    AIM: This study was aimed to evaluate the 5, 10-methylenetetrahydrofolate reductase (MTHFR) C677T mutation in eastern Uttar Pradesh population. MATERIALS AND METHODS: Polymerase chain reaction (PCR) using specific primers followed by amplicon digestion by Hinf I restriction enzyme was used for MTHFR C677T polymorphism analysis. Total 250 subjects were analyzed. RESULTS: The CC genotype was found in 192 subjects, followed by CT in 56 subjects and TT in 2 subject. Genotype frequencies of CC, CT and TT were 0.768, 0.224 and 0.008, respectively. The frequency of C allele was found to be 0.88 and that of T allele was 0.12. CONCLUSION: It is evident from the results of the present study that the percentage of homozygous genotype (CC) is highest in the target population. PMID:22754220

  15. Methylenetetrahydrofolate Reductase (MTHFR) C677T Polymorphism and Alzheimer Disease Risk: a Meta-Analysis.

    Science.gov (United States)

    Rai, Vandana

    2017-03-01

    Methylenetetrahydrofolate reductase (MTHFR) is key enzyme of folate/homocysteine pathway. Case control association studies on MTHFR C677T polymorphism and Alzheimer's disease (AD) have been repeatedly performed over the last two decades, but the results are inconclusive. The aim of the present study was to assess the risk of MTHFR C677T polymorphism for AD. Forty-one studies were identified by a search of PubMed, Google Scholar, Elsevier, and Springer Link databases, up to January 2015. Odds ratios (ORs) with corresponding 95 % confidence interval (CI) were calculated using fixed effect model or random effect model. The subgroup analyses based on ethnicity were performed. MTHFR C677T polymorphism had a significant association with susceptibility to AD in all genetic models (for T vs C OR = 1.29, 95 % CI = 1.07-1.56, p = 0.003; for TT + CT vs CC OR = 1.29, 95 % CI = 1.19-1.40, p = 0.0004; for TT vs CC OR = 1.31, 95 % CI = 1.16-1.48, p = 0.001; for CT vs CC OR = 1.24, 95 % CI = 1.13-1.35, p < 0.004; and for TT vs CT + CC OR = 1.13, 95 % CI = 1.00-1.28, p = 0.02). Results of present meta-analysis supported that the MTHFR C677T polymorphism was associated with an increased risk of AD.

  16. The methylenetetrahydrofolate reductase C677T polymorphism and breast cancer risk in Asian populations.

    Science.gov (United States)

    Rai, Vandana

    2014-01-01

    Methylenetetrahydrofolate (MTHFR) is the key enzyme of the folate metabolic pathway and several studies have pointed to association between the MTHFR C677T polymorphism and breast cancer risk. Although significant association was observed in some studies, in others no clear link could be established. A meta-analysis of published Asian case control studies was therefor carried out to shed further light on any C677T breast cancer association. PubMed, Springer Link, Google Scholar and Elsevier databases were searched for case control studies of associations between MTHFR C677T polymorphism and breast cancer risk. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association. A total of 36 studies including 8,040 cases and 10,008 controls were included in the present meta-analysis. Overall, a significantly elevated breast cancer risk was associated with the T allele and TT genotype in homozygote comparison and dominant genetic models when all studies were pooled into the meta-analysis (T vs C (allele contrast model): OR=1,23, 95%CI=1.13-1.37, p=0.000 ; TT vs CC(homozygote model): OR=1.38, 95%CI=1.16-1.63, p=0.0003; TT+CT vs CC (dominant model): OR=1.12, 95%CI=1.01-1.23, p=0.02). The present meta-analysis strongly suggested a significant association between the MTHFR C677T polymorphism and risk of breast cancer in Asian populations.

  17. The methylenetetrahydrofolate reductase gene variant C677T influences susceptibility to migraine with aura

    Directory of Open Access Journals (Sweden)

    Sundholm James

    2004-02-01

    Full Text Available Abstract Background The C677T variant in the methylenetetrahydrofolate reductase (MTHFR gene is associated with increased levels of circulating homocysteine and is a mild risk factor for vascular disease. Migraine, with and without aura (MA and MO, is a prevalent and complex neurovascular disorder that may also be affected by genetically influenced hyperhomocysteinaemia. To determine whether the C677T variant in the MTHFR gene is associated with migraine susceptibility we utilised unrelated and family-based case-control study designs. Methods A total of 652 Caucasian migraine cases were investigated in this study. The MTHFR C677T variant was genotyped in 270 unrelated migraine cases and 270 controls as well as 382 affected subjects from 92 multiplex pedigrees. Results In the unrelated case-control sample we observed an over-representation of the 677T allele in migraine patients compared to controls, specifically for the MA subtype (40% vs. 33% (χ2 = 5.70, P = 0.017. The Armitage test for trend indicated a significant dosage effect of the risk allele (T for MA (χ2 = 5.72, P = 0.017. This linear trend was also present in the independent family-based sample (χ2 = 4.25, Padjusted = 0.039. Overall, our results indicate that the T/T genotype confers a modest, yet significant, increase in risk for the MA subtype (odds ratio: 2.0 – 2.5. No increased risk for the MO subtype was observed (P > 0.05. Conclusions In Caucasians, the C677T variant in the MTHFR gene influences susceptibility to MA, but not MO. Investigation into the enzyme activity of MTHFR and the role of homocysteine in the pathophysiology of migraine is warranted.

  18. Analysis of the MTHFR C677T variant with migraine phenotypes

    Directory of Open Access Journals (Sweden)

    Haupt Larisa M

    2010-07-01

    Full Text Available Abstract Background The methylenetetrahydrofolate reductase (MTHFR gene variant C677T has been implicated as a genetic risk factor in migraine susceptibility, particularly in Migraine with Aura. Migraine, with and without aura (MA and MO have many diagnostic characteristics in common. It is postulated that migraine symptomatic characteristics might themselves be influenced by MTHFR. Here we analysed the clinical profile, migraine symptoms, triggers and treatments of 267 migraineurs previously genotyped for the MTHFR C677T variant. The chi-square test was used to analyse all potential relationships between genotype and migraine clinical variables. Regression analyses were performed to assess the association of C677T with all migraine clinical variables after adjusting for gender. Findings The homozygous TT genotype was significantly associated with MA (P P = 0.002. While the CT genotype was significantly associated with physical activity discomfort (P P = 0.002. Females with the TT genotype were significantly associated with unilateral head pain (P P P = 0.002, and the use of natural remedy for migraine treatment (P = 0.003. Conversely, male migraineurs with the TT genotype experienced higher incidences of bilateral head pain (63% vs 34% and were less likely to use a natural remedy as a migraine treatment compared to female migraineurs (5% vs 20%. Conclusions MTHFR genotype is associated with specific clinical variables of migraine including unilateral head pain, physical activity discomfort and stress.

  19. Association between the MTHFR-C677T isoform and structure of sperm DNA.

    Science.gov (United States)

    Cornet, Dominique; Cohen, Marc; Clement, Arthur; Amar, Edouard; Fournols, Laetitia; Clement, Patrice; Neveux, Paul; Ménézo, Yves

    2017-10-01

    The aim of this study is to evaluate whether the MTHFR contribution to male decreased fertility can be attributable to anomalies in sperm nucleus DNA structure in relation to defective methylation. The presence of MTHFR C677T, contributing at most for male infertility, was determined from a venous blood sample, using real-time polymerase chain reaction (PCR). Sperm DNA fragmentation (SDF) and sperm nucleus decondensation index (SDI) measurements were performed using acridine orange and flow cytometry. SDF and SDI of men MTHFR C677T heterozygous or homozygous were compared to a general population of hypo-fertile patients RESULTS: SDF is not increased either in homozygous or heterozygous carriers of MTHFR C677T. In contrast, SDI is increased with a higher incidence in homozygous (p = 0.0006) than in heterozygous (p = 0.029) patients when compared with the control population. Using a critical threshold of 20% for either SDI or SDF assayed with our technique, the percentage of patients with results higher than this value is not significant with respect to fragmentation (0.128), but is significantly increased for decondensation (0.0003). Defective methylation linked to MTHFR may contribute to sperm pathogenesis via increased SDI. After DNA structure analysis, especially SDI, treatment with 5-methyl tetrahydrofolate (MTHF), the metabolite downstream from the action of MTHFR, should be recommended as a therapeutic approach. Patients with a high SDI should be tested for MTHFR isoforms as part of a healthcare policy.

  20. The importance of MTHFR C677T/A1298C combined polymorphisms in pulmonary embolism in Turkish population

    Directory of Open Access Journals (Sweden)

    Nursah Basol

    2016-01-01

    Conclusion: We found an association between MTHFR C677T/A1298C combined mutations and PE in the Turkish population. Future genetic studies investigating combined mutations could be very helpful to identify risk population in PE.

  1. Genotype distribution of methylenetetrahydrofolate reductase A1298C and C677T gene in Indonesian infertile men

    OpenAIRE

    Dwi A. Suryandari; Yurnadi Yurnadi; Budi Wiweko; Luluk Yunaini

    2012-01-01

    Background: Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme of folate and methionin metabolism, making it crucial for DNA synthesis and methylation. Variants of MTHFR C677T and A1298C gene result in reduced plasma folate levels and increase the susceptibility to spermatogenic arrest. This research aims to analyses MTHFR C677T and A1298C gene polymorphism in Indonesian infertile men with azoospermia and oligozoospermia.Methods: This cross sectional study takes 3 mL of blood ...

  2. Association of (C677T Gene Polymorphism with Breast Cancer in North India

    Directory of Open Access Journals (Sweden)

    Mohammad Waseem

    2016-01-01

    Full Text Available Background Breast cancer is one of the most common malignancies in women and is associated with a variety of risk factors. The functional single-nucleotide polymorphism (SNP C677T in the gene encoding 5,10-methylenetetrahydrofolate reductase (MTHFR may lead to decreased enzyme activity and affect the chemosensitivity of tumor cells. This study was designed to investigate the association of MTHFR gene polymorphism (SNP in the pathogenesis of breast cancer among the North Indian women population. Materials and Methods Genotyping was performed by polymerase chain reaction (PCR using genomic DNA, extracted from the peripheral blood of subjects with (275 cases or without (275 controls breast cancer. Restriction fragment length polymorphism was used to study C677T polymorphism in the study groups. Results The distribution of MTHFR (C677T genotype frequencies, ie, CC, TT, and CT, among the patients was 64.7%, 2.18%, and 33.09%, respectively. In the healthy control group, the CC, TT, and CT frequencies were 78.91%, 1.09%, and 20.1%, respectively. The frequencies of C and T alleles were 81.2% and 18.7%, respectively, in the patient subjects, while they were 88.9% and 11.09%, respectively, among the healthy control group. Frequencies of the CT genotype and the T allele were significantly different ( P = 0.007 and P = 0.005, respectively between the control and the case subjects. Conclusion This study shows an association of the CT genotype and the T allele of the MTHFR (C667T gene with increased genetic risk for breast cancer among Indian women.

  3. Interaction between the MTHFR C677T polymorphism and traumatic childhood events predicts depression.

    Science.gov (United States)

    Lok, A; Bockting, C L H; Koeter, M W J; Snieder, H; Assies, J; Mocking, R J T; Vinkers, C H; Kahn, R S; Boks, M P; Schene, A H

    2013-07-30

    Childhood trauma is associated with the onset and recurrence of major depressive disorder (MDD). The thermolabile T variant of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism (rs1801133) is associated with a limited (oxidative) stress defense. Therefore, C677T MTHFR could be a potential predictor for depressive symptomatology and MDD recurrence in the context of traumatic stress during early life. We investigated the interaction between the C677T MTHFR variant and exposure to traumatic childhood events (TCEs) on MDD recurrence during a 5.5-year follow-up in a discovery sample of 124 patients with recurrent MDD and, in an independent replication sample, on depressive symptomatology in 665 healthy individuals from the general population. In the discovery sample, Cox regression analysis revealed a significant interaction between MTHFR genotype and TCEs on MDD recurrence (P=0.017). Over the 5.5-year follow-up period, median time to recurrence was 191 days for T-allele carrying patients who experienced TCEs (T+ and TCE+); 461 days for T- and TCE+ patients; 773 days for T+ and TCE- patients and 866 days for T- and TCE- patients. In the replication sample, a significant interaction was present between the MTHFR genotype and TCEs on depressive symptomatology (P=0.002). Our results show that the effects of TCEs on the prospectively assessed recurrence of MDD and self-reported depressive symptoms in the general population depend on the MTHFR genotype. In conclusion, T-allele carriers may be at an increased risk for depressive symptoms or MDD recurrence after exposure to childhood trauma.

  4. Combined genotype and haplotype distributions of MTHFR C677T and A1298C polymorphisms

    Science.gov (United States)

    Fan, Shujun; Yang, Boyi; Zhi, Xueyuan; Wang, Yanxun; Zheng, Quanmei; Sun, Guifan

    2016-01-01

    Abstract Methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms are, independently and/or in combination, associated with many disorders. However, data on the combined genotype and haplotype distributions of the 2 polymorphisms in Chinese population were limited. We recruited 13,473 adult women from 9 Chinese provinces, collected buccal cell samples, and determined genotypes, to estimate the combined genotype and haplotype distributions of the MTHFR C677T and A1298C polymorphisms. In the total sample, the 6 common combined genotypes were CT/AA (29.5%), TT/AA (21.9%), CC/AA (15.4%), CC/AC (14.9%), CT/AC (13.7%), and CC/CC (3.4%); the 3 frequent haplotypes were 677T-1298A (43.6%), 677C-1298A (37.9%), and 677C-1298C (17.6%). Importantly, we observed that there were 51 (0.4%) individuals with the CT/CC genotype, 92 (0.7%) with the TT/AC genotype, 17 (0.1%) with the TT/CC genotype, and that the frequency of the 677T-1298C haplotype was 0.9%. In addition, the prevalence of some combined genotypes and haplotypes varied among populations residing in different areas and even showed apparent geographical gradients. Further linkage disequilibrium analysis showed that the D’ and r2 values were 0.883 and 0.143, respectively. In summary, the findings of our study provide further strong evidence that the MTHFR C677T and A1298C polymorphisms are usually in trans and occasionally in cis configurations. The frequencies of mutant genotype combinations were relatively higher in Chinese population than other populations, and showed geographical variations. These baseline data would be useful for future related studies and for developing health management programs. PMID:27902594

  5. A literature review of MTHFR (C677T and A1298C polymorphisms) and cancer risk.

    Science.gov (United States)

    Izmirli, Muzeyyen

    2013-01-01

    5,10-Methlenetetrahydrofolate reductase (MTHFR) is one of the most important enzymes for folate metabolism. This enzyme is mapped on chromosome 1, which is located at the end of the short arm (1p36.3). The C677T and A1298C are MTHFR polymorphisms that decrease in vitro MTHFR enzyme activity. Folate metabolism plays a key role in cell metabolism. These reactions are associated with purine-pyrimidine synthesis: DNA, RNA, and protein methylation. Polymorphism is also a factor in biodiversity, and be affected by ethnic heritage and geographic locale. In the case of unknown outcomes, not only should all geographical regions be investigated to ascertain biodiversity, but all populations as well to fully understand the variations in the effect. PUBMED was searched from January 2006 to December 2011 to develop an investigatory pursuit strategy. MTHFR, cancer, C677T, A1298C, and polymorphisms were key words used to focus the search. The literature review included all published relevant cancer types and MTHFR polymorphisms for that 5 years period. All selected polymorphisms data for cancer types was listed in tables for easy access and retrieval.

  6. Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism among Gaddi tribe of Indian state of Himachal Pradesh.

    Science.gov (United States)

    Khan, Simi; Thakur, Sunil; Kallur, Saraswathy Nava; Ghosh, Pradeep Kumar; Sachdeva, Mohinder Pal; Vadlamudi, Raghavendra Rao

    2014-01-01

    Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism has been suggested to be positively associated with several disorders. Distribution of the mutant T-allele varies in ethnic and geographical populations of the world. The aim of the present study was to investigate the distribution of methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism in a transhumant (Gaddi) tribal population of Himachal Pradesh dwelling at high and middle altitude and exposed to strong ultraviolet radiation. A total of 486 samples (141 males and 345 females) were randomly enrolled from the individuals aged 25-75 years who were unrelated up to first cousin. Among Gaddis, genotype frequencies of CC, CT and TT were 67.90%, 27.78% and 4.32%, respectively. Among males and females distribution of genotype frequencies also followed a similar trend. The studied population was in Hardy-Weinberg equilibrium (χ(2 )= 2.213, df = 1, p = 0.136). Frequency of mutant T-allele in the Gaddi population was found to be 0.183, which might be due to European ancestry, endogamous nature and selection.

  7. Methylenetetrahydrofolate reductase C677T and overall survival in pediatric acute lymphoblastic leukemia: a systematic review.

    Science.gov (United States)

    Ojha, Rohit P; Gurney, James G

    2014-01-01

    A summary of the evidence pertaining to the association between methylenetetrahydrofolate reductase (MTHFR) C677T and overall survival in pediatric acute lymphoblastic leukemia (ALL) is not currently available. We thus reviewed the literature on the association between MTFHR C677T and overall survival in pediatric ALL. We searched PubMed/MEDLINE, Scopus and ISI Web of Knowledge literature databases without language restrictions to identify observational studies among children diagnosed between ages 0 and 19 years that assessed MTHFR 677 polymorphisms in relation to ALL survival. We identified six studies comprising 909 pediatric patients with ALL. The magnitude of relative risk (RR) for pediatric ALL mortality varied by genotype comparison and study population, ranging from RR = 0.84 (95% confidence limits [CL]: 0.24, 3.0) for a TT vs. CT/CC comparison to RR = 7.0 (95% CL: 0.98, 49) for a TT vs. CC comparison. The current evidence suggests that individuals with MTHFR 677 variants (i.e. at least one T allele) may have a higher relative risk of pediatric ALL mortality, with greater statistical support for MTHFR 677TT. With more detailed supporting evidence, MTHFR 677 genotyping at diagnosis could provide an option for individualizing therapy and further reducing pediatric ALL mortality in certain populations.

  8. MTHFR gene C677T and A1298C variants are associated with FMF risk in a Turkish cohort.

    Science.gov (United States)

    Nursal, Ayse Feyda; Kaya, Süheyla; Sezer, Ozlem; Karakus, Nevin; Yigit, Serbulent

    2017-05-22

    Methylenetetrahydrofolate reductase (MTHFR) is a crucial enzyme in homocysteine (Hcy) metabolism. We aimed to evaluate a possible relationship between MTHFR gene C677T (rs 1801133), A1298C (rs 1801131) variants and susceptibility to FMF in a Turkish cohort. This case-control study included 198 Turkish FMF patients and 100 healthy subjects as controls. MTHFR C677T and A1298C were analyzed by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) methods. The genotype distribution and allele frequency of the MTHFR C677T were statistically different between the patients and the control group (P=.006, P=.001, respectively). The frequency of the TT genotype and T allele of MTHFR C677T was significantly higher in the patients than in the controls. The genotype distribution of MTHFR A1298C variant did not show any statistically significant difference between the patients and the controls (P›.05). The patients had statistically different frequencies in allele C of MTHFR A1298C variant compared with the control (P=.032). We also examined the risk associated with inheriting the combined genotypes for the two MTHFR variants. According to these results, individuals who were CC homozygous at C677T locus and AA homozygous at A1298C locus have a lower risk of developing FMF (P=.002). Individuals who were TT homozygous at C677T locus and AC heterozygous at A1298C locus have higher risk of developing FMF (P=.033). Our findings clearly showed there was an association the MTHFR C677T/A1298C variants and susceptibility to FMF in the Turkish sample. © 2017 Wiley Periodicals, Inc.

  9. The importance of MTHFR C677T/A1298C combined polymorphisms in pulmonary embolism in Turkish population.

    Science.gov (United States)

    Basol, Nursah; Karakus, Nevin; Savas, Asli Yasemen; Kaya, Ilker; Karakus, Kayhan; Yigit, Serbulent

    2016-01-01

    Pulmonary embolism (PE) is an important cardiovascular emergency with high mortality. There are still problems related to the diagnosis of PE and genetic research may play a key role on diagnosis as well as determining risk stratification. In the present study, the aim was to evaluate MTHFR C677T and A1298C polymorphisms that play a role on folate metabolism in PE patients. A total of 118 PE patients and 126 controls were enrolled in the current study. Genomic DNA was isolated and genotyped using polymerase chain reaction (PCR) analyses for the MTHFR C677T and A1298C polymorphisms. There was no association between clinical and demographic characteristics of PE patients and both MTHFR C677T and A1298C polymorphisms. Allele frequencies showed a significant difference between patients and controls. T allele frequency was significantly higher in the patients' group than the control group. There was an association between PE and combined MTHFR C677T and A1298C polymorphisms. We found an association between MTHFR C677T/A1298C combined mutations and PE in the Turkish population. Future genetic studies investigating combined mutations could be very helpful to identify risk population in PE. Copyright © 2016 The Lithuanian University of Health Sciences. Production and hosting by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  10. Folate metabolism gene polymorphisms MTHFR C677T and A1298C and risk for preeclampsia: a meta-analysis.

    Science.gov (United States)

    Wu, Xiaoming; Yang, Kunxian; Tang, Xiaodan; Sa, Yalian; Zhou, Ruoyu; Liu, Jing; Luo, Ying; Tang, Wenru

    2015-05-01

    MTHFR C677T and A1298C have been associated with the risk of preeclampsia (PE), but with conflicting results. We performed this meta-analysis to derive a more precise estimation of the association between MTHFR polymorphisms and PE. An electronic search of PubMed and Chinese Biomedicine database was conducted to select studies for meta-analysis. 54 case controlled studies containing MTHFR C677T and A1298C gene polymorphisms were chosen, and odds ratio (OR) with confidence interval (CI) was used to assess the strength of this association. These studies evaluated 7398 cases and 11230 controls for MTHFR C677T. The overall results suggested that MTHFR C677T was associated with the risk of PE. (T vs. C: OR = 1.157, 95% CI: 1.057-1.266, p = 0.002; TT + CT vs. CC: OR = 1.165, 95% CI : 1.049-1.293, P = 0.004; TT vs. CT + CC: OR = 1.371, 95% CI: 1.153-1.63, p MTHFR A1298C but could not demonstrate an increased risk of PE for this polymorphism (p = 0.667). A symmetric funnel plot, the Egger's test (p = 0.819) suggested a lack of publication bias. This meta-analysis supports the idea that MTHFR C677T genotype is associated with increased risk for PE, especially in the case of Asians and Caucasians.

  11. Methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and fluorouracil-based treatment in Taiwan colorectal cancer.

    Science.gov (United States)

    Wu, Nai-Chun; Su, Shih-Ming; Lin, Tai-Jung; Chin, Jen; Hou, Chun-Fang; Yang, Jhong-Ying; Liu, Wen-Sheng; Chang, Li-Ching

    2015-09-01

    This study aimed to investigate the association between methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and the prognosis of colorectal cancer (CRC) patients undergoing 5-fluorouracil (5-FU)-based chemotherapy in Taiwan. We investigated 126 CRC cases. The most common polymorphisms C677T (rs1801133) and A1298C (rs1801131) in MTHFR were genotyped using PCR-restriction fragment length polymorphism. The frequencies of C677T and A1298C were further compared with those in the HapMap database for Whites and Asians. In this study, we found that TT-homozygosity at MTHFR C677T was significantly associated with survival in CRC patients [PA1298C genotypes had a significant impact on survival (χ=7.103; P=0.029). The MTHFR A1298C CC genotype may increase the risk of death in Taiwanese CRC patients. The MTHFR C677T TT genotype was present at a lower frequency in our CRC patients than in the HapMap Asian population, but the frequency was similar to that in Whites in the HapMap database. The distribution of MTHFR A1298C genotypes was similar in our CRC and in the HapMap Asian population, but was different from that in the White population. This study suggested that MTHFR C677T and A1298C are associated with prognosis in CRC patients undergoing 5-FU-based chemotherapy.

  12. Methylenetetrahydrofolate reductase (C677T and A1298C) polymorphisms, hyperhomocysteinemia, and ischemic stroke in Tunisian patients.

    Science.gov (United States)

    Fekih-Mrissa, Najiba; Mrad, Meriem; Klai, Sarra; Mansour, Malek; Nsiri, Brahim; Gritli, Nasreddine; Mrissa, Ridha

    2013-05-01

    The present study evaluated the role of the methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C gene polymorphisms and correlated these results with plasma homocysteine (Hcy) levels in Tunisian ischemic stroke (IS) patients. Overall, 84 patients with IS were included and compared with 100 healthy controls. The most common stroke risk factors were investigated. Fasting plasma Hcy levels were measured. Genotyping of the MTHFR C677T and A1298 polymorphisms was studied by polymerase chain reaction. Aside from tobacco and alcohol use, the other studied factors were significant risk factors for IS. Mean plasma Hcy levels were significantly higher in IS patients than in controls (16.1 ± 8.28 μmol/L versus 8.76 ± 3.48 μmol/L, P MTHFR 677(CT + TT) and 1298 (AC + CC) genotypes in comparison with controls (P MTHFR 677CT/1298AC (P MTHFR C677T variant (CT and TT genotypes) (P MTHFR A1298C variant (AC and CC genotypes) (P = .31). The MTHFR C677T and A1298 polymorphisms (individually or in concert) and hyperhomocysteinemia represent important risk factors for IS. Elevated Hcy levels were found to be associated with the MTHFR C677T variant; however, no significant association was found with the MTHFR A1298C variant. Copyright © 2013 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  13. Association of methylenetetrahydrofolate reductase A1298C polymorphism but not of C677T with multiple sclerosis in Tunisian patients.

    Science.gov (United States)

    Fekih Mrissa, Najiba; Mrad, Meriem; Klai, Sarra; Zaouali, Jamel; Sayeh, Aycha; Mazigh, Chakib; Nsiri, Brahim; Machgoul, Salem; Gritli, Nasreddine; Mrissa, Ridha

    2013-09-01

    Multiple sclerosis (MS) is a chronic neurological disease characterized by central nervous system (CNS) inflammation and demyelination of nerve axons. The aim of this study was to investigate a possible association between the methylenetetrahydrofolate reductase (MTHFR) gene and multiple sclerosis in Tunisian patients. The genotyping of two missense variants of the methylenetetrahydrofolate reductase (MTHFR) gene, C677T and A1298C was performed in 80 multiple sclerosis patients and 200 healthy controls. No significant differences were found in the frequency of the MTHFR C677T polymorphism between MS patients and healthy controls. However, the genotype prevalence of the missense variant MTHFR A1298C was significantly different between patients and controls (A/C: 55% versus 7%, pMTHFR C677T variants and MS, there is evidence to suggest a significant association between the MTHFR A1298C polymorphisms and MS. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Thermolabile Methylenetetrahydrofolate Reductase C677T Polymorphism and Homocysteine Are Risk Factors for Coronary Artery Disease in Moroccan Population

    Directory of Open Access Journals (Sweden)

    Nawal Bennouar

    2007-01-01

    Full Text Available Increased plasma total homocysteine (tHcy levels have been shown to be a risk factor for coronary artery disease (CAD. The common methylenetetrahydrofolate reductase C677T (MTHFR C677T polymorphism has been reported to be a strong predictor of mild hyperhomocysteinaemia (HHcy. We assessed whether this mutation was associated with increased risk of CAD and plasma levels of tHcy. We also evaluated interactions between this polymorphism, mild elevated tHcy levels and conventional risk factors of CAD. Method. Using PCR-RFLP analysis, we studied the frequency of the C677T genotypes and its effect on CAD and on tHcy concentrations in 400 subjects without and with CAD angiographically confirmed. There were 210 subjects with CAD and 190 subjects without CAD. Results. The frequencies of the C677T genotypes were 53% (59.5% in controls versus 48.1% in cases, 34.8% (32.1 in controls versus 37.1 in cases, and 11.8% (8.4% in controls versus 14.8% in cases, respectively, for 677CC, 677CT, and 677TT. The genotype frequencies were significantly different between case and control groups (P<.05. The 677T allele enhances the risk of CAD associated to HHcy (P<.01. In multivariate analysis models, MTHFR C677T polymorphism effect on CAD was masked by other risk factors. HHcy was only and independently influenced by MTHFR polymorphism and smoking habits, and it is a strong predictor of CAD independently of conventional risk factors. Conclusion. Our data suggest that HHcy is strongly and independently associated to CAD risk increase; and MTHFR C677T polymorphism and smoking habits were the main predictors of tHcy levels. The CAD risk increase is mainly associated with mild HHcy in 677TT, whereas in 677CT and 677CC it is mainly associated with the conventional risk factors.

  15. Genetic polymorphism of MTHFR C677T with preterm birth and low birth weight susceptibility: a meta-analysis.

    Science.gov (United States)

    Wu, Han; Zhu, Ping; Geng, Xingyi; Liu, Zhong; Cui, Liangliang; Gao, Zhongchun; Jiang, Baofa; Yang, Liping

    2017-05-01

    This study aimed at clarifying the association of maternal and neonatal methylenetetrahydrofolate reductase (MTHFR) C677T polymorphisms with preterm birth (PTB) and low birth weight (LBW) susceptibility, respectively. A systematic search of Embase, Medline, China Biological Medicine Database (CBM), Chinese National Knowledge Infrastructure (CNKI), and Wanfang Database was performed before June, 2016. The frequencies of maternal and neonatal MTHFR C677T genotypes in the cases and controls and other information were extracted by two independent investigators. Odds ratios (ORs) with 95% confidence intervals (CIs) were adopted to estimate the relationships between MTHFR C677T polymorphisms and PTB as well as LBW by random or fixed effect models. Twenty-five studies from 20 articles concerning maternal and neonatal MTHFR C677T gene polymorphism with PTB and LBW were included in this study. Maternal MTHFR C677T polymorphism was associated with PTB risk under allele contrast (T vs. C, OR = 1.36, 95% CI 1.02-1.81), homozygote (TT vs. CC, OR = 1.70, 95% CI 1.07-2.68), and recessive (TT vs. CT + CC, OR = 1.49, 95% CI 1.00-2.22) model, but not dominant or heterozygote model. Maternal MTHFR C677T polymorphism was also associated with LBW risk under allele contrast (OR = 1.69, 95% CI 1.25-2.28), homozygote (OR = 2.26, 95% CI 1.44-3.54), dominant (OR = 1.71, 95% CI 1.19-2.47), recessive (OR = 1.79, 95% CI 1.42-2.26) model, but not heterozygote model. No associations between neonatal MTHFR C677T polymorphism and PTB or LBW were found under all genetic models. Identification of maternal MTHFR C677T mutation may play a key role for primary prevention of PTB as well as LBW and screening pregnant women of high risk in developing countries.

  16. Genotype distribution of methylenetetrahydrofolate reductase A1298C and C677T gene in Indonesian infertile men

    Directory of Open Access Journals (Sweden)

    Dwi A. Suryandari

    2012-02-01

    Full Text Available Background: Methylenetetrahydrofolate reductase (MTHFR is an important enzyme of folate and methionin metabolism, making it crucial for DNA synthesis and methylation. Variants of MTHFR C677T and A1298C gene result in reduced plasma folate levels and increase the susceptibility to spermatogenic arrest. This research aims to analyses MTHFR C677T and A1298C gene polymorphism in Indonesian infertile men with azoospermia and oligozoospermia.Methods: This cross sectional study takes 3 mL of blood from 150 infertile men with oligozoospermia and azoospermia. MTHFR gene is analyzed using polymerase chain reaction technique (PCR with specific primers. PCR-RFLP analysis of the MTHFR gene using restriction enzymes MboII and HinfI determines allotypes, both of SNP A1298C and C677T in oligozoospermia and azoospermia in Indonesian population.Results: The results show that the distribution of allotypes of MTHFR gene SNP A1298C and A677T is not significantly different (p>0.05 between patient groups with oligozoospermia and azoospermia.Conclusion: MTHFR gene polymorphisms, both of SNP A1298C and C677T are not associated with male infertility in Indonesian men including patients with severe oligozoospermia and azoospermia. (Med J Indones 2012;21:23-7Keywords: DNA methylation, MTHFR, spermatogenic arrest

  17. Association of C677T polymorphism in the methylenetetrahydrofolate reductase gene (MTHFR gene) with ischemic stroke: a meta-analysis.

    Science.gov (United States)

    Kumar, Amit; Kumar, Pradeep; Prasad, Manya; Sagar, Ram; Yadav, Arun Kumar; Pandit, Awadh Kishor; Jali, Vidishaa Prasad; Pathak, Abhishek

    2015-07-01

    Studies on association between methylenetetrahydrofolate reductase gene (MTHFR) C677T gene polymorphism and ischemic stroke have shown conflicting results. We have conducted a meta-analysis to determine the precise association of the C677T polymorphism of MTHFR gene with risk of ischemic stroke. We searched electronic databases Medline, EMBASE, and Google Scholar (last search dated till August 2014). Pooled odds ratios (ORs) with 95% confidence intervals (CIs) from random or fixed-effects models were calculated. The methodological quality of included studies was determined by the quality assessment scale. Thirty eight case-control studies fulfilled our inclusion criteria comprising 6310 patients and 8297 controls. The significant associations between MTHFR C677T genetic polymorphism and risk of ischemic stroke were observed in dominant (OR, 1·09; 95% CI, 1·06-1·12, P-value MTHFR polymorphism and ischemic stroke was observed (dominant model: OR 1·36, 95% CI 1·23-1·49 and under recessive model OR, 1·29; 95% CI, 1·15-1·45). In the Caucasian population borderline, non-significant association was observed under dominant model of inheritance (OR, 1·05; 95% CI, 0·99-1·10) but significant association was observed under the recessive model of inheritance (OR, 1·33; 95% CI, 1·13-1·58). The present study results suggest that MTHFR C677T genetic polymorphism is a probable risk of ischemic stroke.

  18. The methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and tumor risk: evidence from 134 case-control studies.

    Science.gov (United States)

    Tang, Min; Wang, Shang-Qian; Liu, Bian-Jiang; Cao, Qiang; Li, Bing-Jie; Li, Peng-Chao; Li, Yong-Fei; Qin, Chao; Zhang, Wei

    2014-07-01

    Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme involved in folate metabolism, which is essential for DNA synthesis and methylation. Genetic variations in the MTHFR gene seem to contribute to a decreased activity of MTHFR, ultimately confer increased susceptibility to cancer. As the most extensively studied polymorphism, MTHFR C677T polymorphism was shown to contribute to cancer susceptibility but the results were inconsistent. The authors performed a meta-analysis including 134 studies (46,207 cases and 69,160 controls) to address the issue. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were used to assess the association. Overall, a significant elevated risk of cancer was associated with the MTHFR C677T polymorphism in T-allele versus C-allele comparison (OR = 1.06, 95% CI 1.02-1.11, P(heterogeneity) MTHFR C677T polymorphism and increased risk of esophageal and stomach cancer, especially among Asians. Additionally, more high-quality studies and that the covariates responsible for heterogeneity should be controlled to obtain a more conclusive response about the function of MTHFR C677T in cancer.

  19. MTHFR C677T genotype and cardiovascular risk in a general population without mandatory folic acid fortification

    DEFF Research Database (Denmark)

    Husemoen, Lise Lotte N; Skaaby, Tea; Jørgensen, Torben

    2014-01-01

    Meta-analyses have suggested an effect of MTHFR C677T genotype (rs1801133), a proxy for blood total homocysteine, on cardiovascular disease (CVD) in populations with low population dietary folate. The aim was to examine the association and effect modification by serum folate and vitamin B12 levels...

  20. Prevalence of MTHFR C677T Polymorphism in North Indian Mothers Having Babies with Trisomy 21 Down Syndrome

    Science.gov (United States)

    Kohli, Utkarsh; Arora, Sadhna; Kabra, Madhulika; Ramakrishnan, Lakshmy; Gulati, Sheffali; Pandey, Ravindra

    2008-01-01

    Recent studies have evaluated possible links between polymorphisms in maternal folate metabolism genes and Down syndrome. Some of these studies show a significantly increased prevalence of the C677T polymorphism of the 5,10-methylene tetrahydrofolate reductase (NADPH) gene (MTHFR) among mothers who have had babies with Down syndrome. This study…

  1. Methylenetetrahydrofolate Reductase C677T Polymorphism and Recurrent Pregnancy Loss Risk in Asian Population: A Meta-analysis.

    Science.gov (United States)

    Rai, Vandana

    2016-10-01

    The C677T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene was implicated to be associated with thrombophilia due to its role in catalyzing the formation of 5-methylenetetrahydrofolate, a co-substrate for the conversion of homocysteine to methionine. Several case-control studies were investigated MTHFR C677T polymorphism as risk for recurrent pregnancy loss (RPL). These studies rendered contradictory results, some indicating that the polymorphism is associated with the risk of RPL whereas others concluded there is no association. To shed light on these inconclusive findings, a meta-analysis of all available studies published from Asian population relating the C677T polymorphism to the risk of RPL was conducted. The following electronic databases were searched without language restrictions: PubMed, Google Scholars, Elsevier and Springer Link up to December, 2015. Meta-analysis was performed using MetaAnalyst and Mix version 1.7. Meta-analysis results suggested that MTHFR C677T polymorphism contributed to the increased RPL risk in Asian population using all five genetic models (for T vs. C: OR 1.35, 95 % CI 1.09-1.68, p = 0.009; for TT + CT vs. CC: OR 1.44, 95 % CI 1.14-1.82, p = 0.006; for CT vs. CC: OR 1.39, 95 % CI 1.07-1.8, p = 0.01; for TT vs. CC: OR 1.79, 95 % CI 1.23.2.6, p = 0.007; for TT vs. CT + CC: OR 1.61, 95 % CI 1.02-2.56, p = 0.04). In conclusion, this meta-analysis demonstrates a strong association between the MTHFR C677T variant and RPL in Asian population and raising the importance of the use of folate in its treatment and prevention.

  2. MTHFR C677T and A1298C polymorphisms and risk of lung cancer: a comprehensive evaluation.

    Science.gov (United States)

    Yang, Y; Yang, L J; Deng, M Z; Luo, Y Y; Wu, S; Xiong, L; Wang, D; Liu, Y; Liu, H

    2016-04-07

    Results from previous studies on the association between methylenetetrahydrofolate reductase (MTHFR) polymorphisms C677T and A1298C and lung cancer have been conflicting. The aim of this meta-analysis was to clarify the effect of MTHFR polymorphisms on the risk of lung cancer. An electronic search of PubMed, EMBASE, the Cochrane library, and the China Knowledge Resource Integrated Database for papers on C677T and A1298C and susceptibility to lung cancer was performed. The STATA software (Version 13.0) was used for statistical analysis. Statistical heterogeneity, tests of publication bias, and a sensitivity analysis were performed. Twenty-six studies on C677T (12,324 cases and 12,532 controls) and thirteen studies on A1298C (6773 cases and 8207 controls) were included in the meta-analysis. The MTHFR C677T polymorphism showed significant pooled ORs for the homozygote comparison (TT versus CC: OR = 1.518, 95%CI = 1.220-1.890), heterozygote comparison (CT versus CC: OR = 1.053, 95%CI = 0.940-1.179), dominant model (CT + TT versus CC: OR = 1.143, 95%CI = 1.013-1.291), recessive model (TT versus CT + CC: OR = 1.435, 95%CI = 1.190-1.730), and additive model (T versus C: OR = 1.176, 95%CI = 1.066-1.298). In summary, our meta-analysis showed that the MTHFR C677T polymorphism is associated with a significant increase in lung cancer risk in Asian and overall populations, but not in Caucasian populations. However, no significant association between the MTHFR A1298C polymorphism and lung cancer risk was found in either the Caucasian or Asian group with any genetic models.

  3. Role of methylenetetrahydrofolate reductase C677T and A1298C polymorphisms in polycystic ovary syndrome risk.

    Science.gov (United States)

    Wu, J B; Zhai, J F; Yang, J

    2016-12-23

    Polycystic ovary syndrome is one of the most frequently encountered endocrine malfunctions. Methylenetetrahydrofolate reductase (MTHFR) plays a vital role in folate metabolism, DNA methylation, and RNA synthesis. We carried out a study to investigate the association between MTHFR C677T and A1298C genetic variations and the risk of polycystic ovary syndrome in a Chinese population. We recruited 244 patients and 257 control subjects from an Inner Mongolian Medical University to this hospital-based, case-control study. The genotyping of the MTHFR C677T and A1298C polymorphisms was carried out using polymerase chain reaction coupled with restriction fragment length polymorphism. Using multiple logistic regression analysis, we found that the TT genotype and the T allele of MTHFR C677T carriers showed increased risk of polycystic ovary syndrome compared with the wild-type genotype or allele carriers. The adjusted ORs for the TT genotype and the T allele of MTHFR C677T were 1.84 (1.05-3.26) and 1.38 (1.06-1.81), respectively. Subjects carrying the CC genotype (OR = 3.98, 95%CI = 1.60-11.23) and the C allele (OR = 1.46, 95%CI = 1.07-2.00) of MTHFR A1298C had an elevated risk of polycystic ovary syndrome compared with the AA genotype and A allele carriers. In conclusion, our study suggests that the MTHFR C677T and A1298C polymorphisms may have contributed to the risk of polycystic ovary syndrome in the Chinese women investigated. Further research involving a greater number of individuals is warranted to confirm our results.

  4. Association of the methylenetetrahydrofolate reductase gene C677T polymorphism with the risk of male infertility: a meta-analysis.

    Science.gov (United States)

    Zhu, Xudong; Liu, Zhiguo; Zhang, Maochen; Gong, Ruihong; Xu, Yajun; Wang, Baoming

    2016-01-01

    Several molecular epidemiological studies have been conducted to examine the association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and male infertility susceptibility, but the results remain inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. In this meta-analysis, a total of 26 case-control studies including 5659 infertility cases and 5528 controls were selected to evaluate the possible association. The pooled odds ratios (ORs) with 95% confidence intervals (95% CIs) were used to assess the strength of association of C677T polymorphism with male infertility in the additive model, dominant model, recessive model and allele-frequency genetic model. In the overall analysis, the frequency of the 677T allele was significantly associated with male infertility susceptibility (OR = 2.32, 95%CI = 2.04-2.65 for TT vs. CC genotype; OR = 1.09, 95%CI = 1.00-1.19 for CT vs. CC genotype; OR = 1.19, 95%CI = 1.10-1.29 for CT/TT vs. CC genotype; OR = 1.54, 95%CI = 1.36-1.74 for TT vs. CC/TT genotype; OR = 1.22, 95%CI = 1.15-1.30 for T vs. C allele). A subgroup analysis of the subjects showed that significantly strong association between MTHFR C677T polymorphism and male infertility was present only in Asians, but not in Caucasians. Additionally, MTHFR C677T was associated with a significant increase in the risk of azoospermia in all genetic models. Meanwhile, no significantly increased risks of oligoasthenotertozoospermia (OAT) were found in most of the genetic models. In conclusion, this meta-analysis is in favor that the MTHFR C677T polymorphism is capable of causing male infertility susceptibility, especially in Asians and the subgroup of azoospermia.

  5. Risk of venous thromboembolism associated with single and combined effects of Factor V Leiden, Prothrombin 20210A and Methylenetethraydrofolate reductase C677T

    DEFF Research Database (Denmark)

    Simone, Benedetto; De Stefano, Valerio; Leoncini, Emanuele

    2013-01-01

    Genetic and environmental factors interact in determining the risk of venous thromboembolism (VTE). The risk associated with the polymorphic variants G1691A of factor V (Factor V Leiden, FVL), G20210A of prothrombin (PT20210A) and C677T of methylentetrahydrofolate reductase (C677T MTHFR) genes ha...

  6. Methylenetetrahydrofolate reductase C677T and A1298C polymorphism and susceptibility to acute lymphoblastic leukemia in a cohort of Egyptian children.

    Science.gov (United States)

    Mosaad, Youssef M; Abousamra, Nashwa K; Elashery, Rasha; Fawzy, Iman M; Eldein, Omar A Sharaf; Sherief, Doaa M; El Azab, Hend M M

    2015-01-01

    This case-control study was planned to investigate the possible role of methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms as a risk factor for the development of acute lymphoblastic leukemia (ALL) in a cohort of Egyptian children. Typing of MTHFR C677T and A1298C polymorphisms was done using restriction fragment length polymorphism (RFLP) for 100 children with ALL and 100 age- and sex-matched healthy controls. No significant differences were found between patients with ALL and controls for the frequency of MTHFR C677T and A1298C alleles, genotypes, combined genotypes or haplotypes. The C677T and A1298C genotype frequency was different from that in Korean and Chinese populations (p 0.5). Our findings suggest that MTHFR C677T and A1298C polymorphisms are unlikely to affect the development of childhood ALL in an Egyptian population from Delta.

  7. Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and susceptibility to diabetic nephropathy in Chinese type 2 diabetic patients: a meta-analysis.

    Science.gov (United States)

    Chang, Wei-wei; Zhang, Liu; Yao, Ying-shui; Su, Hong; Jin, Yue-long; Chen, Yan

    2013-08-01

    The association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and diabetic nephropathy (DN) or diabetes mellitus (DM) risk has been widely reported, but the results are still debatable. To investigate the role of MTHFR C677T polymorphism on DM or DN, 13 separate studies in the Chinese population on the relation between MTHFR C677T polymorphism and DM or DN were analyzed by a meta-analysis. Five genetic models were used to estimate the association between MTHFR C677T polymorphism and the risk of DM or DN. Overall, our meta-analysis for DN versus healthy controls produced significant results for all genetic contrasts except for the co-dominant model (allele contrast: OR = 2.24, 95%CI: 1.88-2.65, p MTHFR C677T polymorphism might influence DN risk, but not for DM in the Chinese population.

  8. Evaluation of the MTHFR C677T Polymorphism as a Risk Factor for Colorectal Cancer in Asian Populations.

    Science.gov (United States)

    Rai, Vandana

    2015-01-01

    Genetic and environmental factors play important roles in pathogenesis of digestive tract cancers like those in the esophagus, stomach and colorectum. Folate deficiency and methylenetetrahydrofolate reductase (MTHFR) as an important enzyme of folate and methionine metabolism are considered crucial for DNA synthesis and methylation. MTHFR variants may cause genomic hypomethylation, which may lead to the development of cancer, and MTHFR gene polymorphisms (especially C677T and A1298C) are known to influence predispositions for cancer development. Several case control association studies of MTHFR C677T polymorphisms and colorectal cancer (CRC) have been reported in different populations with contrasting results, possibly reflecting inadequate statistical power. The present meta-analysis was conducted to investigate the association between the C677T polymorphism and the risk of colorectal cancer. A literature search of the PubMed, Google Scholar, Springer link and Elsevier databases was carried out for potential relevant articles. Pooled odds ratio (OR) with corresponding 95 % confidence interval (95 % CI) was calculated to assess the association of MTHFR C677T with the susceptibility to CRC. Cochran's Q statistic and the inconsistency index (I2) were used to check study heterogeneity. Egger's test and funnel plots were applied to assess publication bias. All statistical analyses were conducted by with MetaAnalyst and MIX version 1.7. Thirty four case-control studies involving a total of 9,143 cases and 11,357 controls were retrieved according to the inclusion criteria. Overall, no significant association was found between the MTHFR C677T polymorphism and colorectal cancer in Asian populations (for T vs. C: OR=1.03; 95% CI= 0.92-1.5; p= 0.64; for TT vs CC: OR=0.88; 95%CI= 0.74-1.04; p= 0.04; for CT vs. CC: OR = 1.02; 95%CI= 0.93-1.12; p=0.59; for TT+ CT vs. CC: OR=1.07; 95%CI= 0.94-1.22; p=0.87). Evidence from the current meta-analysis indicated that the C677T

  9. MTHFR C677T and A1298C polymorphisms: diet, estrogen, and risk of colon cancer.

    Science.gov (United States)

    Curtin, Karen; Bigler, Jeannette; Slattery, Martha L; Caan, Bette; Potter, John D; Ulrich, Cornelia M

    2004-02-01

    5,10-methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in folate metabolism, diverting metabolites toward methylation reactions or nucleotide synthesis. Using data from an incident case-control study (1608 cases and 1972 controls) we investigated two polymorphisms in the MTHFR gene, C677T and A1298C, and their associations with risk of colon cancer. All of the combined genotypes were evaluated separately, and the 1298AA/677CC (wild-type/wild-type) group was considered the reference group. Among both men and women, the 677TT/1298AA (variant/wild-type) genotype was associated with a small reduction in risk [men: odds ratio (OR), 0.7, 95% confidence interval (CI), 0.5-1.0; women: OR, 0.8, 95% CI, 0.5-1.2]. However, the 677CC/1298CC (wild-type/variant) genotype was associated with a statistically significant lower risk among women (OR, 0.6; 95% CI, 0.4-0.9) but not men. When the polymorphisms were considered individually, for A1298C a significant risk reduction associated with the homozygous variant CC genotype was seen among women only (OR, 0.6; 95% CI, 0.5-0.9), and nonstatistically significant reduced risks were observed for the variant 677 TT genotypes among both men and women. Stratification by nutrient intakes showed inverse associations with higher intakes of folate, vitamin B(2), B(6), B(12), and methionine among women with the MTHFR 677CC/1298AA genotypes, but not those with 677TT/1298AA. We observed opposite risk trends for both MTHFR variants, depending on whether women used hormone-replacement therapy or not (P for interaction = A1298C polymorphism may be a predictor of colon cancer risk and have functional relevance. The possible interaction with hormone-replacement therapy warrants additional investigation.

  10. C677T methylenetetrahydrofolate reductase and plasma homocysteine levels among Thai vegans and omnivores.

    Science.gov (United States)

    Kajanachumpol, Saowanee; Atamasirikul, Kalayanee; Tantibhedhyangkul, Phieuvit

    2013-01-01

    Hyperhomocysteinemia among vegetarians and vegans is caused mostly by vitamin B12 deficiency. A C-to-T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene results in a thermolabile MTHFR, which may affect homocysteine (Hcy) levels. The importance of this gene mutation among populations depends on the T allele frequency. Blood Hcy, vitamin B12, folate, vitamin B6, and MTHFR C677T mutation status were determined in 109 vegans and 86 omnivores aged 30 - 50 years. The vegans had significantly higher Hcy levels than the omnivores, geometric means (95 % CI) 19.2 (17.0 - 21.7) µmol/L vs. 8.53 (8.12 - 8.95) µmol/L, p vegans increased plasma Hcy, albeit insignificantly; geometric means 18.2 µmol/L, 20.4 µmol/L, and 30.0 µmol/L respectively in CC, CT, and TT MTHFR genotypes. There was also a significant decrease in serum folate; geometric means 12.1 ng/mL, 9.33 ng/mL, and 7.20 ng/mL respectively, in the CC, CT, and TT mutants, p = 0.006, and particularly, in the TT mutant compared with the CC wild type, 7.20 ng/mL vs. 12.1 ng/mL, p = 0.023. These findings were not seen in the omnivores. It was concluded that hyperhomocysteinemia is prevalent among Thai vegans due to vitamin B12 deficiency. C-to-T MTHFR mutation contributes only modestly to the hyperhomocysteinemia.

  11. C677T and A1298C methylenetetrahydropholate reductase (MTHFR) polymorphisms as factors involved in ischemic stroke.

    Science.gov (United States)

    Arsene, D; Găină, Gisela; Bălescu, Carmen; Ardeleanu, Carmen

    2011-01-01

    Ischemic stroke is a major health problem. Data regarding the possible association between ischemic stroke and the polymorphism of methylenetetrahydropholate reductase (MTHFR) C677T and A1298C are still conflictual. The study tried to assess the association of the two MTHFR polymorphisms with ischemic stroke in a series of patients from a unique hospital center. The study comprised a total of 127 patients (67 with non-cardioembolic ischemic stroke diagnosed by computed tomography or magnetic resonance imaging) and 60 control cases. The method we used was reverse hybridization performed on peripheral blood for C677T and A1298C polymorphisms. In all patients a careful clinical examination, laboratory analyses of cholesterol, glucose amount and triglycerides, as well as their medical history were available. The mean age of stroke patients was 68.73 years, and 55.2% were males. Gene analysis for C677T disclosed the presence of TT genotype in more control subjects than in stroke series (15% and 7.46% respectively). Also, the overall T allele (CT+TT cases) was present in 71.6% of control cases, as compared with 44.7% stroke patients. 1298C allele was almost equally distributed among the two series. No statistically significant correlations of the two genotypes with infarct localization and dimensions ant with other potential risk factors (hypertension, lipids, diabetes mellitus) were observed. The two MTHFR polymorphisms, C677T and A1298C, seemed not related to the onset of ischemic stroke in our study. However, they could be rather involved in hemorrhagic stroke, as seen in our control patients. Further evaluation on larger series is mandatory since homocysteine activity (related to MTHFR activity) could be easily influenced by folate or cobalamin derivatives.

  12. Methylenetetrahydrofolate reductase C677T polymorphism in patients with gastric and colorectal cancer in a Korean population

    Directory of Open Access Journals (Sweden)

    Hwang Jun

    2010-05-01

    Full Text Available Abstract Background This study was designed to investigate an association between the methylenetetrahydrofolate reductase (MTHFR C677T polymorphism and the risk of gastric and colorectal cancer in the Korean population. Methods We conducted a population-based large-scale case-control study involving 2,213 patients with newly diagnosed gastric cancer, 1,829 patients with newly diagnosed colorectal cancer, and 1,700 healthy controls. Genotyping was performed with peripheral blood DNA for MTHFR C677T polymorphisms. The statistical significance was estimated by logistic regression analysis. Results The MTHFR C677T frequencies of CC, CT, and TT genotypes were 35.2%, 47.5%, and 17.3% among stomach cancer, 34%, 50.5%, and 15.5% in colorectal cancer, and 31.8%, 50.7%, and 17.5% in the controls, respectively. The MTHFR 677TT genotype showed a weak opposite association with colorectal cancer compared to the homozygous CC genotype [adjusted age and sex odds ratio (OR = 0.792, 95% confidence interval (CI = 0.638-0.984, P = 0.035]. Subjects with the MTHFR 677CT showed a significantly reduced risk of gastric cancer compared whose with the 677CC genotype (age- and sex-adjusted OR = 0.810; 95% CI = 0.696-0.942, P = 0.006. We also observed no significant interactions between the MTHFR C677T polymorphism and smoking or drinking in the risk of gastric and colorectal cancer. Conclusions The T allele was found to provide a weak protective association with gastric cancer and colorectal cancer.

  13. Methylenetetrahydrofolate reductase (MTHFR) C677T/A1298C polymorphisms and susceptibility to Parkinson's disease: a meta-analysis.

    Science.gov (United States)

    Wu, Yi-Le; Ding, Xiu-Xiu; Sun, Ye-Huan; Yang, Hui-Yun; Sun, Liang

    2013-12-15

    The association between the methylenetetrahydrofolate reductase (MTHFR) C677T/A1298C polymorphisms and susceptibility to Parkinson's disease (PD) was controversial in previous studies. The present study was therefore designed to investigate a more reliable estimate. 15 studies were identified by a search of PubMed, EBMBASE, PDGENE, Elsevier, Springer Link, CBM (Chinese Biomedical Database), CNKI (Chinese National Knowledge Infrastructure), VIP (Chinese), and Wanfang (Chinese) databases, up to April 2013. Odds ratios (ORs) with corresponding 95% confidence interval (CI) were calculated using fixed effects model or random effects model. The subgroup analyses were made on the ethnicity. MTHFR C677T polymorphism had a significant association with susceptibility to PD in all genetic models (for T vs. C: OR=1.24, 95% CI=1.11-1.38; for TT+CT vs. CC: OR=1.27, 95% CI=1.10-1.46; for TT vs. CC: OR=1.56, 95% CI=1.22-1.98; for TT vs. CT+CC: OR=1.43, 95% CI=1.14-1.79). Subgroup analyses by ethnicity revealed that the association between the MTHFR C677T polymorphism and PD existed in Caucasian population and Asian population. However, no association was detected between the MTHFR A1298C polymorphism and PD. Results from this meta-analysis supported that the MTHFR C677T polymorphism was associated with an increased risk of PD. The MTHFR A1298C polymorphism may not increase the susceptibility to PD. Further studies are required to confirm our findings. © 2013.

  14. Polymorphism (C677T) in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene: A preliminary study on north Indian men

    OpenAIRE

    Vasisht, S.; Gulati, R; R. Narang; Srivastava, N.; Srivastava, L. M.; Manchanda, S. C.; Agarwal, D. P.

    2002-01-01

    An elevated level of plasma homocysteine, sulfur containing amino acid generated through demethylation of methionine has been widely accepted as a risk factor for cardiovascular disease (CVD). The increase can result from genetic and/or nutrient related disturbances in the remethylation or transsulfuration pathways for homocysteine metabolism. A common mutation (C677T) in the gene encoding for the enzyme 5, 10-methylenetetrahydrofolate reductase (MTHFR) or deficiency of the B vitamins namely ...

  15. MTHFR Gene C677T Mutation and ACE Gene I/D Polymorphism in Turkish Patients with Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Ahmet Inanir

    2013-01-01

    Full Text Available Osteoarthritis is a degenerative joint disorder resulting in destruction of articular cartilage, osteophyte formation, and subchondral bone sclerosis. In recent years, numerous genetic factors have been identified and implicated in osteoarthritis. The aim of the current study was to examine the influence of methylenetetrahydrofolate reductase (MTHFR gene C677T mutation and angiotensin converting enzyme (ACE gene insertion/deletion (I/D variations on the risk of osteoarthritis.

  16. Association of MTHFR C677T polymorphism with loneliness but not depression in cognitively normal elderly males.

    Science.gov (United States)

    Lan, Wen-Hsuan; Yang, Albert C; Hwang, Jen-Ping; Hong, Chen-Jee; Liou, Ying-Jay; Yeh, Heng-Liang; Liu, Mu-En; Tsai, Shih-Jen

    2012-07-11

    Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism is involved in folate and homocysteine metabolism, and has been associated with geriatric disorders, including dementia and late-life depression. The present work aimed to investigate the effect of MTHFR C677T polymorphism on the presence of depression and loneliness in cognitively normal male subjects. A total of 323 cognitively normal male subjects were included in this study (mean age=80.6; SD=5.3). Depression was assessed by the Geriatric Depression Scale-Short Form (GDS-SF) and loneliness by UCLA loneliness scales. Analysis of variance (ANOVA) was used to test the between MTHFR genotype difference in depression and loneliness. Multiple regression was used to test the effect of MTHFR polymorphism on the loneliness, controlling for age, education, cognitive function, and depression. ANOVA showed a significant between-genotype difference in loneliness scores (P=0.015), and post hoc comparisons showed that subjects with C/C genotype had significantly higher loneliness ratings, compared to those with C/T or T/T genotype. Regression analysis indicated that the effect of MTHFR polymorphism on loneliness was independent of age, education, cognitive function, and depression. Our findings suggest that MTHFR C677T polymorphism may be linked more to loneliness than depression in the cognitively normal elderly males, and may be implicated in the pathophysiology of late-life depression in relation to MTHFR genes. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  17. Association of methylenetetrahydrofolate reductase (A1298C and C677T) polymorphisms with retinal vein occlusion in Tunisian patients.

    Science.gov (United States)

    Mrad, Meriem; Wathek, Cheima; Saleh, Mekki Ben; Baatour, Makrem; Rannen, Riadh; Lamine, Khaled; Gabsi, Salem; Gritli, Nasreddine; Fekih-Mrissa, Najiba

    2014-04-01

    The role of two polymorphisms C677T and A1298C of the methylenetetrahydrofolate reductase (MTHFR) gene in the etiology of retinal vein occlusion (RVO) has not been adequately clarified. The aim of this study was to examine the prevalence of these polymorphisms among RVO Tunisian patients with and without systemic risk factors. Seventy-two patients with retinal vein occlusion (RVO) were studied. The control group included140 people matched for age, sex, and risk factors. Participants in the study were genotyped for the MTHFR C677T and A1298C polymorphisms. The genotyping was performed by PCR-RFLP. No significant differences were found in the frequencies of the three genotypes (AA, AC, CC) of the MTHFR A1298C polymorphism between RVO patients and healthy controls. However, the prevalence of the group of mutated genotypes (AC+CC) of the missense variant MTHFR A1298C was significantly different between patients and controls (16.67% vs. 6.42%, p=.01). Additionally, the frequency of the CT genotype as well as the group of combined mutated genotypes (CT+TT) for the C677T variant was significantly higher among RVO patients compared with controls (p<10(-3), p<10(-3)). This suggests an association between this polymorphism and RVO. Large study populations would be required to understand more completely the contribution of these markers in the risk of RVO. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Methylenetetrahydrofolate reductase C677T and A1298C variants do not affect ongoing pregnancy rates following IVF.

    Science.gov (United States)

    Dobson, A T; Davis, R M; Rosen, M P; Shen, S; Rinaudo, P F; Chan, J; Cedars, M I

    2007-02-01

    There is concern that IVF could compromise normal imprinting and methylation of DNA. Methylenetetrahydrofolate reductase (MTHFR) regulates the flow of folic acid-derived, one-carbon moieties for methylation and is critical to early embryonic development. Therefore, we hypothesized that common polymorphisms in MTHFR could associate with IVF outcome. MTHFR C677T and A1298C polymorphism genotyping was performed on 374 subjects for this study, representing 197 couples undergoing IVF in a university setting from July 2005 to January 2006. Analysis of variance (ANOVA), chi-square and/or multivariate analyses were used to assess whether these polymorphisms are associated with embryo quality or with ongoing pregnancy or spontaneous abortion rates. Allele frequencies for C677T ( p=0.67, q=0.33) and A1298C ( p=0.71, q=0.29) were in Hardy-Weinberg equilibrium. The C677T and A1298C variants, either alone or in combination, did not associate with embryo quality or short-term pregnancy outcome. The common polymorphisms in MTHFR are not associated with embryo quality, as defined by cell number or fragmentation score, or with short-term pregnancy outcomes. Therefore, in our population in which women receive adequate folic acid, MTHFR genotypes are not informative in explaining IVF failure. Further studies, however, examining birth outcomes and the other enzymes in the folic acid pathway are warranted.

  19. Methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism and diabetic nephropathy susceptibility in patients with type 2 diabetes mellitus.

    Science.gov (United States)

    Zhou, Tian-Biao; Drummen, Gregor P C; Jiang, Zong-Pei; Li, Hong-Yan

    2015-01-01

    Methylenetetrahydrofolate reductase (MTHFR) is a crucial enzyme that regulates nucleotide synthesis and DNA methylation. The MTHFR C677T gene polymorphism (rs1801133), a C → T transition at nucleotide 677 in exon 4, is a common gene variant of MTHFR and has been implicated in diabetic nephropathy, albeit with inconsistent results. Here, we performed a meta-analysis to assess the common effect size of this polymorphism on DN susceptibility. Case-control studies on the association of the MTHFR C677T gene polymorphism with DN risk were retrieved from databases up to August 1, 2013, and eligible studies were recruited into the meta-analysis and further analyzed. Of 132 studies, 33 were identified as suitable for this analysis. The results showed that T allele and TT genotype were distinctly associated with DN susceptibility in the overall population and Asians, and might be a risk factor in Caucasians and Africans (T allele: Overall population: p MTHFR C677T T allele or TT genotype might be a significant genetic molecular marker to determine the risk of DN in patients with type 2 diabetes and help to develop suitable disease prevention and management strategies.

  20. Risk of colorectal cancer associated with the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism in the Kashmiri population.

    Science.gov (United States)

    Sameer, A S; Shah, Z A; Nissar, S; Mudassar, S; Siddiqi, M A

    2011-06-21

    Methylenetetrahydrofolate reductase (MTHFR) is a critical enzyme in folate metabolism and is involved in DNA synthesis, DNA repair and DNA methylation. The two common functional polymorphisms of MTHFR, 677 C→T and 1298 A→C, have been shown to impact various diseases, including cancer. The 677 C→T polymorphism has been widely investigated in different cancers and has been implicated as a risk factor for the development of various cancers. We investigated MTHFR C677T genotype frequency in colorectal cancer cases in the Kashmiri population and correlated this information with the known clinicopathological characters of colorectal cancer, in a case-control study. Eighty-six colorectal cancer cases were studied for MTHFR C677T polymorphism, compared to 160 controls taken from the general population, employing the PCR-RFLP technique. We found the frequency of the three different genotypes of MTHFR in our ethnic Kashmir population, i.e., CC, CT and TT, to be 68.6, 20.9 and 10.4% among colorectal cancer cases and 75.6, 16.9 and 7.5% among the general control population, respectively. There was a significant association between the MTHFR TT genotype and colorectal cancer in the higher age group. We conclude that the MTHFR C677T polymorphism slightly increases the risk for colorectal cancer development in our ethnic Kashmir population.

  1. C677T and A1298C polymorphisms of methylene tetrahydrofolate reductase in non-Hodgkin lymphoma: southeast Iran.

    Science.gov (United States)

    Mashhadi, Mohammad Ali; Miri-Moghaddam, Ebrahim; Arbabi, Narges; Bazi, Ali; Heidari, Zahra; Sepehri, Zahra; Karimkoshte, Azra; Rezvan, Alireza; Hashemi, Seyed Mahdi

    2017-04-14

    Polymorphisms of the methylene tetrahydrofolate reductase (MTHFR) gene have been reported as risk factors for non-Hodgkin lymphoma (NHL) in some populations. Our goal was to evaluate the potential role of A1298C and C677T polymorphisms of MTHFR in risk of NHL in southeast Iran. In the present case-control study, 127 patients with newly diagnosed NHL along with 150 ethnicity- and age-matched controls were examined. The A1298C and C677T polymorphisms were genotyped using the Tetra Amplification Refractory Mutation System polymerase chain reaction method. There were no significant differences in genotype frequencies between cases and controls regarding either A1298C polymorphism. For this polymorphism, 53.8% of the controls and 54.3% of the patients with NHL showed homozygous wild-type (AA) genotype. Variant 1298C allele was recognized with overall frequency of 34.6% in both groups. Frequencies of CC, CT, and TT genotypes of C677T polymorphism were observed in 73.1%, 25.8%, and 1.3% of the controls, and 64.5%, 33.1%, and 2.4% of the patients with NHL (p>0.05). In combination, CT + TT conferred a significantly higher risk of NHL (odds ratio [OR] 1.5, 95% confidence interval [CI] 0.9-2.4, p = 0.03). Overall, variant 677T allele presented with higher frequency in the patients with NHL than the controls (26.7% versus 21.3%, respectively; OR 1.3, 95% CI 0.8-2.1, p>0.05). Although statistically insignificant, the highest risk of NHL was identified in patients with C677T; A1298C: CT; CC haplotype (OR 4.7, 95% CI 0.4-46.4, p = 0.1). Combination of CT and TT genotypes of C677T polymorphism conferred a significantly higher risk for NHL. It is recommended to investigate further the potential role of this polymorphism in NHL development.

  2. Methylenetetrahydrofolate reductase polymorphism (C677T), hyperhomocysteinemia, and risk of ischemic cardiovascular disease and venous thromboembolism: prospective and case-control studies from the Copenhagen City Heart Study

    DEFF Research Database (Denmark)

    Frederiksen, Jeppe; Juul, Klaus; Grande, Peer

    2004-01-01

    Hyperhomocysteinemia is associated with ischemic cardiovascular disease (ICD) and venous thromboembolism (VTE). We tested the hypothesis that methylenetetrahydrofolate reductase (MTHFR) C677T homozygosity with hyperhomocysteinemia is associated with ICD and VTE. First, 9238 randomly selected whites......) and 19% in ICD/VTE cases versus controls (P MTHFR C677T homozygosity was not associated with increased risk of ICD or VTE in subgroups after stratification...... in homozygotes versus noncarriers did not differ from 1.0. In conclusion, MTHFR C677T homozygosity with hyperhomocysteinemia is not associated with ICD or VTE; however, ICD/VTE is associated with hyperhomocysteinemia. Therefore, ICD and VTE may cause hyperhomocysteinemia, rather than vice versa....

  3. Methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and age of onset in schizophrenia: A combined analysis of independent samples

    DEFF Research Database (Denmark)

    Saetre, Peter; Vares, Maria; Werge, Thomas

    2011-01-01

    Methylenetetrahydrofolate reductase (MTHFR) is involved in the one-carbon cycle, which is of importance for nucleotide synthesis and methylation of DNA, membranes, proteins and lipids. The MTHFR gene includes two common polymorphisms (rs1801133 or C677T; rs1801131 or A1298C) which both alter enzyme...... activity. The T-allele of the C677T polymorphism has recently been associated with earlier age at onset of schizophrenia. In the present study we examined the association between the MTHFR C677T and A1298C polymorphisms and age at onset of schizophrenia in twelve samples consisting of 3,213 unrelated...... schizophrenia patients, including the original Scandinavian sample. There was no consistent relationship between MTHFR C677T, A1298C or combined 677T/1298C carriers and age of onset in schizophrenia when the results of each study were combined using meta-analysis. The present results suggest...

  4. Association between the MTHFR C677T polymorphism and risk of cancer: evidence from 446 case-control studies.

    Science.gov (United States)

    Xie, Shu-Zhe; Liu, Zhi-Zhong; Yu, Jun-hua; Liu, Li; Wang, Wei; Xie, Dao-Lin; Qin, Jiang-Bo

    2015-11-01

    Many molecular epidemiological studies have been performed to explore the association between MTHFR C677T polymorphism and cancer risk in diverse populations. However, the results were inconsistent. Hence, we performed a meta-analysis to investigate the association between cancer risk and MTHFR C677T (150,086 cases and 200,699 controls from 446 studies) polymorphism. Overall, significantly increased cancer risk was found when all eligible studies were pooled into the meta-analysis. In the further stratified and sensitivity analyses, significantly increased breast cancer risk was found in Asians and Indians, significantly decreased colon cancer risk was found, significantly decreased colorectal cancer risk was found in male population, significantly increased gastric cancer risk was found in Caucasians and Asians, significantly increased hepatocellular cancer risk was found in Asians, significantly decreased adult acute lymphoblastic leukemia (AALL) risk was found in Caucasians, significantly decreased childhood acute lymphoblastic leukemia (CALL) risk was found in Asians, and significantly increased multiple myeloma and NHL risk was found in Caucasians. In summary, this meta-analysis suggests that MTHFR C677T polymorphism is associated with increased breast cancer, gastric cancer, and hepatocellular cancer risk in Asians, is associated with increased gastric cancer, multiple myeloma, and NHL risk in Caucasians, is associated with decreased AALL risk in Caucasians, is associated with decreased CALL risk in Asians, is associated with increased breast cancer risk in Asians, is associated with decreased colon cancer risk, and is associated with decreased colorectal cancer risk in male population. Moreover, this meta-analysis also points out the importance of new studies, such as Asians of HNC, Asians of lung cancer, and Indians of breast cancer, because they had high heterogeneity in this meta-analysis (I(2) > 75%).

  5. Methylenetetrahydrofolate reductase gene C677T, A1298C polymorphisms and pre-eclampsia risk: a meta-analysis.

    Science.gov (United States)

    Li, Xing; Luo, Ya L; Zhang, Qiong H; Mao, Chen; Wang, Xi W; Liu, Shan; Chen, Qing

    2014-08-01

    To determine whether methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms are associated with pre-eclampsia susceptibility. Literature searches of the Pubmed, Embase, BIOSIS Previews and Web of Science were conducted to identify all eligible articles up to January 18th, 2013. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) of five genetic models were calculated by fixed-effects or random-effects model. Publication bias, subgroup analysis, meta-regression and sensitivity analysis were also performed. A number of 49 studies including 51 samples consisted of 18,009 subjects (6,238 patients and 11,771 controls) were finally included. MTHFR C677T allele (TT or CT) carriers were 1.12 times more likely to develop pre-eclampsia (95% CI 1.04-1.21) compared with 677CC homozygous individuals. Similar results were obtained under other genetic models. Restricted to severe pre-eclampsia, there was an increased risk for 677TT homozygotes compared with 677CC homozygotes (OR 1.43; 95% CI 1.12-1.83). Subgroup analysis revealed a significant positive association between the C677T polymorphism (TT or CT) and pre-eclampsia in Asians (OR 1.41; 95% CI 1.11-1.79) and white population (OR 1.14; 95% CI 1.03-1.25). Meta-regression showed that study population, blinded genotyping, matching of cases and controls were not substantial sources of heterogeneity. For the MTHFR A1298C, ORs for all genetic models yielded a null association. This meta-analysis suggests that the MTHFR 677T allele might be associated with increased pre-eclampsia risk in Asian and white ethnicity and the subgroup of severe pre-eclampsia, while no association is observed between the MTHFR A1298C polymorphism and pre-eclampsia.

  6. [The associations of methylenetetrahydrofolate reductase gene C677T and A1298C polymorphisms and ulcerative colitis].

    Science.gov (United States)

    Xu, Chang-long; Lin, Xiu-qing; Lan, De-yun; Wang, Jian-zhang; Zheng, Bo; Xue, Zhan-xiong

    2011-05-01

    To investigate the association between the genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR) and ulcerative colitis (UC) of Han ethnic population in Zhejiang, China. Two hundred and seventy-four consecutive patients with UC and 726 healthy controls (HC) were studied. The genetic polymorphisms of MTHFR (C677T and A1298C) were genotyped using PCR-RELP methods. The frequencies of variant allele and genotype in MTHFR A1298C gene were higher in UC patients than in the HC (35.77% vs 29.96%, P = 0.013; 52.19% vs 44.90%, P = 0.039; respectively). However, there were no significant discrepancies of the allele and genotype frequencies in the MTHFR C677T gene between the UC patients and the HC (P > 0.05). In addition, the MTHFR 677TT homozygote, T allele and 677CT/1298AC compound genotype were more prevalent in patients with extensive colitis than in those with distal colitis (37.66% vs 14.72%, P = 0.0002; 49.35% vs 32.99%, P = 0.0004; 29.87% vs 15.23%, P = 0.006; respectively). Furthermore, the variant allele in the MTHFR A1298C gene (C) in severe UC patients was significantly lower than in mild and moderate UC patients (18.97% vs 33.88%, P = 0.022). The genetic polymorphisms of MTHFR C677T and A1298C are obviously associated with Han ethnic population with UC in Zhejiang province.

  7. Methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and variations of homocysteine concentrations in patients with Behcet's disease.

    Science.gov (United States)

    Messedi, M; Frigui, M; Chaabouni, Kh; Turki, M; Neifer, M; Lahiyani, A; Messaouad, M; Bahloul, Z; Ayedi, F; Jamoussi, K

    2013-09-15

    Behcet's disease (BD) is a chronic, relapsing, multi-systemic inflammatory disorder of unknown causes. This disease is mainly characterized by mucocutaneous, ocular, vascular, and central nervous system manifestations. The aim of this study is to investigate the associations between C677T and A1298C polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene and the plasma homocysteine (Hcy), folate, and B12 levels in a relatively large cohort of Tunisian patients with BD. The study included 142 patients with BD and 172 healthy controls. The C677T and A1298C polymorphisms were genotyped using PCR-RFLP. Serum Hcy level was determined using a fluorescence polarization immunoassay. Serum folate and vitamin B12 levels were measured by electrochemiluminescence immunoassay. Genotype and allele frequencies of the two studied MTHFR polymorphisms did not show any significant differences among BD patients compared to controls. Patient carriers of the 677TT variant and the 677T allele displayed significantly higher Hcy concentration. Moreover, no significant association was found between neither A1298C polymorphism nor the C allele and Hcy, folate, and B12 levels. In multivariate analyses, we reported that 677T allele, male gender, and creatinine level were independent risk factors for hyperhomocysteinemia (HHC). In the present study, we report the absence of any significant differences between genotype and allele frequencies for both studied polymorphisms among BD patients compared to healthy controls. Besides, we showed that the T allele of MTHFR C677T polymorphism influenced the Hcy level which is an independent risk factor for HHC in Tunisian BD patients. © 2013 Elsevier B.V. All rights reserved.

  8. The Association of MTHFR C677T and A1298C Polymorphisms with Methotrexate Response and Toxicity in Psoriasis

    Directory of Open Access Journals (Sweden)

    Sauvarat Auepemkiate

    2016-11-01

    Full Text Available Background: Methotrexate (MTX is used to treat psoriasis with various side effects and responsiveness. No predictive indicator of responsiveness or toxicity is available. Objective: To study the association of the C677T and A1298C polymorphisms in the methylenetetrahydrofolate reductase (MTHFR gene with the responsiveness and side effects of MTX in psoriatic Thai patients. Methods: The polymorphisms were identified from 86 MTX-treated patients in three hospitals located in southern Thailand using allele-specific PCR. The patients were monitored for the effectiveness and toxicity of the MTX. Results: The C677T genotype frequencies for C/C, C/T, and T/T were 70.9, 26.8, and 2.3%, respectively, and those of the A1298C genotypes for A/A, A/C, and C/C were 57, 32.5, and 10.5%, respectively. Seventy-three patients (87.9% responded to MTX. The non-responders had higher combined frequencies of C/T and T/T of the C677T (50% than the responders (24.7% with no statistical significance (p = 0.131, but had a lower frequency of CC genotype of the A1298C, although not statistically different (p =0.691. Eleven patients (12.8% suffered toxicity. No association of these polymorphisms and MTX toxicity was found. Conclusion: The study did not show an association between these MTHFR polymorphisms with MTX response and toxicity in these patients.

  9. MTHFR C677T and A1298C polymorphisms and risk of nonsyndromic orofacial clefts in a south Indian population.

    Science.gov (United States)

    Murthy, Jyotsna; Gurramkonda, Venkatesh Babu; Karthik, Nivedita; Lakkakula, Bhaskar V K S

    2014-02-01

    Several lines of evidence suggest that the decrease in folate in periconceptional period or maternal use of folate antagonists has been associated with a higher risk of orofacial clefts (OFCs). MTHFR is a critical enzyme in folate metabolism that catalyzes the irreversible conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, thus playing a vital role in DNA synthesis and DNA methylation. The aim of our study was to determine whether there is any association between the susceptibility to Nonsyndromic cleft lip with or without cleft palate (NSCL/P) amongst the variations of MTHFR genotypes in South Indian population. Our sample comprised 123 cases with NSCL/P and 141 controls without clefts or family history of clefting. The most common polymorphisms C677T (rs1801133) and A1298C (rs1801131) on the MTHFR gene were screened for the genotypes using PCR-RFLP. Both C677T and A1298C are polymorphic with minor allele frequencies of 0.131 and 0.429, respectively, for controls. Genotype data in control and cleft groups are following the Hardy Weinberg Equilibrium. There were no significant differences in genotypes of both polymorphisms between controls and NSCL/P. The pairwise LD values (D' and r(2)) between C677T and A1298C are 1.0 and 0.096 respectively indicating no significant LD between these two SNPs. Haplotype phenotype analysis did not show the evidence for association. Gene-gene interaction showed the distribution of the observed combinations of the two MTHFR polymorphisms was not different between NSCL/P and controls (p=0.887). Our results do not support the hypothesis, that variants in the MTHFR gene confer a risk for NSCL/P in the South Indian population. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  10. Homocysteine and Stroke Risk: Modifying Effect of Methylenetetrahydrofolate Reductase C677T Polymorphism and Folic Acid Intervention.

    Science.gov (United States)

    Zhao, Min; Wang, Xiaobin; He, Mingli; Qin, Xianhui; Tang, Genfu; Huo, Yong; Li, Jianping; Fu, Jia; Huang, Xiao; Cheng, Xiaoshu; Wang, Binyan; Hou, Fan Fan; Sun, Ningling; Cai, Yefeng

    2017-05-01

    Elevated blood homocysteine concentration increases the risk of stroke, especially among hypertensive individuals. Homocysteine is largely affected by the methylenetetrahydrofolate reductase C677T polymorphism and folate status. Among hypertensive patients, we aimed to test the hypothesis that the association between homocysteine and stroke can be modified by the methylenetetrahydrofolate reductase C677T polymorphism and folic acid intervention. We analyzed the data of 20 424 hypertensive adults enrolled in the China Stroke Primary Prevention Trial. The participants, first stratified by methylenetetrahydrofolate reductase genotype, were randomly assigned to receive double-blind treatments of 10-mg enalapril and 0.8-mg folic acid or 10-mg enalapril only. The participants were followed up for a median of 4.5 years. In the control group, baseline log-transformed homocysteine was associated with an increased risk of first stroke among participants with the CC/CT genotype (hazard ratio, 3.1; 1.1-9.2), but not among participants with the TT genotype (hazard ratio, 0.7; 0.2-2.1), indicating a significant gene-homocysteine interaction (P=0.008). In the folic acid intervention group, homocysteine showed no significant effect on stroke regardless of genotype. Consistently, folic acid intervention significantly reduced stroke risk in participants with CC/CT genotypes and high homocysteine levels (tertile 3; hazard ratio, 0.73; 0.55-0.97). In Chinese hypertensive patients, the effect of homocysteine on the first stroke was significantly modified by the methylenetetrahydrofolate reductase C677T genotype and folic acid supplementation. Such information may help to more precisely predict stroke risk and develop folic acid interventions tailored to individual genetic background and nutritional status. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00794885. © 2017 American Heart Association, Inc.

  11. Methylenetetrahydrofolate reductase C677T and methionine synthase A2756G polymorphisms influence on leukocyte genomic DNA methylation level.

    Science.gov (United States)

    Weiner, Alexandra S; Boyarskikh, Uljana A; Voronina, Elena N; Mishukova, Olga V; Filipenko, Maxim L

    2014-01-01

    Methionine synthase (MTR) and methylenetetrahydrofolate reductase (MTHFR) enzymes are involved in the metabolism of methyl groups, and thus have an important role in the maintenance of proper DNA methylation level. In our study we aimed to evaluate the effect of the polymorphism A2756G (rs1805087) in the MTR gene on the level of human leukocyte genomic DNA methylation. Since the well-studied polymorphism C677T (rs1801133) in the MTHFR gene has already been shown to affect DNA methylation, we aimed to analyze the effect of MTR A2756G independently of the MTHFR C677T polymorphism. For this purpose, we collected the groups of 80 subjects with the MTR 2756AA genotype and 80 subjects with the MTR 2756GG genotype, having equal numbers of individuals with the MTHFR 677CC and the MTHFR 677TT genotypes, and determined the level of DNA methylation in each group. Individuals homozygous for the mutant MTR 2756G allele showed higher DNA methylation level than those harboring the MTR 2756AA genotype (5.061 ± 1.761% vs. 4.501 ± 1.621%, P=0.0391). Individuals with wild-type MTHFR 677СC genotype displayed higher DNA methylation level than the subjects with mutant MTHFR 677TT genotype (5.103 ± 1.767% vs. 4.323 ± 1.525%, P=0.0034). Our data provide evidence that the MTR A2756G polymorphism increases the level of DNA methylation and confirm the previous reports that the MTHFR C677T polymorphism is associated with DNA hypomethylation. © 2013 Elsevier B.V. All rights reserved.

  12. Meta-analysis study to evaluate the association of MTHFR C677T polymorphism with risk of ischemic stroke.

    Science.gov (United States)

    Abhinand, P A; Manikandan, M; Mahalakshmi, R; Ragunath, P K

    2017-01-01

    Ischemic stroke is a condition characterized by reduced blood supply to part of the brain, initiating the ischemic cascade, leading to dysfunction of the brain tissue in that area. It is one of the leading causes of death and disability and is estimated to cause around 5.7 million deaths worldwide. Methyl tetra hydro-folate reductase (MTHFR) is a rate limiting enzyme in the methyl cycle which catalyzes the only biochemical reaction which produces 5, Methyl tetra hydro folate, the co-substrate for the re-methylation of homocystiene to produce methionine. MTFHR C677T is a common mutation of MTHFR and those homozygous for the MTFHR C677T produce a thermo-labile form of the protein with drastically reduced catalytic activity resulting in elevated plasma homocystiene levels - a common risk factor for cardiovascular diseases. However, the role of MTHFR C677T in ischemic stroke remains unclear. To evaluate this association, we carried out a meta-analysis of existing published studies, which included 72 studies involving 12390 cases and 16274 controls. The forest plot was made to evaluate the overall risk of the mutation in the etiology of Ischemic Stroke. The overall Odds- ratio of the study was found to be 1.319 for random effects model, revealing a ∼32% increased risk of Ischemic stroke in the presence of MTHFR C667T mutation compared to controls. Publication bias in the study was analyzed using funnel plot which revealed that only 7 studies out of the 72 contributed to publication bias. These 7 studies were excluded and Meta-analysis was repeated for 65 studies and overall odds-ratio was 1.306, which showed that there was a 30% higher risk of Ischemic stroke in the presence of MTHFR C667T.

  13. The importance of MTHFR C677T/A1298C combined polymorphisms in pulmonary embolism in Turkish population

    OpenAIRE

    Nursah Basol; Nevin Karakus; Asli Yasemen Savas; Ilker Kaya; Kayhan Karakus; Serbulent Yigit

    2016-01-01

    Background and objective: Pulmonary embolism (PE) is an important cardiovascular emergency with high mortality. There are still problems related to the diagnosis of PE and genetic research may play a key role on diagnosis as well as determining risk stratification. In the present study, the aim was to evaluate MTHFR C677T and A1298C polymorphisms that play a role on folate metabolism in PE patients. Materials and methods: A total of 118 PE patients and 126 controls were enrolled in the cur...

  14. Methylenetetrahydrofolate reductase C677T polymorphism, hypertension and risk of stroke: a prospective, nested case-control study.

    Science.gov (United States)

    Jiang, Shanqun; Li, Jianping; Zhang, Yan; Venners, Scott A; Tang, Genfu; Wang, Yu; Li, Zhiping; Xu, Xiping; Wang, Binyan; Huo, Yong

    2017-03-01

    Hyperhomocysteinemia is a risk factor for cardiovascular disease. To date, limited prospective studies have examined the joint effects of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, hyperhomocysteinemia and conventional vascular risk factors on risk of stroke and stroke death. A total of 39 165 subjects from nine communities within Anqing, Anhui Province, China were prospectively followed from March 1995 to April 2005, with an average follow-up period of 6.2 years. None of the subjects had any history of vascular events at baseline. At follow-up, 251 incident stroke cases were identified. Using a nested, case-control study design, this analysis includes 106 cases with complete MTHFR C677T genotyping data and plasma samples. We selected 106 controls without vascular events matched for age, sex, community and years of plasma storage. Plasma total homocysteine (tHcy) level was measured by high-performance liquid chromatography. Hypertension was independently associated with incident stroke and stroke death after adjusting for important covariates including plasma log-transformed Hcy level. Relative to non-carriers of the MTHFR 677TT genotype with no hypertension, the adjusted odds ratio (95% confidence interval) of stroke and stroke death among hypertensive carriers of the MTHFR 677TT genotype was 10.6 (3.2 to 34.8), 5.8 (1.6 to 21.3), respectively. After excluding subjects with plasma Hcy above 20 μmol/L, the relative odds for stroke, but not for stroke death, was more significantly pronounced (OR = 24.1, 95% CI: 2.3 to 246.1) among subjects with moderate plasma Hcy levels. However, there was no significant interactive effect between hypertensive status and the MTHFR C677T variant on the odds of the two outcomes as estimated by interaction models. Our major findings suggest that joint effects of the MTHFR C677T polymorphism and hypertension are consistent in predicting a significantly high risk of stroke. In addition for moderate plasma

  15. Methylenetetrahydrofolate reductase C677T polymorphism is associated with increased risk of coronary artery disease in young South African Indians.

    Science.gov (United States)

    Ramkaran, Prithiksha; Phulukdaree, Alisa; Khan, Sajidah; Moodley, Devapregasan; Chuturgoon, Anil A

    2015-10-15

    Methylenetetrahydrofolate reductase (MTHFR) reduces 5',10'-methylenetetrahydrofolate to 5'-methyltetrahydrofolate, and is involved in remethylation of homocysteine to methionine, two important reactions involved in folate metabolism and methylation pathways. The common MTHFR C677T single nucleotide polymorphism (SNP) (rs1801133) has been associated with raised levels of homocysteine, a well known risk factor for coronary artery disease (CAD). CAD is a major cause of mortality worldwide. The age of onset of this chronic disorder is on the decline, particularly in the Indian population. Indians in South Africa (SA) have a higher prevalence of premature CAD compared to Black South Africans. The MTHFR C677T SNP has not been investigated in the SA Indian population. The present study therefore investigated the MTHFR C677T SNP in young SA Indian males with CAD compared to young Indian and Black male controls. A total of 290 subjects were recruited into this study which included 106 CAD patients (diagnosed on angiography, mean age 37.5, range 24-45 years), 100 Indian male controls (mean age 37.5, range 28-45 years), and 84 Black male controls (mean age 36.4, range 25-45). Polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) was used to genotype CAD patients and healthy controls. Data for clinical markers were obtained from pathology reports. There was a significant association between the 677 MTHFR variant (T) allele and CAD patients compared to the healthy Indian controls (p=0.0353, OR=2.105 95% CI 1.077-4.114). Indian controls presented with a higher frequency of the variant allele compared to Black controls (7% vs. 2% respectively, p=0.0515 OR=3.086 95% CI 0.9958-9.564). The MTHFR C677T SNP did not influence levels of total cholesterol, LDL, HDL, triglycerides, fasting glucose, fasting insulin, HbA1c or hsCRP. The higher frequency of the MTHFR 677 variant allele in South African Indians may be a contributing factor to the higher

  16. Evidence for an association of methylene tetrahydrofolate reductase polymorphism C677T and an increased risk of fractures

    DEFF Research Database (Denmark)

    Bathum, Lise; von Bornemann Hjelmborg, Jacob; Christiansen, Lene

    2004-01-01

    established. Previous studies concerning association of the common point mutation C677T in methylentetrahydrofolate reductase (MTHFR) and osteoporosis have revealed contradictory results. The aim of this study was to test the association between the MTHFR polymorphism, homocysteine, and fractures...... in the TT group compared with the CT group. Homocysteine, smoking, and self-reported hormone use provided no significant contribution to fracture risk. Using biometrical modelling, the heritability of the liability to fractures was found to be approximately 0.10, when the effect of the MTHFR locus...

  17. Frequency of the C677T variant of the methylenetetrahydrofolate reductase (MTHFR) gene in patients with migraine with or without aura - a preliminary report.

    Science.gov (United States)

    Szczygioł, Dorota; Motta, Ewa; Gołba, Anna; Stęposz, Arkadiusz; Witecka, Joanna; Dębski, Marek; Błaszkiewicz, Daria; Sieroń, Aleksander

    2012-01-01

    The aim of our study was to evaluate the frequency of the C677T variant in the methylenetetrahydrofolate reductase (MTHFR) gene in patients with migraine with or without aura and to find an association between this variant and vascular lesions in magnetic resonance imaging of the head, presence of patent foramen ovale (PFO) and increased level of homocysteine. Ninety-one patients with migraine, aged 19-57, were investigated in this study. The MTHFR C677T variant was genotyped in this group and levels of homocysteine, folic acid and vitamin B12 were measured. Transcranial Doppler sonography with test for PFO detection by injection of air contrast during the Valsalva manoeuvre was performed in each patient. Frequency of the C677T variant in the MTHFR gene was similar in patients and controls. Hyperhomocysteinaemia was significantly more frequent in migraine patients with the C677T variant. The prevalence of PFO was significantly higher in migraine patients with aura and the homozygous variant of the MTHFR gene. Frequency of the C677T variant in the MTHFR gene was similar in patients and controls. Significantly more frequent prevalence of PFO in migraine patients with aura (with homozygous recessive genotype of MTHFR probably suggests their common genetic basis. Hyperhomocysteinaemia was significantly more frequent in migraine patients with the C677T variant, which could be an additional risk factor of this disease.

  18. The methylenetetrahydrofolate reductase C677T genotype and the risk of obesity in three large population-based cohorts.

    Science.gov (United States)

    Lewis, Sarah J; Lawlor, Debbie A; Nordestgaard, Børge G; Tybjaerg-Hansen, Anne; Ebrahim, Shah; Zacho, Jeppe; Ness, Andy; Leary, Sam; Smith, George Davey

    2008-07-01

    Epidemiological studies have shown that low folate levels are associated with a high body mass index (BMI). These findings have potentially important health implications and warrant further investigation to determine whether a causal relationship exists and the direction of this relationship. The methylenetetrahydrofolate reductase (MTHFR) C677T TT genotype is associated with reduced folate availability and may be a surrogate for measuring folate levels. We sought to determine whether MTHFR C677T genotype was associated with obesity. We carried out our study on four populations from three longitudinal studies based in the UK and Denmark in which DNA for genotyping was obtained along with measures of obesity. Our subjects were taken from the British Women's Heart and Health Study (BWHHS), the Avon Longitudinal Study of Parents and Children (two populations: mothers and children) and the Copenhagen City Heart Study. We performed analyses separately by population, and then carried out a meta-analysis, combining similar populations. Initial findings in the BWHHS suggested that the TT genotype may be associated with an increased risk of obesity BMI > or =30, however, no association was found with BMI or central adiposity in this cohort. This genotype was not associated with obesity in our other cohorts. Our results suggest that the initial positive finding with obesity in the BWHHS was a chance finding. Our findings do not support a causal effect of low folate on obesity.

  19. Population distribution of methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C risk alleles for methotrexate toxicity in Israel.

    Science.gov (United States)

    Efrati, Edna; Elkin, Hela; Nahum, Sagi; Krivoy, Norberto

    2013-04-01

    Methylenetetrahydrofolate reductase (MTHFR) is a central regulatory enzyme in the folate pathway. Two non-synonymous single nucleotide polymorphisms in MTHFR, C677T (rs1801133) and A1298C (rs1801131) have been associated with reduced MTHFR enzyme activity. These polymorphisms, especially C677T, appear to be linked with methotrexate-related toxicity, particularly hepatotoxicity; thus, pretreatment identification of individuals carrying these polymorphisms may be of clinical relevance. The purpose of this study was to determine the frequency and distribution of MTHFR polymorphic variants, known to functionally impair MTHFR activity, in the highly heterogeneous Israeli population. MTHFR genotyping was carried out in the representatives of three major demographic groups in Israel by PCR-restriction fragment length polymorphism and high-resolution melting. The relative distribution of variant alleles 677T and 1298C was found to be similar in individuals of Jewish, Druze and Arab Moslem descent (p = 0.09). However, Ashkenazi Jews displayed a 1.9-fold higher frequency of variant 677T and a 1.8-fold lower frequency of variant 1298C compared to non-Ashkenazi Jews (p A1298C) or Ashkenazi Jews and Arab Moslem (p A1298C). These data underscore the importance of geographic genetic analysis for a better understanding of human pharmacotherapy and personalized medicine.

  20. Associations between asymmetric dimethylarginine, homocysteine, and the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism (rs1801133) in rheumatoid arthritis.

    Science.gov (United States)

    Dimitroulas, T; Sandoo, A; Hodson, J; Smith, J; Douglas, K M; Kitas, G D

    2016-07-01

    The aim of our study was to determine whether asymmetric dimethylarginine (ADMA) levels are associated with homocysteine (Hcy) and methylenetetrahydrofolate reductase (MTHFR) C677T (rs1801133) gene variants in patients with rheumatoid arthritis (RA). Serum ADMA and Hcy levels were measured in 201 RA individuals [155 (77.1%) females, median age 67 years (interquartile range 59-73)]. The MTHFR C677T polymorphism was assessed by using the LightCyclerTM System. Initially, ADMA was compared across the categories of MTHFR using a one-way analysis of variance (ANOVA), followed by a multivariate model, which accounted for Hcy, age, erythrocyte sedimentation rate (ESR), and homeostatic model assessment (HOMA). In univariable analysis, ADMA differed significantly across the categories of MTHFR (p = 0.037). Patients with the MTHFR 677TT genotype had the highest ADMA levels, with a mean of 0.62 (SE = 0.03), significantly higher than either those patients carrying the MTHFR 677CT (0.55, SE = 0.01) or the MTHFR 677CC (0.55, SE = 0.01) genotype (p = 0.042) in both cases. In the multivariable model, Hcy (p = 0.022) and ESR (p MTHFR gene variants and ADMA was found to be non-significant (p = 0.102). Hcy and ADMA are significantly associated in RA. It is plausible that abnormal Hcy metabolism plays an important role in premature atherosclerosis in RA by promoting ADMA accumulation and leading to the derangement of vascular haemostasis.

  1. MTHFR Gene C677T Mutation and ACE Gene I/D Polymorphism in Turkish Patients with Osteoarthritis

    Science.gov (United States)

    Inanir, Ahmet; Yigit, Serbulent; Tural, Sengul; Cecen, Osman; Yildirim, Eren

    2013-01-01

    Osteoarthritis is a degenerative joint disorder resulting in destruction of articular cartilage, osteophyte formation, and subchondral bone sclerosis. In recent years, numerous genetic factors have been identified and implicated in osteoarthritis. The aim of the current study was to examine the influence of methylenetetrahydrofolate reductase (MTHFR) gene C677T mutation and angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) variations on the risk of osteoarthritis. Genomic DNA is obtained from 421 persons (221 patients with osteoarthritis and 200 healthy controls). ACE gene I/D polymorphism genotypes were determined using polymerase chain reaction using I and D allele-specific primers. The MTHFR C677T mutation was analyzed by polymerase chain reaction (PCR) based restriction fragment length polymorphism (RFLP) methods. We found significant difference between the groups with respect to both ACE and MTHFR genotype distributions (p < 0.001, p < 0.001 respectively). Our study suggests that ACE gene DD genotype and MTHFR gene CC genotype could be used as genetic markers in osteoarthritis in Turkish study populations. PMID:23089924

  2. MTHFR C677T and factor V Leiden in recurrent pregnancy loss: a study among an endogamous group in North India.

    Science.gov (United States)

    Mukhopadhyay, Rupak; Saraswathy, Kallur N; Ghosh, Pradeep K

    2009-12-01

    In our study an attempt has been made to find the prevalence of genetic thrombophilia in recurrent pregnancy loss (RPL). Methylene tetrahydrofolate reductase C677 (MTHFR C677T) and factor V Leiden (FVL) were investigated in 84 Rajput women with two or more pregnancy losses and in 80 age- and ethnicity-matched healthy controls. Restriction digestions of polymerase chain reaction product with HinfI and Mnl I were used for MTHFR C677T and FVL polymorphism detection, respectively. MTHFR C677T mutation was found in 9/84 patients (10.71%) and 2/80 controls (2.5%), yielding an odds ratio (OR) for RPL related to MTHFR C677T of 4.68 (95% confidence interval [CI] = 0.98-22.37; p = 0.03). FVL was found in 4/84 patients (4.76%) and none among the controls, yielding a modified OR for RPL related to FVL of 9.00 (95% CI = 0.48-169.9; p = 0.05). Both, MTHFR C677T and FVL were not found to be significantly more prevalent in patients than controls as a whole. However, MTHFR C677T showed significant association with early pregnancy loss (OR = 6.3; 95% CI = 1.22-32.85; p-value = 0.03; Bonferroni-corrected p-value = 0.04). Our study supports the association between MTHFR C677T and patients with early RPL among north Indian Rajputs and strengthens the notion that thrombophilia plays a role in this clinical entity.

  3. The polymorphism of methylenetetrahydrofolate reductase C677T but not A1298C contributes to gastric cancer.

    Science.gov (United States)

    Lv, Long; Wang, Ping; Sun, Beicheng; Chen, Gong

    2014-01-01

    Increasing epidemiological studies have revealed the important role of methylenetetrahydrofolate reductase (MTHFR) in carcinogenesis. The association of MTHFR A1298C and MTHFR C677T polymorphisms with the risk for gastric cancer remains obscure due to inconsistent findings in independent studies among diverse ethnicities. A meta-analysis based on all available publications on this genetic association was performed. The pooled odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated to estimate the effect of MTHFR variants on gastric carcinogenesis. Totally, 25 eligible case-control studies were included into the meta-analysis according to the inclusion criteria. The MTHFR C677T polymorphism was demonstrated to significantly increase the susceptibility to gastric cancer (OR(T vs. C) = 1.21, 95% CI 1.10-1.34; OR(TT vs. CC )= 1.47, 95% CI 1.22-1.76; OR(TC vs. CC )= 1.20, 95% CI 1.03-1.40; OR(TT + TC vs. CC) = 1.27, 95% CI 1.10-1.47; OR(TT vs. CC + TC )= 1.29, 95% CI 1.15-1.46), whereas no significant correlation was observed when assessing the MTHFR A1298C polymorphism (OR(C vs. A )= 1.00, 95% CI 0.90-1.10; OR(CC vs. AA) = 0.99, 95% CI 0.75-1.31; OR(CA vs. AA )= 1.01, 95% CI 0.89-1.14; OR(CC + CA vs. AA) = 1.00, 95% CI 0.89-1.13; OR(CC vs. AA + CA) = 0.97, 95% CI 0.74-1.27). Subgroup analyses by ethnicity and source of controls further confirmed the findings in overall analysis. The meta-analysis suggests that the polymorphism of MTHFR C677T but not MTHFR A1298C confers a risk effect on the development of gastric cancer among Asians and Caucasians, which provides a new insight into the gastric cancer pathogenesis.

  4. Association of MTHFR C677T and A1298C polymorphisms with non-Hodgkin lymphoma susceptibility: evidence from a meta-analysis.

    Science.gov (United States)

    He, Jing; Liao, Xiao-Yu; Zhu, Jin-Hong; Xue, Wen-Qiong; Shen, Guo-Ping; Huang, Shao-Yi; Chen, Wei; Jia, Wei-Hua

    2014-08-22

    Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme involved in folate metabolism and DNA synthesis. A number of studies have examined the association of MTHFR C677T and A1298C polymorphisms with non-Hodgkin lymphoma (NHL) susceptibility; however, the conclusions were contradictory. We searched available publications assessing the polymorphisms of MTHFR and NHL susceptibility from MEDLINE, EMBASE and CBM. Genotype-based mRNA expression analysis was performed using data from 270 individuals with three different ethnicities. Ultimately, a total of 7448 cases and 11146 controls from 25 studies were included for the C677T polymorphism, 6173 cases and 9725 controls from 19 studies for the A1298C polymorphism. Pooled results indicated that neither C677T nor A1298C polymorphism was associated with NHL susceptibility. However, C677T polymorphism showed a statistically significantly increased risk for Caucasians, but a decreased risk for Asians in the subgroup analysis by ethnicity. The same variants may confer increased susceptibility to develop follicular lymphoma (FL). Moreover, A1298C polymorphism was associated with increased NHL risk for Asians. This meta-analysis indicated that C677T polymorphism was associated with altered NHL susceptibility for Caucasians, Asians and FL. Increased NHL risk was also shown for A1298C among Asians. These findings warrant validation in large and well-designed prospective studies.

  5. Polymorphisms of the methylenetetrahydrofolate reductase gene (C677T and A1298C) in the placenta of pregnancies complicated with preeclampsia.

    Science.gov (United States)

    Chedraui, Peter; Andrade, Mariela E; Salazar-Pousada, Danny; Escobar, Gustavo S; Hidalgo, Luis; Ramirez, Cecibel; Spaanderman, Marc E A; Kramer, Boris W; Gavilanes, Antonio W D

    2015-07-01

    Preeclampsia has been related to single-nucleotide polymorphisms (SNPs) of the methylenetetrahydrofolate reductase (MTHFR) gene; however, data regarding the placenta are still lacking. To determine the frequency of C677T and A1298C SNPs of the MTHFR gene in the placenta of preeclamptic pregnancies and healthy controls. Genotyping of C677T and A1298C polymorphisms of the MTHFR gene using RFLP-PCR was performed to the placenta of 100 gestations (n = 50 complicated with preeclampsia and n = 50 normal controls matched for parity and maternal age). Gestational age at birth and neonatal and placental weight were significantly lower in women with preeclampsia as compared to controls. The TT genotype of the C677T polymorphism was threefold more prevalent in preeclamptic placentas as compared to the placenta of controls (24.0% versus 8.0%, p = 0.001). Upon pooled analysis (n = 100), placental and neonatal weights were significantly lower in placentas displaying this genotype (TT, C677T) as compared with the CC genotype. This study found that the frequency of the TT mutant genotype of the C677T polymorphism was higher in the placenta of pregnancies complicated with preeclampsia. There is a need for further research in this matter.

  6. Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and high plasma homocysteine in chronic hepatitis C (CHC) infected patients from the Northeast of Brazil.

    Science.gov (United States)

    Siqueira, Erika R F; Oliveira, Cláudia P M S; Muniz, Maria T C; Silva, Filipe; Pereira, Leila M M B; Carrilho, Flair J

    2011-08-19

    Hyperhomocysteinemia due to Methylenetetrahydrofolate Reductase (MTHFR) gene, in particular the C677T (Ala222Val) polymorphism were recently associated to steatosis and fibrosis. We analyzed the frequency of MTHFR gene in a cross-sectional study of patients affected by Chronic Hepatitis C (CHC) from Northeast of Brazil. One hundred seven-four untreated patients with CHC were genotyped for the C677T MTHFR. Genomic DNA was extracted from peripheral blood cells and the C677T MTHFR polymorphism was identified by PCR-RFLP. The homocysteine (Hcy) levels were determined by chemiluminescence method. All patients were negative for markers of Wilson's disease, hemochromatosis and autoimmune diseases and have current and past daily alcohol intake less than 100 g/week. Among subjects infected with CHC genotype non-1 the frequency of MTHFR genotypes TT was 9.8% versus 4.4% genotype 1 (p = 0.01). Nevertheless, association was found between the MTHFR genotype TT × CT/CC polymorphism and the degree of steatosis and fibrosis in both hepatitis C genotype (p MTHFR C677T polymorphism was more common in CHC genotype non-1 infected patient regardless of histopathological classification and genotype TT+CT frequencies were significant in the presence of fibrosis grade 1+2 and of steatosis in CHC infected patients from the northeast of Brazil regardless of HCV genotype. The genetic susceptibility of MTHFR C677T polymorphism should be confirmed in a large population.

  7. The relationship between MTHFR C677T gene polymorphism and essential hypertension in a sample of an Algerian population of Oran city.

    Science.gov (United States)

    Amrani-Midoun, Asma; Kiando, Soto Romuald; Treard, Cyrielle; Jeunemaitre, Xavier; Bouatia-Naji, Nabila

    2016-12-15

    Many studies have investigated the role of 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism in essential hypertension (EH), but with conflicting results. To determine the eventual association between 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism and hypertension in a sample of Algerian population from the Oran city. A case-control study has been performed in 154 subjects including 82 hypertensives defined as subjects with elevated systolic blood pressure SBD≥140mmHg and or sustained diastolic blood pressure DBP≥90mmHg, and 72 normotensive subjects. Polymerase chain reaction (PCR) combined with restrictive fragment length polymorphism (RFLP) was used to detect the MTHFR C677T variant. We observe no significant differences between allelic and genotypic frequencies between cases and controls for C677T polymorphism (OR=1.51, 95% CI=0.89-2.56, P=0.13). Analyses adjusted for age, sex and body mass index improved the association level, though the association was still not significant (30% vs. 22%, OR=1.75, 95% CI=0.95-3.24, P=0.07). This work showed that genetic polymorphism related to the MTHFR gene (C677T) is not associated with the risk of hypertension in this sample of Algerian population. Larger case-control samples are required to clearly assess the role of this genetic variant in EH. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  8. Changes in lifestyle and total homocysteine in relation to MTHFR (C677T) genotype: the Inter99 study

    DEFF Research Database (Denmark)

    Husemoen, LL; Thomsen, TF; Fenger, M

    2006-01-01

    Hcy in relation to MTHFR(C677T) genotype. DESIGN: A 1 year follow-up study. SETTING: Copenhagen County, Denmark. SUBJECTS: Statistical analyses were based on a population-based sample of 915 men and women aged 30-60 years assessed to be at increased CVD risk at baseline and therefore offered lifestyle...... intervention and re-examination after one year. RESULTS: None of the studied lifestyle changes-- smoking, physical activity, dietary habits, and coffee, tea, and alcohol consumption-- was significantly associated with changes in tHcy, either overall, or in any of the MTHFR genotype subgroups. In addition......, changes in tHcy did not differ between participants randomized to low- and high-intensity lifestyle intervention. However, the MTHFR TT genotype was associated with a significant decrease in tHcy compared with the CC/CT genotype in which an increase was observed. In addition, changes in tHcy were...

  9. Polymorphisms of the methylenetetrahydrofolate reductase gene (C677T and A1298C) in nulliparous women complicated with preeclampsia.

    Science.gov (United States)

    Chedraui, Peter; Salazar-Pousada, Danny; Villao, Alejandro; Escobar, Gustavo S; Ramirez, Cecibel; Hidalgo, Luis; Pérez-López, Faustino R; Genazzani, Andrea; Simoncini, Tommaso

    2014-05-01

    To determine the prevalence of C677T and A1298C Single-nucleotide polymorphisms (SNPs) of the MTHFR gene in nulliparous women complicated with preeclampsia (PE). One hundred fifty gestations complicated with PE and their corresponding controls without the disease were recruited for the genotyping of C677T and A1298C polymorphisms of the MTHFR gene using restriction fragment length polymorphism polymerase chain reaction. Secondarily, homocysteine (HCy) plasma levels were measured in preeclamptic women displaying the CC genotype of the A1298C polymorphism (homozygous) and compared to HCy levels determined among controls with the normal AA genotype for the A1298C variant. Only the mutant CC genotype of the A1298C polymorphism was associated to higher risk of presenting PE, as frequency of this genotype was significantly higher among cases than controls (15.3% versus 0.7%, p A1298C polymorphism as compared to none among preeclamptics with a lower neck circumference (p = 0.0001). Women with the mutant CC A1298C SNP displayed higher plasma HCy levels as compared to controls with normal AA A1298C genotype (8.4 ± 2.6 versus 7.5 ± 2.7 mmoL/L p = 0.04). Prevalence of the CC mutant genotype of the A1298C polymorphism was higher among PE women. This mutation among PE women was related to increased neck circumference and higher HCy levels. Future research should aim at linking these gestational findings with obesity and cardiovascular risk.

  10. Methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and susceptibility to gastric adenocarcinoma in an Italian population.

    Science.gov (United States)

    Boccia, Stefania; Gianfagna, Francesco; Persiani, Roberto; La Greca, Antonio; Arzani, Dario; Rausei, Stefano; D'ugo, Domenico; Magistrelli, Paolo; Villari, Paolo; Van Duijn, Cornelia M; Ricciardi, Gualtiero

    2007-01-01

    Methylenetetrahydrofolate reductase (MTHFR) plays a central role in the metabolism of folate, which provides a methyl donor for DNA methylation and deoxynucleoside synthesis. We performed a case-control study to explore the relationship between two common MTHFR polymorphisms (C677T and A1298C), their combination and interaction with environmental exposures, on gastric adenocarcinoma susceptibility and progression in an Italian population. One hundred and two cases and 254 hospital controls, matched by age and gender, were enrolled. Individuals carrying the MTHFR 677T allele showed an increased risk of gastric cancer (odds ratio (OR) 1.62, 95% confidence interval (CI) 0.98-2.67), particularly among ever smokers (OR 2.10, 95% CI 1.07-5.33) and, among 677 TT individuals, those with a low intake of fruit and vegetables (OR 2.18, 95% CI 1.05-4.54). The strongest effect, however, was noted for the MTHFR 677 TT genotype among the diffuse gastric cancer histotype (OR 2.92, 95% CI 1.12-7.60). No association was detected for the effect of MTHFR A1298C polymorphism. Survival analysis did not show any association between each polymorphism on the overall survival, although when the analysis was restricted to the first year of follow-up after the surgical intervention an improved survival was noted among MTHFR 677 CC subjects compared with the T allele carriers (p value for log-rank test 0.02). In conclusion, MTHFR 677 (any T genotype) appears to modulate an individual's susceptibility to gastric cancer, particularly when combined with cigarette smoking and among those with a low intake of fruit and vegetables. Our results also suggest that an aberrant DNA methylation pattern, through impaired folate metabolism, might play a key role in gastric carcinogenesis. A possible survival effect of the MTHFR C677T genotype in gastric cancer patients deserves further investigations with larger sample sizes.

  11. MTHFR A1298C and C677T gene polymorphisms and susceptibility to chronic myeloid leukemia in Egypt.

    Science.gov (United States)

    Aly, Rabab M; Taalab, Mona M; Ghazy, Hayam F

    2014-01-01

    Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme regulating the intracellular folate metabolism which plays an important role in carcinogenesis through DNA methylation. We aimed to evaluate the association between MTHFR A1298C and C677T polymorphisms and the risks of chronic myeloid leukemia (CML). Eighty-five patients with CML and a control group containing 100 healthy, age and sex matched individuals were examined for MTHFR C677T and A1298C polymorphisms using polymerase chain reaction-restriction fragment-length (PCR-RFLP) method. The frequency of 677TT genotype in patients with CML was significantly higher compared to controls (OR=2.513, 95% CI: 0.722-4.086, P=0.025). No such association was shown for heterozygous 677CT (OR=1.010, 95% CI: 0.460-2.218, P=0.981). Moreover, for A1298C genotype, a statistically significant higher frequency of 1298CC was also detected in CML patients compared to control group (OR=1.1816, 95% CI: 0.952-3.573, P=0.036), 0.036). No such statistical significance was demonstrable for heterozygote 1298AC (OR=1.046, 95% CI: 0.740-1.759, P=0.092). In addition, patients with joint 677CT/1298AC or 677TT/1298CC genotypes showed an association with increased risk of CML (OR=1.849, 95% CI: 0.935-2.540, P=0.024; OR=1.915, 95% CI: 1.202-3.845, P=0.020 respectively). .A statistically significant increased risk of resistant to therapy was observed with 677CT and 1298AC genotypes (P=0.001, P=0.002 respectively). We conclude that both MTHFR 677TT and 1298CC polymorphisms have been associated with risk of CML and both 677CT and 1298AC genotypes are associated with higher risk of resistant to therapy.

  12. Study of the C677T and 1298AC polymorphic genotypes of MTHFR Gene in autism spectrum disorder.

    Science.gov (United States)

    El-Baz, Farida; El-Aal, Mohammed Abd; Kamal, Tarek Moustafa; Sadek, Abdelrahim Abdrabou; Othman, Amr Ahmed

    2017-09-01

    Autism is currently known as "a behaviorally defined syndrome" manifested as impairment in social communication, repetitive routines and restricted interests. There is an increased risk of ASDs associated with common mutations affecting the folate/methylation cycle. The aim of this study was to identify C677T and 1298AC polymorphic genotypes of MTHFR gene among a sample of Egyptian children with autism and to make a phenotype-genotype correlation for the autistic patients. This case-control study was carried out from 2013 through 2015. The study included 31 children with autism and 39 children in a normal control group, the mean age of patients and control was comparable (4.5 years± 2) with males predominant in both groups. We used DSM-V-TR criteria, Stanford-Binet intelligence scale V and childhood autism rating scale (CARS) for assessments. Genotyping for MTHFR gene polymorphic loci C677T and 1298AC was performed on amplified DNA by PCR with subsequent reverse hybridization and restriction fragment length polymorphisms analysis. Data were analyzed by SPSS version 11, using Chi-Square, independent-samples t-test, and ANOVA. There was significant relationship between low birth weight and occurrence of autism (pA1298C polymorphism was highest among patients (41.9%) followed by 35.5% mutant genotype CC and 22.6% normal AA (wild) type and Allele C was detected in patients more than in control (56.45% vs. 11.54%) (pA1298C. Further studies are needed on a larger scale to explore other genes polymorphisms that may be associated with autism, to correlate the genetic basis of autism.

  13. Impact of MTHFR C677T gene polymorphism and vitamins intake on homocysteine concentration in the Polish adult population.

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    Waśkiewicz, Anna; Piotrowski, Walerian; Broda, Grażyna; Sobczyk-Kopcioł, Agnieszka; Płoski, Rafał

    2011-01-01

    Homocysteine (Hcy) levels are modulated by nutritional and genetic factors, among which is the enzyme 5,10-methylenetetrahydrofolate reductase (MTHFR). To determine the effects of the MTHTR C677T polymorphism, as well as the intake of folate, vitamins B(6) and B(12) on serum Hcy concentration in the Polish population. Within the framework of the National Multicentre Health Survey (WOBASZ), a representative sample of the whole Polish population aged 20-74 was screened in 2003-2005. Vitamins intake, Hcy level and known MTHTR C677T genotype were available for 1,561 men and 1,712 women. In the Polish population, T/T, C/T and C/C genotype frequencies were 10%, 43% and 47%, respectively in men, and 9%, 42% and 49%, respectively in women. The T/T genotype was associated with increased levels of Hcy (13.14 μmol/L in men, and 9.77 mmol/L in women) compared to the C/C and C/T genotypes (10.18 and 8.77, respectively), after adjustment for age, methionine, coffee and alcohol intake, smoking and drugs used. In a multivariable linear regression model, among subjects with the T/T genotype, the only factor influencing Hcy was age in women. In the case of the other groups (C/C and C/T), there was a relationship between Hcy and age, alcohol consumption, drugs used, folate and vitamin B(6) in men, and age, smoking, coffee consumption, drugs used, folate and vitamin B(12) in women. The T/T genotype is associated with higher levels of Hcy (29% in men, and 11% in women) compared to other genotypes. Nutritional factors affect Hcy levels only in the C/C and C/T MTHFR genotypes.

  14. Evaluating the role of maternal folic acid supplementation in modifying the effects of methylenetetrahydrofolate reductase (C677T and A1298C gene polymorphisms in oral cleft children

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    Asghar Ebadifar

    2016-01-01

    Full Text Available Background: We studied the role of maternal folic acid supplementation in modifying the effects of methylenetetrahydrofolate reductase (MTHFR C677T and A1298C gene polymorphisms in Iranian children with oral clefts. Materials and Methods: Forty-seven newborn infants with orofacial cleft and their mothers were selected randomly. Mothers were matched regarding dietary folate intake. The genotyping on venous blood was carried out. Consistency between maternal and child genotypes was analyzed. Results: Genotype consistency was not statistically significant in both C677T and A1298C gene variants (P > 0.05. Conclusion: Maternal folic acid consumption may not have any significant effect on modifying C677T and A1298C polymorphisms in children.

  15. Polymorphism in the methylenetetrahydrofolate reductase (C677T) gene and homocysteine levels: a comparison in Brazilian patients with coronary arterial disease, ischemic stroke and peripheral arterial obstructive disease.

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    Sabino, Adriano; Fernandes, Ana Paula; Lima, Luciana Moreira; Ribeiro, Daniel Dias; Sousa, Marinez Oliveira; de Castro Santos, Maria Elizabeth Rennó; Mota, Ana Paula Lucas; Dusse, Luci Maria Sant'Ana; das Graças Carvalho, Maria

    2009-01-01

    This study aimed to compare plasma levels of total homocysteine (tHcy) in different arterial events as well as to investigate an association between homocysteine levels and C677T polymorphism in Brazilian patients. A total of 145 subjects were enrolled in this study including 43 patients with coronary arterial disease (CAD), 21 with ischemic stroke (IS), 44 with peripheral arterial obstructive disease (PAOD) and 37 control subjects. A preliminary analysis showed significant difference for tHcy plasma levels between patients with CAD (P = 0.003) or PAOD (P = 0.03) compared to controls. However, after adjustment for sex, age, total cholesterol, LDL, diabetes, tabagism or C677T polymorphism, no significant differences were detected in tHcy levels among patients groups and controls. No significant correlation was demonstrated for C677T polymorphism and homocysteine levels. These results indicate that increased Hcy levels may not be considered an independent risk factor for atherothrombotic diseases in Brazilian patients.

  16. Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and age at onset of schizophrenia: no consistent evidence for an association in the Nordic population.

    Science.gov (United States)

    Saetre, Peter; Grove, Jakob; Børglum, Anders D; Mors, Ole; Werge, Thomas; Andreassen, Ole A; Vares, Maria; Agartz, Ingrid; Terenius, Lars; Jönsson, Erik G

    2012-12-01

    Methylenetetrahydrofolate reductase (MTHFR) is an enzyme involved in metabolic pathways of importance for nucleotide synthesis and methylation of DNA, membranes, proteins and lipids. The MTHFR gene includes a common polymorphism (rs1801133 or C677T), which is associated with enzyme activity. The T-allele of the C677T polymorphism has been associated with earlier age at onset of schizophrenia in a Scandinavian population, although no association was found in replication attempts in other populations. Extending the study to five Nordic samples consisting of 2,198 patients with schizophrenia, including the original Scandinavian samples, there was no significant association between MTHFR C677T polymorphism and age at onset in schizophrenia. The present results do not suggest that the investigated MTHFR polymorphism has any significant influence on age at onset of schizophrenia in the Nordic population. Copyright © 2012 Wiley Periodicals, Inc.

  17. Association of the maternal MTHFR C677T polymorphism with susceptibility to neural tube defects in offsprings: evidence from 25 case-control studies.

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    Lifeng Yan

    Full Text Available BACKGROUND: Methylenetetrahydrofolate reductase (MTHFR is a critical enzyme in folate metabolism and is involved in DNA methylation, DNA synthesis, and DNA repair. In addition, it is a possible risk factor in neural tube defects (NTDs. The association of the C677T polymorphism in the MTHFR gene and NTD susceptibility has been widely demonstrated, but the results remain inconclusive. In this study, we performed a meta-analysis with 2429 cases and 3570 controls to investigate the effect of the MTHFR C677T polymorphism on NTDs. METHODS: An electronic search of PubMed and Embase database for papers on the MTHFR C677T polymorphism and NTD risk was performed. All data were analysed with STATA (version 11. Odds ratios (ORs with 95% confidence intervals (CIs were estimated to assess the association. Sensitivity analysis, test of heterogeneity, cumulative meta-analysis, and assessment of bias were performed in our meta-analysis. RESULTS: A significant association between the MTHFR C677T polymorphism and NTD susceptibility was revealed in our meta-analysis ( TT versus CC: OR= 2.022, 95% CI: 1.508, 2.712; CT+TT versus CC: OR = 1.303, 95% CI: 1.089, 1.558; TT versus CC+CT: OR= 1.716, 95% CI: 1.448, 2.033; 2TT+CT versus 2CC+CT: OR= 1.330, 95% CI: 1.160, 1.525. Moreover, an increased NTD risk was found after stratification of the MTHFR C677T variant data by ethnicity and source of controls. CONCLUSION: The results suggested the maternal MTHFR C677T polymorphism is a genetic risk factor for NTDs. Further functional studies to investigate folate-related gene polymorphisms, periconceptional multivitamin supplements, complex interactions, and the development of NTDs are warranted.

  18. Methylenetetrahydrofolate reductase C677T and A1298C gene polymorphisms in oral squamous cell carcinoma in south-east Iran.

    Science.gov (United States)

    Miri-Moghaddam, Ebrahim; Saravani, Shirin; Garme, Yasamn; Khosravi, Arezoo; Bazi, Ali; Motazedian, Jamaledin

    2016-02-01

    Methylenetetrahydrofolate reductase (MTHFR) gene encodes an essential enzyme involving in folate metabolism. Due to the role of folate in DNA integrity, polymorphisms of MTHFR are interesting targets for cancer risk studies. Our goal was to evaluate the prevalence of MTHFR C677T and A1298T single nucleotide polymorphisms in oral squamous cell carcinoma (OSCC). The study was conducted on 57 OSCC patients diagnosed within 2004-2013 along with 62 non-OSCC subjects. DNA was extracted by standard kit protocol. Subsequently, tetra-ARMS (amplification refractory mutation system)-PCR was applied to identify the selected polymorphisms. Data showed that CT and TT genotypes of C677T polymorphisms significantly increased the risk of OSCC [odds ratio (OR) = 2.2, 95% CI: 1-5, P = 0.04]. Although allelic distribution was not significantly different between patients and controls, T allele of C677T polymorphism was closely associated with the risk of OSCC (OR = 2.5; 95% CI: 0.9-6.9; P = 0.07). Results indicated that C677T/A1298C: CC/AC and C677T/A1298C: CC/AA haplotypes were the most common combinations in OSCC patient and control groups, respectively. (OR = 1.5, 95% CI: 0.6-3.8, P > 0.05). Our results highlight the possible impact of C677T polymorphism in increasing the risk of OSCC development. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Association between methylenetetrahydrofolate reductase (MTHFR) C677T/A1298C polymorphisms and essential hypertension: a systematic review and meta-analysis.

    Science.gov (United States)

    Wu, Yi-Le; Hu, Cai-Yun; Lu, Shan-Shan; Gong, Feng-Feng; Feng, Fang; Qian, Zhen-Zhong; Ding, Xiu-Xiu; Yang, Hui-Yun; Sun, Ye-Huan

    2014-12-01

    Many studies have investigated the role of 5,10-methylenetetrahydrofolate reductase gene (MTHFR) C677T/A1298C polymorphisms in essential hypertension (EH), but results are inconclusive. The purpose of this meta-analysis was to clarify the effects of MTHFR C677T/A1298C polymorphisms on the risk of EH. Electronic databases were searched to identify relevant studies published until January 2014. Data were extracted by two independent authors. Odds ratios (ORs) with 95%confidence intervals (CIs) were used to assess the association between MTHFR C677T/A1298C polymorphisms and the risk of EH using random effect models or fixed effect models. Finally,30 studies with 5207 cases and 5383 controls were included for C677T polymorphism and 6 studies with 1009 cases and 994 controls were included for A1298C polymorphism. Meta-analysis results indicated that MTHFR C677T polymorphism contributed to an increased risk of EH (for T vs. C: OR=1.30, 95%CI=1.18–1.43; for TT+CT vs. CC: OR=1.34, 95%CI=1.24–1.46; for TT vs. CC: OR=1.62, 95%CI=1.32–1.99; for TT vs. CT+CC: OR=1.41, 95%CI=1.26–1.59). However, no significant association was detected between MTHFR A1298C polymorphism and the risk of EH. This meta-analysis supports that MTHFR C677T polymorphism plays a role in developing EH. MTHFR A1298C polymorphism may not be associated with an increased risk of EH. Further large and well-designed studies are warranted to confirm these findings.

  20. Association between maternal, fetal and paternal MTHFR gene C677T and A1298C polymorphisms and risk of recurrent pregnancy loss: a comprehensive evaluation.

    Science.gov (United States)

    Yang, Yi; Luo, Yunyao; Yuan, Jing; Tang, Yidan; Xiong, Lang; Xu, MangMang; Rao, XuDong; Liu, Hao

    2016-06-01

    Numerous studies have investigated the associations between methylenetetrahydrofolate reductase (MTHFR) gene C677T and A1298C polymorphisms and risk of recurrent pregnancy loss (RPL); however, the results remain controversial. The aim of this study is to drive a more precise estimation of association between MTHFR gene polymorphisms and risk of RPL. We searched PubMed, EMBASE, Cochrane library, Web of Science and China Knowledge Resource Integrated Database for papers on MTHFR gene C677T and A1298C polymorphisms and RPL risk. The pooled odds ratios (ORs) with 95 % confidence intervals (CIs) were used to assess the strength of association in the homozygous model, heterozygous model, dominant model, recessive model and an additive model. The software STATA (Version 13.0) was used for statistical analysis. Overall, 57 articles were included in the final meta-analysis. In maternal group the MTHFR C677T polymorphism showed pooled odds ratios for the homozygous comparison [OR = 2.285, 95 % CI (1.702, 3.067)] and the MTHFR A1298C polymorphism showed pooled odds ratios for recessive model [OR = 1.594, 95 % CI (1.136, 2.238)]. In fetal group the MTHFR C677T polymorphism showed pooled odds ratios for dominant model [OR = 1.037, 95 % CI (0.567, 1.894)] and the MTHFR A1298C polymorphism showed pooled odds ratios for dominant model [OR = 1.495, 95 % CI (1.102, 2.026)]. In summary, the results of our meta-analysis indicate that maternal and paternal MTHFR gene C677T and A1298C polymorphisms are associated with RPL. We also observed a significant association between fetal MTHFR A1298C polymorphism and RPL but not C677T.

  1. The MTHFR C677T Polymorphism Is Related to Plasma Concentration of Oxidized Low-Density Lipoprotein in Adolescents with Cardiovascular Risk Factors.

    Science.gov (United States)

    Morais, Carla C; Alves, Maira C; Augusto, Elaine M; Abdalla, Dulcinéia S P; Horst, Maria A; Cominetti, Cristiane

    2015-01-01

    The aim of this study was to investigate possible relationships among the A1298C (rs1801131) and C677T (rs1801133) polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene and levels of homocysteine, vitamins B6, B12, folic acid and lipid profile, including oxidized low-density lipoprotein (ox-LDL), of adolescents at cardiovascular risk. We recruited 115 adolescents (10-19 years old), 58.3% (n = 67) female, from a public school in Brazil who underwent anthropometric, biochemical and genetic tests as well as food consumption evaluation. An important prevalence of hyperhomocysteinemia (19.1%) and alterations in triacylglycerol (17.4%), total cholesterol (26.9%) and high-density lipoprotein (HDL) cholesterol (48.0%) concentrations were observed, as well as low vitamin B6 concentrations (23.5%). The categorization of homocysteine concentrations into tertiles revealed significant differences in serum concentrations of folate, vitamin B12 and HDL, waist circumference and intake of total and saturated fat among the tertiles. The presence of variant alleles regarding the MTHFR C677T polymorphism interfered with vitamin B6 and ox-LDL cholesterol concentrations. There was a trend for higher waist circumference values in T carriers (C677T), but not in C carriers (A1298C). The MTHFR C677T allele was associated with higher plasma vitamin B6 and ox-LDL compared to the CC genotype. © 2015 S. Karger AG, Basel.

  2. The effect of the MTHFR C677T mutation on athletic performance and the homocysteine level of soccer players and sedentary individuals

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    Dinç Nurten

    2016-06-01

    Full Text Available This study investigated athletic performance and homocysteine (Hcy levels in relation to the methylenetetrahydrofolate reductase (MTHFR C677T mutation and explored the relationship between this mutation and other cardiac risk factors in soccer players and sedentary individuals. The study groups consisted of randomly selected soccer players (n=48 from the Turkish Super and Major League and sedentary male students (n=48 aged 18-27. Anthropometric variables, aerobic and anaerobic thresholds were measured, furthermore, biochemical assays were performed. The level of HDL cholesterol, LDL cholesterol, triglyceride, Hcy, folate, vitamin B12, hemogram and MTHFR C677T was investigated. The results showed that there was a statistical difference between the two groups in terms of body mass, body fat, the BMI, the aerobic threshold heart rate (ATHR, aerobic threshold velocity (ATVL and anaerobic threshold velocity (ANTVL. The soccer players were found to have lower levels of triglyceride, total cholesterol and LDL cholesterol, and higher levels of folate than the sedentary participants. The analysis of the alleles of the MTHFR C677T polymorphism showed that the participants that carried TT genotypes had a lower level of vitamin B12 and folate, and a higher level of Hcy than the participants carrying CC and CT genotypes. In conclusion, the baseline homocysteine and cardiovascular fitness levels of healthy young males with the TT genotypes of the MTHFR C677T genotype were found to strongly correlate with their levels of Hcy.

  3. MTHFR gene C677T and A1298C polymorphisms and homocysteine levels in primary open angle and primary closed angle glaucoma

    NARCIS (Netherlands)

    Micheal, S.; Qamar, R.; Akhtar, F.; Khan, M.I.; Khan, W.A.; Ahmed, A.

    2009-01-01

    PURPOSE: To investigate the methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C genotypes and plasma concentrations of total homocysteine (tHcy) in Pakistani patients with primary open angle glaucoma (POAG) and primary closed angle glaucoma (PCAG). METHODS: This was a prospective

  4. Association of MTHFR C677T and A1298C gene polymorphisms with methotrexate efficiency and toxicity in Algerian rheumatoid arthritis patients

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    Lilya M. Berkani

    2017-11-01

    Full Text Available Methotrexate (MTX is the most used drug in rheumatoid arthritis (RA treatment. However, it shows variability in clinical response, which is explained by an association with genetic polymorphisms. This study aimed to elucidate the role of the two gene polymorphism C677T and A1298C of the methylenetetrahydrofolate reductase (MTHFR in response to MTX in Algerian RA patients. Study included 54 early RA patient treated with MTX for one year. MTX efficiency and toxicity were evaluated at 6 and 12 months respectively and the two gene polymorphisms were genotyped. No association was found between A1298C polymorphism and MTX toxicity. However, T allele of the C677T polymorphism was associated with the occurrence of MTX adverse effects (p = 0,019, OR: 3,63, 95% CI [1,12 - 12,80]. No association was found between C677T polymorphism and MTX efficiency, while A allele of the A1298C polymorphism was associated with good and moderate response (p = 0,02, OR = 3,28, 95% CI: [1,11– 9,42]. The study of RA biological markers kinetics showed that MTX did not affect antibodies rate unlike inflammatory markers. Our study suggests that MTHFR C677T and A1298C genotyping are associated to MTX toxicity and efficiency, respectively, in RA patients. This offers new perspectives in the personalization of RA treatment in Algeria. Keywords: Genetics, Clinical genetics, Internal medicine, Health sciences

  5. MTHFR C677T and A1298C gene polymorphisms and their relation to homocysteine level in Egyptian children with congenital heart diseases.

    Science.gov (United States)

    Zidan, Haidy E; Rezk, Noha A; Mohammed, Doaa

    2013-10-15

    To investigate the association of combined MTHFR C677T and A1298C gene polymorphisms with congenital heart diseases (CHD) in Egyptian children and their mothers and to determine their effect on homocysteine level in these children. MTHFR C677T and A1298C polymorphisms were genotyped in 160 Egyptian children (80 patients with CHD and 80 healthy controls) and their mothers using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), while, homocysteine (Hcy) level was measured optically by enzymatic method. We found that MTHFR 677TT genotype, T allele, 1298CC genotype, and C allele were associated with 2.61, 2.0, 2.91 and 1.99 fold increased risk of CHD in Egyptian children respectively. Furthermore, the frequencies of MTHFR 1298AC and CC genotypes and C allele significantly increased in mothers with CHD affected children. The homocysteine levels were significantly increased in MTHFR 677TT and 1298CC genotypes in children with CHD. Our study demonstrated an association of MTHFR A1298C polymorphisms with CHD in Egyptian children and their mothers, while, MTHFR C677T polymorphisms were significantly associated with the risk of CHD in the children only. An association between combined MTHFR A1298C and C677T polymorphisms and CHD was recorded in the children and their mothers. Also, homocysteine levels were significantly increased with both MTHFR 677TT and 1298CC genotypes in Egyptian children with CHD. © 2013.

  6. MTHFR C677T, MTHFR A1298C, and OPG A163G Polymorphisms in Mexican Patients with Rheumatoid Arthritis and Osteoporosis

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    Aniel Jessica Leticia Brambila-Tapia

    2012-01-01

    Full Text Available MTHFR polymorphisms C677T and A1298C are associated with reduced MTHFR enzyme activity and hyperhomocysteinemia, which has been associated with osteoporosis. The A163G polymorphism in osteoprotegerin (OPG has been studied in osteoporosis with controversial results. The objective of the present study was to investigate the association(s among MTHFR C677T, MTHFR A1298C, and OPG A163G polymorphisms in Mexican patients with rheumatoid arthritis and osteoporosis. The femoral neck and lumbar spine bone mineral densities (BMDs were measured in 71 RA patients, and genotyping for the three polymorphisms was performed via restriction fragment length polymorphism analysis. Patients with osteoporosis/osteopenia exhibited statistically significant differences in the genotype frequencies of MTHFR C677T as well as an association with femoral neck BMD; TT homozygotes had lower BMDs than patients with the CT genotype, and both of these groups had lower BMDs than patients with the CC genotype. The associations of the MTHFR C677T polymorphism with osteoporosis/osteopenia and femoral neck BMD suggest that these polymorphisms confer a risk of developing osteoporosis in patients with rheumatoid arthritis, a risk that may be reduced with folate and B complex supplementation.

  7. Meta- and pooled analyses of the methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and gastric cancer risk: A Huge-GSEC review

    NARCIS (Netherlands)

    S. Boccia (Stefania); R.J. Hung (Rayjean); G. Ricciardi (Gualtiero); F. Gianfagna (Francesco); M.P.A. Ebert (Matthias); J.Y. Fang; C.M. Gao; T. Götze (Tobias); F. Graziano (Francesco); M. Lacasaña-Navarro (Marina); D. Lin (Dongxin); L. López-Carrillo (Lizbeth); Y.L. Qiao; H. Shen (Hongbing); R. Stolzenberg-Solomon (Rachael); T. Takezaki (Toshiro); Y.R. Weng; F.F. Zhang; P. Tikka-Kleemola (Päivi); P. Boffetta (Paolo); E. Taioli (Emanuela)

    2008-01-01

    textabstractMethylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the metabolism of folate, whose role in gastric carcinogenesis is controversial. The authors performed a meta-analysis and individual data pooled analysis of case-control studies that examined the association between C677T

  8. A novel lateral flow assay based on GoldMag nanoparticles and its clinical applications for genotyping of MTHFR C677T polymorphisms

    Science.gov (United States)

    Hui, Wenli; Zhang, Sinong; Zhang, Chao; Wan, Yinsheng; Zhu, Juanli; Zhao, Gang; Wu, Songdi; Xi, Dujuan; Zhang, Qinlu; Li, Ningning; Cui, Yali

    2016-02-01

    Current techniques for single nucleotide polymorphism (SNP) detection require tedious experimental procedures and expensive and sophisticated instruments. In this study, a visual genotyping method has been successfully established via combining ARMS-PCR with gold magnetic nanoparticle (GoldMag)-based lateral flow assay (LFA) and applied to the genotyping of methylenetetrahydrofolate reductase (MTHFR) C677T. C677T substitution of the gene MTHFR leads to an increased risk of diseases. The genotyping result is easily achievable by visual observation within 5 minutes after loading of the PCR products onto the LFA device. The system is able to accurately assess a broad detection range of initial starting genomic DNA amounts from 5 ng to 1200 ng per test sample. The limit of detection reaches 5 ng. Furthermore, our PCR-LFA system was applied to clinical trials for screening 1721 individuals for the C677T genotypes. The concordance rate of the genotyping results detected by PCR-LFA was up to 99.6% when compared with the sequencing results. Collectively, our PCR-LFA has been proven to be rapid, accurate, sensitive, and inexpensive. This new method is highly applicable for C677T SNP screening in laboratories and clinical practices. More promisingly, it could also be extended to the detection of SNPs of other genes.

  9. Association of the 5,10-methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) polymorphisms in Korean patients with adult acute lymphoblastic leukemia.

    Science.gov (United States)

    Oh, Doyeun; Kim, Nam Keun; Jang, Moon Ju; Kim, Hugh Chul; Lee, Jae Hoon; Lee, Jung Ae; Ahn, Myung Ju; Kim, Chul Soo; Kim, Heung Sik; Park, Seonyang; Chio, Hyun Sook; Min, Yoo Hong

    2007-01-01

    Methylenetetrahydrofolate reductase (MTHFR) plays a central role in converting folate to methyl donor for DNA methylation. Because MTHFR is a key enzyme in folate metabolism, changes in its activity resulting from polymorphisms in the MTHFR gene could modify the susceptibility to cancer. Recently, the C677T and A1298C mutations of MTHFR were discovered to be associated with susceptibility in acute lymphoblastic leukemia (ALL). The association between MTHFR polymorphisms and susceptibility and clinical outcome in ALL was studied in 118 adult ALL patients and matched healthy controls (n =427). DNA samples taken from patients with ALL and controls were analyzed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assays to detect the MTHFR C677T and A1298C mutations. No significant difference was found in the development of adult ALL among those with different MTHFR genotypes of the C677T or A1298C polymorphisms. However, the MTHFR 677CT+TT genotype showed a tendency to be associated with adult ALL [crude odds ratio (OR), 0.67; 95% confidence interval (CI), 0.44-1.02; adjusted OR, 0.74 95% CI, 0.47-1.14]. The MTHFR C677T and A1298C polymorphisms are not significant risk factors in adult acute leukemia in the Korean population.

  10. Methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and age of onset in schizophrenia: a combined analysis of independent samples.

    Science.gov (United States)

    Saetre, Peter; Vares, Maria; Werge, Thomas; Andreassen, Ole A; Arinami, Tadao; Ishiguro, Hiroki; Nanko, Shinichiro; Tan, Ene Choo; Han, Doug Hyun; Roffman, Joshua L; Muntjewerff, Jan-Willem; Jagodzinski, Pawel P; Kempisty, Bartosz; Hauser, Joanna; Vilella, Elisabet; Betcheva, Elitza; Nakamura, Yusuke; Regland, Björn; Agartz, Ingrid; Hall, Håkan; Terenius, Lars; Jönsson, Erik G

    2011-03-01

    Methylenetetrahydrofolate reductase (MTHFR) is involved in the one-carbon cycle, which is of importance for nucleotide synthesis and methylation of DNA, membranes, proteins and lipids. The MTHFR gene includes two common polymorphisms (rs1801133 or C677T; rs1801131 or A1298C) which both alter enzyme activity. The T-allele of the C677T polymorphism has recently been associated with earlier age at onset of schizophrenia. In the present study we examined the association between the MTHFR C677T and A1298C polymorphisms and age at onset of schizophrenia in twelve samples consisting of 3,213 unrelated schizophrenia patients, including the original Scandinavian sample. There was no consistent relationship between MTHFR C677T, A1298C or combined 677T/1298C carriers and age of onset in schizophrenia when the results of each study were combined using meta-analysis. The present results suggest that the investigated MTHFR polymorphisms do not influence age of onset in schizophrenia. Copyright © 2011 Wiley-Liss, Inc.

  11. Methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and age of onset in schizophrenia: a combined analysis of independent samples

    NARCIS (Netherlands)

    Saetre, P.; Vares, M.; Werge, T.; Andreassen, O.A.; Arinami, T.; Ishiguro, H.; Nanko, S.; Tan, E.; Han, D.H.; Roffman, J.L.; Muntjewerff, J.W.; Jagodzinski, P.P.; Kempisty, B.; Hauser, J.; Vilella, E.; Betcheva, E.; Nakamura, Y.; Regland, B.; Agartz, I.; Hall, H.; Terenius, L.; Jonsson, E.G.

    2011-01-01

    Methylenetetrahydrofolate reductase (MTHFR) is involved in the one-carbon cycle, which is of importance for nucleotide synthesis and methylation of DNA, membranes, proteins and lipids. The MTHFR gene includes two common polymorphisms (rs1801133 or C677T; rs1801131 or A1298C) which both alter enzyme

  12. Association between methylenetetrahydrofolate reductase (MTHFR C677T gene polymorphism and risk of ischemic stroke in North Indian population: A hospital based case–control study

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    Amit Kumar

    2016-10-01

    Conclusion: Findings of the present study suggest that MTHFR C677T gene polymorphism might be a risk factor of IS mainly for SVD subtypes of IS in North Indian population. Further large prospective studies are required to confirm these findings.

  13. Nutritional Genetics: The Case of Alcohol and the MTHFR C677T Polymorphism in relation to homocysteine in a Black South African Population

    NARCIS (Netherlands)

    Nienaber-Rousseau, C.; Pisa, P.T.; Venster, C.S.; Ellis, S.M.; Kruger, A.; Moss, S.; Boonstra, A.; Towers, G.W.

    2013-01-01

    Background/Aims: It is unknown whether the effect of alcohol consumption on homocysteine (Hcy) is modulated by the methylenetetrahydrofolate reductase (MTHFR) C677T. We explored this hypothesized effect by analyzing cross-sectional data of 1,827 black South Africans. Methods: Total Hcy

  14. Association between the MTHFR C677T polymorphism, blood folate and vitamin B12 deficiency, and elevated serum total homocysteine in healthy individuals in Yunnan Province, China.

    Science.gov (United States)

    Ni, Juan; Zhang, Ling; Zhou, Tao; Xu, Wei-Jiang; Xue, Jing-Lun; Cao, Neng; Wang, Xu

    2017-03-01

    An increased serum total homocysteine (tHcy) concentration is typically associated with genetic defects involved in Hcy metabolism or related nutritional deficiencies. In this study, the combined effects of methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and folate and vitamin B12 deficiency on serum total Hcy (tHcy) levels were evaluated in a healthy Chinese population in Yunnan Province, China. The MTHFR C677T polymorphism was genotyped in 330 volunteers (164 men and 166 women) using polymerase chain reaction-restriction fragment length polymorphism analysis. Folate, vitamin B12, and tHcy concentrations were determined by corpuscle immune chemiluminescence assays. The tHcy concentration was determined using an enzymatic assay. Significant negative correlations (pB12 (r=-0.243). Men had significantly higher serum tHcy concentrations than women (pB12 (r=-0.212, p=0.046). The MTHFR C677T polymorphism, folate deficiency, and B12 deficiency were significantly associated with elevated serum tHcy levels. Among these three factors, folate deficiency had the greatest contribution to the serum tHcy concentration, followed by (in order of decreasing effect) MTHFR C677T and vitamin B12 deficiency. Thus, folic acid and vitamin B12 supplementation could help prevent diseases associated with tHcy accumulation, especially in individuals with the MTHFR 677TT genotype. Copyright © 2017. Published by Elsevier Taiwan LLC.

  15. Association between C677T polymorphism of methylene tetrahydrofolate reductase and congenital heart disease: meta-analysis of 7697 cases and 13,125 controls

    NARCIS (Netherlands)

    Mamasoula, Chrysovalanto; Prentice, R. Reid; Pierscionek, Tomasz; Pangilinan, Faith; Mills, James L.; Druschel, Charlotte; Pass, Kenneth; Russell, Mark W.; Hall, Darroch; Töpf, Ana; Brown, Danielle L.; Zelenika, Diana; Bentham, Jamie; Cosgrove, Catherine; Bhattacharya, Shoumo; Riveron, Javier Granados; Setchfield, Kerry; Brook, J. David; Bu'lock, Frances A.; Thornborough, Chris; Rahman, Thahira J.; Doza, Julian Palomino; Tan, Huay L.; O'Sullivan, John; Stuart, A. Graham; Blue, Gillian; Winlaw, David; Postma, Alex V.; Mulder, Barbara J. M.; Zwinderman, Aelko H.; van Engelen, Klaartje; Moorman, Antoon F. M.; Rauch, Anita; Gewillig, Marc; Breckpot, Jeroen; Devriendt, Koen; Lathrop, G. Mark; Farrall, Martin; Goodship, Judith A.; Cordell, Heather J.; Brody, Lawrence C.; Keavney, Bernard D.

    2013-01-01

    Association between the C677T polymorphism of the methylene tetrahydrofolate reductase (MTHFR) gene and congenital heart disease (CHD) is contentious. We compared genotypes between CHD cases and controls and between mothers of CHD cases and controls. We placed our results in context by conducting

  16. Associations of MTHFR C677T and MTRR A66G Gene Polymorphisms with Metabolic Syndrome: A Case-Control Study in Northern China

    Science.gov (United States)

    Yang, Boyi; Fan, Shujun; Zhi, Xueyuan; Wang, Da; Li, Yongfang; Wang, Yinuo; Wang, Yanxun; Wei, Jian; Zheng, Quanmei; Sun, Guifan

    2014-01-01

    Prior evidence indicates that homocysteine plays a role in the development of metabolic syndrome (MetS). Methylenetetrahydrofolate reductase (MTHFR) C677T and methionine synthase reductase (MTRR) A66G polymorphisms are common genetic determinants of homocysteine levels. To investigate the associations of the MTHFR C677T and MTRR A66G polymorphisms with MetS, 692 Chinese Han subjects with MetS and 878 controls were recruited. The component traits of MetS and the MTHFR C677T and MTRR A66G genotypes were determined. A significant association was observed between the MTHFR 677T allele and increased risk of MetS, high fasting blood glucose, high waist circumference, and increasing number of MetS components. The MTRR A66G polymorphism was associated with an increased risk of MetS when combined with the MTHFR 677TT genotype, although there was no association found between MetS and MTRR A66G alone. Furthermore, the MTRR 66GG genotype was associated with high fasting blood glucose and triglycerides. Our data suggest that the MTHFR 677T allele may contribute to an increased risk of MetS in the northern Chinese Han population. The MTRR A66G polymorphism is not associated with MetS. However, it may exacerbate the effect of the MTHFR C677T variant alone. Further large prospective population-based studies are required to confirm our findings. PMID:25429430

  17. Association of methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism with preterm delivery and placental abruption: a systematic review and meta-analysis.

    Science.gov (United States)

    Chen, Jian; Chen, Liang; Zhu, Li-Hua; Zhang, Si-Tong; Wu, Yi-Le

    2016-02-01

    The aim of this study was to summarize evidence on the association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and odds of preterm delivery and placental abruption. PubMed, EMBASE, CBM (Chinese Biomedical Database) and CNKI (Chinese National Knowledge Infrastructure) were searched to identify eligible studies published in English or Chinese before 12 August 2014. The pooled odds ratios (ORs) with 95% confidence intervals were estimated for the association of MTHFR C677T polymorphism with preterm delivery and placental abruption using random effects models. A total of 22 studies that met inclusion and exclusion criteria were included in this meta-analysis. Regardless of the genetic model tested we found no statistically significant association of MTHFR C677T polymorphism with preterm delivery or placental abruption. Funnel plots inspections, Begg's test and Egger's test did not show evidence of publication bias. This meta-analysis demonstrated that overall there was no association of MTHFR C677T polymorphism with preterm delivery or placental abruption. © 2015 Nordic Federation of Societies of Obstetrics and Gynecology.

  18. Association between MTHFR C677T Polymorphism and Risk of Acute Lymphoblastic Leukemia: A Meta-Analysis Based on 51 Case-Control Studies

    Science.gov (United States)

    Li, Su-yi; Ye, Jie-yu; Liang, En-yu; Zhou, Li-xia; Yang, Mo

    2015-01-01

    Background Studies and systematic reviews have reached inconsistent conclusions on the role of 5, 10-methylenetetrahydrofolate reductase (MTHFR) polymorphism C677T in acute lymphoblastic leukemia (ALL) risk. Material/Methods The present meta-analysis comprising of 51 case-control studies, including 7892 cases and 14 280 controls was performed to reevaluate the association between MTHFR C677T polymorphism and ALL risk. Results Statistical differences were found in the dominant model (TT+CT vs. CC, odd ratio (OR)=0.89, 95% CI, 0.79–1.00, P=0.04) and the CT vs. CC (OR=0.89, 95% CI, 0.80–1.00, P=0.05), but not in the allele contrast model (T vs. C, OR=0.92, 95% CI, 0.84–1.01, P=0.08), additive model (TT vs. CC, OR=0.87, 95% CI, 0.73–1.05, P=0.15), or recessive model (TT vs. CT+CC, OR=0.94, 95% CI, 0.81–1.10, P=0.44) in overall populations. In the subgroup analyses stratified by age (children and adults) and ethnicity (Asian and Caucasian), no significant associations between MTHFR C677T polymorphism and ALL risk were observed. Conclusions The current study found no sufficient evidence of a protective role of MTHFR C677T polymorphism in ALL susceptibility. PMID:25761797

  19. Effect of lifestyle factors on plasma total homocysteine concentrations in relation to MTHFR(C677T) genotype. Inter99 (7)

    DEFF Research Database (Denmark)

    Husemoen, L L N; Thomsen, T F; Fenger, M

    2004-01-01

    OBJECTIVE: To examine the associations between various lifestyle factors--smoking habits, physical activity, dietary habits, coffee, tea, and alcohol consumption--and homocysteine (tHcy) in relation to MTHFR(C677T) genotype. DESIGN: Cross-sectional population-based study. SETTING: Residents...

  20. Correlation Between C677T and A1298C Mutations on the MTHFR Gene With Plasma Homocysteine Levels and Venous Thrombosis in Pregnant Women at Risk of Thrombosis

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    Kazem Ghaffari

    2015-12-01

    Full Text Available Background: Deep venous thrombosis (DVT is a common disease with a high morbidity, mortality and increase in miscarriages. Objectives: The purpose of this study was to assessment the correlation between C677T and A1298C mutations on the methylenetetrahydrofolate reductase (MTHFR gene with total plasma homocysteine levels and deep venous thrombosis in pregnant women at risk of thrombosis. Patients and Methods: In this case-control study, 120 pregnant women with risk of DVT and 100 pregnant women without risk of DVT were included in the study. Assay for identification of MTHFR mutations was carried out by PCR-RFLP. Total plasma homocysteine was measured by ELISA method. Results: Homozygous (MM mutations of MTHFR C677T and A1298C were not associated with DVT in pregnant women with and without DVT, respectively. Plasma homocysteine levels were significantly higher in pregnant women with DVT (18.3 ± 5.9 μmol/L than in the pregnant women without DVT (8.9 ± 6.4 μmol/L in C677T and A1298C mutations on the MTHFR gene, respectively (P = 0.021. Conclusions: Our results showed that MTHFR C677T and MTHFR A1289C polymorphisms are not connected with total plasma homocysteine levels in pregnant women with and without DVT. Also, plasma homocysteine levels were significantly higher in pregnant women with DVT.

  1. Genetic Polymorphism of MTHFR C677T Influences Susceptibility to HBV-Related Hepatocellular Carcinoma in a Chinese Population: a Case-Control Study.

    Science.gov (United States)

    Qiao, Kunyan; Zhang, Shitian; Trieu, Congdoanh; Dai, Qinghai; Huo, Zhixiao; Du, Yanan; Lu, Wei; Hou, Wei

    2017-04-01

    Methylene tetrahydrofolate reductase (MTHFR) is the key enzyme of folic acid metabolism and the C677T mutation is associated with decreased enzyme activity. Several studies have shown its regulatory role in carcinogenesis and tumor growth. HBV (hepatitis B virus)-related HCC (hepatocellular carcinoma) is one of the most common liver cancers worldwide. Therefore, the present case-control study aimed to investigate the role of genetic polymorphism of MTHFR C677T in the development and progression of HBV-related HCC in a Chinese population. Subjects enrolled included 204 HBV-related HCC patients and 211 HBV infected patients without HCC. MTHFR C677T polymorphism was genotyped via a DNA microarray-based assay. The relationship between the MTHFR C677T polymorphism and HBV-related HCC was analyzed. The genotype frequencies of MTHFR C677T were statistically different between the HCC and control groups (p = 0.025). The TT genotype was associated with elevated risk of HBV-related HCC in a Chinese population under different genetic models after an adjustment for age, gender, HBV infection duration, and HCC family history (T vs. C, OR = 1.462, 95% CI: 1.090 - 1.962, p = 0.011; TT vs. CC, OR = 2.151, 95% CI: 1.143 - 4.049, p = 0.018; TT vs. CC+CT, OR = 1.918, 95% CI: 1.215 - 3.026, p = 0.005). When stratified with the known duration of HBV infection, subjects with HBV infection duration of more than 20 years and carrying the homozygous TT genotype had a higher susceptibility to HCC than those with the C allele (CC/CT) (OR = 2.568, 95% CI: 1.244 - 5.303; p = 0.011). There was no significant association between MTHFR C677T genotypes and HCC stages based on BCLC staging system. MTHFR C677T polymorphism with TT genotype could be a factor that increases the risk of HBVrelated HCC in a Chinese population, especially those with HBV infection duration of more than 20 years.

  2. The predictive value of factor V Leiden, prothrombin G20210A and MTHFR C677T Gene mutations on the location of venous thromboembolism

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    Muammer Bilici

    2015-12-01

    Full Text Available Objective: In the present study, we aimed to consider the relation between the manifestations of venous thromboembolism (VTE and gene mutations including factor V Leiden (FVL, prothrombin G20210A and MTHFR C677T. Methods: One hundred and forty four patients with idiopathic VTE were enrolled in this study. The data of patients were obtained from the medical records in hospital information system. The patients were grouped according to the location of VTE. In all subjects FVL, prothrombin G20210A, and MTHFR C677T were analyzed by specific polymerase chain reactions and restriction enzymes. Univariate and multivariate analysis were used to evaluate the relation between the groups and the gene mutations including factor V Leiden (FVL, prothrombin G20210A and MTHFR C677T. Results: The mean age of patients was 41.16 ± 13.23 years and the male / female ratio was 1.18. Among the patients with VTE, 44 (30.6% had only DVT, 41 (28.5% had only PE, 26 (18.1% had both DVT and PE, 23 (16% had cerebral veins thrombosis (CVT and 10 (6.9% had abdominal vein thrombosis The prevalence was found to be 46.5% for FVL, 13.2% for prothrombin G20210A and 45.1% for MTHFR C677T gene mutation among patients. There was no statistically difference between the manifestations of VTE regarding the gene mutations (p>0,05. Conclusion: The findings of this study suggest that gene mutations including factor V Leiden (FVL, prothrombin G20210A and MTHFR C677T are not sufficient to determine the location of VTE.

  3. Association between C677T and A1298C polymorphisms of the MTHFR gene and risk of male infertility: a meta-analysis.

    Science.gov (United States)

    Yang, Y; Luo, Y Y; Wu, S; Tang, Y D; Rao, X D; Xiong, L; Tan, M; Deng, M Z; Liu, H

    2016-04-26

    Published studies on the association between the C677T and A1298C polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene and male infertility risk are controversial. To obtain a more precise evaluation, we performed a meta-analysis based on published case-control studies. We conducted an electronic search of PubMed, EMBASE, the Cochrane Library, the Web of Science, and the China Knowledge Resource Integrated Database for papers on MTHFR gene C677T and A1298C polymorphisms and male infertility risk. Pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were used to assess the strength of association in homozygote, heterozygote, dominant, recessive, and additive models. Statistical heterogeneity, test of publication bias, and sensitivity analysis were carried out using the STATA software (Version 13.0). Overall, 21 studies of C677T (4505 cases and 4024 controls) and 13 studies of A1298C (2785 cases and 3094 controls) were included in this meta-analysis. For C677T, the homozygote comparison results were OR = 1.629, 95%CI (1.215- 2.184), and the recessive model results were OR = 1.462 (1.155- 1.850). For A1298C, the homozygote comparison results were OR = 1.289 (1.029-1.616), and the recessive model results were OR = 1.288 (1.034-1.604). In conclusion, the current meta-analysis showed that the MTHFR C677T polymorphism was associated with a significantly increased male infertility risk in the Asian and overall populations, but not in the Caucasian population, and there was a significant association between the A1298C polymorphism and male infertility risk in the Asian, Caucasian, and overall groups.

  4. Association between MTHFR gene polymorphisms (C677T, A1298C) and genetic susceptibility to prostate cancer: a meta-analysis.

    Science.gov (United States)

    Chen, P L; Li, W T; Wang, J; Jiang, Y D; Wu, P; Chen, T; Zheng, S B

    2015-12-29

    Genetic polymorphisms (C677T and A1298C) in methylenetetrahydrofolate reductase (MTHFR) were shown to be related to prostate cancer risk in previous studies; however, the results are controversial. We performed a meta-analysis of previous studies and quantitatively estimated these associations. Pubmed, Embase, and Cochrane Library Database were searched for published case-control studies evaluating the association between C677T (or A1298C) and prostate cancer risk. Pooled associations were presented as odds ratios (ORs) along with their 95% confidence intervals. Twenty-one case control studies were identified for meta-analysis that included 21,581 participants. No significant associations were found between the MTHFR polymorphisms C677T or A1298C and prostate cancer risk in our meta-analysis. However, in subgroup analyses, the C677T CT polymorphism was associated with increased prostate cancer risk in East Asians (CT vs CC+TT: OR = 1.324, P = 0.03). The A1298C CC polymorphism in MTHFR was also linked to slightly reduced prostate cancer risk in European residents (CC vs AC+AA: OR = 0.751, P = 0.004; CC vs AA: OR = 0.768, P = 0.011), whereas it was associated with a significantly increased prostate cancer risk in Asian residents (CC vs AA: OR = 1.862, P = 0.006). The C677T CT polymorphism of MTHFR may be a risk factor for prostate cancer in East Asians. The association between the MTHFR A1298C CC genotype and prostate cancer risk may vary within different populations. Large-scale well-designed studies are required to confirm these associations.

  5. Folate metabolism gene polymorphisms MTHFR C677T and A1298C and risk for Down syndrome offspring: a meta-analysis.

    Science.gov (United States)

    Wu, Xiaoming; Wang, Xiaohuan; Chan, Ying; Jia, Shuting; Luo, Ying; Tang, Wenru

    2013-04-01

    MTHFR C677T and A1298C have been associated with the risk of having an infant with Down syndrome (DS), but results were conflicting. We performed this meta-analysis to derive a more precise estimation of the association between maternal MTHFR polymorphisms and DS. An electronic search of PubMed and Chinese Biomedicine database was conducted to select studies for meta-analysis. Twenty-eight case-control studies containing MTHFR C677T and A1298C gene polymorphisms were chosen, and odds ratio (OR) with confidence interval (CI) was used to assess the strength of this association. Case-control studies including 2806 cases and 4597controls for MTHFR C677T were identified. The overall results suggested that the variant genotypes MTHFR C677T were associated with DS risk (TT+CT vs. CC: OR=1.305, 95% CI: 0.125-1.514, p=0). In the stratified analysis, individuals with the T-carriers genotype in the dominant model had increased risk of DS (OR=1.171, 95% CI: 0.976-1.405, p=0.09) in Caucasian subjects and in Asian subjects (OR=1.749, 95% CI: 1.084-2.824, p=0.022). In addition, case-control studies including 1854 cases and 2364 controls for MTHFR A1298C were chosen. Associations between MTHFR A1298C and the risk of having a child with DS were not found. A symmetric funnel plot, the Egger's test (p=0.126) suggested a lack of publication bias. This meta-analysis supports the idea that MTHFR C677T genotype is associated with increased risk for DS offspring. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  6. Association of anticardiolipin antibody and C677T in methylenetetrahydrofolate reductase mutation in women with recurrent spontaneous abortions: a new path to thrombophilia?

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    Egle Couto

    Full Text Available CONTEXT: Recurrent spontaneous abortion (RSA has been associated with venous thrombosis in the mother. Acquired and inherited thrombophilia factors are possible causes. OBJECTIVE: To evaluate the association between thrombogenic factors and recurrent spontaneous abortion. TYPE OF STUDY: Case-control study. SETTING: Centro de Atenção Integral à Saúde da Mulher, Universidade Estadual de Campinas. METHODS: 40 ml of blood was collected from 88 women attending an RSA clinic and 88 fertile women attending a family planning clinic, to evaluate the presence of acquired and inherited thrombophilia factors. Anticardiolipin antibodies (ACA, lupus anticoagulant and deficiencies of proteins C and S and antithrombin III were evaluated by enzyme-linked immunosorbent assay (ELISA, dilute Russell Viper Venom time (dRVVT, coagulometric and chromogenic methods. DNA was amplified by the polymerase chain reaction (PCR to study factor V Leiden and G20210A mutations in the prothrombin gene and C677T mutation in the methylenetetrahydrofolate reductase (MTHFR gene. Data were analyzed using odds ratios and a regression model for age adjustment. Fisher’s exact test was used to evaluate statistical relationships between associated factors and RSA. RESULTS: ACA was detected in 11 women with RSA and one fertile woman. Heterozygous C677T was detected in 59 women with RSA and 35 fertile women. Concomitant presence of ACA and C677T was found in eight women with RSA and no fertile women (p < 0.01. DISCUSSION: The meaning of the association between C677T mutation in the MTHFR gene and ACA is still not clear. It is possible that an inherited factor that alone would not strongly predispose a woman to thrombosis could, when associated with an acquired factor, start the process and increase the likelihood of thrombosis expression. CONCLUSIONS: ACA and C677T in the MTHFR gene are statistically associated with RSA. The association of these two conditions is a new finding in

  7. Association of MTHFR C677T and A1298C polymorphisms with oral cancer susceptibility: evidence from a meta-analysis

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    Jiang S

    2017-01-01

    Full Text Available Sui Jiang,1,* Jin-Dong Xu,2 Zhen-Jian Zhuo,3 Zhu-Ming Hua2,* 1Department of Oral and Maxillofacial Surgery, 2Department of Anesthesiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, 3School of Chinese Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, People’s Republic of China *These authors contributed equally to this work Abstract: Methylenetetrahydrofolate reductase (MTHFR is a central enzyme involved in folate metabolism and plays an important role in DNA synthesis and methylation. Several studies have been conducted to illustrate the associations between MTHFR C677T and A1298C polymorphisms with oral cancer susceptibility; however, the results are inconsistent. Therefore, we conducted an updated meta-analysis to obtain a more reliable estimation of the associations. We retrieved eligible studies from PubMed, EMBASE, and CBM databases through September 2016. Ultimately, pooled analyses involved 10 studies with 1443 cases and 1640 controls for the C677T polymorphism, as well as five studies with 973 cases and 1024 controls for the A1298C polymorphism. Risk estimates were presented as odds ratios (ORs and 95% confidence intervals (95% CIs. Pooled results indicated that neither C677T nor A1298C polymorphism was associated with oral cancer susceptibility. However, a borderline significant association was detected between MTHFR C677T polymorphism and a decreased oral cancer risk (homozygous model: OR=0.71, 95% CI=0.50–1.00 in hospital-based studies. Our results suggested that  MTHFR C677T and A1298C polymorphisms might not be associated with oral cancer risk. However, more evidence is needed to further confirm these findings in the future. Keywords:  MTHFR, polymorphisms, oral cancer, susceptibility, meta-analysis

  8. Are polymorphisms in MTRR A66G and MTHFR C677T genes associated with congenital heart diseases in Iranian population?

    Science.gov (United States)

    Noori, Noormohammad; Miri-Moghaddam, Ebrahim; Dejkam, Asieh; Garmie, Yasman; Bazi, Ali

    2017-01-01

    The 5, 10-methyleneterahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) are two essential enzymes involved in folate metabolism. The relationship between genetic polymorphisms and congenital heart defects (CHDs) is inconsistent. Our aim was to investigate the association between two well-known polymorphisms of MTHFR and MTRR genes, C677T and A66G, respectively, and CHDs in Iranian patients. We enrolled 74 patients with ventricular septal defect (VSD) and 79 with tetralogy of fallot (TOF) along with 147 healthy controls. C677T and A66G polymorphisms were detected using tetra-primer ARMS (amplification refractory mutation system) PCR. Individuals carrying homozygote mutant (TT) genotype of C677T polymorphism represented the highest risk for CHDs (OR=7.3, 95% CI: 0.8-61, P=0.06). Also, significantly increased risk of VSD was observed in individuals with TT genotype (OR=10, 95% CI: 1-92.2, P=0.04). However, the frequency for variant allele (T) of C677T polymorphism was not statistically different between cases and controls (16.3% and 20.9%, respectively). For A66G polymorphism, we found that AG and GG genotypes had higher frequencies in the patients (48.4% and 21.6% respectively) than controls (42.9% and 15.6%, respectively). In line with this, combined AG+GG genotype represented with significantly elevated risk of CHDs (OR=1.6; 95% CI: 1-2.6, P=0.03). AG+GG combination was also identified as a risk factor for TOF (OR=1.8, 95% CI: 1-3.3, P=0.04). We demonstrated that C677T polymorphism of MTHFR gene was significantly associated with VSD in our patients. Our study also suggested that A66G polymorphism of MTRR gene may contribute to the development of TOF in Iranians.

  9. Meta-analyses of Blood Homocysteine Levels for Gender and Genetic Association Studies of the MTHFR C677T Polymorphism in Schizophrenia

    Science.gov (United States)

    Nishi, Akira; Numata, Shusuke; Tajima, Atsushi; Kinoshita, Makoto; Kikuchi, Kumiko; Shimodera, Shinji; Tomotake, Masahito; Ohi, Kazutaka; Hashimoto, Ryota; Imoto, Issei; Takeda, Masatoshi; Ohmori, Tetsuro

    2014-01-01

    Previous studies suggest that elevated blood homocysteine levels and the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism are risk factors for schizophrenia. However, the effects of gender and MTHFR C677T genotypes on blood homocysteine levels in schizophrenia have not been consistent. We first investigated whether plasma total homocysteine levels were higher in patients with schizophrenia than in controls with stratification by gender and by the MTHFR C677T genotypes in a large cohort (N = 1379). Second, we conducted a meta-analysis of association studies between blood homocysteine levels and schizophrenia separately by gender (N = 4714). Third, we performed a case-control association study between the MTHFR C677T polymorphism and schizophrenia (N = 4998) and conducted a meta-analysis of genetic association studies based on Japanese subjects (N = 10 378). Finally, we assessed the effect of plasma total homocysteine levels on schizophrenia by a mendelian randomization approach. The ANCOVA after adjustment for age demonstrated a significant effect of diagnosis on the plasma total homocysteine levels in all strata, and the subsequent meta-analysis for gender demonstrated elevated blood homocysteine levels in both male and female patients with schizophrenia although antipsychotic medication might influence the outcome. The meta-analysis of the Japanese genetic association studies demonstrated a significant association between the MTHFR C677T polymorphism and schizophrenia. The mendelian randomization analysis in the Japanese populations yielded an OR of 1.15 for schizophrenia per 1-SD increase in plasma total homocysteine. Our study suggests that increased plasma total homocysteine levels may be associated with an increased risk of schizophrenia. PMID:24535549

  10. Methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and nonsyndromic orofacial clefts susceptibility in a southern Chinese population.

    Science.gov (United States)

    Han, Yue; Pan, Yongchu; Du, Yifei; Tong, Na; Wang, Meilin; Zhang, Zhengdong; Wan, Linzhong; Wang, Lin

    2011-12-01

    Nonsyndromic orofacial clefts (NSOC) are one of the most common congenital anomalies in humans. Great efforts have been taken to unravel its genetic background. Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme in folate metabolism and two of its functional polymorphisms, MTHFR C677T and MTHFR A1298C, might be associated with NSOC susceptibility. The aim of the present study was to investigate their associations with risks of NSOC in a southern Chinese population. We found that MTHFR 677 TT and 677 CT/TT were associated with increased risk of cleft lip with or without cleft palate; meanwhile, MTHFR 1298 AC and 1298 AC/CC had protective effects against cleft lip with or without cleft palate. In further stratified analysis, we found that MTHFR 677 CT contributed to elevated risk of cleft lip only, as did MTHFR 677 CT/TT. On the contrary, MTHFR 1298 AC and 1298 AC/CC appeared to be protective against cleft lip with cleft palate. These results suggested that these two polymorphisms were involved in the development of NSOC in a southern Han Chinese population.

  11. The MTHFR C677T and A1298C polymorphisms and susceptibility to childhood acute lymphoblastic leukemia in Portugal.

    Science.gov (United States)

    Oliveira, Elisabete; Alves, Sandra; Quental, Sofia; Ferreira, Fátima; Norton, Lucília; Costa, Vitor; Amorim, António; Prata, Maria João

    2005-08-01

    Methylenetetrahydrofolate reductase (MTHFR) is an essential enzyme in folate metabolism and in DNA methylation and synthesis. The role of two common polymorphisms at the MTHFR gene, C677T and A1298C, in the etiology of childhood or adult acute lymphoblastic leukemia (ALL) has been previously investigated. Although a protective effect of MTHFR*677T against ALL was systematically reported, the magnitude of the effect appeared to be influenced by population-specific gene-environmental interactions. The evidence of the role of MTHFR*1298C in ALL susceptibility was less consistent, emphasizing the need for enlarging molecular epidemiologic studies to independent trials from different populations. The authors analyzed in North Portugal the association between variations at the two MTHFR positions and risk of ALL by comparing genotypes and gene frequencies in 103 affected children with those in 111 healthy controls. None of the variations was found to significantly affect the risk of developing childhood ALL in North Portugal, and this finding per se is of relevance in further studies aimed at assessing the etiology of the pathology in this specific population. Despite the absence of statistical significance, these data revealed that the frequency of MTHFR*677T was lower in patients than in controls, a result that is congruent with other reports and with the functional model usually invoked to explain its ALL protective effect. Concerning MTHFR1298*C, this study failed to corroborate previous findings of decreased risk of ALL in the presence of the variant.

  12. Spectrum of MTHFR gene SNPs C677T and A1298C: a study among 23 population groups of India.

    Science.gov (United States)

    Saraswathy, Kallur Nava; Asghar, Mohammad; Samtani, Ratika; Murry, Benrithung; Mondal, Prakash Ranjan; Ghosh, Pradeep Kumar; Sachdeva, Mohinder Pal

    2012-04-01

    Elevated homocysteine is a risk factor for many complex disorders. The role of methylenetetrahydrofolate reductase (MTHFR) gene in methylation of homocysteine makes it one of the most important candidate genes for these disorders. Considering the heterogeneity in its distribution in world populations, we screened MTHFR C677T and A1298C single nucleotide polymorphisms in a total of 23 Indian caste, tribal and religious population groups from five geographical regions of India and belonging to four major linguistic groups. The frequencies of MTHFR 677T and 1298C alleles were found to be 10.08 and 20.66%, respectively. MTHFR homozygous genotype 677TT was absent in eight population groups and homozygous 1298CC was absent in two population groups. 677T allele was found to be highest among north Indian populations with Indo-European tongue and 1298C was high among Dravidian-speaking tribes of east India and south India. The less common mutant haplotype 677T-1298C was observed among seven population groups and overall the frequency of this haplotype was 0.008, which is similar to that of African populations. cis configuration of 677T and 1298C was 0.94%. However, we could not find any individual with four mutant alleles which supports the earlier observation that presence of more than two mutant alleles may decrease the viability of foetus and possibly be a selective disadvantage in the population.

  13. Associations between C677T and A1298C polymorphisms of MTHFR and susceptibility to rheumatoid arthritis: a systematic review and meta-analysis.

    Science.gov (United States)

    Yuan, Yi; Shao, Wenjing; Li, Yuying

    2017-04-01

    Methylenetetrahydrofolatereductase (MTHFR) is an important enzyme involved in folate metabolism and DNA synthesis. Although a number of studies have examined the association of the MTHFR C677T and A1298C polymorphisms with susceptibility to rheumatoid arthritis (RA), the conclusions are controversial. A comprehensive literature search using PubMed, Embase, the Cochrane Library, CNKI and Wanfang databases was conducted for relevant studies on the association between MTHFR polymorphisms and RA risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using fixed- and random-effect models. In total, 1854 cases and 1689 controls from 12 studies and 1525 cases and 1455 controls from 10 studies were included for the C677T and A1298C polymorphisms, respectively. Pooled results indicated that both C677T and A1298C polymorphisms were associated with RA susceptibility (C677T: TT vs. CC, OR = 1.31, 95% CI = 1.02-1.67, P = 0.032; TC vs. CC, OR = 1.32, 95% CI = 1.02-1.70, P = 0.032; TT + TC vs. CC, OR = 1.38, 95% CI = 1.07-1.78, P = 0.014; T vs. C, OR = 1.29, 95% CI = 1.06-1.57, P = 0.011; A1298C: CC vs. CA + AA: OR = 1.58, 95% CI = 1.20-2.06, P = 0.001). Further stratification based on ethnicity and geographic region indicated an association between the MTHFR C677T SNP and the risk of RA in Caucasian and patients in Africa. However, there is no evidence of significant association between A1298C polymorphism and RA risk in Caucasian or population in Africa. This meta-analysis indicates that MTHFR C677T and A1298C polymorphisms could be predictors of risk of RA and warrants validation in large and well-designed prospective studies.

  14. Methylenetetrahydrofolate Reductase C677T Polymorphism and Type 2 Diabetes Mellitus in Chinese Population: A Meta-Analysis of 29 Case-Control Studies

    Science.gov (United States)

    Zhu, Bo; Wu, Xiaomei; Zhi, Xueyuan; Liu, Lei; Zheng, Quanmei; Sun, Guifan

    2014-01-01

    Background Methylenetetrahydrofolate reductase (MTHFR), a key enzyme in folate metabolism, had significant effects on the homocysteine levels. The common functional MTHFR C677T polymorphism had been extensively researched. Several studies had evaluated the relationship between MTHFR C677T polymorphism and type 2 diabetes mellitus (T2DM), but the results were still controversial in the Chinese Han population. This meta-analysis was conducted to evaluate the relationship between MTHFR C677T polymorphism and T2DM in the Chinese Han population. Methods We searched the relevant studies in multiple electronic databases, which published up to December 2013. We reviewed and extracted data from all the included studies on the relationship between MTHFR C677T polymorphism and T2DM in the Chinese Han population. The odds ratios (ORs) and their 95% confidence intervals (95%CIs) were used to evaluate the relationship. Fixed-effects and random-effects meta-analysis were used to pool ORs by the heterogeneity. Publication bias and sensitivity analysis were also examined. Results 29 studies were finally included in our meta-analysis, which contained 4656 individuals with T2DM and 2127 healthy controls. There was a significant relationship between MTHFR C677T polymorphism and T2DM under dominant (OR: 1.70, 95% CI: 1.42–2.02), recessive (OR: 1.48, 95% CI: 1.21–1.80), homozygous (OR: 1.89, 95% CI: 1.47–2.42), heterozygous (OR: 1.58, 95% CI: 1.33–1.87), and additive (OR: 1.46, 95% CI: 1.28–1.68) genetic model in a random-effects model. Subgroup analysis also reached similar results. Sensitivity analysis indicated that the overall result were dependable. Conclusions There was a significant relationship between MTHFR C677T polymorphism and T2DM in the Chinese Han population. The results of our meta-analysis suggested that MTHFR 677T allele might be a risk genetic factor of T2DM in the Chinese Han population. PMID:25047451

  15. The C677T Variant in the Methylenetetrahydrofolate Reductase Gene and Idiopathic Spontaneous Abortion in a Romanian Population Group

    Directory of Open Access Journals (Sweden)

    Radu A. POPP

    2012-02-01

    Full Text Available Spontaneous abortions (SA are a major public health problem and a frequent pregnancy associated disorder. Hereditary thrombophilia and hyperhomocysteinemia are considered to be important factors altering the placental circulation, the in utero development and the evolution of pregnancy. The MTHFR gene (methylenetetrahydrofolate reductase exhibits an intensely studied polymorphism, C677T, that was repeatedly associated with hyperhomocysteinemia, increased thrombotic risk and was studied in relation with SA susceptibility. This study was aim to assessing the correlation of this polymorphism with idiopathic sporadic or recurrent SA in a Romanian population. In the case-control study, 131 patients with a history of SA and 135 women with no SA and at least one uneventful term delivery were included. The PCR-RFLP technique (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism was used to genotype the cases and controls and the results were analysed using the ?2 test. The present analysis indicates that the MTHFR 677TT homozygous genotype is positively associated with recurrent idiopathic SA (OR 2.493, 95%CI 0.974, 6.379, p-value 0.06. This association was no longer observed in sporadic SA patients (OR 1.214, 95%CI 0.488, 3.017, p-value 0.814. In conclusion, the present study is consistent with previous reports which state that the presence of MTHFR 677T variant in homozygous status could represent a genetic susceptibility factor for recurrent idiopathic SA. Moreover, this is the first attempt to investigate this correlation in a Romanian group and to offer epidemiological support in estimating the frequencies of some common genetic variants in the Romanian population.

  16. Methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and colorectal cancer: the Fukuoka Colorectal Cancer Study.

    Science.gov (United States)

    Yin, Guang; Kono, Suminori; Toyomura, Kengo; Hagiwara, Tomoko; Nagano, Jun; Mizoue, Tetsuya; Mibu, Ryuichi; Tanaka, Masao; Kakeji, Yoshihiro; Maehara, Yoshihiko; Okamura, Takeshi; Ikejiri, Koji; Futami, Kitaroh; Yasunami, Yohichi; Maekawa, Takafumi; Takenaka, Kenji; Ichimiya, Hitoshi; Imaizumi, Nobutoshi

    2004-11-01

    Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme regulating folate metabolism, which affects DNA synthesis and methylation. This study investigated the relation of MTHFR C677T and A1298C polymorphisms to colorectal cancer in a case-control study in Fukuoka, Japan. The subjects comprised 685 incident cases of histologically confirmed colorectal adenocarcinomas and 778 community controls selected randomly in the study area. The genotype was determined by the PCR-RFLP method using genomic DNA extracted from buffy coat. Alcohol use was ascertained by in-person interview. Statistical adjustment was made for gender, age class, area, and alcohol use. The MTHFR 677TT genotype was associated with a statistically significant decrease in the risk with an adjusted odds ratio of 0.69 (95% confidence interval 0.51-0.93) compared with the 677CC and 677CT combined, and the decrease was most evident in individuals with no alcohol consumption. While the A1298C polymorphism showed no measurable association with the overall risk of colorectal cancer, the 1298CC genotype was associated with a statistically significant increase in the risk when alcohol consumption was high, and was also associated with an approximately 2-fold increase in the risk of each of proximal and distal colon cancer. The findings add to evidence that individuals with the MTHFR 677TT genotype have a decreased risk of colorectal cancer in the absence of folate depletion, suggesting a protective role of folate by ensuring a sufficient thymidylate pool for DNA synthesis. Because very few individuals had the 1298CC genotype, the findings regarding the A1298C polymorphism need careful interpretation and confirmation in larger studies.

  17. Determination of the frequency of MTHFR C677T and MTHFR A1298C polymorphisms in persons with polymorphic MTHFR gene

    OpenAIRE

    Uğuz, Nihal; Erden, Gönül; Güngör, Oya; Bal, Ceylan; Yıldırımkaya, Metin

    2012-01-01

    Amaç: MTHFR enzimi 5,10 metilentetrahidrofolatı 5 metiltetrahidrofolata katalize ederek, homosisteinden metionin remetilasyonu için gerekli olan aktif folat formunu oluşturur. Bu enzimi kodlayan gendeki mutasyonlar ile bir çok hastalık arasındaki ilişki araştırılmaktadır. Çalışmalar, en iyi bilinen MTHFR C677T ve A1298C polimorfizmleri üzerinde yoğunlaşmaktadır. Bu çalışma, MTHFR geninde C677T ve A1298C polimorfizm tespit edilen bireylerde bu polimorfizmlerin sıklığını saptamak amacıyla planl...

  18. Association between C677T polymorphism of methylene tetrahydrofolate reductase and congenital heart disease: meta-analysis of 7697 cases and 13,125 controls.

    Science.gov (United States)

    Mamasoula, Chrysovalanto; Prentice, R Reid; Pierscionek, Tomasz; Pangilinan, Faith; Mills, James L; Druschel, Charlotte; Pass, Kenneth; Russell, Mark W; Hall, Darroch; Töpf, Ana; Brown, Danielle L; Zelenika, Diana; Bentham, Jamie; Cosgrove, Catherine; Bhattacharya, Shoumo; Riveron, Javier Granados; Setchfield, Kerry; Brook, J David; Bu'Lock, Frances A; Thornborough, Chris; Rahman, Thahira J; Doza, Julian Palomino; Tan, Huay L; O'Sullivan, John; Stuart, A Graham; Blue, Gillian; Winlaw, David; Postma, Alex V; Mulder, Barbara J M; Zwinderman, Aelko H; van Engelen, Klaartje; Moorman, Antoon F M; Rauch, Anita; Gewillig, Marc; Breckpot, Jeroen; Devriendt, Koen; Lathrop, G Mark; Farrall, Martin; Goodship, Judith A; Cordell, Heather J; Brody, Lawrence C; Keavney, Bernard D

    2013-08-01

    Association between the C677T polymorphism of the methylene tetrahydrofolate reductase (MTHFR) gene and congenital heart disease (CHD) is contentious. We compared genotypes between CHD cases and controls and between mothers of CHD cases and controls. We placed our results in context by conducting meta-analyses of previously published studies. Among 5814 cases with primary genotype data and 10 056 controls, there was no evidence of association between MTHFR C677T genotype and CHD risk (odds ratio [OR], 0.96 [95% confidence interval, 0.87-1.07]). A random-effects meta-analysis of all studies (involving 7697 cases and 13 125 controls) suggested the presence of association (OR, 1.25 [95% confidence interval, 1.03-1.51]; P=0.022) but with substantial heterogeneity among contributing studies (I(2)=64.4%) and evidence of publication bias. Meta-analysis of large studies only (defined by a variance of the log OR <0.05), which together contributed 83% of all cases, yielded no evidence of association (OR, 0.97 [95% confidence interval, 0.91-1.03]) without significant heterogeneity (I(2)=0). Moreover, meta-analysis of 1781 mothers of CHD cases (829 of whom were genotyped in this study) and 19 861 controls revealed no evidence of association between maternal C677T genotype and risk of CHD in offspring (OR, 1.13 [95% confidence interval, 0.87-1.47]). There was no significant association between MTHFR genotype and CHD risk in large studies from regions with different levels of dietary folate. The MTHFR C677T polymorphism, which directly influences plasma folate levels, is not associated with CHD risk. Publication biases appear to substantially contaminate the literature with regard to this genetic association.

  19. Methylenetetrahydrofolate reductase gene polymorphisms are associated with ischemic and hemorrhagic stroke: Dual effect of MTHFR polymorphisms C677T and A1298C.

    Science.gov (United States)

    Sazci, Ali; Ergul, Emel; Tuncer, Nese; Akpinar, Gurler; Kara, Ihsan

    2006-12-11

    Hyperhomocysteinemia is an independent risk factor for ischemic stroke. The enzyme methylenetetrahydrofolate reductase (MTHFR) plays a critical role in modulating the levels of plasma homocysteine. Two polymorphisms in the MTHFR gene, C677T, A1298C result in reduced enzyme activity. The mechanisms of ischemic and hemorrhagic stroke are not well understood. Although controversial, previous studies have shown evidence of causality of both stroke subtypes in patients with methylenetetrahydrofolate reductase gene polymorphisms. Therefore, we examined whether the C677T and A1298C polymorphisms of MTHFR gene are genetic risk factors for both ischemic and hemorrhagic stroke in a Turkish Caucasian population. In a case-control study, 120 total unrelated stroke patients (92 ischemic stroke, 28 hemorrhagic stroke), and 259 healthy controls were genotyped for C677T and A1298C polymorphisms of the MTHFR gene using a PCR-RFLP based-method. The MTHFR 1298C allele (chi(2)=8.589; P=0.014), C1298C genotype (OR=2.544; P=0.004), and C677C/C1298C compound genotype (OR=3.020; P=0.001) were associated with overall stroke. The MTHFR 1298C allele (chi(2)=11.166; P=0.004), C1298C genotype (OR=2.950; P=0.001), and C677C/C1298C compound genotype (OR=3.463, P=0.0001) were strongly associated with ischemic stroke. Interestingly however, the MTHFR 677T allele (chi(2)=6.033; P=0.049), T677T genotype (OR=3.120; P=0.014), and T677T/A1298A compound genotype (OR=4.211; P=0.002) were associated with hemorrhagic stroke. In conclusion, the C677T and A1298C polymorphisms of the MTHFR gene are genetic risk factors for hamorrhagic and ischemic stroke respectively, independent of other atherothrombotic risk factors.

  20. Associations of methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms with genetic susceptibility to rheumatoid arthritis: a meta-analysis.

    Science.gov (United States)

    Cen, Han; Huang, Hua; Zhang, Li-Na; Liu, Li-Ya; Zhou, Li; Xin, Xia-Fei; Zhuo, Ren-Jie

    2017-02-01

    The aim of our study was to conduct a meta-analysis to assess whether combined evidence shows associations between C677T and A1298C polymorphisms of methylenetetrahydrofolate reductase (MTHFR) and genetic susceptibility to rheumatoid arthritis (RA). A total of 11 articles involving 20 comparisons were included, containing 12 comparisons for the MTHFR C677T polymorphism and 8 comparisons for the MTHFR A1298C polymorphism. Significant evidence was detected for the association of RA susceptibility with the MTHFR C677T polymorphism T allele under allelic contrast and dominant model in Asians (T versus C, OR = 1.300, 95 % CI = 1.104-1.531, p = 0.002; TT + CT versus CC, OR = 1.495, 95 % CI = 1.187-1.882, p = 0.001). Significant association between RA susceptibility and the MTHFR A1298C polymorphism A allele under recessive model was found in the overall meta-analysis (AA versus AC + CC, OR = 1.281, 95 % CI = 1.048-1.565, p = 0.016). Our meta-analysis results demonstrate that the MTHFR C677T polymorphism is involved in the genetic susceptibility of RA in Asians, and the MTHFR A1298C polymorphism is associated with genetic susceptibility to RA in the overall population. Given the paucity of studies, especially in non-Asian populations, further studies with larger sample sizes are required to elucidate the role of MTHFR polymorphisms in the genetic basis of RA in different ethnic populations.

  1. MTHFR gene C677T and A1298C polymorphisms and homocysteine levels in primary open angle and primary closed angle glaucoma

    Science.gov (United States)

    Micheal, Shazia; Qamar, Raheel; Akhtar, Farah; Khan, Muhammad Imran; Khan, Wajid Ali

    2009-01-01

    Purpose To investigate the methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C genotypes and plasma concentrations of total homocysteine (tHcy) in Pakistani patients with primary open angle glaucoma (POAG) and primary closed angle glaucoma (PCAG). Methods This was a prospective case-control study. A total of 295 patients (173 POAG, 122 PCAG) and 143 age- and sex-matched controls were subdivided into two ethnic groups, Punjabis (Punjab province, central Pakistan) and Pathans (North-West Frontier Province, northern Pakistan). Genotypes of the MTHFR C677T and A1298C polymorphisms were detected by polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP). An enzyme-linked immunosorbent assay was used to determine the total serum homocysteine (tHcy) levels. Associations were determined by logistic regression analysis. Results Frequency distributions of genotypes and combined genotypes as well as homocysteine levels were obtained. The overall distribution of the C677T genotype was found to be significantly associated with PCAG (CC 69%, CT 21%, TT 10%; p=0.001, χ2=12.6), but not with POAG (CC 71%, CT 28%, TT 1%; p=0.98, χ2=0.02) as compared to the controls (CC 71%, CT 29%, TT 1%). The Pathan cohorts revealed no association with the disease; however, the Punjabis demonstrated a significant association with PCAG (CC 75%, CT 11%, TT 13%; pA1298C polymorphism (AA 43%, AC 54%, CC 3%; pMTHFR C677T and A1298C polymorphisms and the combined genotype TTAC were associated with PCAG in Punjabi subjects of Pakistani origin and correlated with the high serum tHcy levels seen in these patients. PMID:19936026

  2. Interaction of MTHFR C677T and A1298C, and MTR A2756G gene polymorphisms in breast cancer risk in a population in Northeast Brazil.

    Science.gov (United States)

    de Cássia Carvalho Barbosa, Rita; da Costa, Débora Menezes; Cordeiro, Denise Ellen Francelino; Vieira, Ana Patricia Freitas; Rabenhorst, Silvia Helena Barem

    2012-11-01

    Polymorphisms in genes encoding enzymes of folate metabolism are a focus of breast cancer risk studies due of the role of these enzymes in DNA methylation, synthesis, and repair. MTHFR, encoding for 5,10-methylenetetrahydrofolate reductase, is one of the most studied genes in this regard, but findings are controversial, and the majority of studies have analyzed polymorphisms individually. In this case control study, we examined the combination of the polymorphisms MTHFR C677T and A1298C with MTR A2756G, where MTR, methionine synthase, is an important enzyme of the folate cycle in the methylation pathway. One hundred and forty-two patients with breast cancer and controls were included and the genotypes were determined using PCR-RFLP. In the population studied, individuals carrying the polymorphic allele in the heterozygous state for both enzymes, MTHFR C677T and MTR A2756G, had an increased risk [odds ratio, OR=2.77 (95% confidence interval, CI=1.19-6.52)] for disease, compared to those with the wild genotype. In addition, individuals carrying the MTR 2756 genotype AG had an increased risk when this was combined with the MTHFR 1298 genotype CC [OR=5.13 (95% CI=0.87-38.82)]. No significant results were found from the analyses associating the MTHFR C677T and A1298C genotypes. However, when stratifying the patients by age (50 years old as the cut-off), patients over 50 years old had greater risk, with the presence of both MTHFR polymorphisms in the heterozygous state [OR=5.33 (95% CI=1.42-21.03)]. This study points out the importance of the interactions between the MTHFR C677T, MTHFR A1298C and MTR A2756G polymorphisms, and also highlights the relevance of the MTR A2756G polymorphism and age in breast cancer risk.

  3. Association of polymorphisms MTHFR C677T and A1298C with risk of colorectal cancer, genetic and epigenetic characteristic of tumors, and response to chemotherapy.

    Science.gov (United States)

    Fernández-Peralta, Antonia M; Daimiel, Lydia; Nejda, Nargisse; Iglesias, Daniel; Medina Arana, Vicente; González-Aguilera, Juan J

    2010-02-01

    The enzyme MTHFR plays an important role in folate metabolism, and folate is implicated in carcinogenesis due to its role in DNA methylation, repair, and synthesis. We analyze the relationship of MTHFR C677T and A1298C polymorphisms with biological, clinicopathological, genetic and epigenetic features of tumors, and the patient outcome after treatment with 5-FU-based chemotherapy to determine the contribution of MTHFR genotypes in the risk of colorectal cancer (CRC) and in the response to therapy. Genomic DNA of 143 Spanish sporadic CRC and 103 controls was analyzed by polymerase chain reaction/restriction fragment length polymorphism and sequencing. The C677T polymorphism has protective effect on CRC showing TT genotype an odds ratios of 0.06 (95% confidence interval (CI): 0.10-0.32) and the CT of 0.51 (95% CI: 0.3-0.87). MTHFR A1298C polymorphism is not associated with CRC risk. Patients with 1298CC and AC genotypes exhibit worse survival than those with the wild genotype (log rank, p = 0.001), whereas C677T genotypes do not affect patient survival (log rank, p = 0.92). MTHFR 677T allele carriers responded better to 5-FU-based chemotherapy than patients with the wild CC genotype (log rank, p = 0.05). The variant C allele of A1298C affects negatively the response to 5-FU-based chemotherapy (log rank, p = 0.009). The variant allele of the C677T has a protective effect on CRC development, whereas the variant allele of the A1298C does not produce any effect on disease risk. Both MTHFR polymorphisms are relevant and independent factors of patient outcome after 5FU-based treatment of CRC, and MTHFR genotyping may be of predictive benefit in selecting treatment regimens.

  4. Association between C677T Polymorphism of Methylene Tetrahydrofolate Reductase and Congenital Heart Disease: Meta-Analysis of 7,697 Cases and 13,125 Controls

    Science.gov (United States)

    Mamasoula, Chrysovalanto; Prentice, R. Reid; Pierscionek, Tomasz; Pangilinan, Faith; Mills, James L.; Druschel, Charlotte; Pass, Kenneth; Russell, Mark W.; Hall, Darroch; Töpf, Ana; Brown, Danielle L.; Zelenika, Diana; Bentham, Jamie; Cosgrove, Catherine; Bhattacharya, Shoumo; Riveron, Javier Granados; Setchfield, Kerry; Brook, J. David; Bu'Lock, Frances A.; Thornborough, Chris; Rahman, Thahira J.; Doza, Julian Palomino; Tan, Huay L.; O'Sullivan, John; Stuart, A. Graham; Blue, Gillian; Winlaw, David; Postma, Alex V.; Mulder, Barbara J.M.; Zwinderman, Aelko H.; van Engelen, Klaartje; Moorman, Antoon F.M.; Rauch, Anita; Gewillig, Marc; Breckpot, Jeroen; Devriendt, Koen; Lathrop, G. Mark; Farrall, Martin; Goodship, Judith A.; Cordell, Heather J.; Brody, Lawrence C.; Keavney, Bernard D.

    2013-01-01

    Background Association between the C677T polymorphism of the methylene tetrahydrofolate reductase (MTHFR) gene and congenital heart disease (CHD) is contentious. Methods and Results We compared genotypes between CHD cases and controls, and between mothers of CHD cases and controls. We placed our results in context by conducting metaanalyses of previously published studies. Among 5,814 cases with primary genotype data and 10,056 controls, there was no evidence of association between MTHFR C677T genotype and CHD risk (OR 0.96 [95% CI 0.87-1.07]). A random-effects meta-analysis of all studies (involving 7,697 cases and 13,125 controls) suggested the presence of association (OR 1.25 [95% CI 1.03-1.51]; p=0.022), but with substantial heterogeneity among contributing studies (I2=64.4%), and evidence of publication bias. Meta-analysis of large studies only (defined by a variance of the log OR less than 0.05), which together contributed 83% of all cases, yielded no evidence of association (OR 0.97 [95% CI 0.91-1.03]), without significant heterogeneity (I2=0). Moreover, meta-analysis of 1,781 mothers of CHD cases (829 of whom were genotyped in this study) and 19,861 controls revealed no evidence of association between maternal C677T genotype and risk of CHD in offspring (OR 1.13 [95% CI 0.87-1.47]). There was no significant association between MTHFR genotype and CHD risk in large studies from regions with different levels of dietary folate. Conclusions The MTHFR C677T polymorphism, which directly influences plasma folate levels, is not associated with CHD risk. Publication biases appear to substantially contaminate the literature with regard to this genetic association. PMID:23876493

  5. The Frequent 5,10-Methylenetetrahydrofolate Reductase C677T Polymorphism Is Associated with a Common Haplotype in Whites, Japanese, and Africans

    OpenAIRE

    Rosenberg, Nurit; Murata, Mitsuru; Ikeda, Yasuo; Opare-Sem, Ohene; Zivelin, Ariella; Geffen, Eli; Seligsohn, Uri

    2002-01-01

    The common 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism causes decreased activity of this enzyme and can be associated with mild-to-moderate hyperhomocysteinemia in homozygotes, particularly when there is folic acid deficiency, as well as with vascular dementia, arterial thrombosis, venous thrombosis, neural-tube defects, and fetal loss. When folic acid intake is sufficient, homozygotes for MTHFR 677T appear to be protected against colon cancer and acute lymphatic leuke...

  6. Effects of Maternal 5,10-Methylenetetrahydrofolate Reductase C677T and A1298C Polymorphisms and Tobacco Smoking on Infant Birth Weight in a Japanese Population

    OpenAIRE

    Yila, Thamar Ayo; Sasaki, Seiko; Miyashita, Chihiro; Braimoh, Titilola Serifat; Kashino, Ikuko; Kobayashi, Sumitaka; Okada, Emiko; Baba, Toshiaki; Yoshioka, Eiji; Minakami, Hisanori; Endo, Toshiaki; Sengoku, Kazuo; Kishi, Reiko

    2012-01-01

    Background: Intracellular folate hemostasis depends on the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene. Because 5,10-MTHFR 677TT homozygosity and tobacco smoking are associated with low folate status, we tested the hypothesis that smoking in mothers with 5,10-MTHFR C677T or A1298C polymorphisms would be independently associated with lower birth weight among their offspring. Methods: We assessed 1784 native Japanese mother-child pairs drawn from the ongoing birth cohort of The Hokkai...

  7. Incidence Assessment of MTHFR C677T and A1298C Polymorphisms in Iranian Non-syndromic Cleft Lip and/or Palate Patients

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    Asghar Ebadifar

    2015-06-01

    Full Text Available Background and aims. The aim of the present study is to determine the incidence of MTHFR C677 T and A1298C muta-tions in Iranian patients with cleft lip and/or cleft palate. Materials and methods. We screened 61 Iranian patients with cleft lip and/or cleft palate for mutations in the two alleles of MTHFR gene associated with cleft lip and/or palate: A1298C and C677T, using Polymerase Chain Reaction following by RFLP. Results. The 677T and 1298C homozygote genotypes showed a frequency of 36.1% and 11.4%, respectively. Combined genotype frequencies in newborns having oral clefts showed that the highest genotype was 677TT/1298AA (22.9% and 677TT/1298CC genotypes were not observed. Conclusion. The results showed that 65.6% of all patients had at least one T mutant allele in C677T and 58.9% C mutant allele for A1298C. According to the frequencies of homozygosity of mutant alleles, it could be said that MTHFRgenotype of 677TT shows a greater role in having oral clefts.

  8. Geographical and Ethnic Distributions of the MTHFR C677T, A1298C and MTRR A66G Gene Polymorphisms in Chinese Populations: A Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Xingmin Wang

    Full Text Available The geographical and ethnic distributions of the polymorphic methylenetetrahydrofolate reductase (MTHFR mutations (C677T and A1298C and methionine synthase reductase (MTRR mutation (A66G remain heterogeneous in China. The goal of this study was to estimate the pooled frequencies of the alleles and associated genotypes of these gene polymorphisms among healthy populations in Mainland China.We systematically reviewed published epidemiological studies on the distributions of 3 genetic variants in Chinese healthy populations living in Mainland China through a meta-analysis. The relevant electronic databases were searched. All of the raw data of the eligible citations were extracted. The frequency estimates were stratified by geography, ethnicity and sex.Sixty-six studies were identified with a total of 92277 study participants. The meta-analysis revealed that the frequencies of the MTHFR C677T, A1298C, and MTRR A66G gene polymorphisms varied significantly between different ethnic groups and along geographical gradients. The frequencies of the 677T allele and 677TT genotype increased along the southern-central-northern direction across Mainland China (all Pvalues≤0.001. The frequencies of the 1298C, 1298CC, 66G and 66GG genotypes decreased along the south-central-north direction across the country (all Pvalues≤0.001.Our meta-analysis strongly indicates significant geographical and ethnic variations in the frequencies of the C677T, A1298C, and A66G gene polymorphisms in the folate metabolism pathway among Chinese populations.

  9. Methylenetetrahydrofolate reductase polymorphisms, C677T and A1298C, are associated with methotrexate-related toxicities in Korean patients with rheumatoid arthritis.

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    Choe, Jung-Yoon; Lee, Hwajeong; Jung, Hyun-Young; Park, Sung-Hoon; Bae, Sang-Cheol; Kim, Seong-Kyu

    2012-06-01

    We investigated associations between the methylenetetrahydrofolate reductase (MTHFR) polymorphisms C677T and A1298C and methotrexate (MTX)-related toxicities in Korean patients with rheumatoid arthritis (RA) taking MTX. One hundred sixty-seven patients with RA were enrolled in a cross-sectional study and genotyped for the single-nucleotide polymorphisms C677T and A1298C in MTHFR. Alleles, genotypes, and haplotypes of the C677T and A1298C polymorphisms were not associated with specific MTX toxicities. However, among RA patients with the 1298CC genotype, the proportion who experienced at least one toxicity was significantly greater than the proportion of patients with 1298AA who did (P = 0.043). In addition, the proportion of patients with the 677C/1298A haplotype who experienced toxicity was greater than the proportion of those with 677C/1298C who did (P = 0.032, odds ratio = 2.085, 95% confidence interval 1.058-4.106). In this study, MTHFR polymorphisms were associated with MTX toxicities in Korean patients with RA. Further study for association of MTHFR polymorphisms with MTX toxicities should be needed in larger RA population.

  10. MTHFR C677T and A1298C polymorphisms were associated with bladder cancer risk and disease progression: a meta-analysis.

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    You, Wu; Li, Zuo; Jing, Chen; Qian-Wei, Xing; Yu-Ping, Zhang; Weng-Guang, Li; Hua-Lei, Li

    2013-05-01

    Epidemiological studies have investigated that functional polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene may play an essential role in bladder carcinogenesis, but the association between these single-nucleotide polymorphisms in the MTHFR gene and the susceptibility of bladder cancer (BC) was inconsistent in previous studies. The objective of this current study was to conduct an update analysis investigating the association between three polymorphisms in the MTHFR gene and the risk of BC. We performed a meta-analysis of 13 publications involving an association between BC and MTHFR gene three polymorphisms (C677T, A1298C, and G1793A). We assessed the strength of the association, using odds ratios (ORs) with 95% confidence intervals (CIs). On one hand, we found that the C677T polymorphism was associated with increased BC risk among Asians, however, with decreased BC risk among a mixed population. Interestingly, BC patients who carried the T-allele (TT+TC) had a higher percentage than the individuals who carried the CC genotype (OR=1.38, 95% CI=1.13-1.69, p=0.002). On the other hand, the A1298C polymorphism may increase BC risk among Asians and Africans, but played a decreased association among Europeans. Results from the current update analysis suggested that the C677T and A1298C polymorphisms in the MTHFR gene were associated with BC risk and disease progression.

  11. Methyltetrahydrofolate vs Folic Acid Supplementation in Idiopathic Recurrent Miscarriage with Respect to Methylenetetrahydrofolate Reductase C677T and A1298C Polymorphisms: A Randomized Controlled Trial.

    Science.gov (United States)

    Hekmatdoost, Azita; Vahid, Farhad; Yari, Zahra; Sadeghi, Mohammadreza; Eini-Zinab, Hassan; Lakpour, Niknam; Arefi, Soheila

    2015-01-01

    To determine whether 5-methylenetetrahydrofolate (MTHF) is more effective than folic acid supplementation in treatment of recurrent abortion in different MTHFR gene C677T and A1298C polymorphisms. A randomized, double blind, placebo-controlled trial conducted April 2011-September 2014 in recurrent abortion clinics in Tehran, Iran. The participants were women with three or more idiopathic recurrent abortion, aged 20 to 45 years. Two hundred and twenty eligible women who consented to participate were randomly assigned to receive either folic acid or 5-MTHF according to the stratified blocked randomization by age and the number of previous abortions. Participants took daily 1 mg 5-methylentetrahydrofolate or 1 mg folic acid from at least 8 weeks before conception to the 20th week of the pregnancy. The primary outcome was ongoing pregnancy rate at 20th week of pregnancy, and the secondary outcomes were serum folate and homocysteine at the baseline, after 8 weeks, and at the gestational age of 4, 8, 12, and 20 weeks, MTHFR gene C677T and A1298C polymorphisms. There was no significant difference in abortion rate between two groups. Serum folate increased significantly in both groups over time; these changes were significantly higher in the group receiving 5-MTHF than the group receiving folic acid (value = 2.39, pMTHFR C677T and/or A1298C polymorphism. ClinicalTrials.gov NCT01976676.

  12. Association of Methylenetetrahydrofolate Reductase (MTHFR Gene C677T and A1298C Polymorphisms with Myocardial Infarction From North of Fars Province

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    Mahboobeh Nasiri

    2014-08-01

    Full Text Available Background: The association between Methylene tetrahydrofolate reductase polymorphism and Coronary Artery diseases risk has been both confirmed and refuted in a number of published studies. The aim of this study was to investigate whether genetic polymorphisms of MTHFR (C677T, A1298C contributed to the development of myocardial infarction (MI. Materials and Methods: The present case-control study consisted of 54 patients with a history of MI and 54 gender-matched normal controls. The SNPs genotypes were determined using polymerase chain reaction followed by restriction fragment length polymorphism method. Results: No significant association of the MTHFR A1298C with the risk of MI was observed. However, the allele frequencies of C677T SNP differed significantly among patients and controls (0.83 vs. 0.30. A strong positive relationship between the TT genotype and the risk of MI supported with a significant p-value < 0.001 (OR= 11.87, 95% CI: 4.7- 29.9, p < 0.001. Conclusions: The results of the present study show the importance of C677T SNP as a potential biomarker for screening susceptible cases to MI.

  13. Geographical and Ethnic Distributions of the MTHFR C677T, A1298C and MTRR A66G Gene Polymorphisms in Chinese Populations: A Meta-Analysis.

    Science.gov (United States)

    Wang, Xingmin; Fu, Jinjian; Li, Qianxi; Zeng, Dingyuan

    2016-01-01

    The geographical and ethnic distributions of the polymorphic methylenetetrahydrofolate reductase (MTHFR) mutations (C677T and A1298C) and methionine synthase reductase (MTRR) mutation (A66G) remain heterogeneous in China. The goal of this study was to estimate the pooled frequencies of the alleles and associated genotypes of these gene polymorphisms among healthy populations in Mainland China. We systematically reviewed published epidemiological studies on the distributions of 3 genetic variants in Chinese healthy populations living in Mainland China through a meta-analysis. The relevant electronic databases were searched. All of the raw data of the eligible citations were extracted. The frequency estimates were stratified by geography, ethnicity and sex. Sixty-six studies were identified with a total of 92277 study participants. The meta-analysis revealed that the frequencies of the MTHFR C677T, A1298C, and MTRR A66G gene polymorphisms varied significantly between different ethnic groups and along geographical gradients. The frequencies of the 677T allele and 677TT genotype increased along the southern-central-northern direction across Mainland China (all Pvalues≤0.001). The frequencies of the 1298C, 1298CC, 66G and 66GG genotypes decreased along the south-central-north direction across the country (all Pvalues≤0.001). Our meta-analysis strongly indicates significant geographical and ethnic variations in the frequencies of the C677T, A1298C, and A66G gene polymorphisms in the folate metabolism pathway among Chinese populations.

  14. The analysis of the relationship between A1298C and C677T polymorphisms of the MTHFR gene with prostate cancer in Eskisehir population.

    Science.gov (United States)

    Muslumanoglu, Muhammed H; Tepeli, Emre; Demir, Selma; Uludag, Ahmet; Uzun, Derya; Atli, Engin; Canturk, Kemal M; Ozdemir, Muhsin; Turgut, Mehmet

    2009-10-01

    Prostate cancer is the most common cause of cancer deaths in men and is a major health problem worldwide. Methylene tetrahydrofolate reductase (MTHFR) plays an important role for folate metabolism and is also an important source for DNA methylation and DNA synthesis (nucleotide synthesis). The objective of this study was to investigate the relationship between the A1298C and C677T polymorphisms of the MTHFR gene and prostate cancer in the Turkish population. In our study, 93 prostate cancer patients between the ages of 50-89 and a control group of 166 benign prostate hyperplasia patients were evaluated. C677T and A1298C polymorphism ratios were compared among these two groups, and an analysis was made to see if there is a statistically meaningful difference. In this study, it has been observed that C677T polymorphism of the MTHFR gene produces no statistically significant difference for T allele frequency and the genotype frequency in prostate cancer patients and male controls with benign prostate hyperplasia not having prostate cancer, whereas it has been observed that A1298C polymorphism produces a statistically significant difference for C allele frequency in prostate cancer patients and controls and that it also produces a statistically marginal significance for genotype frequencies.

  15. MTHFR C677T and A1298C polymorphisms as predictors of radiotherapy response in head and neck squamous cell carcinoma.

    Science.gov (United States)

    Anders, Q S; Stur, E; Agostini, L P; Garcia, F M; Reis, R S; Santos, J A; Mendes, S O; Maia, L L; Peterle, G T; Stange, V; Carvalho, M B; Tajara, E H; Santos, M; Silva-Conforti, A M A; Louro, I D

    2015-10-27

    The C677T and A1298C polymorphisms in methylene-tetrahydrofolate reductase (MTHFR), which regulates the release of active folate in the body, may have reduced activity. Given that folate participates in important intracellular pathways, such as nucleotide synthesis and biomolecule methylation, it seems plausible that patients with head and neck squamous cell carcinoma (HNSCC) may respond differently to radiotherapy treatments, based on genetic polymor-phisms. Therefore, this study sought to understand the role of these polymorphisms in HNSCC patient radiotherapy response. Genotypes were detected by PCR-RFLP after extraction of DNA from peripheral blood lymphocytes. Survival curves were analyzed by the Kaplan- Meier model, and significant differences were analyzed by the Wil-coxon test. Response to radiotherapy in patients with laryngeal SCC was significantly associated with the MTHFR C677T polymorphism (P = 0.030). Indeed, the presence of at least one T allele decreases the mortality rate up to 3-fold. Therefore, we propose that MTHFR C677T may represent a putative biomarker for radiotherapy prognosis in la-ryngeal SCC patients.

  16. The C677T polymorphism of the methylenetetrahydrofolate reductase gene in Mexican mestizo neural-tube defect parents, control mestizo and native populations.

    Science.gov (United States)

    Dávalos, I P; Olivares, N; Castillo, M T; Cantú, J M; Ibarra, B; Sandoval, L; Morán, M C; Gallegos, M P; Chakraborty, R; Rivas, F

    2000-01-01

    The C677T mutation of the methylenetetrahydrofolate reductase (MTHFR) gene, associated with the thermolabile form of the enzyme, has reportedly been found to be increased in neural-tube defects (NTD), though this association is still unclear. A group of 107 mestizo parents of NTD children and five control populations: 101 mestizo (M), 50 Huichol (H), 38 Tarahumara (T), 21 Purepecha (P) and 20 Caucasian (C) individuals were typed for the MTHFR C677T variant by the PCR/RFLP (HinfI) method. Genotype frequencies were in agreement with the Hardy-Weinberg expectations in all six populations. Allele frequency (%) of the C677T variant was 45 in NTD, 44 in M, 56 in H, 36 in T, 57 in P, 35 in C. Pairwise inter-population comparisons of allele frequency disclosed a very similar distribution between NTD and M groups (exact test, P=0.92). Among controls, differences between M and individual native groups were NS (0.06Huichol and Purepecha natives, as compared with other groups world wide.

  17. Association between the methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism and ischemic stroke in the Chinese population: a meta-analysis.

    Science.gov (United States)

    Zhu, Xiao-Yan; Hou, Rong-Yao; Pan, Xu-Dong; Wang, Yu-Chun; Zhang, Zheng-Shou; Guo, Rui-You

    2015-01-01

    The association between the methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism and ischemic stroke (IS) has been extensively studied; however, the results from genetic association studies have been inconsistent even in the Chinese population. As far as we know, there was no previous meta-analysis concerning this association in the Chinese population. Therefore, the aim of our meta-analysis was to further evaluate the association in the Chinese population. We collected all of the relevant studies from Pubmed, OVID, Embase, Chinese Wan Fang database, CNKI, Chongqing VIP database and CBM up to August 2014. The available data was analyzed by Stata (version 12.0). We used odds ratios (ORs) and corresponding 95% confidence intervals (CIs) to present the strength of the association. Heterogeneity was evaluated by the Q-test and I(2) statistic. Different genetic models, subgroup analysis, publication bias and sensitivity analysis were used to improve the comprehensive understanding. The results showed a significant association between the MTHFR gene C677T polymorphism and IS in six genetic models (additive model: OR = 1.34, 95%CI: 1.17 ∼ 1.54, p MTHFR gene C677T polymorphism and IS, the T allele might be a risk factor for IS in the Chinese population.

  18. The Impact of Methylenetetrahydrofolate Reductase C677T Polymorphism on Patients Undergoing Allogeneic Hematopoietic Stem Cell Transplantation with Methotrexate Prophylaxis.

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    Ja Min Byun

    Full Text Available Pharmacogenomics can explain the inter-individual differences in response to drugs, including methotrexate (MTX used for acute graft-versus-host disease (aGVHD prophylaxis during hematopoietic stem cell transplantation (HSCT. In real-world practice, preplanned MTX dose is arbitrarily modified according to observed toxicity which can lead to unexpected and severe aGVHD development. We aimed to validate the influence of MTHFR C677T polymorphism on the outcomes of allogenic HSCT in a relatively under-represented homogenous Asian population. A total of 177 patients were divided into 677TT group versus 677C-carriers (677CT+677CC, and clinical outcomes along with baseline characteristics were analyzed and compared. Although there was a tendency towards increased peak liver function test results and accordingly greater delta values between the highest and the baseline in 677TT group, we found no associations between genotypes and hepatotoxicity. However, the incidence of acute liver GVHD (≥ grade 2 was significantly higher in the 677TT group than in the 677CC + 677CT group (P = 0.016. A total of 25 patients (14.1% expired due to transplantation related mortality (TRM during the first 180 days after HSCT. Patients carrying 677TT genotype were more likely to experience early TRM than 677C-carriers. The same pattern was observed in the cumulative TRM rate, and 677TT genotype patients were more prone to cumulative TRM (P = 0.010. This translated into shorter OS for patients with 677TT compared to 677C-carriers (P = 0.010. The 3-year survival after HSCT was 29.9% for 677TT cases and 47.1% for 677C-carriers. The multivariate analysis identified 677TT genotype (HR = 1.775. 95% CI 1.122-2.808, P = 0.014 and non-CR state (HR = 2.841. 95% CI 1.627-4.960, P<0.001 as predictors for survival. In conclusion, the MTHFR 677TT genotype appears to be associated with acute liver GVHD, and represent a risk factor for TRM and survival in patients undergoing HSCT with MTX

  19. Individual and Joint Associations of Methylenetetrahydrofolate Reductase C677T Genotype and Plasma Homocysteine With Dyslipidemia in a Chinese Population With Hypertension.

    Science.gov (United States)

    Liu, Yanhong; Li, Kang; Venners, Scott A; Hsu, Yi-Hsiang; Jiang, Shanqun; Weinstock, Justin; Wang, Binyan; Tang, Genfu; Xu, Xiping

    2017-04-01

    We aimed to examine the cross-sectional associations of plasma total homocysteine (tHcy) concentrations and methylenetetrahydrofolate reductase ( MTHFR) C677T genotype with dyslipidemia. A total of 231 patients with mild-to-moderate essential hypertension were enrolled from the Huoqiu and Yuexi communities in Anhui Province, China. Plasma tHcy levels were measured by high-performance liquid chromatography. Genotyping was performed by TaqMan allelic discrimination technique. Compared with MTHFR 677 CC + CT genotype carriers, TT genotype carriers had higher odds of hypercholesterolemia (adjusted odds ratio [OR] [95% confidence interval (CI)]: 2.7 [1.4-5.2]; P = .004) and higher odds of abnormal low-density lipoprotein cholesterol (adjusted OR [95% CI]: 2.3 [1.1-4.8]; P = .030). The individuals with the TT genotype had higher concentrations of log(tHcy) than those with the 677 CC + CT genotype (adjusted β [standard error]: .2 [0.03]; P genotype and the tHcy ≥ 10 μmol/L had the highest odds of hypercholesterolemia (adjusted OR [95% CI]: 4.1 [1.8-9.4]; P = .001) and low-density lipoprotein cholesterol (adjusted OR [95% CI]: 2.4 [1.0-6.0]; P = .064). This study suggests that both tHcy and the MTHFR C677T gene polymorphism may be important determinants of the incidence of dyslipidemia in Chinese patients with essential hypertension. Further studies are needed to confirm the role of tHcy and the MTHFR C677T mutation in the development of dyslipidemia in a larger sample.

  20. Folic acid supplementation during pregnancy may protect against depression 21 months after pregnancy, an effect modified by MTHFR C677T genotype.

    Science.gov (United States)

    Lewis, S J; Araya, R; Leary, S; Smith, G Davey; Ness, A

    2012-01-01

    As low folate status has been implicated in depression, high folate intake, in the form of supplements, during pregnancy might offer protection against depression during pregnancy and postpartum. We examined the association between change in self-reported depressive symptoms (Edinburgh Postnatal Depression Scale) at different timepoints during and following pregnancy and self-reported folic acid supplementation during pregnancy in a prospective cohort of 6809 pregnant women. We also tested whether there was a main effect of methylenetetrahydrofolate reductase (MTHFR) C677T genotype (which influences folate metabolism and intracellular levels of folate metabolites and homocysteine) on change in depression scores, and carried out our analysis of folic acid supplementation and depression stratifying by genotype. We found no strong evidence that folic acid supplementation reduced the risk of depression during pregnancy and up to 8 months after pregnancy. However, we did find evidence to suggest that folic acid supplements during pregnancy protected against depression 21 months postpartum, and that this effect was more pronounced in those with the MTHFR C677T TT genotype (change in depression score from 8 months to 21 months postpartum among TT individuals was 0.66 (95% CI=0.31-1.01) among those not taking supplements, compared with -1.02 (95% CI=-2.22-0.18) among those taking supplements at 18 weeks pregnancy, P(difference)=0.01). Low folate is unlikely to be an important risk factor for depression during pregnancy and for postpartum depression, but may be a risk factor for depression outside of pregnancy, especially among women with the MTHFR C677T TT genotype.

  1. Relationship between MTHFR C677T and A1298C gene polymorphisms and complications of type 2 diabetes mellitus in an Emirati population.

    Science.gov (United States)

    El Hajj Chehadeh, Sarah W; Jelinek, Herbert F; Al Mahmeed, Wael A; Tay, Guan K; Odama, Unini O; Elghazali, Gehad E B; Al Safar, Habiba S

    2016-09-01

    Type 2 diabetes mellitus (T2DM) is the most common form of diabetes with clinical consequences giving rise to chronic multiple organ complications. Methylenetetrahydrofolate reductase (MTHFR) polymorphisms are genetic variations that have been linked to T2DM, and micro/macrovascular complications. The link between MTHFR and T2DM however is strongly dependent on the ethnic group studied. The objective of this study was to investigate the possible association between two MTHFR polymorphisms (C677T and A1298C) and T2DM and specifically examine if there are any associations with clinical and demographic characteristics among patients in the United Arab Emirates (UAE). The study included 169 T2DM patients and 209 healthy controls. Genomic DNA was isolated and genotyped using TaqMan real-Time PCR assays for the MTHFR C677T and A1298C polymorphisms. There were no significant differences in genotype and haplotype distributions observed between groups. A significant association was observed between the C677T polymorphism and history of cerebrovascular accident (CVA) (p = 0.0330), history of nephropathy (p = 0.0280) and levels of LDL cholesterol (p = 0.0409). Also, the A1298C polymorphism was associated with hypertriglyceridemia (p = 0.0305) in T2DM patients. These findings demonstrate that the MTHFR gene polymorphisms are not related to T2DM in the Emirati population. However, these polymorphisms can be used as risk markers for CVA, nephropathy, high LDL cholesterol and triglycerides in T2DM patients and allow timely treatment.

  2. Prenatal exposure to maternal depressed mood and the MTHFR C677T variant affect SLC6A4 methylation in infants at birth.

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    Angela M Devlin

    2010-08-01

    Full Text Available Prenatal and early postnatal exposure to maternal depression may "program" childhood behavior via epigenetic processes such as DNA methylation. Methylenetetrahydro-folate reductase (MTHFR is an important enzyme in the generation of methyl groups for DNA methylation. The common MTHFR C677T variant is associated with depression in men and non-pregnant women, and with global changes in DNA methylation. This study investigated the effect of maternal MTHFR C677T genotype on antenatal maternal mood, and their impact on the gene-specific methylation in pregnant women and their newborn infants. The methylation status of SLC6A4, which encodes the transmembrane serotonin transporter, and BDNF, which encodes brain derived neurotrophic factor, were assessed because of their potential role in behaviour.Depressed mood was assessed by the Edinburgh Postnatal Depression Scale (EPDS and the Hamilton Rating Scale for Depression (HAM-D in women (n = 82, all taking folate during the 2(nd and 3(rd trimesters of pregnancy. The methylation status of SLC6A4 and BDNF were assessed in 3rd trimester maternal peripheral leukocytes and in umbilical cord leukocytes collected from their infants at birth. Women with the MTHFR 677TT genotype had greater 2(nd trimester depressed mood (p<0.05. Increased 2(nd trimester maternal depressed mood (EPDS scores was associated with decreased maternal and infant SLC6A4 promoter methylation (p<0.05, but had no effect on BDNF promoter methylation.These findings show that the MTHFR C677T variant is associated with greater depressed mood during pregnancy. We further showed that prenatal exposure to maternal depressed mood affects gene-specific DNA methylation patterns. These findings support the concept that alterations in epigenetic processes may contribute to developmental programming of behaviour by maternal depression.

  3. Methyltetrahydrofolate vs Folic Acid Supplementation in Idiopathic Recurrent Miscarriage with Respect to Methylenetetrahydrofolate Reductase C677T and A1298C Polymorphisms: A Randomized Controlled Trial.

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    Azita Hekmatdoost

    Full Text Available To determine whether 5-methylenetetrahydrofolate (MTHF is more effective than folic acid supplementation in treatment of recurrent abortion in different MTHFR gene C677T and A1298C polymorphisms.A randomized, double blind, placebo-controlled trial conducted April 2011-September 2014 in recurrent abortion clinics in Tehran, Iran. The participants were women with three or more idiopathic recurrent abortion, aged 20 to 45 years. Two hundred and twenty eligible women who consented to participate were randomly assigned to receive either folic acid or 5-MTHF according to the stratified blocked randomization by age and the number of previous abortions. Participants took daily 1 mg 5-methylentetrahydrofolate or 1 mg folic acid from at least 8 weeks before conception to the 20th week of the pregnancy. The primary outcome was ongoing pregnancy rate at 20th week of pregnancy, and the secondary outcomes were serum folate and homocysteine at the baseline, after 8 weeks, and at the gestational age of 4, 8, 12, and 20 weeks, MTHFR gene C677T and A1298C polymorphisms.There was no significant difference in abortion rate between two groups. Serum folate increased significantly in both groups over time; these changes were significantly higher in the group receiving 5-MTHF than the group receiving folic acid (value = 2.39, p<00.1 and the result was the same by considering the time (value = 1.24, p<0.01. Plasma tHcys decreased significantly in both groups over time; however these changes were not significantly different between the groups (value = 0.01, p = 0.47.The results do not support any beneficial effect of 5-MTHF vs. folate supplementation in women with recurrent abortion with any MTHFR C677T and/or A1298C polymorphism.ClinicalTrials.gov NCT01976676.

  4. Combined genotype and haplotype distributions of MTHFR C677T and A1298C polymorphisms: A cross-sectional descriptive study of 13,473 Chinese adult women.

    Science.gov (United States)

    Fan, Shujun; Yang, Boyi; Zhi, Xueyuan; Wang, Yanxun; Zheng, Quanmei; Sun, Guifan

    2016-11-01

    Methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms are, independently and/or in combination, associated with many disorders. However, data on the combined genotype and haplotype distributions of the 2 polymorphisms in Chinese population were limited.We recruited 13,473 adult women from 9 Chinese provinces, collected buccal cell samples, and determined genotypes, to estimate the combined genotype and haplotype distributions of the MTHFR C677T and A1298C polymorphisms.In the total sample, the 6 common combined genotypes were CT/AA (29.5%), TT/AA (21.9%), CC/AA (15.4%), CC/AC (14.9%), CT/AC (13.7%), and CC/CC (3.4%); the 3 frequent haplotypes were 677T-1298A (43.6%), 677C-1298A (37.9%), and 677C-1298C (17.6%). Importantly, we observed that there were 51 (0.4%) individuals with the CT/CC genotype, 92 (0.7%) with the TT/AC genotype, 17 (0.1%) with the TT/CC genotype, and that the frequency of the 677T-1298C haplotype was 0.9%. In addition, the prevalence of some combined genotypes and haplotypes varied among populations residing in different areas and even showed apparent geographical gradients. Further linkage disequilibrium analysis showed that the D' and r values were 0.883 and 0.143, respectively.In summary, the findings of our study provide further strong evidence that the MTHFR C677T and A1298C polymorphisms are usually in trans and occasionally in cis configurations. The frequencies of mutant genotype combinations were relatively higher in Chinese population than other populations, and showed geographical variations. These baseline data would be useful for future related studies and for developing health management programs.

  5. Evaluation of Factor V Leiden, Prothrombin G20210A, MTHFR C677T and MTHFR A1298C gene polymorphisms in retinopathy of prematurity in a Turkish cohort.

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    Aydin, Hatip; Gunay, Murat; Celik, Gokhan; Gunay, Betul Onal; Aydin, Umeyye Taka; Karaman, Ali

    2016-12-01

    To assess Factor V Leiden (FVL) (rs6025), Prothrombin G20210A (rs1799963), MTHFR C677T (rs1801133), and MTHFR A1298C (rs1801131) gene mutations as risk factors in the development of retinopathy of prematurity (ROP). A total of 105 children were included in this cross-sectional study. Patients were divided into two groups. The study group consisted of 55 infants with a history of ROP and the control group comprised 50 healthy infants with term birth. All subjects were screened for the presence of certain mutations (FVL, Prothrombin G20210A, MTHFR C677T and MTHFR A1298C) by Real-Time PCR at 1 year of age. The mean gestational age (GA) and birth weight (BW) of the study group were, 28.65 ± 2.85 weeks and 1171 ± 385.74 g, respectively. There were no significant differences of genotype and allele frequency of Prothrombin G20210A, MTHFR A1298C and MTHFR C677T between the study and control groups (p > 0.05). Eight children (14.5 %) had heterozygous and one child (1.8%) had homozygous FVL mutation in the study group. One child (2%) in the control group had heterozygous FVL mutation. There was statistically significant differences of FVL allele and genotype frequencies between the groups (p < 0.05). The prevalence of FVL polymorphism (16.3 %) was higher in ROP patients than control subjects in this Turkish cohort. We suggest a possible association of FVL mutation with ROP at the end of the study.

  6. Effects of maternal 5,10-methylenetetrahydrofolate reductase C677T and A1298C Polymorphisms and tobacco smoking on infant birth weight in a Japanese population.

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    Yila, Thamar Ayo; Sasaki, Seiko; Miyashita, Chihiro; Braimoh, Titilola Serifat; Kashino, Ikuko; Kobayashi, Sumitaka; Okada, Emiko; Baba, Toshiaki; Yoshioka, Eiji; Minakami, Hisanori; Endo, Toshiaki; Sengoku, Kazuo; Kishi, Reiko

    2012-01-01

    Intracellular folate hemostasis depends on the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene. Because 5,10-MTHFR 677TT homozygosity and tobacco smoking are associated with low folate status, we tested the hypothesis that smoking in mothers with 5,10-MTHFR C677T or A1298C polymorphisms would be independently associated with lower birth weight among their offspring. We assessed 1784 native Japanese mother-child pairs drawn from the ongoing birth cohort of The Hokkaido Study on Environment and Children's Health. Data (demographic information, hospital birth records, and biological specimens) were extracted from recruitments that took place during the period from February 2003 to March 2006. Maternal serum folate were assayed by chemiluminescent immunoassay, and genotyping of 5,10-MTHFR C677T/A1298C polymorphisms was done using a TaqMan allelic discrimination assay. The prevalence of folate deficiency (MTHFR 677CT genotype was independently associated with an increase of 36.40 g (95% CI: 2.60 to 70.30, P = 0.035) in mean infant birth weight and an increase of 90.70 g (95% CI: 6.00 to 175.50, P = 0.036) among male infants of nonsmokers. Female infants of 677TT homozygous passive smokers were 99.00 g (95% CI: -190.26 to -7.56, P = 0.034) lighter. The birth weight of the offspring of smokers with 5,10-MTHFR 1298AA homozygosity was lower by 107.00 g (95% CI: -180.00 to -33.90, P = 0.004). The results suggest that, in this population, maternal 5,10-MTHFR C677T polymorphism, but not the 5,10-MTHFR A1298C variant, is independently associated with improvement in infant birth weight, especially among nonsmokers. However, 5,10-MTHFR 1298AA might be associated with folate impairment and could interact with tobacco smoke to further decrease birth weight.

  7. C677T and A1298C polymorphisms of the methylenetetrahydrofolate reductase gene: effect on methotrexate-related toxicity in adult acute lymphoblastic leukaemia.

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    Eissa, Deena Samir; Ahmed, Tamer Mohamed

    2013-03-01

    Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme involved in folate metabolism. Two polymorphisms, C677T and A1298C, were described leading to reduced enzyme activity. Methotrexate (MTX) is an antifolate agent of consolidation and maintenance therapy of acute lymphoblastic leukaemia (ALL). Despite its clinical success, MTX can be associated with serious toxicities resulting in treatment interruption or discontinuation, impacting disease outcome. There is evidence that MTX toxicity can be affected by polymorphisms in genes encoding for drug-metabolizing enzymes such as MTHFR. Therefore, we aimed to investigate the influence of MTHFR C677T and A1298C polymorphisms on the frequency of MTX-related toxicity, disease outcome and patients' survival. MTHFR polymorphisms were assessed in 50 adult patients with de novo ALL using real-time PCR. Patients were followed-up for the development of haematologic and/or nonhaematologic toxicity and assessment of clinical outcome. Frequency of C677T polymorphisms was 42% for TT, 24% for CT and 34% for CC; A1298C polymorphisms were 28, 6 and 66% for CC, AC and AA, respectively. MTX therapy was significantly associated with neutropaenia, hepatic and gastrointestinal toxicities, unfavourable response at day 14 of induction therapy, increased relapse and mortality rates and shorter survival in patients with 677 TT genotype than in those with CC and CT, whereas 1298 CC genotype patients had lower frequency of neutropaenia, hepatic toxicity and relapse than in those with AA and AC. Our study suggests MTHFR polymorphism as an attractive predictor of MTX-related toxicity in adult ALL, considering it a potential prognostic factor influencing disease outcome.

  8. Association of the MTHFR C677T and A1298C polymorphisms with methotrexate toxicity in rheumatoid arthritis: a meta-analysis.

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    Song, Gwan Gyu; Bae, Sang-Cheol; Lee, Young Ho

    2014-12-01

    The aim of this study was to explore whether the C677T and A1298C polymorphisms of methylenetetrahydrofolate reductase (MTHFR) play a role in methotrexate (MTX) toxicity in rheumatoid arthritis (RA). MEDLINE and EMBASE database searches and subsequent manual searches were utilized to identify articles in which C677T and A1298C MTHFR polymorphisms were evaluated in RA patients taking MTX. A meta-analysis was conducted to identify associations between MTHFR polymorphisms and MTX toxicity. Twelve studies comprising a total of 2,288 RA patients were included in our meta-analysis. Meta-analysis revealed an association between the overall toxicity of MTX and the MTHFR 677TT genotype (odds ratio [OR] = 1.615, 95 % confidence interval [CI] = 1.185-2.200, p = 0.002). Stratification by ethnicity indicated an association between the MTHFR 677TT genotype and the overall toxicity of MTX in East Asians (OR = 1.583, 95 % CI = 1.075-2.331, p = 0.020). The toxicity of MTX also was found to be associated with the TT genotype in patients taking folate (OR = 1.893, 95 % CI = 1.283-2.793, p = 0.001). Stratification by toxicity type indicated an association between the MTHFR 677TT genotype and any adverse effects (OR = 1.716, 95 % CI = 1.127-2.612, p = 0.012). Meta-analysis stratified by toxicity type indicated an association between the MTHFR 1298CC genotype and any adverse effects (OR = 0.501, 95 % CI = 0.284-0.886, p = 0.017). The results of our meta-analysis suggest that the MTHFR C677T and A1298C polymorphisms are associated with MTX toxicity in RA patients.

  9. [Relationship between genetic polymorphism of MTHFR C677T and nonsyndromic cleft lip with or without cleft palate in Shanxi Province of China].

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    Nan, Xinrong; Liu, Ming; Yuan, Guanghui

    2014-07-01

    To assess the association between polymorphism of methylenetetrahydrofolate reductase (MTHFR) gene C677T locus and nonsyndromic cleft lip with or without cleft palate (NSCL/P) in Shanxi Province of China. Blood samples from 150 patients and their parents and 150 controls and their mothers were collected. The polymorphism of MTHFR gene C677T locus were analyzed by the methods of polymerase chain reaction and restriction fragment length polymorphism technique(PCR-RFLP). Case-control analysis, transmission-disequilibrium test(TDT) and haplotype-based haplotype relative risk analysis(HHRR) were used to study the correlation between the gene mutation and NSCL/P. Hardy-Weinberg equilibrium test results showed that, the offspring and mother genotype in the case group and the control group was not deviated from the Hardy-Weinberg law of genetic equilibrium (P > 0.05). The distribution of genotype CC, CT and TT in offspring had significant difference between the two groups (P < 0.05). In the offspring and mother of case group and the control group, the carriers of the TT genotype compared to CC genotype, the OR are greater than 1 and 95% CI do not contain 1 (offspring OR: 2.692, 95% CI: 1.319-5.495; mother OR: 2.469, 95% CI: 1.136-5.363). The distribution of C allele and T mutation gene were significantly different in the offspring and mother between the two groups (P < 0.05). The TDT test showed: chi2 = 4.507, P < 0.05. The HHRR test showed: P < 0.05. The single nucleotide polymorphism of MTHFR C677T locus is associated with the development of NSCL/P in Shanxi Province.

  10. MTHFR C677T and postmenopausal breast cancer risk by intakes of one-carbon metabolism nutrients: a nested case-control study.

    Science.gov (United States)

    Maruti, Sonia S; Ulrich, Cornelia M; Jupe, Eldon R; White, Emily

    2009-01-01

    The C677T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene has been hypothesized to increase breast cancer risk. However, results have been inconsistent, and few studies have reported the association by menopausal status or by intakes of nutrients participating in one-carbon metabolism. Our aims were to investigate whether MTHFR C677T was associated with postmenopausal breast cancer risk and whether this relation was modified by intakes of folate, methionine, vitamins B(2), B(6), and B(12), and alcohol. We studied 318 incident breast cancer cases and 647 age- and race-matched controls participating in a nested case-control study of postmenopausal women within the VITamins And Lifestyle (VITAL) cohort. Genotyping was conducted for MTHFR C677T and dietary and supplemental intakes were ascertained from a validated questionnaire. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression. We observed a 62% increased risk of breast cancer among postmenopausal women with the TT genotype (OR = 1.62; 95% CI: 1.05 to 2.48). Women with a higher number of variant T alleles had higher risk of breast cancer (P for trend = 0.04). Evidence of effect-modification by intakes of some B vitamins was observed. The most pronounced MTHFR-breast cancer risks were observed among women with the lowest intakes of dietary folate (P for interaction = 0.02) and total (diet plus supplemental) vitamin B(6) (P for interaction = 0.01), with no significant increased risks among women with higher intakes. This study provides support that the MTHFR 677TT genotype is associated with a moderate increase in risk of postmenopausal breast cancer and that this risk may be attenuated with high intakes of some one-carbon associated nutrients.

  11. Geographical and Ethnic Distributions of the MTHFR C677T, A1298C and MTRR A66G Gene Polymorphisms in Chinese Populations: A Meta-Analysis

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    Zeng, Dingyuan

    2016-01-01

    Background The geographical and ethnic distributions of the polymorphic methylenetetrahydrofolate reductase (MTHFR) mutations (C677T and A1298C) and methionine synthase reductase (MTRR) mutation (A66G) remain heterogeneous in China. The goal of this study was to estimate the pooled frequencies of the alleles and associated genotypes of these gene polymorphisms among healthy populations in Mainland China. Objective and Methods We systematically reviewed published epidemiological studies on the distributions of 3 genetic variants in Chinese healthy populations living in Mainland China through a meta-analysis. The relevant electronic databases were searched. All of the raw data of the eligible citations were extracted. The frequency estimates were stratified by geography, ethnicity and sex. Results Sixty-six studies were identified with a total of 92277 study participants. The meta-analysis revealed that the frequencies of the MTHFR C677T, A1298C, and MTRR A66G gene polymorphisms varied significantly between different ethnic groups and along geographical gradients. The frequencies of the 677T allele and 677TT genotype increased along the southern-central-northern direction across Mainland China (all Pvalues≤0.001). The frequencies of the 1298C, 1298CC, 66G and 66GG genotypes decreased along the south-central-north direction across the country (all Pvalues≤0.001). Conclusions Our meta-analysis strongly indicates significant geographical and ethnic variations in the frequencies of the C677T, A1298C, and A66G gene polymorphisms in the folate metabolism pathway among Chinese populations. PMID:27089387

  12. Investigation of MTHFR C677T gene polymorphism, biochemical and clinical parameters in Turkish migraine patients: association with allodynia and fatigue.

    Science.gov (United States)

    Bahadir, Anzel; Eroz, Recep; Dikici, Suber

    2013-11-01

    We investigated whether there is any relationship between biochemical and clinical parameters of migraine and methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism, associated with the migraine subtypes, symptoms, and gender. A total of 150 migraine patients with and without aura (MA and MO) and 107 non-sufferers were included in the study. Biochemical and clinical parameters were measured and genetic analysis was performed. The MTFHR C677T genotype was significantly higher in the migraine group (p = 0.000). The CT genotype frequency of individuals with a family history of migraine was significantly higher (p = 0.025). This genotype frequency was higher in patients who suffer from compression, allodynia, fatigue, and sleeplessness (p = 0.027, 0.023, 0.006, and 0.05, respectively). Homocysteine and total cholesterol levels were significantly higher in the migraine group than the control group (p = 0.007 and 0.010, respectively). However, the other biochemical and clinical parameters did not differ from each other (p > 0.05), with only attack frequency being significantly higher in the MO group (p = 0.005). While the folate and HDL levels were significantly higher in females (p = 0.001 and 0.000, respectively), the homocysteine and triglyceride levels were significantly higher in males (p = 0.000 for each one). BMIs were significantly lower in the control than the migraine group (p = 0.021); however, an association between the C677T variant and BMI was not found (p = 0.787) in the migraine group. An association between the MTHFR C667T polymorphism and migraine susceptibility was found. Additional studies including genetic, clinic, and biochemical parameters should be conducted to better understand the disease.

  13. Plasma homocysteine, methylene tetrahydrofolate reductase C677T and factor II G20210A polymorphisms, factor VIII, and VWF in central retinal vein occlusion

    OpenAIRE

    Boyd, S.; Owens, D.; Gin, T; Bunce, K.; Sherafat, H; Perry, D; Hykin, P

    2001-01-01

    AIMS—To determine whether plasma homocysteine, methylene tetrahydrofolate reductase (MTHFR) C677T and factor II G20210A polymorphisms, factor VIII, and vWF are risk factors for central retinal vein occlusion (CRVO).
METHOD—Prospective comparison of 63 consecutive patients with central retinal vein occlusion and 63 age matched controls. Plasma homocysteine and vWF were estimated by ELISA, the MTFHR and factor II G20210A polymorphisms determined by polymerase chain reaction with restriction enz...

  14. Evaluation of gestational diabetes mellitus risk in South Indian women based on MTHFR (C677T and FVL (G1691A mutations

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    Imran Ali Khan

    2015-05-01

    Full Text Available We aimed to scrutinize the extent to which single amino acid substitutions in the MTHFR and FVL genes affect the risk of GDM in pregnant women of South Indian descendant. This case-control study was implemented once the ethical approval has been obtained. Overall 237 women were recruited in this study: 137 had been diagnosed with GDM and the remaining 100 women were used as normal controls or non-GDM. The diagnosis of GDM was confirmed with biochemical analysis i.e., GCT and OGTT tests. Five milliliters of peripheral blood was collected and used for biochemical and molecular analyses. DNA was isolated and genotyping for MTHFR (C677T and FVL (G1691A mutations was performed using PCR-RFLP. FVL (G1691A locus was not polymorphic in the investigated sample. There was no significant difference in the allele and genotype frequencies of C677T polymorphism between GDM and non-GDM women (p=0.8892

  15. Association of methylenetetrahydrofolate reductase C677T-A1298C polymorphisms with risk for esophageal adenocarcinoma, Barrett's esophagus, and reflux esophagitis.

    Science.gov (United States)

    Ekiz, F; Ormeci, N; Coban, S; Karabulut, H G; Aktas, B; Tukun, A; Tuncali, T; Yüksel, O; Alkış, N

    2012-07-01

    Incidence of the esophagus adenocarcinoma has been dramatically increasing in Western countries since the last decade. Gastroesophageal reflux disease and Barrett's esophagus are risk factors for adenocarcinoma. Methylenetetrahydrofolate reductase (MTHFR) genes play a key role not only in folate metabolism but also in esophagus, stomach, pancreatic carcinoma, and acute leukemias. Studies have suggested that genetic polymorphisms of MTHFR (C677T) may clarify the causes and events involved in esophageal carcinogenesis. In this study, we evaluated MTHFR C677T and A1298C polymorphisms, and vitamin B12, folate, and plasma homocystein levels in patients with esophageal adenocarcinoma (EAC), Barrett's esophagus (BE), chronic esophagitis, and healthy controls (n = 26, n = 14, n = 30, and n = 30, respectively). The mean age of patients in the EAC and BE groups was significantly higher compared with the control group (P MTHFR gene polymorphisms. No differences were found in terms of MTHFR gene polymorphisms, homocystein, and B12 levels among the groups. MTHFR gene polymorphisms and folate deficiency are not predictors of early esophageal carcinoma. However, further studies using larger series of patients are needed to evaluate the effect of genetic polymorphisms in the folate metabolic pathway and to clarify the role of folate deficiency and folate metabolism in the development of esophagus adenocarcinoma. © 2011 Copyright the Authors. Journal compilation © 2011, Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus.

  16. Influence of Methylenetetrahydrofolate Reductase C677T, A1298C, and G80A Polymorphisms on the Survival of Pediatric Patients with Acute Lymphoblastic Leukemia

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    Dayse Maria Vasconcelos de Deus

    2012-01-01

    Full Text Available The influence of genic polymorphisms involved in metabolism of chemotherapeutic agents as the methotrexate (MTX has been studied mainly in acute lymphoblastic leukemia (ALL of childhood. Advances in treatment may be attributed to identification of prognostic factors added to chemotherapy protocol. The aim of this study was to analyze the association of the C677T, A1298C, and G80A polymorphisms on MTHFR gene and on the overall survival of pediatric patients (n=126 with lymphoblastic leukemia treated with MTX according to the Brazilian protocol in 187 months. The C677T and G80A polymorphisms were genotyped by PCR-RFLP and A1298C polymorphism by allele-specific PCR. We observed that ALL patients presented rate (dead/alive of 0.36 for the 677CC genotype, corresponding also to lower overall survival (P=0.0013; on the other hand, the 677TT genotype showed a better survival (98%. Thus, we believe that patients with 80AA genotype presented a small reduction in MTX plasma level, suggesting that ALL children, carrying the 80AA genotype, showed a high toxicity to MTX (P<0.0001.

  17. Association between MTHFR C677T and A1298C polymorphisms and NSCL/P risk in Asians: a meta-analysis.

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    Mengmeng Zhao

    Full Text Available OBJECTIVE: Several studies have reported the association between methylenetetrahydrofolate reductase (MTHFR C677T and A1298C polymorphisms and nonsyndromic cleft lip with or without palate (NSCL/P in Asian populations. However, findings have been conflicting. In order to investigate the association, a meta-analysis was performed. METHODS: We searched Pubmed, MedLine and EmBase database to selected eligible studies. The pooled odds ratios (ORs with 95% confidence intervals (95%CIs were calculated using fixed effects model or random effects model to assess the association between MTHFR polymorphisms and NSCL/P in both Asian children and mothers. RESULTS: Finally, nine case-control studies were included. Overall, the MTHFR C677T polymorphism and NSCL/P showed pooled ORs (95%CI of 1.41(1.23-1.61 in Asian children, and 1.70(1.19-2.42 in Asian mothers. Subgroup analyses by geographical locations further identified the association in Eastern Asian children, Western/Central Asian children and mothers, but not in Eastern Asian mothers. However, no significant relationship between MTHFR A1298C polymorphism and NSCL/P was found in this meta-analysis. CONCLUSIONS: The MTHFR 677T allele was associated with an increased risk of NSCL/P in Asian populations.

  18. Association between MTHFR C677T and A1298C Polymorphisms and NSCL/P Risk in Asians: A Meta-Analysis

    Science.gov (United States)

    Zhao, Mengmeng; Ren, Yangwu; Shen, Li; Zhang, Yue; Zhou, Baosen

    2014-01-01

    Objective Several studies have reported the association between methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and nonsyndromic cleft lip with or without palate (NSCL/P) in Asian populations. However, findings have been conflicting. In order to investigate the association, a meta-analysis was performed. Methods We searched Pubmed, MedLine and EmBase database to selected eligible studies. The pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were calculated using fixed effects model or random effects model to assess the association between MTHFR polymorphisms and NSCL/P in both Asian children and mothers. Results Finally, nine case-control studies were included. Overall, the MTHFR C677T polymorphism and NSCL/P showed pooled ORs (95%CI) of 1.41(1.23–1.61) in Asian children, and 1.70(1.19–2.42) in Asian mothers. Subgroup analyses by geographical locations further identified the association in Eastern Asian children, Western/Central Asian children and mothers, but not in Eastern Asian mothers. However, no significant relationship between MTHFR A1298C polymorphism and NSCL/P was found in this meta-analysis. Conclusions The MTHFR 677T allele was associated with an increased risk of NSCL/P in Asian populations. PMID:24658649

  19. Plasma homocysteine, methylene tetrahydrofolate reductase C677T and factor II G20210A polymorphisms, factor VIII, and VWF in central retinal vein occlusion.

    Science.gov (United States)

    Boyd, S; Owens, D; Gin, T; Bunce, K; Sherafat, H; Perry, D; Hykin, P G

    2001-11-01

    To determine whether plasma homocysteine, methylene tetrahydrofolate reductase (MTHFR) C677T and factor II G20210A polymorphisms, factor VIII, and vWF are risk factors for central retinal vein occlusion (CRVO). Prospective comparison of 63 consecutive patients with central retinal vein occlusion and 63 age matched controls. Plasma homocysteine and vWF were estimated by ELISA, the MTFHR and factor II G20210A polymorphisms determined by polymerase chain reaction with restriction enzyme product digestion and factor VIII by one stage automated clotting assay. Plasma homocysteine (patients: median 12.4 micromol/l, controls: median 11.6 micromol OR = 1.05, p=0.20), factor VIII (patients: median = 115 U/dl, controls: median = 113 U/dl), and vWF (patients: median = 115 U/dl, controls: median = 108 U/dl) were not statistically higher in patients than in controls. Five CRVO patients and seven controls were homozygous for the MTHFR C677T mutation. One control was heterozygous for the factor II G20210A mutation. This study has not identified new risk factors for CRVO.

  20. Geographical distribution of MTHFR C677T, A1298C and MTRR A66G gene polymorphisms in China: findings from 15357 adults of Han nationality.

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    Boyi Yang

    Full Text Available BACKGROUND: Methylenetetrahydrofolate reductase (MTHFR C677T, A1298C and methionine synthase reductase (MTRR A66G polymorphisms are important genetic determinants for homocysteine (Hcy levels, and are associated with several disorders. These polymorphisms are heterogeneously distributed worldwide. Our objective was to explore the geographical distributions of these polymorphisms in China. METHODOLOGIES: 15357 healthy adults were recruited from 10 regions. Buccal samples were collected and genomic DNA was isolated. Genotyping was performed using the fluorogenic 5'-nuclease assay. PRINCIPAL FINDINGS: The prevalence of the three polymorphisms among different populations from China varied significantly and showed apparent geographical gradients. For MTHFR C677T, the frequencies of the 677T allele and the 677TT genotype were significantly higher among northern populations and ranged from the lowest values (24.0% and 6.4%, respectively in Hainan (southern to the highest values (63.1% and 40.8%, respectively in Shandong (northern. For MTHFR A1298C, the 1298C allele and the 1298CC genotype frequencies were significantly higher among southern populations and increased from low values (13.1% and 1.4%, respectively in Shandong to high values (25.7% and 6.7%, respectively in Hainan. For A66G, the 66G allele and the 66GG genotype frequencies increased from lower values (23.7% and 5.4%, respectively in Shandong to higher values (29.2% and 8.6%, respectively in Hainan. The overall frequency of the 677T allele, 677TT genotype, 1298C allele, 1298CC genotype, 66G allele and 66GG genotype in the Chinese Han population was 45.2%, 23.2%, 18.6%, 3.9%, 25.7%, and 6.6%, respectively. No gender differences were found in the prevalence of both the MTHFR C677T and MTRR A66G polymorphisms. CONCLUSIONS: This study indicates that there are marked geographical variations in the prevalence of the three polymorphisms among Chinese Han populations. Our baseline data may be

  1. Geographical Distribution of MTHFR C677T, A1298C and MTRR A66G Gene Polymorphisms in China: Findings from 15357 Adults of Han Nationality

    Science.gov (United States)

    Yang, Boyi; Liu, Yuyan; Li, Yongfang; Fan, Shujun; Zhi, Xueyuan; Lu, Xiangxiang; Wang, Da; Zheng, Quanmei; Wang, Yinuo; Wang, Yanxun; Sun, Guifan

    2013-01-01

    Background Methylenetetrahydrofolate reductase (MTHFR) C677T, A1298C and methionine synthase reductase (MTRR) A66G polymorphisms are important genetic determinants for homocysteine (Hcy) levels, and are associated with several disorders. These polymorphisms are heterogeneously distributed worldwide. Our objective was to explore the geographical distributions of these polymorphisms in China. Methodologies 15357 healthy adults were recruited from 10 regions. Buccal samples were collected and genomic DNA was isolated. Genotyping was performed using the fluorogenic 5′-nuclease assay. Principal Findings The prevalence of the three polymorphisms among different populations from China varied significantly and showed apparent geographical gradients. For MTHFR C677T, the frequencies of the 677T allele and the 677TT genotype were significantly higher among northern populations and ranged from the lowest values (24.0% and 6.4%, respectively) in Hainan (southern) to the highest values (63.1% and 40.8%, respectively) in Shandong (northern). For MTHFR A1298C, the 1298C allele and the 1298CC genotype frequencies were significantly higher among southern populations and increased from low values (13.1% and 1.4%, respectively) in Shandong to high values (25.7% and 6.7%, respectively) in Hainan. For A66G, the 66G allele and the 66GG genotype frequencies increased from lower values (23.7% and 5.4%, respectively) in Shandong to higher values (29.2% and 8.6%, respectively) in Hainan. The overall frequency of the 677T allele, 677TT genotype, 1298C allele, 1298CC genotype, 66G allele and 66GG genotype in the Chinese Han population was 45.2%, 23.2%, 18.6%, 3.9%, 25.7%, and 6.6%, respectively. No gender differences were found in the prevalence of both the MTHFR C677T and MTRR A66G polymorphisms. Conclusions This study indicates that there are marked geographical variations in the prevalence of the three polymorphisms among Chinese Han populations. Our baseline data may be useful for

  2. Relationship between Genetic Polymorphisms in MTHFR (C677T, A1298C and their Haplotypes) and the Incidence Of Breast Cancer among Jordanian Females--Case-Control Study.

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    Awwad, Nemah; Yousef, Al-Motassem; Abuhaliema, Ali; Abdalla, Ihab; Yousef, Muhammad

    2015-01-01

    Breast cancer is a major cause of morbidity and mortality in Jordan and worldwide. Abnormality of DNA methylation is a possible mechanism for the development of cancer. Methylenetetrahydrofolate reductase (MTHFR) is involved in DNA methylation. Our aim was to study the association between genetic polymorphisms of MTHFR at two sites (C677T and A1298C) and their haplotypes and the risk of breast cancer among Jordanian females. A case-control study involving 150 breast cancer cases and 150 controls was conducted. Controls were age-matched to cases. Polymerase chain reaction/restriction fragment length polymorphism (PCR-RFLP) technique and sequencing were conducted to determine the genotypes. There was a significant difference in genotype frequency of C677T in the 41-60 year age category [cases: CC (37.4%), CT (49.5%) and TT (13.2%); controls: CC (56.3%), CT (35.6%) and TT (8%), p=0.04; ORTT vs. CC: 2.5, 95% CI: (0.9-6.9); ORat least on T: 2.1, 95%CI: (1.2-3.9)]. There was no significant difference in genotype frequency of A1298C between cases and controls [cases: AA (46.6%), AC (41.8%) and CC (11.6%); controls: AA (43%), AC (47.4%) and CC (9.6%); p=0.6]. There was a significant difference of MTHFR genetic polymorphism haplotypes among breast cancer cases and controls [cases/control: CA: 38.3/45.4%; CC: 28.9/25.2%; TA: 29.2/21; TC: 3.6/8.3; p value=0.01; ORTA vs. CA=1.6; 95% CI (1.1-2.5); p=0.02]. Genetic polymorphism of MTHFR C677T may modulate the risk of breast cancer especially in the 41-60 year age group. Additionally, TA haplotype amends the risk of breast cancer. Future studies with a larger sample size are needed to validate the role of MTHFR genetic polymorphisms in breast cancer.

  3. Folate intake, alcohol consumption, and the methylenetetrahydrofolate reductase (MTHFR C677T gene polymorphism: influence on prostate cancer risk and interactions

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    Lindsay C Kobayashi

    2012-08-01

    Full Text Available Purpose: Folate is essential to DNA methylation and synthesis and may have a complex dualistic role in prostate cancer. Alcohol use may increase risk and epigenetic factors may interact with lifestyle exposures. We aimed to characterize the independent and joint effects of folate intake, alcohol consumption, and the MTHFR C677T gene polymorphism on prostate cancer risk, while accounting for intakes of vitamins B2, B6, B12, methionine, total energy, and confounders.Methods: A case-control study was conducted at Kingston General Hospital of 80 incident primary prostate cancer cases and 334 urology clinic controls, all with normal age-specific PSA levels (to exclude latent prostate cancers. Participants completed a questionnaire on folate and alcohol intakes and potential confounders prior to knowledge of diagnosis, eliminating recall bias, and blood was drawn for MTHFR genotyping. Joint effects of exposures were assessed using unconditional logistic regression and significance of multiplicative and additive interactions using general linear models.Results: Folate, vitamins B2, B6, B12, methionine, and the CT and TT genotypes were not associated with prostate cancer risk. The highest tertile of lifetime alcohol consumption was associated with increased risk (OR=2.08; 95% CI: 1.12-3.86. Consumption of >5 alcoholic drinks/week was associated with increased prostate cancer risk among men with low folate intake (OR=2.38; 95% CI: 1.01-5.57 and higher risk among those with the CC MTHFR genotype (OR=4.43; 95% CI: 1.15-17.05. Increased risk was also apparent for weekly alcohol consumption when accounting for the multiplicative interaction between folate intake and MTHFR C677T genotype (OR=3.22; 95% CI: 1.36-7.59.Conclusion: Alcohol consumption is associated with increased prostate cancer risk, and this association is stronger among men with low folate intake, with the CC MTHFR genotype, and when accounting for the joint effect of folate intake and MTHFR C

  4. Effects of Maternal 5,10-Methylenetetrahydrofolate Reductase C677T and A1298C Polymorphisms and Tobacco Smoking on Infant Birth Weight in a Japanese Population

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    Yila, Thamar Ayo; Sasaki, Seiko; Miyashita, Chihiro; Braimoh, Titilola Serifat; Kashino, Ikuko; Kobayashi, Sumitaka; Okada, Emiko; Baba, Toshiaki; Yoshioka, Eiji; Minakami, Hisanori; Endo, Toshiaki; Sengoku, Kazuo; Kishi, Reiko

    2012-01-01

    Background Intracellular folate hemostasis depends on the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene. Because 5,10-MTHFR 677TT homozygosity and tobacco smoking are associated with low folate status, we tested the hypothesis that smoking in mothers with 5,10-MTHFR C677T or A1298C polymorphisms would be independently associated with lower birth weight among their offspring. Methods We assessed 1784 native Japanese mother-child pairs drawn from the ongoing birth cohort of The Hokkaido Study on Environment and Children’s Health. Data (demographic information, hospital birth records, and biological specimens) were extracted from recruitments that took place during the period from February 2003 to March 2006. Maternal serum folate were assayed by chemiluminescent immunoassay, and genotyping of 5,10-MTHFR C677T/A1298C polymorphisms was done using a TaqMan allelic discrimination assay. Results The prevalence of folate deficiency (MTHFR 677CT genotype was independently associated with an increase of 36.40 g (95% CI: 2.60 to 70.30, P = 0.035) in mean infant birth weight and an increase of 90.70 g (95% CI: 6.00 to 175.50, P = 0.036) among male infants of nonsmokers. Female infants of 677TT homozygous passive smokers were 99.00 g (95% CI: −190.26 to −7.56, P = 0.034) lighter. The birth weight of the offspring of smokers with 5,10-MTHFR 1298AA homozygosity was lower by 107.00 g (95% CI: −180.00 to −33.90, P = 0.004). Conclusions The results suggest that, in this population, maternal 5,10-MTHFR C677T polymorphism, but not the 5,10-MTHFR A1298C variant, is independently associated with improvement in infant birth weight, especially among nonsmokers. However, 5,10-MTHFR 1298AA might be associated with folate impairment and could interact with tobacco smoke to further decrease birth weight. PMID:22277790

  5. 5,10-Methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms: genotype frequency and association with homocysteine and folate levels in middle-southern Italian adults.

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    Zappacosta, Bruno; Graziano, Mirella; Persichilli, Silvia; Di Castelnuovo, Augusto; Mastroiacovo, Pierpaolo; Iacoviello, Licia

    2014-01-01

    Two genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene (C677T and A1298C) can influence the plasma homocysteine (Hcy) levels, especially in the presence of an inadequate folate status. The aim of this study was to evaluate the frequencies of C677T and of A1298C MTHFR polymorphisms and their correlation with Hcy and serum folate concentrations in a population of blood donors living in a region of middle-southern Italy (the Molise Region). One hundred ninety seven blood donors were studied for total plasma Hcy, serum folate and C677T and A1298C MTHFR genotypes. The frequency of C677T genotypes was 20.8% (CC), 49.8% (CT) and 29.4% (TT); for the A1298C genotypes: 48.7% (AA), 43.7% (AC) and 7.6% (CC). Hcy and serum folate concentrations were significantly different among genotypes of the C677T polymorphism (CC versus CT versus TT: A1298C polymorphism, the difference among genotypes (AA versus AC versus CC; p: 0.026 for Hcy and 0.014 for serum folate), showed an opposite trend for both parameters, with Hcy higher in the wild-type and lower in the homozygotes and serum folate higher in CC than in AA subjects. In conclusion, we found a high frequency of MTHFR allele associated with high level of Hcy and low levels of folate in an Italian southern population. Copyright © 2013 John Wiley & Sons, Ltd.

  6. Effect of lifestyle factors on plasma total homocysteine concentrations in relation to MTHFR(C677T) genotype. Inter99 (7)

    DEFF Research Database (Denmark)

    Husemoen, L L N; Thomsen, T F; Fenger, M

    2004-01-01

    OBJECTIVE: To examine the associations between various lifestyle factors--smoking habits, physical activity, dietary habits, coffee, tea, and alcohol consumption--and homocysteine (tHcy) in relation to MTHFR(C677T) genotype. DESIGN: Cross-sectional population-based study. SETTING: Residents...... a Fluorescent Polarization Immuno Assay. MTHFR-genotype was determined by PCR and RFLP analysis. Information about lifestyle factors was obtained from a self-administered questionnaire. RESULTS: Daily smoking, less healthy dietary habits, and coffee drinking were associated with elevated tHcy concentrations...... independent of other determinants. Wine consumption was related to tHcy in a J-shaped manner, whereas beer consumption was negatively associated with tHcy after multiple adjustments. Interaction was observed between smoking status and MTHFR-genotype, smoking status and sex, and beer consumption and age...

  7. Methylenetetrahydrofolate reductase polymorphism (C677T), hyperhomocysteinemia, and risk of ischemic cardiovascular disease and venous thromboembolism: prospective and case-control studies from the Copenhagen City Heart Study

    DEFF Research Database (Denmark)

    Frederiksen, Jeppe; Juul, Klaus; Grande, Peer

    2004-01-01

    Hyperhomocysteinemia is associated with ischemic cardiovascular disease (ICD) and venous thromboembolism (VTE). We tested the hypothesis that methylenetetrahydrofolate reductase (MTHFR) C677T homozygosity with hyperhomocysteinemia is associated with ICD and VTE. First, 9238 randomly selected whites...... for sex, age, cholesterol, high-density lipoprotein cholesterol, lipoprotein(a), fibrinogen, triglycerides, body mass index, smoking, diabetes mellitus, hypertension, and factor V Leiden genotype. Finally, in case-control studies odds ratios for ischemic heart disease and ischemic cerebrovascular disease...... from the general population were followed for 23 years. Second, 2125 whites with ischemic heart disease and 836 whites with ischemic cerebrovascular disease were compared with 7568 controls from the general population. Plasma homocysteine was elevated 25% in homozygotes versus noncarriers (P

  8. Chronic idiopathic acrocyanosis and methylenetetrahydrofolate reductase C677T (p.Ala222Val) and A1298C (p.Glu429Ala) polymorphisms.

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    Sampogna, Francesca; Camaioni, Diana Bella; Giampetruzzi, Anna Rita; Corona, Rosamaria; Ruzzi, Laura; Silvestri, Lorena; Didona, Biagio

    2013-01-01

    Chronic idiopathic acrocyanosis is a common acrosyndrome. Methylenetetrahydrofolate reductase (MTHFR) is an enzyme involved in the metabolism of folate. Two functional polymorphisms of MTHFR have been identified, C677T and A1298C. To compare the prevalence of these two MTHFR polymorphisms in patients with chronic idiopathic acrocyanosis to a control group. The study was conducted on 43 consecutive patients with acrocyanosis and on 100 controls. The risk of acrocyanosis was significantly higher in patients homozygous for the mutation c.677C>T compared to those with no mutation (OR = 4.8 (95%CI 1.5-14.9)). The homozygosity TT was associated with an increased homocysteine level. On the basis of our findings, acrocyanosis could be considered as a cutaneous sign of a "latent" cardiovascular risk. This should be taken into account particularly when acrocyanosis is associated either to other medical conditions that determine vessel wall damage or to conditions that predispose to the risk of thromboembolism.

  9. Gender-specific interactions of MTHFR C677T and MTRR A66G polymorphisms with overweight/obesity on serum lipid levels in a Chinese Han population.

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    Zhi, Xueyuan; Yang, Boyi; Fan, Shujun; Wang, Yanxun; Wei, Jian; Zheng, Quanmei; Sun, Guifan

    2016-10-28

    Little is known regarding the interactions of methylenetetrahydrofolate reductase (MTHFR) C677T and methionine synthase reductase (MTRR) A66G polymorphisms with overweight/obesity on serum lipid profiles. The aim of the current study was to explore interactions between the two polymorphisms and overweight/obesity on four common lipid levels in a Chinese Han population and further to evaluate whether these interactions exhibit gender-specificity. A total of 2239 participants (750 females and 1489 males) were enrolled into this study. The genotypes of the MTHFR C677T and MTRR A66G were determined by a TaqMan assay. Overweight and obesity were defined as a body mass index between 24 and 27.99 and ≥ 28 kg/m(2), respectively. The interactions were examined by factorial design covariance analysis, and further multiple comparisons were conducted by Bonferroni correction. There was no significant difference in the genotypic and allelic frequencies between females and males (MTHFR 677 T allele: 54.47 % for females and 54.40 % for males; MTRR 66G allele: 24.73 % for females and 24.71 % for males). Interaction between the MTHFR C677T polymorphism and overweight/obesity on serum triglyceride levels, and interaction between the MTRR A66G polymorphism and overweight/obesity on serum high-density lipoprotein cholesterol levels were detected in women (P = 0.015 and P = 0.056, respectively). For female subjects with overweight/obesity, the serum triglyceride levels in MTHFR 677TT genotype [1.09 (0.78-1.50) mmol/L] were significantly higher as compared with MTHFR 677CC genotype [0.90 (0.60-1.15) mmol/L, P = 0.007], and the MTRR 66GG genotype carriers had higher serum high-density lipoprotein cholesterol levels than those with MTRR 66AG genotype (1.46 ± 0.50 vs. 1.19 ± 0.31 mmol/L, P = 0.058). Furthermore, in male subjects with overweight/obesity, the MTHFR 677CT genotype carriers had higher low-density lipoprotein cholesterol levels than those

  10. Role of C677T and A1298C MTHFR, A2756G MTR and -786 C/T eNOS gene polymorphisms in atrial fibrillation susceptibility.

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    Betti Giusti

    Full Text Available BACKGROUND: Hyperhomocysteinemia has been suggested to play a role in the NonValvular Atrial Fibrillation (NVAF pathogenesis. Polymorphisms in genes coding for homocysteine (Hcy metabolism enzymes may be associated with hyperhomocysteinemia and NVAF. METHODOLOGIES: 456 NVAF patients and 912 matched controls were genotyped by an electronic microchip technology for C677T and A1298C MTHFR, A2756G MTR, and -786C/T eNOS gene polymorphisms. Hcy was determined by an immunoassay method. PRINCIPAL FINDINGS: The genotype distribution of the four polymorphisms as well as genotype combinations did not differ in patients and controls. Hcy was higher in patients than in controls (15.2, 95%CI 14.7-15.7 vs 11.3, 95%CI 11.0-11.6 micromol/L; p<0.0001. In both populations, a genotype-phenotype association (p<0.0001 between Hcy and C677T MTHFR polymorphism was observed; in controls a significant (p = 0.029 association between tHcy and -786C/T eNOS polymorphism was also observed. At the multivariate analysis the NVAF risk significantly increased in the upper quartiles of Hcy compared to the lowest: OR from 2.8 (1.68-4.54 95%CI in Q2 to 12.9 (7.96-21.06 95%CI in Q4. CONCLUSIONS: Our data demonstrated the four polymorphisms, although able, at least in part, to affect Hcy, were not associated with an increased risk of NVAF per se or in combination.

  11. Aberrant DNA Methylation of P16, MGMT, and hMLH1 Genes in Combination with MTHFR C677T Genetic Polymorphism in gastric cancer.

    Science.gov (United States)

    Song, Binbin; Ai, Jiang; Kong, Xianghong; Liu, Dexin; Li, Jun

    2013-11-01

    We aimed to explore the association of P16, MGMT and HMLH1 with gastric cancer and their relation with Methylenetetrahydrofolate reductase (MTHFR). 322 gastric patients who were confirmed with pathological diagnosis were included in our study. Aberrant DNA methylation of P16, MGMT and HMLH1 and polymorphisms of MTHFR C677T and A1298C were detected using PCR-RFLP. The proportions of DNA hypermethylation in P16, MGMT and hMLH1 genes in gastric cancer tissues were 75.2% (242/322), 27.6% (89/322) and 5.3% (17/322), respectively. In the remote normal-appearing tissues, 29.5% (95/322) and 16.1%(52/322) showed hypermethylation in P16 and MGMT genes, respectively. We found a significantly higher proportion of DNA hypermethylation of P16 in patients with N1 TNM stage in cancer tissues and remote normal-appearing tissues (P<0.05). Similarly, we found DNA hypermethylation of MGMT had significantly higher proportion in N1 and M1 TNM stage (P<0.05). Individuals with homozygotes (TT) of MTHFR C677T had significant risk of DNA hypermethylation of MGMT in cancer tissues [OR (95% CI)=4.27(1.76-7.84)], and a significant risk was also found in those carrying MTHFR 677CT/TT genotype [OR (95% CI)= 3.27(1.21-4.77)]. We found the aberrant hypermethylation of cancer-related genes, such as P16, MGMT and HMLH1, could be predictive biomarkers for detection of gastric cancer.

  12. Methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and the risk of primary hepatocellular carcinoma (HCC) in a Chinese population.

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    Mu, Li-Na; Cao, Wei; Zhang, Zuo-Feng; Cai, Lin; Jiang, Qing-Wu; You, Nai-Chieh; Goldstein, Binh Yang; Wei, Guo-Rong; Chen, Chuan-Wei; Lu, Qing-Yi; Zhou, Xue-Fu; Ding, Bao-Guo; Chang, Jun; Yu, Shun-Zhang

    2007-08-01

    Methylenetetrahydrofolate reductase (MTHFR), which is expressed in the liver, may be involved in both DNA methylation and DNA synthesis. It is also indicated as a potential risk factor of liver cancer in patients with chronic liver disease. To date, no study has been conducted on MTHFR and hepatocellular carcinoma (HCC) using a population-based design. The objective of this study was to evaluate the effects of polymorphisms of the MTHFR gene on the risk of primary liver cancer and their possible effect modifications on various environmental risk factors. A population-based case-control study was conducted in Taixing, China. MTHFR C677T and A1298C were assayed by PCR-RFLP techniques. The frequency of MTHFR 677 C/C wild homozygotes genotype was 25.8% in cases, which was lower than that in controls (34.5%). The adjusted odds ratios (ORs) for the MTHFR 677 C/T and T/T genotype were 1.66(95% CI: 1.06-2.61), 1.21(95% CI: 0.65-2.28) respectively when compared with the MTHFR 677 C/C genotype. Subjects carrying any T genotype have the increased risk of 1.55(95% CI: 1.01-2.40) for development of primary hepatocellular carcinoma. A high degree of linkage disequilibrium was observed between the C677T and A1298C polymorphisms, with the D' of 0.887 and p < 0.01. The MTHFR 677 any T genotype was suggested to have potentially more than multiplicative interactions with raw water drinking with p-value for adjusted interaction of 0.03. We observed that the MTHFR 677 C/T genotype was associated with an increased risk of primary liver cancer in a Chinese population. The polymorphism of MTHFR 677 might modify the effects of raw water drinking on the risk of primary hepatocellular carcinoma.

  13. Additive Interaction of MTHFR C677T and MTRR A66G Polymorphisms with Being Overweight/Obesity on the Risk of Type 2 Diabetes

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    Xueyuan Zhi

    2016-12-01

    Full Text Available Although both methylenetetrahydrofolate reductase (MTHFR C677T and methionine synthase reductase (MTRR A66G polymorphisms have been associated with type 2 diabetes (T2D, their interactions with being overweight/obesity on T2D risk remain unclear. To evaluate the associations of the two polymorphisms with T2D and their interactions with being overweight/obesity on T2D risk, a case-control study of 180 T2D patients and 350 healthy controls was conducted in northern China. Additive interaction was estimated using relative excess risk due to interaction (RERI, attributable proportion due to interaction (AP and synergy index (S. After adjustments for age and gender, borderline significant associations of the MTHFR C677T and MTRR A66G polymorphisms with T2D were observed under recessive (OR = 1.43, 95% CI: 0.98–2.10 and dominant (OR = 1.43, 95% CI: 1.00–2.06 models, respectively. There was a significant interaction between the MTHFR 677TT genotype and being overweight/obesity on T2D risk (AP = 0.404, 95% CI: 0.047–0.761, in addition to the MTRR 66AG/GG genotypes (RERI = 1.703, 95% CI: 0.401–3.004; AP = 0.528, 95% CI: 0.223–0.834. Our findings suggest that individuals with the MTHFR 677TT or MTRR 66AG/GG genotypes are more susceptible to the detrimental effect of being overweight/obesity on T2D. Further large-scale studies are still needed to confirm our findings.

  14. Influence of Methylenetetrahydrofolate Reductase C677T Polymorphism on the Risk of Lung Cancer and the Clinical Response to Platinum-Based Chemotherapy for Advanced Non-Small Cell Lung Cancer: An Updated Meta-Analysis

    Science.gov (United States)

    Zhu, Ning; Gong, Yi; He, Jian; Xia, Jingwen

    2013-01-01

    Purpose Methylenetetrahydrofolate reductase (MTHFR) has been implicated in lung cancer risk and response to platinum-based chemotherapy in advanced non-small cell lung cancer (NSCLC). However, the results are controversial. We performed meta-analysis to investigate the effect of MTHFR C677T polymorphism on lung cancer risk and response to platinum-based chemotherapy in advanced NSCLC. Materials and Methods The databases of PubMed, Ovid, Wanfang and Chinese Biomedicine were searched for eligible studies. Nineteen studies on MTHFR C677T polymorphism and lung cancer risk and three articles on C677T polymorphism and response to platinum-based chemotherapy in advanced NSCLC, were identified. Results The results indicated that the allelic contrast, homozygous contrast and recessive model of the MTHFR C677T polymorphism were associated significantly with increased lung cancer risk. In the subgroup analysis, the C677T polymorphism was significantly correlated with an increased risk of NSCLC, with the exception of the recessive model. The dominant model and the variant T allele showed a significant association with lung cancer susceptibility of ever smokers. Male TT homozygote carriers had a higher susceptibility, but the allelic contrast and homozygote model had a protective effect in females. No relationship was observed for SCLC in any comparison model. In addition, MTHFR 677TT homozygote carriers had a better response to platinum-based chemotherapy in advanced NSCLC in the recessive model. Conclusion The MTHFR C677T polymorphism might be a genetic marker for lung cancer risk or response to platinum-based chemotherapy in advanced NSCLC. However, our results require further verification. PMID:24142642

  15. The impact of C677T and A1298C MTHFR polymorphisms on methotrexate therapeutic response in East Bohemian region rheumatoid arthritis patients.

    Science.gov (United States)

    Soukup, Tomas; Dosedel, Martin; Pavek, Petr; Nekvindova, Jana; Barvik, Ivan; Bubancova, Iva; Bradna, Petr; Kubena, Ales Antonin; Carazo, Alejandro Fernández; Veleta, Tomas; Vlcek, Jiri

    2015-07-01

    Some single-nucleotide polymorphisms (SNPs) might be predictive of methotrexate (MTX) therapeutic outcome in rheumatoid arthritis (RA). The aim of this study was to determine whether SNPs in the methylenetetrahydrofolate reductase (MTHFR) gene are predictive of MTX response. Comparison was made using EULAR response criteria and according to the change of DAS28 (∆DAS28) after a 6-month MTX treatment in RA patient cohort. The two SNPs C677T (rs1801133) and A1298C (rs1801131) have been genotyped. A total of 120 patients were enrolled in the study, and all of them fulfilled the American College of Rheumatology 1987 RA criteria and are currently or previously taking MTX oral treatment, either as a monotherapy (n = 65) or in a combination with other disease-modifying antirheumatic drugs (n = 55). Genotyping was performed using qPCR allelic discrimination. We did not found any association of C677T and A1298C genotypes with MTX treatment inefficacy in dominant model (OR 1.23, 95 % CI 0.57-2.65, P = 0.697; and OR 0.98, 95 % CI 0.47-2.14, P = 1.0, respectively), or in recessive and codominant models. However, when ∆DAS28 after a 6-month therapy was used as a measure of treatment efficacy, the 677CT and 1298AC genotypes were found to be significantly associated with less favorable response to MTX (P = 0.025 and P = 0.043, respectively). In addition, even lower ∆DAS28 was determined for double-mutated 677CT-1298AC heterozygotes. It means that a synergistic effect of 677CT and 1298AC genotypes was observed. Nevertheless, the DAS28 baseline was lower here comparing to other genotypes. Unexpectedly, quite the opposite trend-i.e., better response to MTX-was found in genotypes 677CC-1298CC and 677TT-1298AA. It is an intriguing finding, because these double-mutated homozygotes are known for their low MTHFR-specific activity. Global significance was P = 0.013, η (2) = 0.160-i.e., large-size effect. Thus, our data show greater ability of 677CC-1298CC and 677TT

  16. Genetic susceptibility of methylenetetrahydrofolate reductase (MTHFR) gene C677T, A1298C, and G1793A polymorphisms with risk for bladder transitional cell carcinoma in men.

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    Safarinejad, Mohammad Reza; Shafiei, Nayyer; Safarinejad, Shiva

    2011-12-01

    We performed a case-control study of 158 bladder transitional cell carcinoma (TCC) cases and 316 controls to investigate the association between methylenetetrahydrofolate reductase (MTHFR) C677T, A1298G, and G1793A polymorphisms and bladder cancer susceptibility by polymerase chain reaction restriction fragment length polymorphism (PCR-RLFP) technique. The controls were frequency-matched to the cases by age (± 5 years), ethnicity, and smoking status. We also measured serum levels of total homocysteine (tHcy), folate, and vitamin B12. It was found that the 1298AC (odds ratio, OR = 3.74; 95% confidence interval, CI = 2.34-5.47; P = 0.001) and 1298CC (OR = 3.46, 95% CI = 2.37-5.52; P = 0.001) genotypes of MTHFR A1298C were significantly associated with increased risk of bladder TCC. The MTHFR C677T and G1793A polymorphisms were not associated with bladder TCC. After stratification for grade and stage, we observed that the 677TT (OR = 4.47, 95% CI = 2.74-6.72; P = 0.001) and MTHFR 1298CC (OR = 4.78, 95% CI = 2.82-6.89; P = 0.001) genotypes of MTHFR were associated with increased risk of muscle-invasive bladder TCC. We also found that the MTHFR 677CT+1298AA genotypes were associated with an approximately 70% reduction in risk of bladder cancer (OR = 0.31; 95% CI = 0.15-0.68) compared to the combined referent genotype. There were 8 haplotypes and 16 haplotype genotypes based on these three variants. When we used the haplotypes and assumed that the 677T, 1298C, and 1793G alleles were risk alleles, the adjusted odds ratios increased as the number of risk alleles increased: 1.00 for 0-1 variant, 1.88 (1.4-2.7) for any two risk alleles and 2.07 (1.6-2.8) for any three risk alleles. Serum tHcy levels were significantly higher in carriers of the 677T, 1298C, and 1793G alleles compared to noncarriers (all P < 0.01). There was no significant correlation between serum levels of tHcy and folate and bladder cancer risk. Further studies in larger samples size and different

  17. Associations between two common variants C677T and A1298C in the methylenetetrahydrofolate reductase gene and measures of folate metabolism and DNA stability (strand breaks, misincorporated uracil, and DNA methylation status) in human lymphocytes in vivo.

    Science.gov (United States)

    Narayanan, Sabrina; McConnell, Josie; Little, Julian; Sharp, Linda; Piyathilake, Chandrika J; Powers, Hilary; Basten, Graham; Duthie, Susan J

    2004-09-01

    Homozygosity for variants of the methylenetetrahydrofolate reductase (MTHFR) gene is associated with decreased risk for colorectal cancer. We have investigated the relationships between two variants of the MTHFR gene (C677T and A1298C) and blood folate, homocysteine, and genomic stability (strand breakage, misincorporated uracil, and global cytosine methylation in lymphocytes) in a study of 199 subjects. The frequencies of homozygosity for the C677T and A1298C variants of the MTHFR gene were 12.6% and 14.6%, respectively. Plasma homocysteine, folate, vitamin B12, 5-methyltetrahydrofolate, and RBC folate were determined in the C677T genotypes. Plasma folate was significantly lower (P A1298C variant did not influence plasma homocysteine, folate, 5-methyltetrahydrofolate, vitamin B12, or RBC folate. Lymphocyte DNA stability biomarkers (strand breaks, misincorporated uracil, and global DNA methylation) were similar for all MTHFR C677T or A1298C variants. Data from this study do not support the hypothesis that polymorphisms in the MTHFR gene increase DNA stability by sequestering 5,10-methylenetetrahydrofolate for thymidine synthesis and reducing uracil misincorporation into DNA.

  18. C677T and A1298C Mutations in the Methylenetetrahydrofolate Reductase Gene in Patients with Recurrent Abortion from the Iranian Azeri Turkish

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    Morteza Bagheri

    2010-01-01

    Full Text Available Background: To assess whether the C677T and A1298C mutations in the methylenetetrahydrofolatereductase (MTHER gene are associated with recurrent abortion (RA, we determined the frequenciesof the T677 and C1298 mutations in patients and controls.Materials and Methods: Mutations were determined by a RFLP-PCR method in 53 patients and61 matched controls.Results: The frequencies of T alleles were 0.26 in patients and 0.29 in controls. The frequencies ofC/C, T/C and T/T genotypes were 34 (55.7%, 22 (36.1% and 5 (8.2% in patients, and 27 (50.9%,21 (39.6% and 5 (9.43% in controls. The C allele frequencies were 0.38 in patients and controls.C/C, A/C and A/A genotype distributions were 9 (14.8%, 28 (45.9% and 24 (39.3% in patients,and 8 (15.1%, 24 (45.3% and 21 (39.6% in controls.Conclusion: There were no significant differences between patients and controls concerning theT677 and C1298 mutations.

  19. Ethnic variation of the C677T and A1298C polymorphisms in the methylenetetrahydrofolate-reductase (MTHFR) gene in southwestern Mexico.

    Science.gov (United States)

    Antonio-Véjar, V; Del Moral-Hernández, O; Alarcón-Romero, L C; Flores-Alfaro, E; Leyva-Vázquez, M A; Hernández-Sotelo, D; Illades-Aguiar, B

    2014-09-29

    In this study, we examined the distribution of genotype and allele frequencies of the C677T and A1298C polymorphisms in the methylenetetrahydrofolate-reductase gene (MTHFR) in two ethnic groups in the State of Guerrero, Mexico, which were compared with those of the Mestizo population of the region. A comparative study was conducted on 455 women from two ethnic groups and a group of Mestizo women of the State of Guerrero, Mexico: 135 Nahuas, 124 Mixtecas, and 196 Mestizas. Genotyping of both polymorphisms were performed by using polymerase chain reaction-restriction fragment length polymorphism methods. We found that the 677TT genotype was more frequent in Nahua and Mixteca women compared to Mestiza women (P = 0.008), and the most prevalent genotype in both ethnic groups was the 1298AA genotype (P A1298C polymorphisms between the two ethnic groups and the Mestizo population of the State of Guerrero. In addition, we found strong differences with other ethnic groups in Mexico. These results could be useful for future studies investigating diseases related to folate metabolism, and could help the government to design specific nutrition programs for different ethnic groups.

  20. Homocysteine Metabolism Gene Polymorphisms (MTHFR C677T, MTHFR A1298C, MTR A2756G and MTRR A66G Jointly Elevate the Risk of Folate Deficiency

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    Wen-Xing Li

    2015-08-01

    Full Text Available Folate deficiency is strongly associated with cardiovascular disease. We aimed to explore the joint effect of the methylenetetrahydrofolate reductase (MTHFR C677T and A1298C, methionine synthase (MTR A2756G, and methionine synthase reductase (MTRR A66G polymorphisms on folate deficiency in a Chinese hypertensive population. A total of 480 subjects aged 28–75 were enrolled in this study from September 2005–December 2005 from six hospitals in different Chinese regions. Known genotypes were detected by PCR-RFLP methods and serum folate was measured by chemiluminescence immunoassay. Our results showed that MTHFR 677TT and MTR 2756AG + GG were independently associated with a higher risk of folate deficiency (TT vs. CC + CT, p < 0.001 and AG + GG vs. AA p = 0.030, respectively. However, the MTHFR A1298C mutation may confer protection by elevating the serum folate level (p = 0.025. Furthermore, patients carrying two or more risk genotypes showed higher odds of folate deficiency than null risk genotype carriers, especially those carrying four risk genotypes. These findings were verified by generalized multifactor dimensionality reduction (p = 0.0107 and a cumulative effects model (p = 0.001. The results of this study have shown that interactions among homocysteine metabolism gene polymorphisms lead to dramatic elevations in the folate deficiency risk.

  1. Association of methylenetetrahytrofolate reductase (MTHFR) C677T and A1298C polymorphisms with the susceptibility of childhood acute lymphoblastic leukaemia (ALL) in Chinese population.

    Science.gov (United States)

    Li, Xiaolei; Liao, Qingchuan; Zhang, Shunguo; Chen, Minling

    2014-01-29

    The aim of this study was to investigate the relationship between the polymorphisms of the methylenetetrahytrofolate reductase (MTHFR) gene and susceptibility to childhood acute lymphoblastic leukemia (ALL). A case-control study was conducted among 98 children with ALL and 93 age- and sex- matched non-ALL controls. Genotyping of MTHFR C677T and A1298C polymorphisms was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The odds ratios (ORs) of MTHFR genotypes were used to assess the associations of these polymorphisms with childhood ALL susceptibility. No significant differences were observed for frequencies of the 677CC, 677CT and 677TT genotypes between patients and controls. Frequencies of the 1298AA, 1298 AC and 1298CC genotypes between the two groups were significantly different. The risk of ALL with the 1298C allele carriers (AC + CC) was elevated by 1.1 times compared with the AA genotype [OR = 2.100; 95% CI (1.149; 3.837); P = 0.015]. The MTHFR A1298C polymorphism is associated with susceptibility to childhood ALL in the Chinese population.

  2. Methylenetetrahydrofolate reductase gene germ-line C677T and A1298C SNPs are associated with colorectal cancer risk in the Turkish population.

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    Ozen, Filiz; Sen, Metin; Ozdemir, Ozturk

    2014-01-01

    Colorectal cancer (CRC) is the third most common cause of death due to cancer in the worldwide and the incidence is also increasing in Turkey. Our present aim was to investigate any association between germ-line methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and CRC risk in Turkey. A total of 86 CRC cases and 212 control individuals of the same ethnicity were included in the current study. Peripheral blood-DNA samples were used for genotyping by StripAssay technique, based on the reverse- hybridization principle and real-time PCR methods. Results were compared in Pearson Chi-square and multiple logistic regression models. The MTHFR 677TT (homozygous) genotype was found in 20.9% and the T allele frequency 4.2-fold increased in CRC when compared with the control group.The second SNP MTHFR 1298CC (homozygous) genotype was found in 14.0% and the C allele frequency 1.4-fold elevated in the CRC group. The current data suggest strong associations between both SNPs of germ-line MTHFR 677 C>T and 1298 A>C genotypes and CRC susceptibility in the Turkish population. Now the results need to be confirmed with a larger sample size.

  3. Homocysteine Metabolism Gene Polymorphisms (MTHFR C677T, MTHFR A1298C, MTR A2756G and MTRR A66G) Jointly Elevate the Risk of Folate Deficiency.

    Science.gov (United States)

    Li, Wen-Xing; Dai, Shao-Xing; Zheng, Jun-Juan; Liu, Jia-Qian; Huang, Jing-Fei

    2015-08-10

    Folate deficiency is strongly associated with cardiovascular disease. We aimed to explore the joint effect of the methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, methionine synthase (MTR) A2756G, and methionine synthase reductase (MTRR) A66G polymorphisms on folate deficiency in a Chinese hypertensive population. A total of 480 subjects aged 28-75 were enrolled in this study from September 2005-December 2005 from six hospitals in different Chinese regions. Known genotypes were detected by PCR-RFLP methods and serum folate was measured by chemiluminescence immunoassay. Our results showed that MTHFR 677TT and MTR 2756AG + GG were independently associated with a higher risk of folate deficiency (TT vs. CC + CT, p MTHFR A1298C mutation may confer protection by elevating the serum folate level (p = 0.025). Furthermore, patients carrying two or more risk genotypes showed higher odds of folate deficiency than null risk genotype carriers, especially those carrying four risk genotypes. These findings were verified by generalized multifactor dimensionality reduction (p = 0.0107) and a cumulative effects model (p = 0.001). The results of this study have shown that interactions among homocysteine metabolism gene polymorphisms lead to dramatic elevations in the folate deficiency risk.

  4. Methylenetetrahydrofolate reductase (MTHFR) C677T, A1298C and G1793A genotypes, and the relationship between maternal folate intake, tibia lead and infant size at birth

    Science.gov (United States)

    Kordas, Katarzyna; Ettinger, Adrienne S.; Lamadrid-Figueroa, Héctor; Tellez-Rojo, Martha M.; Hérnandez-Avila, Mauricio; Hu, Howard; Wright, Robert O.

    2011-01-01

    Small size at birth continues to be a problem worldwide and many factors, including reduced folate intake and Pb exposure, are associated with it. However, single factors rarely explain the variability in birth weight, suggesting a need for more complex explanatory models. We investigated environment–gene interactions to understand whether folate intake and maternal Pb exposure were associated with smaller newborn size in 474 women with uncomplicated pregnancies delivering term infants in Mexico City. We examined if folate intake modified the negative effects of maternal Pb burden on birth size. We also asked if maternal and infant methylenetetrahydrofolate reductase (MTHFR) genotypes (C677T, A1298C and G1793A) modified the effects of folate intake or Pb exposure on birth size. Women were aged 24·6 (SD 5·1) years; 43·5 % were primiparous. Maternal blood Pb at delivery was 86 (SD 42) μg/l, with 26·7 % having levels ≥100 μg/l. Tibia Pb level was 9·9 (SD 9·8) μg/g. Of the women, 35·3 % had folate intakes MTHFR modify the association between Pb or folate intake on birth size. Although modest, the relationship between maternal nutrition, Pb burden and birth size does underscore the importance of environmental exposures to child health because patterns of fetal growth may affect health outcomes well into adulthood. PMID:19338708

  5. Role of methylenetetrahydrofolate reductase gene polymorphisms (C677T, A1298C, and G1793A) in the development of early onset vasculogenic erectile dysfunction.

    Science.gov (United States)

    Safarinejad, Mohammad Reza; Safarinejad, Shiva; Shafiei, Nayyer

    2010-08-01

    The methylenetetrahydrofolate reductase (MTHFR) gene plays a key role in the metabolism of folate and homocysteine (Hcy) and its mutations have been associated with high serum Hcy level. Elevated serum Hcy has been linked to impaired endothelial function and occlusive vascular disease. We studied the association among the different genotypes of all three MTHFR polymorphisms (C677T, A1298C, and G1793A) and the risk of early-onset vasculogenic erectile dysfunction (VED). We performed a case-control study of 114 men with early-onset VED and 228 age-matched controls. Genotyping of MTHFR gene polymorphisms was performed using polymerase chain reaction restriction fragment length polymorphism (PCR-RLFP) technique. We also measured plasma lipids, Hcy, folate, and vitamin B12 levels. Patients with early-onset VED had higher serum Hcy levels (12.29 ± 2.32 vs. 9.82 ± 2.35 μmol/L, p = 0.001) and higher prevalence of 677TT homozygocity compared to controls (15.8% vs. 11.4%, p = 0.01). Serum Hcy concentration was significantly higher in individuals with 677TT, 1298CC, and 1793GG genotypes. Subgroup analysis according to severity of ED (mild, moderate, and severe) showed that patients with severe VED had higher serum Hcy levels compared to patients with mild VED (13.48 ± 2.51 vs. 11.21 ± 2.32 μmol/L, p = 0.001). Odds ratio seems to demonstrate that individuals with the MTHFR 677TT genotype and the 677TT + 1298AC combined genotype had a 3.16- and 3.89-fold increased risk for developing VED, suggesting a possible association of MTHFR polymorphisms with the risk of early-onset VED. Copyright © 2010 IMSS. Published by Elsevier Inc. All rights reserved.

  6. Polymorphisms of MTHFR C677T and A1298C associated with survival in patients with colorectal cancer treated with 5-fluorouracil-based chemotherapy.

    Science.gov (United States)

    Yeh, Chih-Ching; Lai, Ching-Yu; Chang, Shih-Ni; Hsieh, Ling-Ling; Tang, Reiping; Sung, Fung-Chang; Lin, Yi-Kuei

    2017-06-01

    This study examined the association between methylenetetrahydrofolate reductase (MTHFR) polymorphisms and survival of patients with colorectal cancer (CRC) treated with 5-fluorouracil (5-FU)-based chemotherapy in Taiwan. We genotyped MTHFR polymorphisms C677T (rs1801133) and A1298C (rs1801131) for 498 CRC patients treated with 5-FU-based chemotherapy after receiving surgery. Survival analyses on MTHFR polymorphisms were performed using log-rank test and Kaplan-Meier curve. Cox proportional hazards models were used to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between MTHFR genotypes and survival. Overall survival (OS) was significantly longer in CRC patients with MTHFR 677 CT+TT genotypes compared with those with 677 CC genotype (HR 0.77; 95% CI 0.60-0.98). Although the MTHFR A1298C polymorphism was not associated with OS in CRC, this polymorphism was associated with significantly shorter OS in rectal cancer. Among rectal cancer patients, OS was shorter for patients with AC+CC genotypes than for those with the AA genotype (HR 1.95; 95% CI 1.35-2.83). In haplotype analysis, better OS was found for colon cancer patients carrying the MTHFR 677T-1298A haplotype (HR 0.73; 95% CI 0.55-0.97), but worse survival was linked to rectal cancer patients carrying the MTHFR 677C-1298C haplotype (HR 1.53; 95% CI 1.08-2.18). Our findings suggest that MTHFR genotypes provide prognostic information for CRC patients treated with 5-FU-based chemotherapy.

  7. Glucose Tolerance, MTHFR C677T and NOS3 G894T Polymorphisms, and Global DNA Methylation in Mixed Ancestry African Individuals

    Directory of Open Access Journals (Sweden)

    Tandi E. Matsha

    2016-01-01

    Full Text Available The aim of this study is to quantify global DNA methylation and investigate the relationship with diabetes status and polymorphisms in MTHFR C677T and NOS3 G894T genes in mixed ancestry subjects from South Africa. Global DNA methylation was measured, and MTHFR rs1801133 and NOS3 rs1799983 polymorphisms were genotyped using high throughput real-time polymerase chain reaction and direct DNA sequencing. Of the 564 participants, 158 (28% individuals had T2DM of which 97 (17.2% were screen-detected cases. Another 119 (21.1% had prediabetes, that is, impaired fasting glucose, impaired glucose tolerance, or the combination of both, and the remainder 287 (50.9% had normal glucose tolerance. Global DNA methylation was significantly higher in prediabetes and screen-detected diabetes than in normal glucose tolerance (both p≤0.033 and in screen-detected diabetes compared to known diabetes on treatment (p=0.019. There was no difference in global DNA methylation between known diabetes on treatment and normal glucose tolerance (p>0.999. In multivariable linear regression analysis, only NOS3 was associated with increasing global DNA methylation (β=0.943; 95% CI: 0.286 to 1.560. The association of global DNA methylation with screen-detected diabetes but not treated diabetes suggests that glucose control agents to some extent may be reversing DNA methylation. The association between NOS3 rs1799983 polymorphisms and DNA methylation suggests gene-epigenetic mechanisms through which vascular diabetes complications develop despite adequate metabolic control.

  8. Association of Vitamin B12 Deficiency with Homozygosity of the TT MTHFR C677T Genotype, Hyperhomocysteinemia, and Endothelial Cell Dysfunction.

    Science.gov (United States)

    Shiran, Avinoam; Remer, Eric; Asmer, Ihab; Karkabi, Basheer; Zittan, Eran; Cassel, Aliza; Barak, Mira; Rozenberg, Orit; Karkabi, Khaled; Flugelman, Moshe Y

    2015-05-01

    Hyperhomocysteinemia is associated with increased cardiovascular risk, but treatment with folic acid has no effect on outcome in unselected patient populations. To confirm previous observations on the association of homozygosity for the TT MTHFR genotype with B12 deficiency and endothelial dysfunction, and to investigate whether patients with B12 deficiency should be tested for 677MTHFR genotype. We enrolled 100 individuals with B12 deficiency, tested them for the MTHFR C677T polymorphism and measured their homocysteine levels. Forearm endothelial function was checked in 23 B12-deficient individuals (13 with TT MTHFR genotype and 10 with CT or CC genotypes). Flow-mediated dilatation (FMD) was tested after short-term treatment with B12 and folic acid in 12 TT MTHFR homozygotes. Frequency of the TT MTHFR genotype was 28/100 (28%), compared with 47/313 (15%) in a previously published cohort of individuals with normal B12 levels (P = 0.005). Mean homocysteine level was 21.2 ± 16 μM among TT homozygotes as compared to 12.3 ± 5.6 μM in individuals with the CC or CT genotype (P = 0.008). FMD was abnormal ( 6%) in 9/13 TT individuals with B12 deficiency (69%), and was still abnormal in 7/12 of those tested 6 weeks after B12 and folic treatment (58%). Among individuals with B12 deficiency, the frequency of the TT MTHFR genotype was particularly high. The TT polymorphism was associated with endothelial dysfunction even after 6 weeks of treatment with B12 and folic acid. Based on our findings we suggest that B12 deficiency be tested for MTHFR polymorphism in order to identify potential vascular abnormalities and increased cardiovascular risk.

  9. Meta- and Pooled Analyses of the Methylenetetrahydrofolate Reductase (MTHFR) C677T Polymorphism and Colorectal Cancer: A HuGE-GSEC Review

    Science.gov (United States)

    Taioli, E.; Garza, M. A.; Ahn, Y. O.; Bishop, D. T.; Bost, J.; Budai, B.; Chen, K.; Gemignani, F.; Keku, T.; Lima, C. S. P.; Le Marchand, L.; Matsuo, K.; Moreno, V.; Plaschke, J.; Pufulete, M.; Thomas, S. B.; Toffoli, G.; Wolf, C. R.; Moore, C. G.; Little, J.

    2009-01-01

    Worldwide, over 1 million cases of colorectal cancer (CRC) were reported in 2002, with a 50% mortality rate, making CRC the second most common cancer in adults. Certain racial/ethnic populations continue to experience a disproportionate burden of CRC. A common polymorphism in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene has been associated with a lower risk of CRC. The authors performed both a meta-analysis (29 studies; 11,936 cases, 18,714 controls) and a pooled analysis (14 studies; 5,068 cases, 7,876 controls) of the C677T MTHFR polymorphism and CRC, with stratification by racial/ethnic population and behavioral risk factors. There were few studies on different racial/ethnic populations. The overall meta-analysis odds ratio for CRC for persons with the TT genotype was 0.83 (95% confidence interval (CI): 0.77, 0.90). An inverse association was observed in whites (odds ratio = 0.83, 95% CI: 0.74, 0.94) and Asians (odds ratio = 0.80, 95% CI: 0.67, 0.96) but not in Latinos or blacks. Similar results were observed for Asians, Latinos, and blacks in the pooled analysis. The inverse association between the MTHFR 677TT polymorphism and CRC was not significantly modified by smoking status or body mass index; however, it was present in regular alcohol users only. The MTHFR 677TT polymorphism seems to be associated with a reduced risk of CRC, but this may not hold true for all populations. PMID:19846566

  10. MTHFR C677T genotype influences the isotopic enrichment of one-carbon metabolites in folate-compromised men consuming d9-choline123

    Science.gov (United States)

    Yan, Jian; Wang, Wei; Gregory, Jesse F; Malysheva, Olga; Brenna, J Thomas; Stabler, Sally P; Allen, Robert H; Caudill, Marie A

    2011-01-01

    Background: Homozygosity for the variant 677T allele in the methylenetetrahydrofolate reductase (MTHFR) gene increases the requirement for folate and may alter the metabolic use of choline. The choline adequate intake is 550 mg/d for men, although the metabolic consequences of consuming extra choline are unclear. Objective: Deuterium-labeled choline (d9-choline) as tracer was used to determine the differential effects of the MTHFR C677T genotype and the effect of various choline intakes on the isotopic enrichment of choline derivatives in folate-compromised men. Design: Mexican American men with the MTHFR 677CC or 677TT genotype consumed a diet providing 300 mg choline/d plus supplemental choline chloride for total choline intakes of 550 (n = 11; 4 with 677CC and 7 with 677TT) or 1100 (n = 12; 4 with 677CC and 8 with 677TT) mg/d for 12 wk. During the last 3 wk, 15% of the total choline intake was provided as d9-choline. Results: Low but measurable enrichments of the choline metabolites were achieved, including that of d3-phosphatidylcholine (d3-PtdCho)—a metabolite produced in the de novo pathway via choline-derived methyl groups. Men with the MTHFR 677TT genotype had a higher urinary enrichment ratio of betaine to choline (P = 0.041), a higher urinary enrichment of sarcosine (P = 0.041), and a greater plasma enrichment ratio of d9-betaine to d9-PtdCho with the 1100 mg choline/d intake (P = 0.033). Conclusion: These data show for the first time in humans that choline itself is a source of methyl groups for de novo PtdCho biosynthesis and indicate that the MTHFR 677TT genotype favors the use of choline as a methyl donor. PMID:21123458

  11. MTHFR C677T genotype influences the isotopic enrichment of one-carbon metabolites in folate-compromised men consuming d9-choline.

    Science.gov (United States)

    Yan, Jian; Wang, Wei; Gregory, Jesse F; Malysheva, Olga; Brenna, J Thomas; Stabler, Sally P; Allen, Robert H; Caudill, Marie A

    2011-02-01

    Homozygosity for the variant 677T allele in the methylenetetrahydrofolate reductase (MTHFR) gene increases the requirement for folate and may alter the metabolic use of choline. The choline adequate intake is 550 mg/d for men, although the metabolic consequences of consuming extra choline are unclear. Deuterium-labeled choline (d9-choline) as tracer was used to determine the differential effects of the MTHFR C677T genotype and the effect of various choline intakes on the isotopic enrichment of choline derivatives in folate-compromised men. Mexican American men with the MTHFR 677CC or 677TT genotype consumed a diet providing 300 mg choline/d plus supplemental choline chloride for total choline intakes of 550 (n = 11; 4 with 677CC and 7 with 677TT) or 1100 (n = 12; 4 with 677CC and 8 with 677TT) mg/d for 12 wk. During the last 3 wk, 15% of the total choline intake was provided as d9-choline. Low but measurable enrichments of the choline metabolites were achieved, including that of d3-phosphatidylcholine (d3-PtdCho)--a metabolite produced in the de novo pathway via choline-derived methyl groups. Men with the MTHFR 677TT genotype had a higher urinary enrichment ratio of betaine to choline (P = 0.041), a higher urinary enrichment of sarcosine (P = 0.041), and a greater plasma enrichment ratio of d9-betaine to d9-PtdCho with the 1100 mg choline/d intake (P = 0.033). These data show for the first time in humans that choline itself is a source of methyl groups for de novo PtdCho biosynthesis and indicate that the MTHFR 677TT genotype favors the use of choline as a methyl donor.

  12. The one-carbon-cycle and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism in recurrent major depressive disorder; influence of antidepressant use and depressive state?

    Science.gov (United States)

    Lok, A; Mocking, R J T; Assies, J; Koeter, M W; Bockting, C L; de Vries, G J; Visser, I; Derks, E M; Kayser, M; Schene, A H

    2014-09-01

    An important biological factor suggested in the pathophysiology of (recurrent) Major Depressive Disorder (MDD) concerns a polymorphism in a gene encoding for the MTHFR-enzyme of the one-carbon (1-C)-metabolism. Integratively investigating key 1-C-components (folate, homocysteine, vitamin B6 and B12), including the possible effects of antidepressant medication and depressive state, could provide more insight in the possible association between the MTHFR-polymorphism and recurrent MDD. We compared the MTHFR C677T-polymorphism together with the key 1-C-components in clinically ascertained patients with recurrent MDD (n=137) to age- and gender-matched healthy controls (n=73). First, patients had lower folate (t=2.25; p=.025) as compared to controls; a difference that resolved after correction for demographics (t=1.22; p=.223). Second, patients that were depressed during sampling had lower vitamin B6 (t=-2.070; p=.038) and higher homocysteine (t=2.404; p=.016) compared to those in remission. Finally, current use of antidepressants had no influence on the 1-C-components. Despite investigation of a specific recurrently depressed patient population, we found no clear associations with the 1-C-cycle, except for higher homocysteine and lower vitamin B6 during the depressed state. This suggests that 1-C-cycle alterations in MDD are state-associated, possibly resulting from high levels of acute (psychological) stress, and may provide a treatment target to reduce cardiovascular risk in this population. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Association of a common allelic polymorphism (C677T) in the methylene tetrahydrofolate reductase gene with a reduced risk of osteoporotic fractures. A case control study in Danish postmenopausal women

    DEFF Research Database (Denmark)

    Jørgensen, H L; Madsen, J S; Madsen, B

    2002-01-01

    Twin studies indicate a substantial genetic component in the development of osteoporosis. One of the latest studied candidate genes is the one coding for methylene tetrahydrofolate reductase (MTHFR) (C677T) in which a point mutation gives rise to a thermolabile variant of MTHFR. The aim......-matched controls were included. All had broadband ultrasound attenuation (BUA) and speed of sound (SOS) measured at the heel as well as bone mineral density (BMD) measured by dual X-ray absorptiometry at the distal forearm. The MTHFR (C677T) genotypes were determined using polymerase chain reaction restriction...... homozygotic for the C-allele with those homozygotic for the T-allele: lower forearm fracture OR = 3.93 (1.25; 12.40, P = 0.02), hip fracture OR = 6.99 (l.35; 36.92, P = 0.02) and the fractures combined OR = 4.33 (1.73; 10.81, P = 0.002). In this study, the MTHFR (C677T) genotypes were not significantly...

  14. ACE I/D sequence variants but not MTHFR C677T, is strongly linked to malignant glioma risk and its variant DD genotype may act as a promising predictive biomarker for overall survival of glioma patients.

    Science.gov (United States)

    Pandith, Arshad A; Qasim, Iqbal; Zahoor, Wani; Shah, Parveen; Bhat, Abdul R

    2018-01-10

    ACE I/D and MTHFR C677T gene polymorphisms can be seen as candidate genes for glioma on the basis of their biological functions and their involvement in different cancers. The aim of this study was to analyze potential association and overall survival between MTHFR C677T and ACE I/D polymorphism in glioma patients in our population. We tested genotype distribution of 112 glioma patients against 141 cancer-free controls from the same region. Kaplan-Meier survival analysis was performed to evaluate overall survival of patients for both genes. No significant differences were found among MTHFR C677T wild type C and variant genotypes CT/TT with glioma patients. In ACE, the distribution of variant ID and DD was found to be significantly higher in glioma cases as compared to controls (pDD genotypes were highly presented in glioma cases 26.8% versus 10.6% in controls (pDD genotypes had the least estimated overall survival of 13.4months in comparison to 21. 7 and 17.6months for ACE II and I/D genotypes respectively. We conclude ACE I/D polymorphism plays a vital role in predisposition of higher risk for glioma. We also suggest that ACE DD genotypes may act as an important predictive biomarker for overall survival of glioma patients. Copyright © 2017. Published by Elsevier B.V.

  15. MTHFR C677T, A1298C and MS A2756G Gene Polymorphisms and Male Infertility Risk in a Chinese Population: A Meta-Analysis.

    Science.gov (United States)

    Ren, Zhengju; Ren, Pengwei; Yang, Bo; Fang, Kun; Ren, Shangqing; Liao, Jian; Liu, Shengzhuo; Liu, Liangren; Peng, Zhufeng; Dong, Qiang

    2017-01-01

    Methylenetetrahydrofolate reductase gene (MTHFR C677T and A1298C) and methionine synthase gene (MS A2756G) polymorphisms have shown an association with male infertility risk in several ethnic populations. Although several studies have evaluated these associations in Chinese populations, their small sample sizes and inconsistent outcomes have prevented strong conclusions. Therefore, the present meta-analysis was performed with published studies to evaluate the associations of the three single nucleotide polymorphisms (SNPs) and male infertility in a Chinese population. We conducted a search of PubMed, Embase, Web of Science, Chinese National Knowledge Infrastructure (CNKI), China biology medical literature (CBM), VIP, and Chinese literature (Wan Fang) databases up to May 31, 2016. Odds ratios (ORs) and 95% confidence intervals (95%CIs) were used to assess the strength of associations with a random-effect model or a fixed-effect model based on the heterogeneity analysis results. Sensitivity analysis was used to confirm the reliability and stability of the meta-analysis. A total of nine studies, including 1,713 cases and 1,104 controls, were included in the meta-analysis. The pooled results indicated that the MTHFR C667T polymorphism was significantly associated with increased risk of male infertility in the Chinese population in the allele model (T vs. C: OR = 1.47, 95%CI = 1.32-1.63), the dominant model (TT + CT vs. CC: OR = 1.51, 95%CI = 1.30-1.77), the additive model (TT vs. CC: OR = 2.08, 95%CI = 1.68-2.58) and the recessive model (TT vs. CT+CC: OR = 1.58, 95%CI = 1.31-1.90), whereas the MTHFR A1298C and MS A2756G polymorphisms were not risk factors. There was no significant heterogeneity in any genotype contrasts among the studies. The sensitivity analysis indicated that the results of this meta-analysis were relatively stable. This study suggests that the MTHFR C667T polymorphism may contribute to the genetic susceptibility to male infertility in the Chinese

  16. MTHFR C677T, A1298C and MS A2756G Gene Polymorphisms and Male Infertility Risk in a Chinese Population: A Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Zhengju Ren

    Full Text Available Methylenetetrahydrofolate reductase gene (MTHFR C677T and A1298C and methionine synthase gene (MS A2756G polymorphisms have shown an association with male infertility risk in several ethnic populations. Although several studies have evaluated these associations in Chinese populations, their small sample sizes and inconsistent outcomes have prevented strong conclusions. Therefore, the present meta-analysis was performed with published studies to evaluate the associations of the three single nucleotide polymorphisms (SNPs and male infertility in a Chinese population.We conducted a search of PubMed, Embase, Web of Science, Chinese National Knowledge Infrastructure (CNKI, China biology medical literature (CBM, VIP, and Chinese literature (Wan Fang databases up to May 31, 2016. Odds ratios (ORs and 95% confidence intervals (95%CIs were used to assess the strength of associations with a random-effect model or a fixed-effect model based on the heterogeneity analysis results. Sensitivity analysis was used to confirm the reliability and stability of the meta-analysis.A total of nine studies, including 1,713 cases and 1,104 controls, were included in the meta-analysis. The pooled results indicated that the MTHFR C667T polymorphism was significantly associated with increased risk of male infertility in the Chinese population in the allele model (T vs. C: OR = 1.47, 95%CI = 1.32-1.63, the dominant model (TT + CT vs. CC: OR = 1.51, 95%CI = 1.30-1.77, the additive model (TT vs. CC: OR = 2.08, 95%CI = 1.68-2.58 and the recessive model (TT vs. CT+CC: OR = 1.58, 95%CI = 1.31-1.90, whereas the MTHFR A1298C and MS A2756G polymorphisms were not risk factors. There was no significant heterogeneity in any genotype contrasts among the studies. The sensitivity analysis indicated that the results of this meta-analysis were relatively stable.This study suggests that the MTHFR C667T polymorphism may contribute to the genetic susceptibility to male infertility in the

  17. Risk of venous thromboembolism associated with single and combined effects of Factor V Leiden, Prothrombin 20210A and Methylenetethraydrofolate reductase C677T: a meta-analysis involving over 11,000 cases and 21,000 controls

    Science.gov (United States)

    Simone, B; De Stefano, V; Leoncini, E; Zacho, J; Martinelli, I; Emmerich, J; Rossi, E; Folsom, AR; Almawi, WY; Scarabin, PY; den Heijer, M; Cushman, M; Penco, S; Vaya, A; Angchaisuksiri, P; Okumus, G; Gemmati, D; Cima, S; Akar, N; Oguzulgen, KI; Ducros, V; Lichy, C; Fernandez-Miranda, C; Szczeklik, A; Nieto, JA; Torres, JD; Le Cam-Duchez, V; Ivanov, P; Cantu, C; Shmeleva, VM; Stegnar, M; Ogunyemi, D; Eid, SS; Nicolotti, N; De Feo, E; Ricciardi, W; Boccia, S

    2014-01-01

    BACKGROUND Genetic and environmental factors interact in determining the risk of venous thromboembolism (VTE). The risk associated with the polymorphic variants G1691A of factor V (Factor V Leiden,FVL), G20210A of prothrombin (PT20210A) and C677T of methylentetrahydrofolate reductase (C677T MTHFR) genes has been investigated in many studies. METHODS We performed a pooled analysis of case-control and cohort studies investigating in adults the association between each variant and VTE, published on Pubmed, Embase or Google through January 2010. Authors of eligible papers, were invited to provide all available individual data for the pooling. The Odds Ratio (OR) for first VTE associated with each variant, individually and combined with the others, were calculated with a random effect model, in heterozygotes and homozygotes (dominant model for FVL and PT20210A; recessive for C677T MTHFR). RESULTS We analysed 31 databases, including 11,239 cases and 21,521 controls. No significant association with VTE was found for homozygous C677T MTHFR (OR: 1.38; 95% confidence intervals [CI]: 0.98–1.93), whereas the risk was increased in carriers of either heterozygous FVL or PT20210 (OR=4.22; 95% CI: 3.35–5.32; and OR=2.79;95% CI: 2.25–3.46, respectively), in double hterozygotes (OR=3.42; 95%CI 1.64-7.13), and in homozygous FVL or PT20210A (OR=11.45; 95%CI: 6.79-19.29; and OR: 2.79; 95%CI: 2.25 – 3.46, respectively). The stratified analyses showed a stronger effect of FVL on individuals ≤45 years (p-value for interaction = 0.036) and of PT20210A in women using oral contraceptives (p-value for interaction = 0.045). CONCLUSIONS In this large pooled analysis, inclusive of large studies like MEGA, no effect was found for C677T MTHFR on VTE; FVL and PT20210A were confirmed to be moderate risk factors. Notably, double carriers of the two genetic variants produced an impact on VTE risk significantly increased but weaker than previously thought. PMID:23900608

  18. Determinación del polimorfismo C677T de metilentetrahidrofolato reductasa (MTHFR en una población piloto de estudiantes de la Universidad del Rosario

    Directory of Open Access Journals (Sweden)

    María Martínez-Agüero

    2010-04-01

    Full Text Available Introduction: the 5, 10-methylenetetrahydrofolate reductase (MTHFR is an essential enzyme in folate metabolism; their polymorphisms have been associated with heart disease risk increase, obstetric problems,neural tube defects in fetuses and cancer susceptibility. This genehas a single nucleotide polymorphism, a C-T change at nucleotide 677, which affects significantly its enzymatic activity. Objective: because of the biological importance of this enzyme and the Colombian population genetic heterogeneity characteristic, a study was performed to determine allele and genotype frequencies of MTHFR C677Tpolymorphism in healthy individuals, taking into account that in Colombia there are only studies that have involved casecontrol methodology. Methods: we analyzed this polymorphism trough the amplification of the DNA of a 206 students sample population.Additionally, Colombian overall frequencies were calculated, usingdata from healthy controls reported in other studies. Results: aHardy-Weinberg disequilibrium was found in the sample tested. For theColombian data, we found that the global population was in equilibrium. Conclusion: T allele population frequency seems to beunder positive selection pressure, which is reflected inthe population allele increase, despite its deleterious effect. ASpanish study reported similar results and identified folic acidsupplementation on expectant mothers as a probably cause of thischange.

  19. Genetic polymorphisms in MTHFR (C677T, A1298C), MTR (A2756G) and MTRR (A66G) genes associated with pathological characteristics of prostate cancer in the Ecuadorian population.

    Science.gov (United States)

    López-Cortés, Andrés; Jaramillo-Koupermann, Gabriela; Muñoz, María J; Cabrera, Alejandro; Echeverría, Carolina; Rosales, Felipe; Vivar, Nicolás; Paz-y-Miño, César

    2013-12-01

    The methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTR) and MTR reductase (MTRR) enzymes act in the folate metabolism, which is essential in methylation and synthesis of nucleic acids. The single nucleotide polymorphisms, MTHFR C677T, A1298C, MTR A2756G and MTRR A66G, cause alteration in the homocysteine levels and reduced enzymatic activity that generates deficiency in the assimilation of folates associated with DNA damage; that is, why it is important to know if the single nucleotide polymorphisms are associated with the pathological characteristics and development of prostate cancer, through a case-control retrospective study. DNA was extracted from 110 healthy and 104 affected men. The genotypes were determined by means of the polymerase chain reaction-restriction fragment length polymorphism and confirmed with genomic sequencing. We found significant association between the genotypes of the MTHFR C677T polymorphism: C/T (odds ratio [OR] = 2.2; 95% confidence interval [CI] = 1.3-3.9; P = 0.008) and C/T + T/T (OR = 2.2; 95% CI = 1.3-3.9; P = 0.009) with the risk of prostate cancer development, and a slight association with MTRR A66G. Regarding pathological characteristics, we found significant risk between the C/T + T/T genotypes and the Gleason score (7-10) of poorly differentiated carcinoma (OR = 5.2; 95% CI = 1.7-16.2; P = 0.007). On the other hand, a significant association between A1298C, A66G, and A2756G with the pathological characteristics was not found (P > 0.05). The MTHFR C677T polymorphism has significant effects on susceptibility to prostate cancer in Ecuadorian population, especially with the Gleason grade.

  20. Genética molecular del alcoholismo

    Directory of Open Access Journals (Sweden)

    Mauricio Rey-Buitrago

    2015-07-01

    Full Text Available El alcoholismo es una patología psiquiátrica compleja y de origen multifactorial en la que el factor genético explica alrededor del 50 % del fenómeno. Son numerosos los genes que se han asociado a esta enfermedad, pero su aporte individual es mínimo y contradictorio. Estos genes operan a través de características intermedias como la impulsividad y la sensibilidad al alcohol, lo que hace compleja la definición del fenotipo del alcoholismo. Los estudios de asociación de SNPs, de asociación a todo el genoma, de expresión y epigenéticos han identificado una amplia gama de variantes genéticas y epigenéticas, blancos para los estudios de susceptibilidad, diagnóstico y tratamiento farmacológico. Actualmente se comprenden mucho más estas relaciones y el desarrollo rápido de nuevas metodologías de estudio promete continuar este proceso, así como la generación de algoritmos de diagnóstico, prevención y tratamientos más acertados y confiables.

  1. Aberrant DNA methylation of the P16, MGMT, and hMLH1 genes in combination with the methylenetetrahydrofolate reductase C677T genetic polymorphism and folate intake in gastric cancer.

    Science.gov (United States)

    Lin, J; Zeng, R M; Li, R N; Cao, W H

    2014-03-24

    Epidemiological studies have indicated that folate metabolism is correlated with increased risk of gastric cancer. Since methylenetetrahydrofolate reductase (MTHFR) is an important enzyme involved in folate metabolism, in this study, we examined whether polymorphisms and haplotypes of MTHFR are correlated with the risk of gastric cancer. The polymorphisms MTHFR C677T and MTHFR A1298C were genotyped by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis in 285 patients and 570 healthy controls. Association analyses based on binary logistic regression were conducted to determine the odds ratio (OR) and its 95% confidence interval (95%CI) for each genotype. The MTHFR 677TT genotype was significantly related with a reduced risk of gastric cancer (OR = 0.60, 95%CI = 0.39-0.92) compared to the CC genotype. Similarly, the MTHFR 1298CC genotype was significantly associated with a decreased risk of cancer (OR = 0.52, 95%CI = 0.32- 0.81). Haplotype analysis showed that the TC haplotype was associated with a reduced risk of gastric cancer compared to the most common haplotype, CA (OR = 0.28, 95%CI = 0.12-0.60). Our results suggest that the MTHFR C677T and MTHFR A1298C polymorphisms are related to gastric cancer susceptibility in the Chinese population.

  2. A lower degree of PBMC L1 methylation in women with lower folate status may explain the MTHFR C677T polymorphism associated higher risk of CIN in the US post folic acid fortification era.

    Directory of Open Access Journals (Sweden)

    Suguna Badiga

    Full Text Available Studies in populations unexposed to folic acid (FA fortification have demonstrated that MTHFR C677T polymorphism is associated with increased risk of higher grades of cervical intraepithelial neoplasia (CIN 2+. However, it is unknown whether exposure to higher folate as a result of the FA fortification program has altered the association between MTHFR C677T and risk of CIN, or the mechanisms involved with such alterations. The current study investigated the following in a FA fortified population: 1 The association between MTHFR C677T polymorphism and risk of CIN 2+; 2 The modifying effects of plasma folate concentrations on this association; and 3 The modifying effects of plasma folate on the association between the polymorphism and degree of methylation of long interspersed nucleotide elements (L1s, in peripheral blood mononuclear cell (PBMC DNA, a documented biomarker of CIN risk.The study included 457 US women diagnosed with either CIN 2+ (cases or ≤ CIN 1 (non-cases. Unconditional logistic regression models were used to test the associations after adjusting for relevant risk factors for CIN.The 677CT/TT MTHFR genotypes were not associated with the risk of CIN 2+. Women with CT/TT genotype with lower folate, however, were more likely to be diagnosed with CIN 2+ compared to women with CT/TT genotype with higher folate (OR = 2.41, P = 0.030. Women with CT/TT genotype with lower folate were less likely to have a higher degree of PBMC L1 methylation compared to women with CT/TT genotype with higher folate (OR = 0.28, P = 0.017.This study provides the first evidence that the MTHFR 677CT/TT genotype-associated lower degree of PBMC L1 methylation increases the risk of CIN 2+ in women in the US post-FA fortification era. Thus, even in the post-FA fortification era, not all women have adequate folate status to overcome MTHFR 677CT/TT genotype-associated lower degree of L1 methylation.

  3. Genética del comportamiento: abejas, un ejemplo.

    OpenAIRE

    Nates Parra, Guiomar

    2011-01-01

    El concepto de que el comportamiento de los animales esta determinado genéticamente no es nuevo si se considera que ya Darwin en su famosa obra El origen del hombre, en 1871 mencionaba que… “los rasgos del temperamento de los animales son heredados”. Pero solo hasta hace casi 50 años fue que la genética del comportamiento surgió como una especialidad importante dentro de la Genética; desde esa época muchos son los avances que refuerzan la idea generalmente aceptada de que todos los patrones c...

  4. Evaluation of C677T polymorphism of the methylenetetra hydrofolate reductase gene and its association with levels of serum homocysteine, folate, and vitamin B12 as maternal risk factors for Down syndrome.

    Science.gov (United States)

    Mohanty, Pankaj K; Kapoor, Seema; Dubey, Anand P; Pandey, Sanjeev; Shah, Renuka; Nayak, Hemant K; Polipalli, Sunil K

    2012-09-01

    Evaluation of C677T polymorphisms of the methylenetetra hydrofolate reductase (MTHFR) gene and its association with level of serum homocysteine, folate, and vitamin B12 as possible maternal risk factors for Down syndrome. This was a case-control study. Fifty-two mothers (mean age 27.6 years) with babies having free trisomy 21 of North Indian ethnicity and 52 control nonlactating mothers (mean age 24.9 years) of same ethnicity attending services of genetic lab for bloodletting for other causes were enrolled after informed written consent. Fasting blood was collected and was used for determination of plasma homocysteine, vitamin B12, and folate (serum and RBC), and for PCR amplification of the MTHFR gene. The prevalence of MTHFR C677T polymorphism in north Indian mothers of babies with trisomy 21 Down syndrome was 15.38% compared to 5.88 % in controls. The difference between two groups was not statistically significant (P = 0.124). Low serum folate was demonstrated in 34.62% of cases vs. 11.54% in controls, which was significant (P = 0.005). Low RBC folate was found in 30.7% of cases versus 11.53% in controls, which was not significant (P = 0.059), when analyzed independently. But on multiple regression analysis the difference was statistically significant. Low serum vitamin B12 was found in 42.31% of cases versus 34.62% in controls, which was not significant (P = 0.118). The mean serum homocysteine in cases was 10.35 ± 0.68 while controls were 9.02 ± 0.535. Serum levels of folate were low in cases. The RBC folate levels were comparable in both groups. However the combined serum folate and RBC folate were low in cases compared to control groups. Homocysteine levels in our study were higher in Down syndrome mothers compared to controls; however high-serum level of Homocysteine had no association with MTHFR polymorphism. No association of serum vitamin B12 with MTHFR polymorphism in occurrence of Down syndrome births was found. Peri- or preconceptional folate

  5. MTRR A66G, RFC1 G80A, and MTHFR C677T and A1298C Polymorphisms and Disease Activity in Mexicans with Rheumatoid Arthritis Treated with Methotrexate.

    Science.gov (United States)

    González-Mercado, Mirna Gisel; Rivas, Fernando; Gallegos-Arreola, M Patricia; Morán-Moguel, M Cristina; Salazar-Páramo, Mario; González-López, Laura; Gámez-Nava, J Iván; Muñoz-Valle, J Francisco; Medina-Coss Y León, Ricardo; González-Mercado, Anahí; Aceves, Mario A; Dávalos, Nory O; Macías-Chumacera, Agustín; Dávalos, Ingrid P

    2017-11-01

    To investigate the relationships of polymorphisms in genes whose protein products are related in the metabolic pathway of folic acid, particularly MTRR A66G, RFC1 G80A, and MTHFR C677T and A1298C, and disease activity in Mexican patients with rheumatoid arthritis (RA) treated with methotrexate (MTX). Sixty-eight patients with RA were included in the study who were being treated with MTX, either with or without other drugs. In addition to general data, disease activity was measured by the disease activity score 28 (DAS28). Single nucleotide polymorphisms (SNPs) genotyping was performed by allelic discrimination using real-time polymerase chain reaction. Differences in genotype (homozygotic or heterozygotic for each allele), allele distributions, and phenotype were not statistically different between the RA group and control populations. We did not find any association between the studied polymorphisms and disease activity nor with the intragroup variables (e.g., clinical activity, body mass index, and single- or combined-drug treatment) or between genetic markers; we also did not find any association within the RA group or between the RA group and control populations. Additional studies of more polymorphisms related to this or other metabolic pathways are required to determine the influence of genetics on disease activity in RA.

  6. Low maternal folate concentrations and maternal MTHFR C677T polymorphism are associated with an increased risk for neural tube defects in offspring: a case-control study among Pakistani case and control mothers.

    Science.gov (United States)

    Nauman, Nuzhat; Jalali, Samina; Shami, Sajjad; Rafiq, Shireen; Große, Greta; Hilger, Alina C; Zhang, Rhong; Mansoor, Saira; Ludwig, Michael; Reutter, Heiko

    2018-01-01

    There is considerable evidence that periconceptional maternal folate deficiency and coding variants in maternal genes coding for critical enzymes in the folate pathway are associated with neural tube defects (NTDs) in offspring. In a case-control study we investigated C677T polymorphism in the 5,10- methylenetetrahydrofolate reductase (MTHFR) gene in case and control mothers of Pakistani origin, and compared these with the respective maternal folate concentrations measured at the time of delivery. A case-control study was conducted among 109 case and 100 control mothers identified through the Holy Family Hospital Rawalpindi, Quaid-i-Azam University, Islamabad, Pakistan. Red blood cell (RBC) and serum folate concentrations and MTHFRC677T polymorphism were compared between case and control mothers. Mean RBC folate and serum folate concentrations were significantly lower in cases compared with control mothers (pcases compared with control mothers (CC vs TT pcases compared with control mothers (C vs T pCase mothers with 677CT or 677TT genotypes had significantly lower serum (pstudy provides further evidence that maternal folate deficiency and MTHFRC677T polymorphism might be associated with an increased risk for NTDs in offspring. Our results are limited by the fact that maternal folate concentrations were not obtained during the periconceptional period, but at delivery. Further analyses, including maternal folate levels during the periconceptional period, are warranted.

  7. Association of a common allelic polymorphism (C677T) in the methylene tetrahydrofolate reductase gene with a reduced risk of osteoporotic fractures. A case control study in Danish postmenopausal women

    DEFF Research Database (Denmark)

    Jørgensen, H L; Madsen, J S; Madsen, B

    2002-01-01

    of this study was to investigate the influence of this mutation on peripheral measures of bone density and on the odds ratios (OR) for hip and lower forearm fracture in a case control study of Danish postmenopausal women. A total of 74 women with lower forearm fracture, 41 women with hip fracture, and 207 age...... homozygotic for the C-allele with those homozygotic for the T-allele: lower forearm fracture OR = 3.93 (1.25; 12.40, P = 0.02), hip fracture OR = 6.99 (l.35; 36.92, P = 0.02) and the fractures combined OR = 4.33 (1.73; 10.81, P = 0.002). In this study, the MTHFR (C677T) genotypes were not significantly...... associated with BMD at the lower forearm or with ultrasound parameters measured at the calcaneus. However, a significant increase in the odds ratio of fracture was found for the wild-type C-allele....

  8. Methylenetetrahydrofolate reductase (MTHFR) C677T gene ...

    Indian Academy of Sciences (India)

    Keywords. homocysteine; MTHFR; Mendelian population; gene–environment interaction. Author Affiliations. Huidrom Suraj Singh1 2 Salam Kabita Devi1 3 Kallur Nava Saraswathy1. Molecular Anthropology Laboratory, Department of Anthropology, University of Delhi, New Delhi 110 007, India; Department of Anthropology ...

  9. Methylenetetrahydrofolate reductase (MTHFR) C677T gene ...

    Indian Academy of Sciences (India)

    including cardiovascular diseases, pregnancy complications, neural tube defects, Alzheimer disease, schizophrenia, cancer, etc. Available literatures elucidated that both gene and. Keywords. homocysteine; MTHFR; Mendelian population; gene–environment interaction. Journal of Genetics, Vol. 94, No. 1, March 2015. 121 ...

  10. Methylenetetrahydrofolate Reductase C677T Polymorphism And ...

    African Journals Online (AJOL)

    reduction of 5, 10-methylenetetrahydrofolate to 5- methyltetrahydrofolate. A 677 C/T single nucleotide polymorphism (SNP) localized in the MTHFR gene was associated with both thermo ability and reduced activity of the enzyme and is associated with increased homocysteine levels. The aim of this study was to establish

  11. Methylenetetrahydrofolate reductase (MTHFR) gene C677T, A1298C and G1793A polymorphisms: association with risk for clear cell renal cell carcinoma and tumour behaviour in men.

    Science.gov (United States)

    Safarinejad, M R; Shafiei, N; Safarinejad, S

    2012-05-01

    Methylenetetrahydrofolate reductase (MTHFR) plays a crucial role in regulating folate metabolism, which affects DNA synthesis and methylation. This study investigated whether MTHFR C677T, A1298C and G1793A polymorphisms modified clear cell renal cell carcinoma (CCRCC) risk independently as well as in combination with serum total homocysteine (Hcy) and folate levels. A case-control study of 152 cases (men) and 304 age-matched healthy controls was conducted in one geographical area of Iran. Genotyping of MTHFR gene polymorphisms was carried out using a polymerase chain reaction restriction fragment length polymorphism technique. Serum levels of total Hcy, folate and vitamin B12 were also determined. The MTHFR 677T and 1298C allele frequencies were 42.8 and 47.4% in cases, compared with 33.7 and 33.1% in controls. After controlling for confounding factors, a significant increase in CCRCC risk was found among carriers of the 677CT genotype compared with those with the 677CC genotype (odds ratio 2.21, 95% confidence interval 1.31-3.76), with a significant trend (P=0.014). Statistically significant odds ratios were also found in patients homozygous for MTHFR C677T, who have a 1.58-fold higher risk of developing CCRCC (95% confidence interval=1.21-2.44; P=0.024). Compared with the MTHFR 677CC genotype, the odds ratio (95% confidence interval) for the MTHFR 677TT genotype was 6.18 (95% confidence interval=4.75-8.34) for stage IV cancer and 4.68 (95% confidence interval=2.72-6.54) for grade 3 CCRCC (both P=0.0001). After adjustment for selected variants, the MTHFR 1298AC genotype showed a significantly increased risk of CCRCC compared with the wild-type (odds ratio=3.71, 95% confidence interval=2.22-5.33; P=0.001), and the 1298C allele carrier showed a positive association with the risk of CCRCC compared with the wild-type (odds ratio=3.9, 95% confidence interval=2.55-6.02; P=0.001). Furthermore, subjects carrying at least one copy of the variant allele showed a 4.4 times

  12. Presence of the methylenetetrahydrofolate reductase gene polymorphism MTHFR C677T in molar tissue but not maternal blood predicts failure of methotrexate treatment for low-risk gestational trophoblastic neoplasia.

    Science.gov (United States)

    Qu, Jia; Usui, Hirokazu; Kaku, Hiroshi; Shozu, Makio

    2017-01-05

    Gestational trophoblastic neoplasia (GTN) is a rare tumor, and its genomic constitution is different from the maternal genome because of its gestational origin. Methotrexate (MTX) is a standard chemotherapeutic agent for low-risk GTN. An association between polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene and MTX treatment outcome has been reported in various diseases. Thus, we examined the association between clinical outcome and MTHFR polymorphisms in both tumor and blood DNA of low-risk GTN patients. MTHFR C677T (rs1801133) and A1298C (rs1801131) were genotyped using high-resolution melting assays in 62 Japanese low-risk GTN patients and in 52 antecedent molar tissues. We compared the genotypes of MTHFR polymorphisms with the clinical outcome of 5-day MTX treatment. Twenty-five patients entered remission and 37 patients developed drug resistance or adverse effects that necessitated a drug change. The MTHFR 677T allele in molar tissue was significantly related to the need for drug change (P=0.006; odds ratio [OR], 3.13; 95% confidence interval [CI], 1.31-7.49), in contrast to MTHFR 1298C (P=0.18; OR, 0.63; 95% CI, 0.32-1.25). The MTHFR 677T and 1298C alleles obtained from patients' blood DNA were not related to MTX treatment outcome (P=0.49; OR 1.31; 95% CI, 0.61-2.91 and P=0.10; OR 0.52; 95% CI, 0.22-1.15, respectively). These data demonstrate for the first time that the genotype of MTHFR 677TT in molar tissue is associated with ineffective MTX treatment in Japanese low-risk GTN patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Venöz Tromboz Ön Tanısı Olan Hastalarda Faktör V Leiden, Protrombin G20210A, MTHFR C677T ve MTHFR A1298C Mutasyonlarının Dağılımı

    OpenAIRE

    FİDANCI, Şenay BALCI; YAROĞLU, Hatice YILDIRIM; ÜNAL, Nil; GÜNEŞ, Gülcan; SERT, Gökçen ALICI; SUCU, Nehir; AYAZ, Lokman; GÜMÜŞ, Lülüfer TAMER

    2010-01-01

    AbstractDistribution of Factor V Leiden, Prothrombine G20210A, MTHFR C677T and MTHFR A1298C Mutations in Venous Thrombosis Pre-diagnosed Patients Aim: Thrombotic diseases in the world are regarded as one of the major causes of morbidity and mortality. Various acquired and hereditary factors are implicated in the development of thrombotic diseases. Screening of the mutations related to venous thrombosis with the multifactorial pathogenesis may help for the confirmation of clinical diagnosis...

  14. Relationship between three polymorphisms of methylenetetrahydrofolate reductase (MTHFR C677T, A1298C, and G1793A) gene and risk of prostate cancer: a case-control study.

    Science.gov (United States)

    Safarinejad, Mohammad Reza; Shafiei, Nayyer; Safarinejad, Shiva

    2010-11-01

    We hypothesized that genetic polymorphisms in methylenetetrahydrofolate reductase (MTHFR) gene are associated with prostate cancer risk. We genotyped three MTHFR polymorphisms (C677T, A1298C, and G1793A) and measured serum total homocysteine (tHcy), folate, and vitamin B12 levels in a case-control study of 174 cases and 348 normal healthy controls. The cancer-free controls were frequency matched to the cases by age (±2 years), educational level, occupational status, ethnicity, and smoking status. We found that the MTHFR 677TT and 1298CC genotypes were associated with an about 40% reduction in risk of prostate cancer (adjusted OR = 0.59, 95% CI = 0.41-0.94, and adjusted OR = 0.58, 95% CI = 0.32-0.91, respectively) compared to the 677CC, and 1298AA genotypes. The combined variant genotypes of 1298AC + 677CC were associated with a 30% reduction in risk of prostate cancer (OR = 0.70; 95% CI = 0.53-0.79). In contrast, the variant genotypes of 1793GA + 677CT were associated with slightly increased risk for prostate cancer (OR = 1.64; 95% CI = 0.86-2.15). Regarding prostate cancer aggressiveness, the 677TT genotype was associated with more than 50% decreased risk of high-grade prostate cancer (Gleason score >7) compared with the 677CC and 677CT genotypes (OR = 0.35, 95% CI = 0.24-0.64; P = 0.001). There was no significant difference in plasma levels of tHcy, folate, and vitamin B12 between the two groups with any genotypes. These data suggest that all three MTHFR polymorphisms may play a pivotal role in the developing prostate cancer. Larger studies in different ethnic populations and incorporating dietary folate intake are needed to replicate our findings.

  15. Enfermedades genéticas del ADN mitocondrial humano

    Directory of Open Access Journals (Sweden)

    Solano Abelardo

    2001-01-01

    Full Text Available Las enfermedades mitocondriales son un grupo de trastornos que están producidos por un fallo en el sistema de fosforilación oxidativa (sistema Oxphos, la ruta final del metabolismo energético mitocondrial, con la consiguiente deficiencia en la biosíntesis del trifosfato de adenosina (ATP, por sus siglas en inglés. Parte de los polipéptidos que componen este sistema están codificados en el ácido desoxirribonucleico (DNA mitocondrial y, en los últimos años, se han descrito mutaciones que se han asociado con síndromes clínicos bien definidos. Las características genéticas del DNA mitocondrial, herencia materna, poliplasmia y segregación mitótica, confieren a estas enfermedades propiedades muy particulares. Las manifestaciones clínicas de estas enfermedades son muy heterogéneas y afectan a distintos órganos y tejidos por lo que su correcto diagnóstico implica la obtención de datos clínicos, morfológicos, bioquímicos y genéticos. El texto completo en inglés de este artículo está disponible en: http://www.insp.mx/salud/index.html

  16. Evaluation of GenoFlow Thrombophilia Array Test Kit in Its Detection of Mutations in Factor V Leiden (G1691A), Prothrombin G20210A, MTHFR C677T and A1298C in Blood Samples from 113 Turkish Female Patients

    Science.gov (United States)

    Aytekin, Ebru; Ergun, Sezen Guntekin; Percin, Ferda E.

    2014-01-01

    Thrombophilia is a heritable blood disease characterized by an increased tendency to form abnormal blood clots that can block blood vessels. In obstetrics and gynecology, it has been shown by a number of reports that a proportion of recurrent miscarriages involve thrombophilia-related mutations, in particular, Factor V G1691A, prothrombin G20210A, and MTHFR C677T and A1298C. In this study, we examined the frequency of these four mutations in 113 female Turkish patients who had prior complications in pregnancy, using the DiagCor GenoFlow Thrombophilia Array Test kit. Heterozygous MTHFR C677T and A1298C mutations were detected in 46% of the patients, and among these patients, 60% of them carried double heterozygous mutations. In contrast, the heterozygous Factor V G1691A and prothrombin G20210A were detected only in a smaller number of patients, respectively, 13% and 3%. The GenoFlow kit demonstrated 100% concordance with results from Sanger sequencing, which can be translated into sensitivity and specificity both at 100% within this series of patients. PMID:25153695

  17. Distancias genéticas en poblaciones del NOA

    Directory of Open Access Journals (Sweden)

    Acreche, Noemí

    1996-01-01

    Full Text Available La mayor parte de los trabajos realizados en nuestro país sobre polimorfismos hematológicos, abordan la necesaria descripción de las poblaciones. Se pone de relieve la importancia de encarar estudios, en base a la valiosa información publicada, que vinculen los grupos con técnicas que permitan realizar nuevas inferencias sobre sus relaciones. Conocidas en gran medida en cuanto a sus manifestaciones culturales, pueden aportar desde lo genético a la comprensión de los procesos microevolutivos ocurridos en una región. Para el NOA, se ha considerado la presencia de comunidades aborígenes incluídas en cuatro familias lingüísticas. Se tendrán en cuenta estos complejos como representativos de afinidades que se establecen a partir de estrechas relaciones entre las etnias, no sólo por la lengua, sino también por las características de sus sistemas productivos, religiosidad y organización. En base a las frecuencias génicas publicadas correspondientes a los siguientes alelos: I*A, I*B, I*O; M, N, S, s; Dia , Dib; P1, P2; C, c; D, d, E, e; Le, le; Fya, Fyb; Jka, Jkb; K y k se construyeron tablas de frecuencias. Se estimaron los coeficientes de distancias genéticas que fueron analizados y posteriormente incluídos en la construcción de un fenograma de los grupos de estudio, mediante agrupaciones (Sahn Cluster secuenciales, aglomerativas, jerárquicas y anidadas. De acuerdo a la información recopilada de las frecuencias de los 25 alelos estudiados en trece poblaciones de aborígenes del NOA y Paraguay, las distancias genéticas obtenidas reflejan los caracteres lingüístico-culturales.

  18. Estructura genética poblacional del gen lactoferrina bovino en vacas Holstein del departamento de Antioquia

    Directory of Open Access Journals (Sweden)

    Nancy Rodríguez C.

    2013-03-01

    Full Text Available Objetivo. Estimar algunos parámetros de estructura poblacional en una población Holstein del departamento de Antioquia. Materiales y métodos. El estudio se realizó con 427 vacas de la raza Holstein pertenecientes a 5 municipios del departamento de Antioquia. La genotipificación se llevó a cabo usando la técnica de PCR-PFLPs. La Heterocigocidad observada (Ho y Heterocigocidad esperada (He, la prueba de Hardy-Weinberg (HW y la estructura y diferenciación genética entre las poblaciones se calculó mediante los parámetros F de Wright, evaluados mediante el software GENEPOP. Las frecuencias alélicas y genotípicas se evaluaron con el método descrito por Hartl. Resultados. Las frecuencias genotípicas encontradas fueron 0.61, 0.34 y 0.05 para los genotipos AA, AB y BB respectivamente y las frecuencias de los alelos fueron 0.78 y 0.22 para A y B, encontrándose la población en equilibrio de HW. La heterocigocidad fue media entre poblaciones (Ho=0.368. Los valores FIS, FST y FIT de la población total fueron -0.0717, 0.0099 y -0.0611. Conclusiones. No fue posible asumir endogamia, ni exogamia en los municipios analizados, exceptuando el municipio de San Pedro de los Milagros, en cuyo caso se percibe de manera más fuerte el efecto del mejoramiento genético y la disminución de la heterocigocidad.

  19. Variabilidade genética MTHFR no desenvolvimento da doença arterial coronária MTHFR genetic variability on coronary artery disease development

    Directory of Open Access Journals (Sweden)

    Patrícia Matos Biselli

    2009-01-01

    Full Text Available OBJETIVO: Concentração elevada de homocisteína (Hcy é considerada um fator de risco para doença arterial coronária (DAC. Alterações genéticas da enzima metilenotetrahidrofolato redutase (MTHFR, envolvida no metabolismo da Hcy, podem reduzir sua termolabilidade contribuindo para o desenvolvimento de lesões ateroscleróticas. O objetivo deste estudo foi investigar a relação entre os polimorfismos MTHFR C677T e A1298C e a presença, extensão e gravidade da DAC. MÉTODOS: Foram avaliados 175 pacientes com DAC, confirmada por angiografia e 108 indivíduos sem DAC (grupo controle. O polimorfismo MTHFR C677T foi investigado por reação em cadeia da polimerase (PCR seguida de digestão enzimática. A genotipagem do polimorfismo MTHFR A1298C foi realizada pela técnica de PCR alelo-específica. RESULTADOS: A frequência do alelo alterado MTHFR 677C foi de 0,38 no grupo DAC e 0,37 no grupo controle. Em relação ao alelo polimórfico MTHFR 1298C, a frequência foi de 0,22 e 0,27, respectivamente. As distribuições genotípicas MTHFR C677T e A1298C não diferiram em relação ao número de artérias lesadas (P > 0,05. Também não foi observada relação entre o polimorfismo para MTHFR C677T e grau de obstrução arterial coronária (P > 0,05, assim como MTHFR A1298C (P > 0,05. CONCLUSÃO: Nossos resultados não demonstraram associação entre os polimorfismos MTHFR A1298C e MTHFR C677T e presença, extensão ou gravidade da DAC.OBJECTIVE: Increased homocysteine (Hcy concentration is considered a risk factor for coronary artery disease (CAD. Genetic alterations of the metylenetetrahydrofolate reductase (MTHFR enzyme could reduce its thermolability and alter the Hcy metabolism, contributing to development of atherosclerotic lesions. Objective of this study was to investigate the relation between MTHFR C677T and A1298C polymorphisms and presence, extension, and severity of CAD. METHODS: One hundred seventy-five patients with CAD confirmed by

  20. Muş İlinde Tekrarlayan Gebelik Kayıpları İle Mthfr C677t ve A1298c ve Pai-1 4g/5g Polimorfizmleri Arasındaki İlişki ve Alel rekansları

    OpenAIRE

    BAYRAM, Banu; KILIÇÇI, Çetin; BOZARI, Sedat; ÖNLÜ, Harun; ŞAHİN, Fezan

    2015-01-01

    Amaç: Bu çalışmada plazminojen aktivator inhibitör tip1 geni 4G/5G ile metilentetrahidrofolat redüktaz geni C677T ve A1298C polimorfizmlerinin Muş ilinde tekrarlayan gebelik kayıpları ile arasındaki ilişkinin belirlenmesi ve alel frekanslarının saptanması amaçlanmıştır. Gereç ve Yöntem: Genomik DNA tekrarlayan gebelik kayıpları olan 34 hasta ve 34 sağlıklı kontrolün kan örneklerinden izole edilmiştir. DNA PAI-1 geni 4G/5G polimorfizmi için 4G ve 5G spesifik primerler ile amplifiye edilerek, M...

  1. El dopaje genético, la ética del deporte y la sociedad transhumanista

    OpenAIRE

    Pérez Triviño, José Luis

    2016-01-01

    El aumento genético en el rendimiento deportivo parece inevitable y por lo tanto, es necesario establecer criterios racionales sobre el dopaje genético. Una estrategia para establecer estos parámetros normativos es atender a dos criterios: la extensión de los efectos del tratamiento y el tipo de intervención genética. Habiendo examinado estas posibilidades de modificación genética en relación con el deporte se pueden sugerir algunas conclusiones: 1) Mejora somática Intervenciones: su aplic...

  2. Sobre el origen del código Genético

    OpenAIRE

    Fumiyoshi Watanabe; Michelle Robles; José A. García

    2007-01-01

    Existen ciertas evidencias experimentales que sugieren un mundo primitivo en el que la molécula de ácido ribonucleico (RNA) era la molécula responsable de codificar la información genética y de catalizar un número limitado de reacciones. En este "mundo de RNA" pudo darse el origen del código genético actual. En este manuscrito se presenta una breve discusión sobre las principales teorías que se han propuesto sobre el origen del código genético.

  3. Estructura y diversidad genética en vacas Holstein de Antioquia usando un polimorfismo del gen bGH

    Directory of Open Access Journals (Sweden)

    Juan Rincon F.

    2013-03-01

    Full Text Available Objetivo. Determinar las frecuencias alélicas y genotípicas del polimorfismo del intrón 3 del gen bGH y estimar algunos parámetros de estructura poblacional en ganado Holstein. Materiales y métodos. El estudio se realizó con 1366 vacas Holstein en 120 hatos de 11 municipios del departamento de Antioquia. Se extrajo DNA por el método de Salting out y la genotipificación se realizó usando la técnica de PCR-RFLPs. La diversidad genética se determinó mediante la comparación de las heterocigosidades, El equilibrio de Hardy-Weinberg (HW y la diferenciación genética entre las poblaciones se realizó usando el software Arlequín 2.0 Las frecuencias alélicas y genotípicas se evaluaron mediante el paquete estadístico SAS®. Resultados. Las frecuencias genotípicas encontradas fueron 0.764 (+/+, 0.223 (+/- y 0.013 (-/- y las frecuencias alélicas 0.876 (+ y 0.124 (-. No se encontraron desviaciones del Equilibrio de Hardy Weinberg en ninguna de las subpoblaciones. La diversidad genética determinada mediante la comparación de las heterocigosidades fue relativamente baja entre poblaciones pero al interior de estas no. El valor de FST de toda la población fue de 0.0068 y significativo (p<0.05, algunos FST pareados también lo fueron, tomando valores desde 0.0 a 0.13. Los estadísticos FIT y FIS no fueron significativos. Conclusiones. El gen bGH es un candidato interesante para evaluar características de importancia económica ya que no parece haber sido sometido a selección directa, presenta una variabilidad media en las poblaciones, observándose diferenciación genética significativa entre distintos municipios, producto de los diferentes sistemas de producción y acceso a las biotecnologías.

  4. Aspectos genéticos y neuroendocrinos en el trastorno del espectro autista

    OpenAIRE

    Oviedo, Norma; Manuel-Apolinar, Leticia; De la Chesnaye, Elsa; Guerra-Araiza, Christian

    2015-01-01

    El autismo, hoy en día definido como trastornos del espectro autista, fue descrito inicialmente en 1943. Se caracteriza por alteraciones en la comunicación, la interacción social y un espectro restringido de intereses del paciente. Generalmente se identifica en etapas tempranas del desarrollo a partir de los 18 meses de edad. Actualmente el autismo se considera un desorden neurológico con un espectro que abarca diferentes grados que se asocian con factores genéticos, no genéticos y del medio ...

  5. Divergencia genética en poblaciones peruanas detectada a partir de las frecuencias haplotípicas del mtDNA y del gen nuclear MBL

    Directory of Open Access Journals (Sweden)

    Jesús H. Córdova

    2011-01-01

    Full Text Available Objetivos: Avanzar en el conocimiento del origen de las poblaciones peruanas estudiadas en un contexto filogeográfico. Diseño: Estudio genético poblacional. Instituciones: Laboratorio de Genética Humana, Facultad de Ciencias Biológicas, Universidad Nacional Mayor de San Marcos, e Instituto de Genética y Biología Molecular, Facultad de Medicina, Universidad San Martín de Porras, Lima, Perú. Participantes: Siete poblaciones peruanas. Metodología: Análisis comparativo de los resultados a partir del estudio del mtDNA y el gen nuclear MBL de siete poblaciones peruanas, procesados de manera separada y luego combinados, utilizando el programa PHYLYP 3.65, para obtener valores FST de diferenciación genética y la construcción de árboles de distancias por aplicación del algorritmo UPGMA y el análisis subsecuente de los agrupamientos (clusters generados. Principales medidas de resultados: Árboles genéticos generados. Resultados: De manera separada, los árboles generados para cada marcador genético tuvieron topologías propias y diferentes entre sí. Procesados de manera combinada, el árbol resultante demostró que los mayores valores de diferenciación genética se hallaron en las Islas del Lago Titicaca (Puno, Perú conocidas -Taquile, Amantani y Anapia-, que fue calificada como muy alta, porque mostró valores de FST de 0.3113, 0.2949 y 0.3348 respecto de las poblaciones estudiadas, tanto fuera del Departamento de Puno -como Chachapoyas, Pucallpa y Chiclayo, respectivamente-, así como a la de los Uro del mismo Puno y del mismo Lago Titicaca (0.2837. Fuera de Puno, el par de poblaciones Chachapoyas-Pucallpa fue el menos divergente, al alcanzar entre ellas un valor de FST de 0.0108, calificándosele de pequeña. Conclusiones: El árbol obtenido del procesamiento de los marcadores vía una matriz combinada demostró que las poblaciones que habitan las islas de Taquile, Amantani y Anapia, divergen notablemente de las restantes cuatro

  6. Aspectos genéticos y neuroendocrinos en el trastorno del espectro autista

    Directory of Open Access Journals (Sweden)

    Norma Oviedo

    2015-01-01

    Full Text Available El autismo, hoy en día definido como trastornos del espectro autista, fue descrito inicialmente en 1943. Se caracteriza por alteraciones en la comunicación, la interacción social y un espectro restringido de intereses del paciente. Generalmente se identifica en etapas tempranas del desarrollo a partir de los 18 meses de edad. Actualmente el autismo se considera un desorden neurológico con un espectro que abarca diferentes grados que se asocian con factores genéticos, no genéticos y del medio ambiente. Dentro de los factores genéticos se han referido diversos síndromes relacionados con este trastorno. Asimismo, el autismo se ha estudiado a nivel genético, neurofisiológico, neuroquímico y neuropatológico. Las técnicas de neuroimagen han mostrado múltiples anormalidades estructurales en estos pacientes. También se han observado alteraciones relacionadas en los sistemas serotoninérgico, GABAérgico, catecolaminérgico y colinérgico. En este trabajo se presenta una actualización de la información de los aspectos genéticos y neuroendocrinos del trastorno del espectro autista.

  7. Algoritmos evolutivos inspirados en la teoría del gen egoísta

    OpenAIRE

    Villagra, Andrea; San Pedro, María Eugenia de; Lasso, Marta Graciela; Pandolfi, Daniel

    2004-01-01

    En este trabajo se exploran dos implementaciones computacionales diferentes basadas en la teoría biológica del Gen egoísta propuesta por Richard Dawkins en 1976. Este enfoque computacional fue propuesto inicialmente por Corno et al en problemas de optimización y llamado Algoritmo del Gen Egoísta. Las modificaciones discutidas aquí tienen como objetivo mejorar la velocidad de convergencia del algoritmo introduciendo modificaciones en la estructura de la población virtual de genes y la aplicaci...

  8. Genotipos del Gen Kappa-Caseína en Ganado Bovino Criollo del Distrito de Bambamarca, Cajamarca, Perú

    OpenAIRE

    Almeyda R., Marcos; Sección de Biología y Genética Molecular, Laboratorio de Microbilogía y Parasitología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima; Rosadio A., Raúl; Laboratorio de Microbilogía y Parasitología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima; Maturrano H., Lenin; Laboratorio de Zootecnia y Producción Agropecuaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima

    2016-01-01

    El presente estudio tuvo como objetivo determinar la frecuencia alélica y genotípica del gen kappa-caseína (κ-CN) en ganado bovino criollo. Se recolectaron 48 muestras de sangre de bovinos de nueve centros poblados del distrito de Bambamarca (Cajamarca, Perú). Se extrajo el ADN y la genotipificación se realizó mediante análisis de RFLP-PCR del gen κ-CN. Las frecuencias genotípicas encontradas fueron de 0.56, 0.27 y 0.17 para los genotipos AB, AA y BB, respectivamente, en tanto que las frecuen...

  9. Contraception-related deep venous thrombosis and pulmonary embolism in a 17-Year-old girl heterozygous for factor V leiden, prothrombin G20210A mutation, MTHFR C677T and homozygous for PAI-1 mutation: report of a family with multiple genetic risk factors and review of the literature.

    Science.gov (United States)

    Lenicek Krleza, Jasna; Jakovljevic, Gordana; Bronic, Ana; Coen Herak, Désirée; Bonevski, Aleksandra; Stepan-Giljevic, Jasminka; Roic, Goran

    2010-01-01

    We present the case of a 17-year-old girl who suddenly woke up with localized pain in the left groin and the inability to twist her leg. After comprehensive physician and laboratory examinations, deep venous thrombosis with consequent pulmonary embolism was ascertained. She had not experienced any recent trauma, but she had started to take oral contraceptives 6 months prior to the onset of the symptoms. Her parents and sisters had been asymptomatic throughout their lives, but the family history revealed a few thromboembolic accidents. Using DNA analysis, heterozygosity for factor V Leiden, prothrombin gene mutation G20210A and methylenetetrahydrofolate reductase C677T, as well as the homozygous 4G/4G genotype in the plasminogen activator inhibitor 1 were identified in our patient. Subsequently, DNA analysis was performed in all living family members, and multiple factors associated with thrombophilia were discovered. Our case confirms the multifactorial cause of thromboembolic events and emphasizes the importance of oral contraceptive use in the onset of venous thrombosis, especially in teenage females. In addition, this case indicates that teenage females with a family history of thrombosis who are making choices about contraception could most likely benefit from advanced thrombophilia testing. Copyright © 2010 S. Karger AG, Basel.

  10. Algunas aplicaciones de la estructura booleana del código genético

    OpenAIRE

    Gladys Casas Cardoso; Robersy Sánchez Rodríguez; Deborah Galpert Cañizares; Maria del Carmen Chávez; Ricardo Grau Ábalo; Eberto Morgado Morales

    2011-01-01

    Las estructuras boolenas del código genético constituyen modelos matemáticos minimales y muy simplificados que nos ayudan a comprender mejor la lógica subyacente del código genético. Más específicamente, estas estructuras reflejan una fuerte conexión entre los órdenes del código genético y las propiedades físico-químicas de los aminoácidos. En este artículo presentamos dos aplicaciones de esta estructura algebraica en problemas típicos de Bioinformática. El primer es el de la clasificación de...

  11. Prevalencia de bacterias Gram negativas portadoras del gen blaKPC en hospitales de Colombia

    Directory of Open Access Journals (Sweden)

    Robinson Pacheco

    2014-04-01

    Full Text Available Introducción. Las enzimas carbapenemasas de tipo KPC tienen gran capacidad de diseminación, son causantes de epidemias y se asocian a mayor mortalidad y estancia hospitalaria. En Colombia se han venido reportando cada vez más desde 2007, pero se desconoce la prevalencia hospitalaria. Objetivo. Estimar la prevalencia hospitalaria del gen blaKPC. Materiales y métodos. Se evaluó la presencia del gen blaKPC y su ‘clonalidad’ en aislamientos de enterobacterias y Pseudomonas aeruginosa de pacientes hospitalizados. Resultados. De los 424 aislamientos evaluados durante el periodo de estudio, 273 cumplieron con criterios de elegibilidad, 31,1 % fue positivo para el gen blaKPC y, al ajustar por ‘clonalidad’, la positividad fue de 12,8 %. El gen blaKPC se encontró con mayor frecuencia en Klebsiella pneumoniae seguido de P. aeruginosa y otras enterobacterias. A pesar de que la unidad de cuidados intensivos aportó el mayor número de aislamientos, no se encontró un patrón más prevalente del gen blaKPC en las ellas que en las otras salas. El aparato respiratorio fue el sitio anatómico de origen con la mayor prevalencia. No se presentó estacionalidad en la frecuencia de los aislamientos portadores del gen blaKPC. Conclusión. Este estudio reveló la alta prevalencia del gen blaKPC en diferentes microorganismos aislados en varias instituciones hospitalarias del país. La extraordinaria capacidad de propagación del gen blaKPC, las dificultades del diagnóstico y la limitada disponibilidad de antibióticos plantean la apremiante necesidad de fortalecer los sistemas de vigilancia epidemiológica y ajustar oportunamente las políticas institucionales de uso racional de antibióticos con el fin de contener su diseminación a otras instituciones de salud del país.

  12. Asociación de polimorfismos del gen del receptor de la vitamina D (VDR) con el hiperparatiroidismo

    OpenAIRE

    Suárez Vega, I.; Alía Ramos, Pedro; García Santamarina, S.; Rigo Bonnin, R. F.; Rosel Soria, P.; Villabona Artero, Carlos; Moreno Llorente, Pablo; Navarro Moreno, Miguel Ángel

    2005-01-01

    El hiperparatiroidismo (HPT) se caracteriza por el aumento de la secreción de la paratirina (PTH) y se manifiesta por la descalcificación ósea e hipercalcemia. Aunque se desconocen la mayoría de los procesos implicados en la patogenia de esta lesión, diversos autores han descrito una asociación entre los polimorfismos del gen VDR con la presencia de esta enfermedad. El objetivo de este trabajo es comprobar si los polimorfismos del gen VDR se asocian a la presencia de HPT.

  13. Prevalence of methylenetetrahydrofolate reductase C677T and ...

    African Journals Online (AJOL)

    OR =3.5, 95% CI= 1.1–11.6, p= 0.032 and OR= 2.2, 95% CI =0.7–6.9, p= 0.004 respectively). Additionally, no significant associations between lipid/glucose metabolic indexes with MTHFR genotypes among diabetic patients were observed.

  14. Variabilidad del gen de la envoltura del VIH-1 en tres grupos humanos con diferentes conductas sexuales de riesgo para adquirir ITS-VIH

    OpenAIRE

    Carlos Yábar V; Javier Salvatierra F; Eberth Quijano G

    2007-01-01

    Objetivo: Determinar la variabilidad genética del gen de la envoltura porción C2-V3-C3 (env) del VIH-1 infectando grupos humanos con diferente conducta sexual de riesgo para adquirir ITS-VIH. Materiales y métodos: Se seleccionaron 50 sujetos infectados con VIH-1 de los cuales 19 fueron hombres trabajadores sexuales (HTS), 8 mujeres trabajadoras sexuales (MTS) y 23 sujetos heterosexuales (SH). Se realizó la extracción de ADN genómico y la amplificación del gen env por PCR. Se identificó el sub...

  15. INCORPORACIÓN DEL GEN Mi A VARIEDADES DE TOMATE MEDIANTE EL MARCADOR Aps-1

    OpenAIRE

    Marta Alvarez; Regla M. Lara; Rodríguez, J.; Fernández, R.; Cuartero, J.

    2006-01-01

    Frente a los nematodos del género Meloidogyne es la resistencia genética, junto a métodos de lucha integrada, la opción más recomendada para el tomate, por lo que los cultivares e híbridos modernos portan, en su mayoría, el gen Mi, que confiere resistencia no completa a varias especies del género Meloidogyne. El Instituto Nacional de Ciencias Agrícolas (INCA), con la colaboración de la Estación Experimental La Mayora-CSIC, España, ha desarrollado un programa de mejora genética, con el objetiv...

  16. Un primer acercamiento al aprendizaje del código genético usando redes neuronales

    OpenAIRE

    Weinbach, Natalia L.; Chesñevar, Carlos Iván

    2005-01-01

    La bioinformática constituye un área interdisciplinaria que ha tenido un fuerte desarrollo en los últimos años. Dentro de dicha área, el aprendizaje del código genético a través de modelos computacionales apropiados constituye una problemática de gran importancia. El objetivo de este trabajo es presentar un primer acercamiento al aprendizaje del código genético a través de redes neuronales utilizando la herramienta de software Weka. Dentro del aprendizaje del código genético, el problema c...

  17. Com gens tan semblants generen morfologies tan diverses? El paper clau de la genètica del desenvolupament i la genòmica comparada en la visió darwiniana de l'evolució

    OpenAIRE

    Baguñà Monjo, Jaume

    2009-01-01

    D'ençà que Darwin (i Wallace) van formular la teoria de l'evolució per selecció natural, les relacions entre el desenvolupament embrionari i l'evolució morfològica han estat, llevat d'un breu període inicial, de mútua i absoluta ignorància. D'ençà de la dècada dels setanta, la biologia molecular i, molt especialment, la genètica del desenvolupament, la genòmica comparada i l'evo-devo (evolució i desenvolupament) han capgirat completament el panorama. Els gens controlen el desen...

  18. Caracterización de las mutaciones del gen de la 21-hidroxilasa en familias colombianas

    Directory of Open Access Journals (Sweden)

    Melo G.

    2001-06-01

    Full Text Available La deficiencia de la 21-Hidroxilasa 21(OH es la causa más frecuente de Hiperplasia SuprarenalCongénita. Aproximadamente 75% de los casos son causados por mutaciones puntuales y 25%son debidas a deleciones y grandes conversiones del gen. En el presente estudio se buscó evaluarla deleción del gen y 5 mutaciones puntuales en 19 individuos afectados por la forma clásica dela enfermedad (CL. Por medio de PCR se realizó la amplificación selectiva del gen CYP21 y luegomediante la aplicación de la metodología de ACRS (Amplication Created Restriction Sites seidentificaron las mutaciones. Se observó la deleción del gen en 2 de los alelos estudiados (5.26%.La mutación Q318Stop, que resulta de un cambio de C-T en el codón 318 se encontró en 13alelos (34.21%. La mutación empalme en el Intrón 2 que se produce por el cambio de A-Glo que altera el marco de lectura y produce un codón de parada prematuro, se halló en 10 ale-los (26.32%.

  19. Polimorfismos del gen ob en bovinos de raza holstein en la Comarca Lagunera, México

    Directory of Open Access Journals (Sweden)

    Sarai S. Mendoza-Retana

    2017-01-01

    Full Text Available La Comarca Lagunera es la cuenca lechera más importante de México. En la actualidad se están utilizando diversas técnicas que permiten evaluar genéticamente el animal a una edad temprana, permitiendo seleccionar futuros reproductores con características deseables. Entre los genes relacionados con la producción de leche, se encuentran el gen Ob también llamado gen Leptina el cual actúa sobre el sistema nervioso central y tejidos periféricos jugando un papel muy importante en la modulación regulación del apetito, ganancia de peso vivo, incremento del metabolismo energético y el anabolismo muscular. Este trabajo se realizó para determinar el polimorfismo de longitud del fragmento de restricción ACI I de gen leptina en el exón 2 y correlacionarlo con los parámetros de producción y calidad de leche. Se recolectaron 100 muestra de sangre de vacas en producción del establo “Lácteos Florida” de Francisco I. Madero municipio de Coahuila, México con tres esta tus de producción: altas, medias y bajas La extracción de ADN se realizó por el método modificado de Salting - Out. Se realizó PCR del gen leptina originando un fragmento de 272 bp de longitud y se realizó PCR - RFLP con la enzima de restricción ACI I y secue nciación, correlacionando los genotipos TT, CT Y CC con tres estatus de producción de leche: altas, medias, bajas. El análisis estadístico indicó que las vacas portadoras del genotipo homocigoto (TT tienen un efecto significativo (P<0.01 con respecto a l as características de producción y calidad de leche ya que tuvieron un mayor consumo de alimento, ganancia de peso, además de una elevada producción de leche en comparación a los genotipos heterocigoto (CT y homocigoto (CC. Los resultados obtenidos muest ran que l a identificación molecular de polimorfismos del gen Ob puede usarse como herramienta de selección genética en bovinos de raza Holstein.

  20. Evaluation of Factor V G1691A, prothrombin G20210A, Factor XIII V34L, MTHFR A1298C, MTHFR C677T and PAI-1 4G/5G genotype frequencies of patients subjected to cardiovascular disease (CVD) panel in south-east region of Turkey.

    Science.gov (United States)

    Oztuzcu, Serdar; Ergun, Sercan; Ulaşlı, Mustafa; Nacarkahya, Gülper; Iğci, Yusuf Ziya; Iğci, Mehri; Bayraktar, Recep; Tamer, Ali; Çakmak, Ecir Ali; Arslan, Ahmet

    2014-06-01

    Cardiovascular disease (CVD) risk factors, such as arterial hypertension, obesity, dyslipidemia or diabetes mellitus, as well as CVDs, including myocardial infarction, coronary artery disease or stroke, are the most prevalent diseases and account for the major causes of death worldwide. In the present study, 4,709 unrelated patients subjected to CVD panel in south-east part of Turkey between the years 2010 and 2013 were enrolled and DNA was isolated from the blood samples of these patients. Mutation analyses were conducted using the real-time polymerase chain reaction method to screen six common mutations (Factor V G1691A, PT G20210A, Factor XIII V34L, MTHFR A1298C and C677T and PAI-1 -675 4G/5G) found in CVD panel. The prevalence of these mutations were 0.57, 0.25, 2.61, 13.78, 9.34 and 24.27 % in homozygous form, respectively. Similarly, the mutation percent of them in heterozygous form were 7.43, 3.44, 24.91, 44.94, 41.09 and 45.66%, respectively. No mutation was detected in 92 (1.95%) patients in total. Because of the fact that this is the first study to screen six common mutations in CVD panel in south-east region of Turkey, it has a considerable value on the diagnosis and treatment of these diseases. Upon the results of the present and previous studied a careful examination for these genetic variants should be carried out in thrombophilia screening programs, particularly in Turkish population.

  1. La Dislexia del Desarrollo: Gen, Cerebro y Cognición Developmental Dyslexia: Gen, Brain, and Cognition

    Directory of Open Access Journals (Sweden)

    Alberto M Galaburda

    2006-11-01

    Full Text Available La dislexia del desarrollo es un trastorno que se caracteriza por dificultades en el aprendizaje de la lectura. Recientemente se ha podido vincular la dislexia a cuatro distintos genes candidatos de riesgo: DYX1C1, KIAA0319, DCDC2 y ROBO1. Estos cuatro genes participan en el desarrollo cerebral, y anomalías de dicho desarrollo constituyen los elementos conocidos del cuadro biológico que subyace a la dislexia. En animales experimentales, la inducción de anomalías del desarrollo cerebral similares produce problemas en el procesamiento de ciertos sonidos. En humanos, problemas de procesamiento de sonidos semejantes se asocian a un trastorno de aprendizaje de la lectura. Por consiguiente, es posible por primera vez, trazar una trayectoria tentativa entre una característica genética, variaciones del desarrollo del cerebro, y trastornos conductuales y cognitivos asociados a la dislexia.Developmental dyslexia is a disorder characterized by difficulties in reading acquisition. Recently, dyslexia has been related to four different genes which are prone-risk candidates: DYX1C1, KIAA0319, DCDC2, and ROBO1. These four genes participate in brain development, and anomalies in that development comprise the known elements of the biological constellation underlying dyslexia. The induction of similar brain development anomalies in experimental animals produces problems in the processing of certain sounds. In humans, similar sound processing problems are related to a reading acquisition disorder. Consequently, for the first time it is possible to delineate a tentative path between a genetic characteristic, brain development variations, and behavioral and cognitive disorders related to dyslexia.

  2. Genómica del Trypanosoma cruzi. Nuevas oportunidades para tratar el mal de Chagas

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    Jorge A. Huete-Pérez

    2006-12-01

    Full Text Available LA SECUENCIACIÓN DEL GENOMA HUMANO PUBLICADA EN FEBRERO de 2001 ha sido considerada como el hito científico más importante del siglo XX. La secuenciación, cuatro años más tarde, de tres parásitos tripanosmatidas, entre ellos el Trypanosoma cruzi, podría ser también catalogada como uno de los acontecimientos científicos más importantes para la salud publica del continente americano. Aquí se presenta un panorama general sobre los resultados más significativos del estudio geonómico del T. cruzi, se abordan los trabajos realizados por nuestro laboratorio en la Universidad Centroamericana, finalizando con una discusión sobre las perspectivas del uso de la genómica en Nicaragua.

  3. VARIABILIDAD DEL GEN NUCLEAR G3PDH EN JATROPHA CURCAS L.

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    Sonia Castro Guzmán

    2015-11-01

    Full Text Available Jatrophacurcas L.es una especie nativa de América tropical; en nuestro país se ha venido utilizando principalmente como medicinal y alimenticia desde la época prehispánica. Actualmente el aceite extraído de sus semillas ha adquirido importancia internacional ya que puede ser transformado a biodiesel. El conocimiento que existe sobre la variabilidad genética de la especie es escaso. Un gen utilizado con éxito para el estudio de patrones de variación y origen de la yuca (ManihotesculentaL. y del caco (Theobromacacao L. es el gen nuclearG3pdh(Gliceraldehído3 fosfato deshidrogenasa involucrado en la fotosíntesis. Con base en ello, en este trabajo se exploró la variabilidad del gen G3pdh en individuos deJ. curcasprovenientes de 15 poblaciones de los estados de Veracruz, Campeche, Yucatán y Quintana Roo. Para obtener el gen G3pdh completo de alrededor de 1000 pares de bases, se amplificó utilizando losprimersdiseñados porStrandet al. (1997 y los dosprimersinternos reverse diseñados porOlsenySchaal(1999 para obtener segmentos más cortos, de 600 y 800 pares de bases aproximadamente. Por primera vez se amplificaron aproximadamente 500pby los resultados demuestran que el gen G3pdh es útil para analizar la variabilidad deJ. curcas, y con un importante potencial para evaluar la distribución y evolución de sus poblaciones en México, conocer las relaciones ancestro descendiente a nivel poblacional y explicar las causas de la distribución de los distintoshaplotipos.

  4. CLONACIÓN Y FILOGENIA MOLECULAR DE UN SEGMENTO DEL GEN CODANTE DE LA ACTINA DE MYRCIARIA DUBIA “CAMU-CAMU”: UN CANDIDATO PARA GEN DE REFERENCIA

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    Juan Castro Gómez

    2012-12-01

    Full Text Available Myrciaria dubia “camu-camu” es un frutal amazónico caracterizado por su amplia variación de vitamina C. Pero los estudios genético moleculares que puedan explicar esta variación son limitados. Por ello nuestro objetivo fue realizar la clonación y filogenia molecular de un segmento del gen codante de la actina de M. dubia. Las muestras fueron obtenidas de la colección de germoplasma del INIA. Luego, el ARN fue purificado y mediante RT-PCR con cebadores degenerados se amplificó un segmento del gen. En base a la secuencia obtenida se diseñaron cebadores específicos para PCR en tiempo real. Los resultados muestran que se ha aislado, clonado y secuenciado un segmento del gen codante de actina de M. dubia y detectado su expresión en hojas, pulpa y cáscara de M. dubia. Así, con el soporte de herramientas bioinformáticas y uso de técnicas de biología molecular hemos aislado, clonado y secuenciado un segmento del gen codante de la actina de M. dubia. Asimismo, los análisis realizados muestran que el gen se expresa y presenta niveles similares de expresión en hojas, pulpa y cáscara de M. dubia. Sin embargo, es necesario realizar más experimentos a fin de verificar su estabilidad de expresión.

  5. Análisis genético del virus peruano de la fiebre amarilla

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    Carlos Yábar V

    2002-01-01

    Full Text Available Objetivo: Determinar las variantes genéticas de aislamientos del virus peruano de la Fiebre Amarilla (FA. Materiales y métodos: la región carboxiterminal del gen de la envoltura (E de cinco aislamientos de FA obtenidas de pacientes provenientes de Ayacucho 1978 (PER1, Junín 1995 (PER2, Cerro de Pasco (PER3, Cusco (1998 y San Martín (1999 fue amplificada por PCR, secuenciada y analizada con programas software de ADN. Resultados: el índice de similaridad de la secuencia de nucleótidos entre los cinco aislamientos reveló valores oscilantes entre 94,3% y 99,3%, mientras que la secuencia de aminoácidos presentó valores entre 97,6% y 99,7% de similaridad. El análisis filogenético demostró una distancia genética entre 0,40 y 6,50 mediante la secuencia de nucleótidos y a través de la secuencia de aminoácidos se observó un rango de 0,30 y 4,29. Sin embargo, las secuencias correspondientes a los sitios de glicosilación y a los epítopes de reconocimiento humoral fueron conservadas entre los cinco aislamientos, con excepción de algunos aislamientos de referencia reportados por otros autores. Conclusiones: los virus de FA peruanos forman un grupo filogenético distinto a otros virus de FA sudamericanos, basados en el análisis genéticos del gen E.

  6. FILOGENIA DE ESPECIES DEL SUBGENERO Parides (LEPIDOPTERA: PAPILIONIDAE BASADA EN SECUENCIAS DEL GEN CITOCROMO OXIDASA I

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    INGRID MARCELA GUTIÉRREZ R.

    2012-01-01

    Full Text Available Parides Hübner es el taxón terminal de Troidini, un grupo de mariposas aposemáticas diversificado en el trópico y subtrópico, y modelos de varios complejos miméticos bate- sianos y mullerianos. Varias de las especies americanas de Parides son simpátricas e involucran poblaciones con variaciones intraespecíficas en los patrones de coloración, lo que genera confusiones en la definición del estatus taxonómico, especialmente en Colombia, punto de convergencia de las biotas de Norte y Suramérica. Este trabajo genera una aproximación a la filogenia de este grupo de mariposas y establece una definición más robusta de algunos de los taxones. Para ello se analizaron ejemplares pertenecientes a 15 taxones del subgénero americano Parides (Parides como grupo interno y se utilizó como grupo externo especies de otros dos géneros estrechamente relacionados de Troidini. Para la extracción del ADN se utilizó el protocolo de Pascual et al. (1997 y DNeasy Kit. Se amplificó el fragmento final del gen Citocromo Oxidasa I (COI de 476 pb. Para obtener una hipótesis filogenética se realizaron análisis de máxima parsimonia y se evaluó el soporte de cada nodo mediante Jackknife y soporte absoluto de Bremer. También se realizó un análisis bayesiano. La hipótesis resultante sugiere que el subgénero Parides es un grupo parafilético. Molecularmente se hicieron también válidas una especie y cinco subespecies. Los ejemplares analizados de Parides se dividieron en tres grupos principales coincidentes con los grupos Lysander (grupo 1 y Aeneas (grupos 2 y 3 de Rothschild y Jordan (1906.

  7. FILOGENIA DE ESPECIES DEL SUBGENERO Parides (LEPIDOPTERA: PAPILIONIDAE BASADA EN SECUENCIAS DEL GEN CITOCROMO OXIDASA I

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    GIOVANNY FAGUA

    2012-09-01

    Full Text Available El género Parides Hübner es el taxón terminal de Troidini, un grupo de mariposas aposematicas diversificado en el trópico y subtrópico, modelos de varios complejos miméticos batesianos y mullerianos. Varias de las especies americanas de Parides son simpátricas e involucran poblaciones con variaciones intraespecíficas de los patrones de coloración, lo que genera confusiones en la definición del estatus taxonómico, especialmente en Colombia, punto de convergencia de las biotas de Norte y Suramérica. Este trabajo genera una aproximación a la filogenia de este grupo de mariposas y establece una definición más robusta de algunos de los taxones. Para ello se analizaron ejemplares pertenecientes a 15 taxones del subgénero americano como grupo interno y se utilizó como grupo externo especies de otros dos géneros estrechamente relacionados de Troidini. Para la extracción del ADN se utilizó el protocolo de Pascual et al. (1997 y DNeasy Kit. Se amplificó el fragmento final del gen Citocromo Oxidasa I (COI  de 476 pb mediante PCR. Para obtener una hipótesis filogenética se realizaron análisis de Máxima Parsimonia (TNT y se evaluó el soporte de cada nodo mediante Jackknife y soporte absoluto de Bremer. También se realizó un análisis Bayesiano. La hipótesis resultante plantea al subgénero Parides como un grupo parafilético, a nivel molecular se hicieron válidas una especie y cinco subespecies. Los ejemplares analizados de Parides se dividieron en tres grupos principales coincidentes con los grupos Lysander (grupo 1 y Aeneas (grupos 2 y 3 de Rothschild y Jordan (1906.

  8. ESTUDIO PRELIMINAR DE LOS POLIMORFISMOS DEL GEN GRIN-1 DEL RECEPTOR NMDA EN UNA POBLACIÓN SANA COLOMBIANA

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    V. Villegas

    2006-06-01

    Full Text Available Se ha encontrado que el gen GRIN-1 juega un papel fundamental en muchas funciones cerebrales y se le ha asociado con numerosas enfermedades razón por la cual ha despertado un gran interés científico el conocimiento del polimorfismo de este gen entre la población normal y enferma. Hasta el momento no han sido identificados polimorfismos que lleven a un cambio de aminoácido en la proteína y los estudios poblacionales hechos hasta la fecha sólo incluyen caucásicos, africanos americanos y asiáticos. En este trabajo se estudiaron los polimorfismos genéticos del gen GRIN-1 ubicados en la región 5’-UTR y en los exones 3, 6 y 16. Se encontró que la población estudiada se diferencia significativamente de caucásicos y no difiere significativamente de otros grupos étnicos.

  9. Medicina Genómica Aspectos éticos, legales y sociales del Genoma Humano

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    Rodolfo E. Ávila

    2011-01-01

    Full Text Available La Medicina Genómica es el uso de la inf ormación de los genomas y sus deriv ados (ARN, proteínas y met abolitos que permite guiar la toma de decisiones médicas, es un c omponente clave de la medicina personalizada. La Medicina Genómica permite conocer la cartografía del genoma hum ano y proporciona una valiosa información a tener en cuenta a la hora de detect ar genes implicados en ciert as enfermedades. Esto conlleva a que en la actualidad nos centremos más en la predicción de patologías que en l a prevención, por lo que la tendencia es que en el futuro la Medicina Genómica acabe desbancando a la Medicina P reventiva. El Proyecto Genoma Humano presenta diversas aplicaciones que, al no tener una clara cobert ura legal, traen consigo un nuevo paradigma con problemas éticos, sociales y legales que la comunidad científica trat a de resolver para compaginar los aspectos morales con el progreso en la investigación. El objetivo del presente trabajo es describir brevemente los aspectos éticos, legales y sociales del Genoma Humano.

  10. Bases genéticas y moleculares del síndrome de Brugada mediado por canales de sodio

    OpenAIRE

    Barajas-Martínez,Héctor; Hu, Dan; Antzelevitch, Charles

    2013-01-01

    El síndrome de Brugada es una enfermedad hereditaria caracterizada por una anormalidad electrocardiográfica y un aumento del riesgo de muerte súbita cardiaca. El síndrome de Brugada puede ser causado por la presencia de mutaciones en el gen SCN5A en aproximadamente el 20% de los casos familiares. El gen SCN5A codifica la subunidad a del canal iónico de sodio en las células cardiacas. Estudios realizados durante la última década en genética molecular han permitido identificar 11 nuevos genes c...

  11. Polimorfismos del gen BoLA-DRB3.2* en ganado criollo colombiano

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    Darwin Hernández H.

    2013-10-01

    Full Text Available Objetivo. Caracterizar el polimorfismo del gen BoLA-DRB3.2* en las razas bovinas criollas y colombianas. Materiales y métodos. En 360 muestras de ADN de ocho razas bovinas criollas (Blanco Orejinegro, Casanareño, Costeño con Cuernos, Chino Santandereano, Caqueteño, Hartón del Valle, Romosinuano y San Martinero, dos razas sintéticas Colombianas (Lucerna y Velásquez y dos razas foráneas (Brahman y Holstein se evaluó el polimorfismo del gen BoLA-DRB3.2 mediante técnicas moleculares (PCR-RFLP; se calculó el número promedio de alelos (NPA, las frecuencias, la heterocigocidad esperada (He y observada (Ho, el equilibrio de Hardy-Weinberg, la estructura genética y los valores de FST y FIS. Resultados. El NPA fue 14.6 ± 3.8 siendo Caqueteño la raza con mayor NPA (25 y el menor el Chino Santandereano (10. Se encontraron 41 alelos BoLA-DRB3.2* los más frecuentes fueron *28, *37, *24, *23, *20, *27, *8, *16, *39 (0.17, 0.11, 0.10, 0.09, 0.09, 0.07, 0.07 y 0.06 respectivamente. Se encontró alta diversidad genética (He = 0.878 con mayor valor en Caqueteño (0.96 y menor en San Martinero (0.81. Todas las razas se encontraron en equilibrio de Hardy-Weinberg, se encontraron valores altamente significativos de diferenciación genética (FST= 0.044 y de coeficiente de endogamia (FIS = 0.249. Conclusiones. El ganado criollo colombiano posee alto polimorfismo del gen BoLA-DRB3.2* representado en los altos valores de NPA y diversidad génetica.

  12. Del lector en Borges: de cruces genéricos e intertextuales

    OpenAIRE

    Centenera Tapia, Gerardo

    2013-01-01

    Resumen: Exposición de las propuestas teóricas de Borges sobre el género literario. Se plantea la pertinencia de aplicarlas en el análisis de su propia obra. Se discute su validez como herramienta crítica, su influencia en la crítica ulterior y su relación con el conjunto del pensamiento del autor.  Palabras clave: Borges, género, recepción, hibridez genérica, crítica creativa  Abstract: Relation of Borges’ theoretical ideas about literary genre. We comtemplate the suitability of applying the...

  13. Historia del nombre genérico Escallonia mutis ex L. Fil. Historia del nombre genérico Escallonia mutis ex L. Fil.

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    Fernández Alonso J. L.

    1991-06-01

    Full Text Available According with the historical context of the Real Expedición Botánica del Nuevo Reino de Granada (1783-1816, the nomenclatural history of the generic name Escallonia Mutis ex L. fiI. (Grossulariaceae is discussed. The extant misinterpretation concerning the name in the manuscript documentation of the Expedition, is brigthened; four species of diferent  families appear associated to this name in the manuscripts. Type specimens of two species, Escallonia myrtilloides L. fiI. and Dichondra evolvulacea (L. fiI. Britton are located or selected. Dentro del contexto histórico de la Real Expedición Botánica del Nuevo Reino de Granada (1783-1816, se realiza el seguimiento del nombre genérico Escallonia Mutis ex L. fiI. (Grossulariaceae. Se aclara la confusión existente acerca de este nombre en la documentación manuscrita de la Expedición (Archivos de Mutis y Linneo, donde se encuentra asociado a descripciones originales de cuatro especies de diferentes familias. Se localiza y selecciona material tipo de dos de ellas: Escallonia myrtilloides L. fil. Y Dichondra evolvulacea (L. IiI. Britton.

  14. Fenomenología del pago. Elementos para una fenomenología genética del dinero.

    OpenAIRE

    González Guardiola, Joan

    2013-01-01

    [spa] El objetivo del presente trabajo consiste en sentar las bases para una fenomenología del dinero. Pero hacer una fenomenología del dinero es hacer una fenomenología de sus funciones, dado que el dinero es aquello que el dinero hace. Aquí presentamos los fundamentos para una fenomenología de la función monetaria de medio de pago, poniendo especial énfasis en la descripción genética de los pagos a través de una fenomenología del préstamo. [eng] The aim of this paper is to lay the groundwor...

  15. Influencia del Polimorfismo SST-I del gen de la Apolipoproteína C-III sobre el metabolismo lipoprotéico en pacientes hipertensos enseciales

    OpenAIRE

    Barrios Artillo, Manuel

    2006-01-01

    Basándose en lo expuesto, los objetivos del estudio son: 1. Calcular la frecuencia del polimorfismo Sst-I del gen de la apo C-III en un grupo de pacientes hipertensos esenciales. 2. Determinar los niveles plasmáticos de lípidos en estos pacientes según el genotipo Sst-I del gen de la apo C-III. 3. Evaluar la posible asociación entre el alelo raro S2 y un perfil m ás aterogénico entre los pacientes hipertensos esenciales. 4. Determinar la influencia de este polimorfismo sobre el metabolismo hi...

  16. Una revisión de la genética del autismo.

    OpenAIRE

    Alison Mcinnes

    2002-01-01

    El autismo es un severo trastorno del desarrollo neuropsicológico, caracterizado por una alteración de la comunicación y de la interacción social, y por restringidas, repetitivas y obsesivas pautas de conducta. Afecta más a hombres que a mujeres y, con frecuencia, existe un bajo cociente intelectual. Recientes estimaciones de su prevalencia en California muestran un creciente aumento. Se piensa en posibles causas genéticas y ambientales con un carácter fuertemente hereditario. Existen progres...

  17. Influencia del polimorfismo genético inserción/deleción del gen del enzima convertidor de la Angiotensina (ACE) sobre variables antropométricas y somatotipos en jugadores de balonmano

    OpenAIRE

    Cembranos Bruzón, Rebeca

    2011-01-01

    Numerosos estudios previos realizados en deportistas de diversas disciplinas deportivas (tanto a nivel profesional como amateur) evidencian una posible relación entre el rendimiento deportivo y la presencia o ausencia del polimorfismo inserción/deleción del gen de la Enzima Convertidora de la Angiotensina I (ACE). Dichos trabajos han puesto de manifiesto la relación existente entre el alelo I (inserción) de dicho polimorfismo y el rendimiento en actividades físicas de resistencia; mientras qu...

  18. Variabilidad del gen de la envoltura del VIH-1 en tres grupos humanos con diferentes conductas sexuales de riesgo para adquirir ITS-VIH

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    Carlos Yábar V

    2007-07-01

    Full Text Available Objetivo: Determinar la variabilidad genética del gen de la envoltura porción C2-V3-C3 (env del VIH-1 infectando grupos humanos con diferente conducta sexual de riesgo para adquirir ITS-VIH. Materiales y métodos: Se seleccionaron 50 sujetos infectados con VIH-1 de los cuales 19 fueron hombres trabajadores sexuales (HTS, 8 mujeres trabajadoras sexuales (MTS y 23 sujetos heterosexuales (SH. Se realizó la extracción de ADN genómico y la amplificación del gen env por PCR. Se identificó el subtipo genético por ensayo de movilidad de heterodúplex (HMA y se confirmaron los resultados por análisis filogenético. Asimismo, se realizó el análisis de recombinación intragenética, diversidad y distancia genética en las tres poblaciones. Resultados: Se amplificó el gen env en 49 muestras (98% y se logró secuenciar el fragmento en 40 de ellas. Se observó que el 97,5% de las muestras de VIH fueron subtipo B mientras que una muestra no pudo ser clasificada filogenéticamente. Asimismo, se encontraron pequeños tramos de recombinación en el gen env de VIH en MTS (33%, HTS (43% y SH (45%. El mayor índice de diversidad de nucleótidos (Pi de env se encontró entre las muestras de VIH provenientes de SH y HTS (0,12 y 0,13 respectivamente. Conclusiones: Se encontró una mayor variabilidad genética del gen env de VIH-1 en las poblaciones de HTS y SH, sin embargo, el subtipo genético y la frecuencia de recombinación de este fragmento genético fue similar en los tres grupos estudiados.

  19. Polimorfismo del gen de la banda 3 eritrocítica en grupos étnicos de Costa Rica

    OpenAIRE

    Chaves-Villalobos, M; Jiménez-Arce, G.; Sandí-Díaz, M

    2014-01-01

    Banda 3 (AE1) es una de las proteínas más abundantes de la membrana del eritrocito humano. Ésta funciona como un intercambiador aniónico cloruro / bicarbonato y es el punto de anclaje de varias proteínas del citoesqueleto del eritrocito. Se han descrito varias mutaciones y muchas variantes polimórficas se han asociado a esferocitosis hereditaria. La identificación de un marcador genético en el extremo 5’ del gene AE1 podría asociarse a varios defectos moleculares del eritrocito. Este marcador...

  20. Polimorfismo del gen de la banda 3 eritrocítica en grupos étnicos de Costa Rica

    OpenAIRE

    M Chaves-Villalobos; G Jiménez-Arce; M Sandí-Díaz

    2004-01-01

    Banda 3 (AE1) es una de las proteínas más abundantes de la membrana del eritrocito humano. Ésta funciona como un intercambiador aniónico cloruro / bicarbonato y es el punto de anclaje de varias proteínas del citoesqueleto del eritrocito. Se han descrito varias mutaciones y muchas variantes polimórficas se han asociado a esferocitosis hereditaria. La identificación de un marcador genético en el extremo 5’ del gene AE1 podría asociarse a varios defectos moleculares del eritrocito. Este marcador...

  1. Genética aplicada a la práctica clínica en trastornos del neurodesarrollo

    OpenAIRE

    Fernández-Jaén, Alberto; Cigudosa, Juan C.; Martín Fernández-Mayoralas, Daniel; Suela, Javier; Fernández-Perrone, Ana L.; Calleja-Pérez, Beatriz; López Martín, Sara

    2014-01-01

    Las evidencias genéticas de los trastornos del neurodesarrollo están ampliamente sustentadas en la literatura médica. Los avances en la genética y la tecnología han incrementado la rentabilidad diagnóstica de los estudios actuales de un 3-5% a un 30-40% en los pacientes con discapacidad intelectual o trastornos del espectro autista. En este sentido, los estudios por microarrays cromosómicos muestran un mayor poder diagnóstico que las técnicas convencionales (cariotipo, análisis de...

  2. NCG61/25: Plan de Estudios de M??ster en Condicionantes Gen??ticos, Nutricionales y Ambientales del Crecimiento y Desarrollo

    OpenAIRE

    Universidad de Granada

    2012-01-01

    Plan de Estudios de M??ster en Condicionantes Gen??ticos, Nutricionales y Ambientales del Crecimiento y Desarrollo. Resoluci??n de 5 de marzo de 2012, de la Universidad de Granada, por la que se publica el plan de estudios de M??ster en Condicionantes Gen??ticos, Nutricionales y Ambientales del Crecimiento y Desarrollo

  3. Obtención del Valor Genético Predicho en Animales Incluyendo el Efecto del Medio Ambiente Permanente Obtención del Valor Genético Predicho en Animales Incluyendo el Efecto del Medio Ambiente Permanente

    Directory of Open Access Journals (Sweden)

    Mauricio Valencia Posadas

    2012-02-01

    Full Text Available The genetic improvement of the animals based in productive records and genealogical information, is a fundamental mechanism to increase the economic income of the commercial farms, through the estimation of the predicted breeding values (VGP’s. The VGP’s allows the identification of animals genetically superior to be used as parents of the next generation. In many parts of the world the best linear unbiased predictor procedure (MPLI is used as an animal model, for its appropriate properties, to obtain the VGP’s. In these models the permanent environment effect is usually included in order to increase the accuracy of the VGP’s. In this work a developed example is presented using supposed data to obtain VGP’s with the MPLI procedure and an animal model where the methodology, interpretation and use of the VGP’s are shown.El mejoramiento genético de los animales, con base en los registros de rendimiento e información genealógica, es un mecanismo fundamental para incrementar los rendimientos económicos de las explotaciones comerciales, a partir de la estimación de valores genéticos predichos (VGP’s. Los VGP permiten identificar a los animales genéticamente superiores de una forma objetiva, para que sean utilizados como padres de la siguiente generación. En muchas partes del mundo se utiliza el procedimiento del mejor predictor lineal insesgado (MPLI con un modelo animal por sus adecuadas propiedades para obtenerlos VGP’s. En dichos modelos se suele incluir el efecto del medio ambiente permanente con el objeto de incrementar la precisión de los VGP’s. En este trabajos e presenta un ejemplo desarrollado utilizando datos supuestos para obtener VGP’s con el procedimiento MPLI y un modelo animal, donde se muestra la metodología, interpretación y uso que tienen los VGP’s.

  4. Historia y genética del poblamiento de Marinilla y su zona de influencia (MZI

    Directory of Open Access Journals (Sweden)

    Andrés Ruiz

    2001-04-01

    Full Text Available

    Diferentes estudios sugieren que ciertas regiones de Antioquia han estado aisladas geográficamente, desde su fundación en la colonia, hasta principios del siglo XX. La información existente sobre MZI, uno de los núcleos principales de poblamiento en Antioquia, es incipiente e incluso anecdótica. A pesar de que se cuenta con varios
    estudios históricos, de isonimia y prevalencia de algunos rasgos recesivos, aún no se comprende a cabalidad cómo se originó este grupo poblacional, ni su relación histórico-genética con el núcleo mayor de Santafé.

     

     

  5. Diferenciación genética de tres poblaciones colombianas de Triatoma dimidiata (Latreille, 1811 mediante análisis molecular del gen mitocondrial ND4

    Directory of Open Access Journals (Sweden)

    Nelson Grisales

    2010-08-01

    Conclusión. Este trabajo demostró diferenciación genética entre las poblaciones de T. dimidiata de La Guajira, Cesar y Santander. Se sugiere una posible relación entre tal subdivisión y algunas características eco-epidemiológicas que posee T. dimidiata en el centro-oriente y en el norte de Colombia. Finalmente, este trabajo describe, por primera vez, la utilidad del ND4 como un marcador molecular para el estudio de poblaciones naturales de T. dimidiata.

  6. Diversidad genética del jengibre (Zingiber officinale Roscoe. A nivel molecular: Avances de la última década

    Directory of Open Access Journals (Sweden)

    Eleonora Zambrano-Blanco

    2015-01-01

    Full Text Available El jengibre ( Zingiber officinale es una especie medicinal, aromática y condimentaria que se cultiva principalmente en regiones tropicales y subtropicales del mundo. Por tratarse de una especie de propagación vegetativa, su variabilidad genética tiende a ser baja; sin embargo es posible hallar una amplia variabilidad genética principalmente en la China e India, considerándose actualmente como el principal centro de origen y diversidad de esta especie. Conocer y caracterizar la diversidad genética del jengibre es una tarea de vital importancia para fomentar programas de conservación ex situ o in vitro que ayuden a evitar la erosión genética de esta especie, así como para direccionar correctamente estrategias de mejoramiento genético. Marcadores moleculares han sido ampliamente usados en los últimos años con la finalidad de estudiar la variabilidad genética del jengibre, directamente a nivel del ADN. En este artículo, los avances en la investigación en diversidad genética del jengibre, usando marcadores moleculares, son revisados. Esto con la finalidad de hacer un análisis sobre sus impli - caciones para la conservación y el mejoramiento genético de la especie.

  7. Variabilidad genética del Aedes aegypti determinada mediante el análisis del gen mitocondrial Nd4 en once áreas endémicas para dengue en el Perú

    Directory of Open Access Journals (Sweden)

    Pamela Yáñez

    2013-06-01

    Full Text Available Con el objetivo de establecer la variabilidad genética de Aedes aegypti determinada por el análisis del gen mitocondrial ND4, se analizaron 51 especímenes de Ae. aegypti en once regiones endémicas para dengue en el Perú. La variabilidad genética se determinó mediante la amplificación y secuenciación de un fragmento de 336 pares de bases del gen mitocondrial ND4. El análisis de filogenia intraespecífica se realizó con el programa Network Ver. 4.6.10; y el análisis filogenético, con el método de distancia Neighbor Joining. Se identificó la presencia de cinco haplotipos de Ae. aegypti agrupados en dos linajes: el primero agrupa a los haplotipos 1, 3 y 5 y el segundo agrupa los haplotipos 2 y 4, se muestra además la distribución geográfica de cada uno de los haplotipos encontrados. Se concluye que esta variabilidad se debe tanto a la migración activa de este vector como a la migración pasiva mediada por la actividad humana.

  8. Enfermedades genéticas del ADN mitocondrial humano Genetic diseases of the mitochondrial DNA

    Directory of Open Access Journals (Sweden)

    Abelardo Solano

    2001-04-01

    Full Text Available Las enfermedades mitocondriales son un grupo de trastornos que están producidos por un fallo en el sistema de fosforilación oxidativa (sistema Oxphos, la ruta final del metabolismo energético mitocondrial, con la consiguiente deficiencia en la biosíntesis del trifosfato de adenosina (ATP, por sus siglas en inglés. Parte de los polipéptidos que componen este sistema están codificados en el ácido desoxirribonucleico (DNA mitocondrial y, en los últimos años, se han descrito mutaciones que se han asociado con síndromes clínicos bien definidos. Las características genéticas del DNA mitocondrial, herencia materna, poliplasmia y segregación mitótica, confieren a estas enfermedades propiedades muy particulares. Las manifestaciones clínicas de estas enfermedades son muy heterogéneas y afectan a distintos órganos y tejidos por lo que su correcto diagnóstico implica la obtención de datos clínicos, morfológicos, bioquímicos y genéticos. El texto completo en inglés de este artículo está disponible en: http://www.insp.mx/salud/index.htmlMitochondrial diseases are a group of disorders produced by defects in the oxidative phosphorylation system (Oxphos system, the final pathway of the mitochondrial energetic metabolism, resulting in a deficiency of the biosynthesis of ATP. Part of the polypeptide subunits involved in the Oxphos system are codified by the mitochondrial DNA. In the last years, mutations in this genetic system have been described and associated to well defined clinical syndromes. The clinical features of these disorders are very heterogeneous affecting, in most cases, to different organs and tissues and their correct diagnosis require precise clinical, morphological, biochemical and genetic data. The peculiar genetic characteristics of the mitochondrial DNA (maternal inheritance, polyplasmia and mitotic segregation give to these disorders very distinctive properties. The English version of this paper is available at

  9. FRECUENCIAS ALELICAS Y GENOTIPICAS DEL GEN KAPPA CASEINA EN BOVINOS DE DOBLE PROPOSITO

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    Nohémi Gabriela Cortes López

    2012-01-01

    Full Text Available En este trabajo, las frecuencias alélicas (A y B del gen CAS se determinaron como criterio de selección en la calidad de la leche en el ganado bovino de doble propósito. Se tomaron muestras sanguíneas de 200 hembras bovinas y se colocaron en tubos que contenían EDTA. Se amplifico el marcador MB002 a partir de material genético extraído. Los RFLP se realizaron con la enzima de restricción Hinf I para el diagnóstico de los alelos A y B en CASκ. Las frecuencias genotípicas obtenidas correspondían a 0.34, 0.01 y 0.65 para los alelos AA, BB y AB, respectivamente. Las frecuencias alélicas fueron de 0.67 y 0.33 para los alelos A y B, respectivamente. Además, se registró una heterocigosidad promedio de 0.6481. La población es estudio no se encuentra en equilibrio Hardy Weinberg, el valor ji cuadrada fue de 2 = 14.8 con 2 grados de libertad (P < 0.005. Basado en la frecuencia alélica de CAS  B (0.34 observada en este estudio, el ganado de doble propósito puede ser una opción viable para aumentar la calidad de la leche si se utilizan sementales con el genotipo BB para el cruce. De esta manera, los alelos B asociados a la calidad de la leche pueden mejorarse en pocas generaciones.

  10. Estudio de bioequivalencia del ibuprofeno genérico 400mg tabletas

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    Ofelia Villalva-Rojas

    2007-10-01

    Full Text Available Objetivo. Determinar la biodisponibilidad de dos formulaciones de ibuprofeno 400mg tabletas, para establecer si el medicamento multifuente (genérico es bioequivalente al de referencia (Motrin® 400mg. Materiales y métodos. Se diseñó un estudio abierto, randomizado, cruzado, dos periodos, con siete días de lavado, con 12 voluntarios sanos de ambos sexos, entre 21 y 48 años, quienes ingirieron una tableta del medicamento genérico o de referencia, según randomización, con 200mL de agua. Luego de ingerir el medicamento se colectó 4mL de sangre por voluntario para la cuantificación plasmática de ibuprofeno. Las muestras de plasma se analizaron por cromatografía líquida acoplada al espectrofotómetro de masas (LC-MS/MS con ionización electrospray ión negativo, aplicando monitoreo de reacción selectiva. La bioequivalencia se determinó con los parámetros farmacocinéticos de área bajo la curva AUC(0-t, AUC(0-∞ y concentración máxima (Cmax. Resultados. Según análisis estadístico, se encontraron: AUCmultifuente(0-t = 86,85 (μg*h/ mL, AUCRef.(0-t= 81,20 (μg*h/mL, AUCmultifuente(0-∞= 88,67 (μg*h/mL, AUCRef.(0-∞= 82,83(μg*h/mL, Cmαxmultifuente = 17,70 ug/mL, CmαxRef. =18,09 μg/mL, con rango de 0,93-1,24 para AUC(0-t, 0,93-1,24 para AUC(0-∞ y 0,81-1,19 para Cmax. Conclusión. Los valores encontrados de ibuprofeno están dentro de los requisitos de la OMS y la FDA, para establecer bioequivalencia (0,80-1,25, demostrándose que el ibuprofeno genérico es bioequivalente al de referencia en velocidad y cantidad de ibuprofeno absorbido en el organismo.

  11. Filogenia de especies del subgenero parides (lepidoptera: papilionidae) basada en secuencias del gen citocromo oxidasa i

    OpenAIRE

    FAGUA, GIOVANNY; GUTIÉRREZ R, INGRID MARCELA

    2012-01-01

    El género Parides Hübner es el taxón terminal de Troidini, un grupo de mariposas aposematicas diversificado en el trópico y subtrópico, modelos de varios complejos miméticos batesianos y mullerianos. Varias de las especies americanas de Parides son simpátricas e involucran poblaciones con variaciones intraespecíficas de los patrones de coloración, lo que genera confusiones en la definición del estatus taxonómico, especialmente en Colombia, punto de convergencia de las biotas de Norte y Suramé...

  12. FILOGENIA DE ESPECIES DEL SUBGENERO Parides (LEPIDOPTERA: PAPILIONIDAE) BASADA EN SECUENCIAS DEL GEN CITOCROMO OXIDASA I

    OpenAIRE

    INGRID MARCELA GUTIÉRREZ R.; GIOVANNY FAGUA

    2012-01-01

    Parides Hübner es el taxón terminal de Troidini, un grupo de mariposas aposemáticas diversificado en el trópico y subtrópico, y modelos de varios complejos miméticos bate- sianos y mullerianos. Varias de las especies americanas de Parides son simpátricas e involucran poblaciones con variaciones intraespecíficas en los patrones de coloración, lo que genera confusiones en la definición del estatus taxonómico, especialmente en Colombia, punto de convergencia de las biotas de Norte y Suramérica. ...

  13. Diversidad genómica de aislamientos del virus del papiloma humano de los tipos 16, 18, 31 y 35, en una población mexicana

    OpenAIRE

    CALLEJA M., ITZEL E.; KALANTARI, MINA; HUH, JOHN; ORTIZ L., ROCÍO; ROJAS M., AUGUSTO; GONZÁLEZ G., JUAN F.; W., ANNA-LISE; HAGMAR, BJÓRN; WILEY, DOROTHY J.; VILLARREAL, LUIS; BERNARD, HANS-ULRICH; BARRERA S., HUGO A.

    2004-01-01

    Analizamos secuencias genÛmicas de variantes mexi- canas del HPV-16, 18, 31 y 35. Entre 112 muestras HPV-16 se detectaron catorce variantes E y 98 AA. Entre 15 muestras HPV-18, trece E y dos africanas. Se construyeron árboles filogenÈticos con las varian- tes del HPV-31 y 35. En 46 asilados HPV-31 se detectaron 35 cambios nucleotÌdicos. En 27 muestras HPV-35 se detectaron once mutaciones. La alta prevalencia de las variantes carcinogÈnicas AA del HPV- 16 y la extensiva diversidad de las varia...

  14. Algunas ideas del alumnado de secundaria sobre conceptos básicos de genética

    OpenAIRE

    Caballero Armenta, Manuela

    2008-01-01

    Las ideas previas del alumnado inciden de una manera muy directa en el proceso de enseñanza-aprendizaje. En este trabajo se muestran las que tienen algunos alumnos de educación secundaria sobre determinados conceptos de genética y sobre otros aspectos relacionados con el aprendizaje de esta disciplina. Pupils’ preconceptions very directly affect the education learning process. This paper includes those that some secondary pupils have about certain genetics concepts and other aspects relate...

  15. Diferencias genéticas entre poblaciones de Aedes aegypti de municipios del norte de Colombia, con baja y alta incidencia de dengue

    Directory of Open Access Journals (Sweden)

    Sandy Milena Caldera

    2013-08-01

    Full Text Available Introducción. Aedes aegypti es el principal vector del dengue en zonas urbanas. A pesar de su importancia epidemiológica, se desconoce la variabilidad genética de las poblaciones del vector en Colombia. Objetivo. Determinar la variabilidad genética del gen mitocondrial ND4, que codifica para la subunidad 4 de la enzima NADH-deshidrogenasa, entre poblaciones de Ae. aegypti de los municipios de Sincelejo y Guaranda, donde se registra alta y baja incidencia de dengue, respectivamente. Materiales y métodos. A partir del material genético extraído de 36 hembras de Ae. aegypti, se determinó la secuencia parcial del gen mitocondrial ND4 y se estimaron los parámetros de diversidad de nucleótidos, diversidad haplotípica, estructura genética y flujo de genes entre las poblaciones de Sincelejo y Guaranda. También, se analizó la varianza molecular y se construyó una red haplotípica. Resultados. Se obtuvieron 36 secuencias de nucleótidos de 282 pb; éstas presentaron doce sitios polimórficos y se agruparon en diez haplotipos, dos presentes en ambas poblaciones, tres exclusivos de la población de Sincelejo y cinco de la población de Guaranda. Los estimadores de estructura genética (FST=0,15 y de flujo de genes (Nm=1,40 evidencian diferenciación genética y un limitado intercambio de genes entre las poblaciones. Conclusión. Las poblaciones de Ae. aegypti de Sincelejo y Guaranda son genéticamente divergentes.   doi: http://dx.doi.org/10.7705/biomedica.v33i0.1573

  16. Estudio de las aneuplodías del cromosoma 17 y deleción del gen tp53 en neoplasias hematológicas por la técnica del fish-bicolor

    OpenAIRE

    Carlos Mario Muñetón Peña; Gloria Cecilia Ramírez Gaviria; Juan Carlos Herrera Patiño

    2008-01-01

    Las neoplasias hematológicas se caracterizan por presentar una amplia diversidad de alteraciones genéticas. Se analizaron 15 muestras de diferentes tipos de neoplasias hematológicas mediante el FISH, para detectar aneuplodías del cromosoma17 y la deleción del gen TP53. En 11 de las 15 muestras se realizaron análisis cromosómicos por citogenética convencional; 6 de las 11 muestras tenían cariotipo anormal (54.5%), se detectaron 3 translocaciones y 3 mosaicismos. Análisis de FISH en 15 muestras...

  17. Identificación de Yarrowia lipolytica (Ascomycota: Hemiascomycetes como contaminante en la obtención de amplificados del gen 28S rRNA de moluscos

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    Jenny Chirinos

    2011-05-01

    Full Text Available En el presente trabajo se identifica una secuencia de DNA no esperada proveniente de los amplificados del gen 28S rRNA de moluscos terrestres. Las extracciones de DNA se realizaron del tejido del pie de caracoles terrestres por el método del CTAB modificado. Las PCRs fueron llevadas a cabo con primers universales para el gen COI e iniciadores diseñados para moluscos, para el marcador 16S rRNA, 28S rRNA y la región ITS-2. Los tamaños aproximados de las bandas de los amplificados de moluscos fueron de 706 pb para el COI, 330 pb para el 16S rRNA, 900 pb para el ITS-2 y 583 pb para el 28S rRNA; un amplificado del último marcador fue de una longitud inesperada, ~340 pb. Las secuencias de DNA fueron comparadas con la base de datos del GenBank mediante el programa BLASTn y la muestra con la banda de tamaño inesperado resultó en un 100% de identidad y cobertura del 99% con el gen 26S rRNA de la levadura Yarrowia lipolytica. El análisis filogenético con Neighbour-Joining y los valores de divergencia confirmaron la identificación, proporcionando resultados que apoyan la ubicación taxonómica de la especie dentro del clado de los Hemiascomycetes.

  18. Recursos genéticos del boniato (Ipomoea batatas (L. Lam. en Cuba. Especies silvestres

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    Oscar Leopoldo Parrado Alvarez

    2013-01-01

    Full Text Available RESUMEN Se presentan los resultados de la valoración de los recursos genéticos del boniato (Ipomoea batatas (L. Lam a partir del estudio de material de herbario y fuentes bibliográficas teniendo en consideración el criterio de grupo taxón de Maxted de acuerdo con el cual en Cuba se reporta la presencia de los grupos siguientes: Grupo Taxón 2 – misma serie o sección que el cultivo (7 especies; Grupo Taxón 3 – mismo subgénero que el cultivo Eriospermum (45 especies dentro de este grupo se encuentran 21 especies endémicas y el Grupo Taxón 4 – mismo género que el cultivo (57 especies lo que potencia a Cuba como un centro de diversidad importante para Ipomoea batatas en Latinoamérica y el Caribe . Se ofrece una descripción sucinta de las especies tratadas que incluye distribución, fenología, datos etnobotánicos y el material de herbario consultado. Genetic resources of sweet potato (Ipomoea batatas (L. lam. in Cuba. Wild species. ABSTRACT The results of the evaluation of the genetic resources of sweet potato (Ipomoea batatas (L. Lam are presented from the study of herbarium material and bibliographic sources taking into account the criterion of Maxted´s taxon group according to which in Cuba is reported the presence of the following groups : Taxon group 2 - same series or section cultivation (7 species Taxon group 3 - same subgenus Eriospermum the crop (45 species within this group are 21 endemic species and Taxon group 4 - same genus as the crop (57 species that fact potenciate to Cuba as an important center of diversity for Ipomoea batatas in Latin America and the Caribbean. A brief description of the treated species including distribution, phenology, ethnobotanical data and herbarium material consulted is provided. A brief description of the treated species including distribution, phenology, ethnobotanical data and herbarium material consulted is provided.

  19. Caracterización Estructural y Funcional del GEN p53 Litopenaeus Vannamei E Implementación de la Tecnología de la Edición Genómica Talen para su Mutación Dirigida

    OpenAIRE

    Salvatierra Alor, Max

    2016-01-01

    RESUMEN El gen Lvp53 del langostino Litopenaeus vannamei (Lvp53) ha sido caracterizado a nivel del ADN complementario (ADNc), encontrando motivos homólogos a p53 de humanos y relación con la respuesta a diferentes tipos de estrés. Sin embargo, aún se desconoce la estructura de este gen, así como su funcionalidad. En este estudio se propuso caracterizar parcialmente la secuencia genómica del gen Lvp53, estudiar su expresión ante un estrés térmico e implementar metodologías de transfección i...

  20. Disección genética de los mecanismos reguladores del desarrollo de la semilla de maiz

    OpenAIRE

    Paniagua Marcos, Carlos

    2011-01-01

    En esta tesis se ha desarrollado una nueva técnica para la búsqueda del gen causal de fenotipos de interés en una colección de plantas de maíz mutagenizadas con el transposón Mu. Dicha técnica se basa en la amplificación de FSTs (secuencias flanqueantes de la inserción) desde RNA previo paso a cDNA mediante RACE 5? o 3?. Se ha observado que un paso de SSH (?supresive substraction hibridization?) de los cDNAs FSTs de dos individuos mutantes independientes con el procedente de otro silvestre me...

  1. Genetica del trigo. Los cereales. Biología Molecular e Ingeniería Genética

    OpenAIRE

    García Olmedo, Francisco; Sanchez Monge, Enrique

    1986-01-01

    El presente artículo revisa sucintamente un conjunto de investigaciones sobre los cereales, realizadas en el Departamento de Bioquímica de la E.T.S. de Ingenieros Agrónomos de la Universidad Politécnica de Madrid. En dichas investigaciones se han utilizado técnicas bioquímicas, citogenéticas y de ingeniería genética para el conocimiento básico y la manipulación práctica del conjunto de especies cultivadas denominadas cereales. Los estudios realizados han abarcado los siguientes aspectos princ...

  2. BÚSQUEDA DE LA MUTACIÓN Phe-809 EN EL GEN DEL SUSTRATO DEL RECEPTOR DE INSULINA -1 (IRS-1) EN RATAS DIABÉTICAS eSS

    OpenAIRE

    Stella Maris Daniele; Silvana Marisa Montenegro; María Cristina Tarrés; Stella Maris Martínez

    2010-01-01

    El gen del sustrato del receptor de insulina IRS-1 juega un rol clave en la transducción de señales de insulina en músculo esquelético. Diversos polimorfismos del gen IRS-1 han sido reportados en estados de insulinorresistencia como obesidad y diabetes tipo 2.Las ratas eSS desarrollan espontáneamente diabetes tipo 2 magra, con insulinoresistencia caracterizada por hiperglucemia e hiperinsulinemia. Durante el segundo año existe disminución progresiva de la insulinemia y agravamiento del síndro...

  3. Estudio de las aneuplodías del cromosoma 17 y deleción del gen tp53 en neoplasias hematológicas por la técnica del fish-bicolor

    Directory of Open Access Journals (Sweden)

    Carlos Mario Muñetón Peña

    2008-12-01

    Full Text Available Las neoplasias hematológicas se caracterizan por presentar una amplia diversidad de alteraciones genéticas. Se analizaron 15 muestras de diferentes tipos de neoplasias hematológicas mediante el FISH, para detectar aneuplodías del cromosoma17 y la deleción del gen TP53. En 11 de las 15 muestras se realizaron análisis cromosómicos por citogenética convencional; 6 de las 11 muestras tenían cariotipo anormal (54.5%, se detectaron 3 translocaciones y 3 mosaicismos. Análisis de FISH en 15 muestras mostró un 26.7% de aneuplodía del cromosoma 17 y un 33.3% con deleción del gen TP53. De los 6 casos con cariotipo anormal, 2 tenían alteraciones por FISH. En 5 casos se detectaron alteraciones cromosómicas por FISH, las cuales no se observaron por citogenética convencional. Solo 3 (20% de las 15 muestras analizadas fueron normales para el análisis cromosómico por citogenética convencional y FISH. En este trabajo se corrobora que la aneuplodía del cromosoma 17 y la deleción del gen TP53 tienen una baja incidencia en las neoplasias hematológicas. Si embargo, el valor pronóstico de estas alteraciones genéticas no esta bien definido.

  4. Secuenciación del exoma en anemia de Fanconi: del diagnóstico al descubrimiento de un nuevo gen

    OpenAIRE

    Bogliolo, Massimo

    2015-01-01

    La anemia de Fanconi (AF) es un trastorno genético raro de inestabilidad genómica que se caracteriza por insuficiencia de la médula ósea y predisposición al cáncer. Las 19 proteínas AF conocidas hasta el día de hoy están implicadas en la reparación de los enlaces entrecruzados del ADN (ICL). El diagnóstico molecular es de capital importancia para los pacientes AF y sus familias. La caracterización de las mutaciones permite el diagnóstico prenatal y preimplantacional, de identificar portadores...

  5. Divergencia genética en poblaciones prehistóricas del área andina centro meridional

    Directory of Open Access Journals (Sweden)

    Varela, Héctor Hugo

    2007-01-01

    Full Text Available La historia del poblamiento del Área Andina Centro Meridional estuvo determinada por un conjunto de factores culturales, económicos y biológicos que influyeron en la estructura de la población y determinaron una particular dispersión de las frecuencias génicas. En este trabajo se presenta el análisis de una extensa muestra representada por 1586 individuos de ambos sexos del Norte de Chile, N.O. Argentino, y los Valles del este de Bolivia (ca 3000 aC-1500 dC. La variación dentro y entre poblaciones es evaluada dentro del marco de la teoría de la genética de poblaciones mediante caracteres cuantitativos del cráneo y la aplicación de diferentes técnicas estadísticas de análisis multivariado. Los resultados indican que los habitantes de los valles de Cochabamba (Bolivia estuvieron más emparentados con los del Norte de Chile y N.O. Argentino que los de estas subáreas entre sí. Se observa una divergencia genética promedio para el Área Andina Centro Sur de 0.195, presentando el NOA el mayor aislamiento espacial (FST= 0.143 y el Norte de Chile el más bajo (FST= 0.043. Además, se demuestra un mayor aislamiento temporal de los grupos que habitaron los oasis de Atacama (FST= 0.031 y la Costa de Azapa (FST= 0.04 que los del Valle de Azapa (FST= 0.026. Estas evidencias confirman un proceso de poblamiento basado en la dispersión de varias líneas a partir de una misma población ancestral, las cuales se diferenciaron en el espacio y el tiempo dependiendo del tamaño efectivo y de la tasa de flujo génico entre ellas.

  6. Efecto del silenciamiento del gen "ZEITLUPE (ZTL)", involucrado en el control del ritmo circadiano, sobre el desarrollo en Petunia hybrida.

    OpenAIRE

    Casanova De La Rosa, Miguel Ángel

    2016-01-01

    El ritmo circadiano de una planta es controlado por una red compleja de genes, expresados por la mañana, al mediodía y por la noche, con interacciones tanto al nivel de transcripción y traducción. El reloj circadiano afecta a muchos aspectos del desarrollo de planta, incluyendo el crecimiento y el tiempo de floración, resistencia al frío, apertura de la flor, la emisión de volátiles y por lo tanto la atracción de polinizadores y la repulsión de herbívoros. La emisión de volátiles florales en ...

  7. Acceso a recursos genéticos y distribución de beneficios en Colombia: desafíos del régimen normativo

    Directory of Open Access Journals (Sweden)

    Luciana Carla Silvestri

    2015-10-01

    Full Text Available La investigación analiza los retos que presenta el régimen colombiano sobre acceso a recursos genéticos y distribución de beneficios mediante la utilización del método jurídico, con un enfoque descriptivo, comparativo y propositivo. El mecanismo de acceso y distribución de beneficios pretende desacelerar la pérdida de diversidad genética, entre otros fines. El marco legal se encuentra incompleto y no sistematizado. Asimismo, el procedimiento de acceso a recursos genéticos surge burocrático e ineficiente y obstaculiza así la investigación de la biodiversidad del país. Afortunadamente, la reciente simplificación del procedimiento para investigar recursos genéticos con fines no comerciales podría ayudar a resolver el mencionado problema para este tipo de proyectos. Además, la consulta previa articulada para el acceso a recursos genéticos ubicados en territorios de las comunidades indígenas y negras no garantiza la efectiva participación de aquellas. Por último, las medidas de cumplimiento establecidas, que circunscriben el control al acatamiento de la legislación colombiana y la de los países andinos, no satisfacen las disposiciones del Protocolo de Nagoya al respecto.

  8. Acceso a recursos genéticos y distribución de beneficios en Colombia: desafíos del régimen normativo

    Directory of Open Access Journals (Sweden)

    Luciana Carla Silvestri

    2016-06-01

    Full Text Available La investigación analiza los retos que presenta el régimen colombiano sobre acceso a recursos genéticos y distribución de beneficios mediante la utilización del método jurídico, con un enfoque descriptivo, comparativo y propositivo. El mecanismo de acceso y distribución de beneficios pretende desacelerar la pérdida de diversidad genética, entre otros fines. El marco legal se encuentra incompleto y no sistematizado. Asimismo, el procedimiento de acceso a recursos genéticos surge burocrático e ineficiente y obstaculiza así la investigación de la biodiversidad del país. Afortunadamente, la reciente simplificación del procedimiento para investigar recursos genéticos con fines no comerciales podría ayudar a resolver el mencionado problema para este tipo de proyectos. Además, la consulta previa articulada para el acceso a recursos genéticos ubicados en territorios de las comunidades indígenas y negras no garantiza la efectiva participación de aquellas. Por último, las medidas de cumplimiento establecidas, que circunscriben el control al acatamiento de la legislación colombiana y la de los países andinos, no satisfacen las disposiciones del Protocolo de Nagoya al respecto.

  9. Expresión transitoria del gen GUS en caña de azúcar usando Agrobacterium tumefaciens

    Directory of Open Access Journals (Sweden)

    Martha Liliana Bonilla Betancourt

    2008-10-01

    Full Text Available En el estudio se desarrolló una metodología de transformación genética mediante Agrobacterium tumefaciens en cultivares colombianos de caña de azúcar. La transformación se evaluó mediante la expresión del gen GUS. Callos embriogénicos y explantes meristemáticos de los genotipos CC85-92, CC84-75 y CC87-505 se transformaron usando tres cepas (AGL-1, LBA4404 y EHA105 con el plásmido pCambia 1305.2 y dos (EHA105 y LBA4404 con pCambia 2301. Se usó el medio de infiltración (IM con acetosiringona y se evaluó el tiempo de cocultivo y la densidad óptica de la bacteria al momento de la inducción. Los genotipos mostraron respuesta diferencial con las combinaciones cepa-plásmido: obtuvieron mayor expresión del gen GUS cuando el genotipo CC85-92 se transformó con la cepa AGL-1-pCambia 1305.2. CC84-75 y CC87-505 mostraron mayor expresión cuando se transformaron con la cepa EHA105-pCambia 1305.2. Mayor eficiencia en la expresión se obtuvo cuando la bacteria se indujo en IM después de siete días de cocultivo y cuando la densidad óptica de la bacteria fue de 0.2(600nm al momento de la inducción. Se demostró superioridad de los explantes en la eficiencia de transformación.

  10. Identificación de un polimorfismo del gen Est9 relacionado con resistencia a piretroides en Rhipicephalus (Boophilus microplus

    Directory of Open Access Journals (Sweden)

    Edgar Diaz R.

    2013-10-01

    Full Text Available Objetivo. Mediante procedimientos de PCR-RFLP, detectar un polimorfismo en el gen Est9 de garrapatas Rhipicephalus (Boophilus microplus resistentes a piretroides en Ibagué, Colombia, determinando el grado de asociación entre los fenotipos y los genotipos resultantes. Materiales y métodos. El ADN de 30 teleoginas R. (Boophilus microplus fenotípicamente susceptibles, resistentes o medianamente resistentes a piretroides en una prueba de Drummond modificada, fue amplificado por PCR con cebadores específicos para obtener un fragmento de 372 pb del gen Est9, que fue sometido a digestión con la enzima EcoRI para estudiar los RFLPs generados y poder diferenciar los respectivos genotipos. El grado de asociación entre los fenotipos y los genotipos resultantes se determinó mediante la prueba exacta de Fisher. Resultados. Luego de digerir el fragmento con la endonucleasa, se generaron dos segmentos en teleoginas con algún nivel de resistencia, mientras en las teleoginas susceptibles no hubo división del fragmento de 372 pb, demostrándose así la presencia de una mutación puntual y los genotipos homocigoto natural, homocigoto mutante y heterocigoto. Las diferencias altamente significativas (p<0.01 entre teleoginas susceptibles y aquellas con algún nivel de resistencia, mostraron una relación directa entre el genotipo y el fenotipo con un nivel de confianza de p=0.0009852. Conclusiones. Se comprobó, por primera vez en Colombia, la presencia de una mutación puntual en el gen Est9 de garrapatas R. (Boophilus microplus resistentes a piretroides, sugiriendo la necesidad de realizar estudios para detectar alteraciones moleculares en otros genes relacionados con quimioresistencia.

  11. Base Molecular del asesoramiento genético de fibrosis quística

    OpenAIRE

    Muñoz Domínguez, Carlos

    1997-01-01

    La Fibrosis Quística (FQ) es una enfermedad autosómica recesiva producida por mutaciones en el gen CFTR. Dicho gen produce una proteína (CFTR) implicada en el transporte de iones Cl- a través de la membrana plasmática. La alteración ... La consecuencia de estas secreciones afecta principalmente a pulmones, páncreas exocrino, aparato reproductor masculino y glándulas sudoríparas, provocando un cuadro clínico muy variable de unos pacientes a otros. Tanto la elevada concentración iónica en el su...

  12. Variabilidad genética del robalo común Centropomus undecimalis (Perciformes: Centropomidae) en ambiente marino y ribereño interconectados

    OpenAIRE

    Ulises Hernández-Vidal; Julia Lesher-Gordillo; Wilfrido M Contreras-Sánchez; Xavier Chiappa-Carrara

    2014-01-01

    El robalo común Centropomus undecimalis habita en áreas ribereñas y marinas del sur del Golfo de México donde es sujeto a explotación intensiva. Aunque la identificación de las poblaciones de peces representa una valiosa herramienta para el manejo de las poblaciones silvestres, no hay información disponible para identificar genéticamente las poblaciones de peces de esta especie en la región. El objetivo de este estudio fue determinar la relación genética entre C. undecimalis capturado en ambi...

  13. Estudio molecular de la inactivación del cromosoma X en mujeres y su relación con los distintos fenotipos asociados al gen FMR1

    OpenAIRE

    Martínez Ramos, Raquel

    2008-01-01

    Falta por incorporar las palabras clave Las premutaciones y mutaciones en el gen FMR1 se asocian con diferentes fenotipos. Además, por ser un gen que se localiza en el cromosoma X la afectación es diferente en varones y mujeres. Nuestra hipótesis de trabajo es que el sesgo en la inactivación del cromosoma X determina el grado de afectación en las mujeres portadoras de premutación o de mutación completa. Aunque se postula que en la población general la inactivación del cromosoma X es al aza...

  14. Estudio de la influencia de la nutrici??n y gen??tica maternas sobre la programaci??n del desarrollo del tejido adiposo fetal (Estudio PREOBE)

    OpenAIRE

    Campoy Folgoso, Cristina; Mart??n-Bautista, Elena; Garc?a-Vald?s, Luz; Florido Nav??o, Jes??s; Agil, Ahmad; Lorente, Jos?? Antonio; Marcos, Ascensi?n; L??pez-Sabater, Mar??a del Carmen; Miranda Le??n, Mar??a Teresa; Sanz, Yolanda; Molina Font, Juan Antonio; Grupo PREOBE

    2008-01-01

    Introducci??n: La gen??tica y la alimentaci??n de la madre antes y durante el embarazo, las distintas patolog??as metab??licas maternas, as?? como la ingesta de nutrientes en los primeros meses de vida del reci??n nacido parecen estar implicados en la etiolog??a de la obesidad y sus consecuencias a largo plazo. La posible contribuci??n de estos y otros factores, los mecanismos y sus efectos en el metabolismo y desarrollo de la enfermedad est??n a??n en fase de investig...

  15. Caracterizaci??n gen??tica y bioqu??mica del catabolismo bacteriano aer??bico del colesterol y mol??culas estructuralmente relacionadas

    OpenAIRE

    Rodr??guez Fern??ndez, Joaqu??n

    2014-01-01

    313 p. Durante la realizaci??n de esta Tesis Doctoral, se ha pretendido caracterizar bioqu??mica y gen??ticamente la ruta o rutas catab??licas responsables de la degradaci??n bacteriana aer??bica de compuestos de naturaleza esteroidea. Para llevar a cabo el estudio de la ruta o rutas metab??licas requeridas para la asimilaci??n bacteriana aer??bica del colesterol y de otros compuestos estructuralmente relacionados se aislaron y caracterizaron distintas cepas bacterianas capaces de metab...

  16. Au-delà du moralisme : Madame de Genlis et l’hospitalité

    Directory of Open Access Journals (Sweden)

    Sophie Bourgault

    2013-09-01

    Full Text Available Très peu de philosophes politiques se sont intéressés à l’oeuvre de Genlis, en partie parce que son oeuvre est communément réduite à un moralisme religieux insipide. Si Alice Laborde con-clut sa biographie en soulignant que Genlis « est moraliste avant tout », les travaux récents de Mary Trouille mettent tout autant l’accent sur le fait que la comtesse est « moralist to the core ». La visée du présent article est de nuancer cette lecture, non pas en niant le moralisme de Genlis, mais plutôt en montrant que celui-ci ne l’a pas empêchée de publier des textes à portée politique qui mériteraient notre attention aujourd’hui—particulièrement l’attention de ceux et celles qui se donnent pour tâche de penser l’accueil et le soin de l’Autre. A partir du Discours sur la sup-pression des convens et du Discours sur le luxe et l’hospitalité, nous indiquons non seulement l’actualité, mais aussi la surprenante radicalité des textes publiés par Genlis en période révolu-tionnaire.

  17. Manipulación genética y el estudio del parásito protozoario Leishmania.

    Directory of Open Access Journals (Sweden)

    Tania M. Cortázar

    2004-12-01

    Full Text Available Durante los últimos 15 años se ha dado paso al entendimiento de muchos aspectos de la genómica funcional de Leishmania gracias a los avances en la metodología de transfección de ADN dentro de la célula de este protozoario, la eliminación y la complementación de genes por medio de recombinación homóloga y las estrategias para la selección de células transfectadas. Estos acercamientos tienen el potencial de brindar información sobre la expresión génica y la función de las proteínas en el contexto del parásito intacto. Dado que el genoma de Leishmania muestra una carencia acentuada de los factores conocidos de iniciación de la transcripción y que la expresión génica está regulada casi completamente a nivel postranscripcional (a través del empalme de los ARNm y los mecanismos que involucran el procesamiento diferencial de la región no traducida 3' del ARNm (3?UTR, la transfección génica representa una herramienta útil para la identificación y el análisis funcional de los genes de interés así como de los mecanismos que dirigen su regulación. El desarrollo de los sistemas de manipulación genética también ha abierto nuevos horizontes para la identificación de genes esenciales involucrados en la virulencia, la supervivencia intracelular y la resistencia a drogas de Leishmania, así como para la validación de proteínas específicas del parásito como nuevos blancos quimio e inmunoterapéuticos. En esta revisión presentamos los avances más recientes en el campo de la manipulación genética en Leishmania, los cuales permiten análisis estructurales, funcionales y de fenotipo, por medio de la eliminación y complementación génica a través de la transfección transitoria o permanente de genes en este parásito.

  18. Variabilidad genética de la colección de piñón (Jatropha Curcas L.) del Instituto Nacional de Investigaciones Agropecuarias del Ecuador, usando marcadores tipo microsatélites

    OpenAIRE

    Mendoza, Heriberto; de Mendoza, Javier; López, Julio; Mejía, Nelly; Zambrano, Freddy; Mendoza, María; Ponce, Wilmer

    2017-01-01

    Para conocer la diversidad genética del piñón (Jatropha curcas L.) existente en Ecuador, se realizó un estudio mediante el uso de marcadores moleculares tipo microsatélites. Fue analizada la variabilidad genética de la colección del Instituto Nacional de Investigaciones Agropecuarias (INIAP) conformada por 158 accesiones, de las cuales 151 fueron colectadas en seis provincias del Ecuador, 4 provinieron de Perú y 3 de Brasil. Como muestras para el estudio se tomaron 15 gramos de brotes tiernos...

  19. Análisis de las mutaciones más frecuentes del gen BRCA1 (185delAG y 5382insC en mujeres con cáncer de mama en Bucaramanga, Colombia

    Directory of Open Access Journals (Sweden)

    María Carolina Sanabria

    2009-03-01

    Conclusión. Se requieren más estudios en la región que abarquen la tamización de la totalidad del gen BRCA1, para hacer una mayor contribución al conocimiento de la epidemiología molecular del cáncer de mama en Bucaramanga, Santander, Colombia.

  20. Mejora de la calidad nutritiva del tomate: búsqueda de fuentes de variabilidad, estudio de la influencia del ambiente y determinación del control genético

    OpenAIRE

    Adalid Martinez, Ana Maria

    2011-01-01

    Recientemente se ha demostrado la importancia de las vitaminas y carotenoides del tomate en la prevención de enfermedades degenerativas, por lo que resultaría de gran interés mejorar el contenido de estos compuestos en dicha hortaliza. Pero para iniciar un programa de mejora se deberían cumplir los siguientes objetivos: (i) estudiar la variabilidad presente en germoplasma de Solanum, (ii) ver la influencia del ambiente en estos caracteres, (iii) estudio del control genético de dichos caracter...

  1. Análisis de la diversidad genética de 21 aislamientos del hongo Moniliophthora roreri basado en marcadores RAPD

    Directory of Open Access Journals (Sweden)

    Boris Gutarra Castillo

    2013-12-01

    Full Text Available Objetivos: Estudiar la diversidad genética de 21 aislamientos del hongo que afecta al cultivo del cacao, Moniliophthora roreri, en tres zonas cacaoteras del Perú (Tocache, Mariscal Cáceres y Leoncio Prado. Métodos: Se utilizó 14 iniciadores RAPD (random amplified polymorphic DNA polimórficos y una pareja de oligonucleótidos, los que fueron empleados bajo condiciones de amplificación estandarizadas. Con los datos obtenidos se construyó un dendograma utilizando el coeficiente de Jaccard y el algoritmo UPGMA (Unweighted Pair-Group Method using Arithmetic Average. La estructura genética fue estimada en función del análisis molecular de variancia (AMOVA y la diversidad mediante los índices de Shannon y Nei. Resultados: Fueron conseguidas 59 bandas RAPD con un 73% de polimorfismo. El dendograma obtenido a un índice de similitud de 0,70, claramente dividió los individuos en tres grupos. El análisis de la diversidad genética mostró altos valores en las zonas estudiadas de acuerdo con el índice de Shannon (0,3936 y de Nei (0,2622, con mayor riqueza en Leoncio Prado. Estas zonas presentan alta variabilidad, y según el AMOVA realizado: 88% entre accesiones por zona y solo 12% entre zonas. Conclusiones: Existe más de un grupo genético de Moniliophthora roreri en la Amazonía del Perú. Estos grupos, provenientes del Ecuador, pudieron haber ingresado por el intercambio de semillas y/o de forma natural por medio de los ríos en común y estarían originando nuevos grupos genéticos locales.

  2. Los suelos del Parque Nacional Viñales, Pinar del Río, Cuba. Condiciones genéticas y ambientales.

    Directory of Open Access Journals (Sweden)

    Efrén Jaimez Salgado

    2006-01-01

    Full Text Available Se realiza la cartografía digital y actualización de la clasificación y diagnóstico de suelos del área del «Parque Nacional Viñales», a partir de la implementación de un Sistema de Información de Suelos (sobre plataforma SIG, para el manejo y consulta oportuna de las correspondientes bases de datos por parte de las autoridades del Parque. Los suelos predominantes por excelencia corresponden al grupo Leptosoles (90%. Están seguidos en segundo lugar por el grupo Acrisoles (4,5%, los que se encuentran en asociación genética con el grupo Alisoles, (4,4% tratándose en ambos casos de suelos con muy alto grado de evolución edáfica, cuyo origen y evolución se deriva de la combinación de materiales parentales ricos en cuarzo y silicatos de aluminio, así como la existencia de períodos climáticos antiguos muy húmedos en esta zona montañosa del occidente de Cuba. Se describen los principales procesos degradantes encontrados en los suelos del Parque y algunas de las medidas más importantes a tomar para atenuarlos.

  3. Genómica Funcional de Plantas: Estudio del Desarrollo de Flores y Frutos Genómica Funcional de Plantas: Estudio del Desarrollo de Flores y Frutos

    Directory of Open Access Journals (Sweden)

    Octavio Rubén Salazar Moya

    2012-02-01

    Full Text Available La última fase del desarrollo floral es la fertilización de los óvulos y la formación de los frutos,que son muy importantes tanto biológica como económicamente. Notoriamente, más del 80% de los alimentos que son consumidos por el ser humano proviene de flores y frutos.La obtención de conocimientos acerca de las bases moleculares del desarrollo de frutos en especies modelo es de gran interés científico, y un paso indispensable para poder facilitar investigaciones y de ser factible, aplicaciones en frutos de consumo humano. Especialmente en un país como México, con tal riqueza en la diversidad de frutos, este tipo de estudios es necesario y científicamente muy interesante, y tiene repercusiones económicas potenciales importantes. La meta del laboratorio es descubrir genes nuevos involucrados en el desarrollo de frutos, empleando los recursos que brindan plantas modelo como Arabidopsisthaliana. Se hace un enfoque especial en genes que afectan la identidad celular, morfología y que causan partenocarpia (frutos carentes de semillas, para más tarde estudiarlos enotras especies y hacer ensayos para conocer sus alcances en dichas especies.The last stages of fl oral development are ovule fertilization and fruit formation. Fruits are very important both biologically and economically. Notably, more than 80% of human food is obtained from flowers and fruits. Gathering basic knowledge about the molecular mechanisms of fruit development from model species is of great scientific interest, and is an essential step to facilitate research and, when feasible, applications in fruits consumed by humans. Especially in countries like Mexico, which has such a great diversity of fruits, this kind of research is both necessary and scientifically interesting, and has potentially important economic repercussions. The goal of the lab is to discover new genes that are involved inflower development, making use of the resources provided by model plants like

  4. Polimorfismo del gen de la banda 3 eritrocítica en grupos étnicos de Costa Rica

    Directory of Open Access Journals (Sweden)

    M Chaves-Villalobos

    2004-09-01

    Full Text Available Banda 3 (AE1 es una de las proteínas más abundantes de la membrana del eritrocito humano. Ésta funciona como un intercambiador aniónico cloruro / bicarbonato y es el punto de anclaje de varias proteínas del citoesqueleto del eritrocito. Se han descrito varias mutaciones y muchas variantes polimórficas se han asociado a esferocitosis hereditaria. La identificación de un marcador genético en el extremo 5’ del gene AE1 podría asociarse a varios defectos moleculares del eritrocito. Este marcador genético es un fragmento de restricción de longitud polimórfica "RFLP" producido por la endonucleasa de restricción Pst I. Se analizaron para este polimorfismo un total de 216 individuos de siete poblaciones: una hispanomestiza (Valle Central, dos afrodescendientes (Limón y Guanacaste y cuatro amerindias (bribri, cabecar, maleku y guaymí. El alelo más frecuente en la población hispanomestiza fue el 2, mientras en los grupos afrodescendientes y amerindios se encontró el 1. No se observaron diferencias significativas con respecto al equilibrio de Hardy-Weinberg en seis de las poblaciones, sin embargo, el grupo Guaymí si presenta diferencias significativas con respecto al equilibrio de Hardy-Weinberg.Polymorphism of the erythrocyte band 3 gene (EPB3 in ethnic groups of Costa Rica. Band 3 (AE1 is one of the most abundant proteins in the membrane of the human erythrocyte. This protein works as an anionic CI - and HCO3- exchanger and it also functions as an anchor for several proteins of the erythrocyte's cytoesqueleton. Several mutations have been described and many polymorphic variants have been associated to hereditary spherocytosis. The identification of a genetic marker at position 5' of the AE1 gene could be associated to several molecular defects of the erythrocyte. This genetic marker is a restriction fragment length polymorphism (RFLP produced by restriction enzime Pst I. For this polymorphism a total of 216 individuals belonging to

  5. (FVL G1691A and MTHFR C677T) in patients with myocardial ...

    African Journals Online (AJOL)

    Background: Inherited thrombophilia may be caused by mutations, polymorphisms in a variety of genes mainly involved in haemostatic pathways. Aim of the study, was to find the prevalence of thrombophilic gene factor V Leiden (FVL) and methylene tetrahydrofolate reductase (MTHFR) gene polymorphism in patients with ...

  6. Association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and age of onset in schizophrenia

    DEFF Research Database (Denmark)

    Vares, Maria; Saetre, Peter; Deng, Hong

    2010-01-01

    ) significantly affected age at onset of schizophrenia in a dose-dependent manner (P = 0.0015), with lower age of onset with increasing numbers of the mutant T-allele. There was no evidence of rs1801131 (A1298C) affecting age of onset in schizophrenia. Within the Chinese high-risk families carriers of the MTHFR......Different lines of evidence indicate that methylenetetrahydrofolate reductase (MTHFR) functional gene polymorphisms, causative in aberrant folate-homocysteine metabolism, are associated with increased vulnerability to several heritable developmental disorders. Opposing views are expressed...... considering the possible association between MTHFR and susceptibility for schizophrenia. In order to evaluate if age of onset could explain some of this discrepancy we investigated the relationship between two functional MTHFR gene polymorphisms and age at onset in this disorder. Scandinavian patients (n...

  7. Association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and age of onset in schizophrenia

    DEFF Research Database (Denmark)

    Vares, Maria; Saetre, Peter; Deng, Hong

    2010-01-01

    = 820) diagnosed with schizophrenia, schizoaffective disorder, and schizophreniform disorder were investigated. Two functional MTHFR single nucleotide polymorphisms (SNPs; rs1801131 and rs1801133) were genotyped and the effect of MTHFR polymorphisms on the age of onset was examined with survival......Different lines of evidence indicate that methylenetetrahydrofolate reductase (MTHFR) functional gene polymorphisms, causative in aberrant folate-homocysteine metabolism, are associated with increased vulnerability to several heritable developmental disorders. Opposing views are expressed...... considering the possible association between MTHFR and susceptibility for schizophrenia. In order to evaluate if age of onset could explain some of this discrepancy we investigated the relationship between two functional MTHFR gene polymorphisms and age at onset in this disorder. Scandinavian patients (n...

  8. Association of MTHFR (C677T) Gene Polymorphism With Breast Cancer in North India

    National Research Council Canada - National Science Library

    Mohammad Waseem; Syed Rizwan Hussain; Shashank Kumar; Mohammad Serajuddin; Farzana Mahdi; Satyendra Kumar Sonkar; Cherry Bansal; Mohammad Kaleem Ahmad

    2016-01-01

    ... pathway, methylenetetrahydrofolate reductase (MTHFR) is the key enzyme that catalyzes the irreversible reduction of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, which is the primary circulating form of folate and the methyl donor in DNA methylation. MTHFR, a critical enzyme in one-carbon metabolism, is of interest because aberration...

  9. C677t (rs1801133 ) MTFHR gene polymorphism frequency in a colombian population

    OpenAIRE

    Consuelo Romero-Sanchez; Alberto Gomez-Gutierrez; Piedad Elena Gomez; María Consuelo Casas-Gomez; Ignacio Briceño

    2015-01-01

    Introduction:Abnormal levels of the enzyme methylenetetrahydrofolate reductase (MTHFR) are associated with an increased risk of both cardiovascular and cerebrovascular disease and higher concentrations of homocysteine. Abnormal levels are also related to birth defects, pregnancy complications, cancer and toxicity to methotrexate (MTX). Polymorphisms of MTHFR affect the activity of the enzyme. Genetic associations have been related to treatment efficacy.Objective:To establish the frequency of ...

  10. Estructura genética en poblaciones prehispánicas del centro de Argentina

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    Fabra, Mariana

    2007-01-01

    Full Text Available Se analizan, a partir de nuevos datos craneométricos, las relaciones interpoblacionales y los roles relativos cumplidos por las fuerzas evolutivas sistemáticas vs las aleatorias en la diferenciación biológica de las poblaciones que ocuparon el actual territorio de Córdoba y otras que habitaron otras regiones geográfico-ecológicas de Argentina. La muestra está compuesta por 14 poblaciones, incluyendo 274 adultos masculinos, analizados en 10 variables craneofaciales. Se utiliza el análisis de componentes principales (PCA y el análisis de Relethford y Blangero (1990, basado en el modelo de Harpending y Ward (1982, para datos morfológicos. De acuerdo a este modelo, bajo presión sistemática uniforme, existe una correlación lineal y negativa entre la diversidad genética observada (en el caso de rasgos morfológicos se toma la variación fenotípica de forma análoga y la distancia genética de cada población a un hipotético antecesor común. El PCA muestra a Córdoba en una posición intermedia, cercana a San Luís y a otras poblaciones de las regiones pampeana y centro de Patagonia. El análisis de Relethford-Blangero ubica a Córdoba muy cercana al origen y sobre la línea de regresión, lo cual sugiere un tamaño poblacional grande y/o una separación reciente de la población ancestral, o bien la existencia de alto flujo genético con las poblaciones de las regiones mencionadas en el PCA.

  11. Diversidad genética del jengibre (Zingiber officinale Roscoe.) A nivel molecular: Avances de la última década

    OpenAIRE

    Eleonora Zambrano-Blanco

    2015-01-01

    El jengibre ( Zingiber officinale ) es una especie medicinal, aromática y condimentaria que se cultiva principalmente en regiones tropicales y subtropicales del mundo. Por tratarse de una especie de propagación vegetativa, su variabilidad genética tiende a ser baja; sin embargo es posible hallar una amplia variabilidad genética principalmente en la China e India, considerándose actualmente como el principal centro de origen y diversidad de esta especie. Conocer y caracterizar la diversidad...

  12. Informe del proyecto Variabilidad genética, incompatibilidad floral y calidad de fruto en cerezo (RTA2012-00103-00-00)

    OpenAIRE

    Wünsch, Ana; Centro de Investigación y Tecnología Agroalimentaria de Aragón - CITA

    2017-01-01

    Aunque existen regiones donde algunas variedades locales siguen teniendo importancia, la producción de cereza en España se basa, en su mayor parte, en cultivares obtenidos en programas de mejora genética de otros países. A pesar de la buena producción y calidad que presentan estos cultivares, en España se han identificado caracteres de interés para la mejora del cultivo en el material vegetal local. Siendo España un reservorio de diversidad genética de cerezo y el cerezo un cultivo con una b...

  13. Variabilidad genética del mildiu (Bremia lactucae Regel) en Salamanca y San Miguel de Allende, Guanajuato, mediante RAPD e ISSR

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    Martínez Martínez, Susana

    2012-01-01

    Bremia lactucae Regel causa una de las enfermedades de mayor importancia en la lechuga a nivel mundial. Debido a que este pseudohongo presenta dos tipos de reproducción: sexual y asexual, su diversidad genética es amplia y puede dar origen a nuevas razas. Dicha situación se desconoce en México, por lo que es importante conocer este aspecto en las zonas productoras de esta hortaliza, así como también la influencia que ejercen los factores ambientales sobre la incidencia y severidad del patógen...

  14. Polimorfismo GHRd3 del gen del receptor de la hormona de crecimiento en niños peruanos con talla baja idiopática

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    Carlos Del Águila

    2016-01-01

    Full Text Available Objetivos. Describir la estandarización de la detección molecular y la frecuencia del polimorfismo de GHRd3 del gen del receptor de la hormona de crecimiento en una población de niños peruanos con talla baja idiopática. Materiales y métodos. Se estudiaron 64 muestras de sangre periférica de pacientes con diagnóstico de talla baja idiopática atendidos en el servicio de endocrinología del Instituto Nacional de Salud del Niño en Lima, Perú. La amplificación del exón 3 se llevó a cabo empleando los cebadores G1, G2 y G3 optimizándose las condiciones de PCR, como la temperatura de hibridización y las concentraciones de magnesio. Resultados. Se determinó la especificidad de los cebadores a 67 °C y no se obtuvo diferencias entre las concentraciones de magnesio probadas. El 67% de los pacientes fueron homocigotos para GHRfl, 28% fueron heterocigotos y 5% fueron homocigotos para GHRd3. Conclusiones. La técnica permitió establecer los genotipos de los pacientes con talla baja idiopática, determinándose que solo el 5% de ellos presenta el genotipo susceptible de mejor respuesta al tratamiento con rhGH, lo cual puede ser considerado en la decisión de iniciar la terapia.

  15. Variabilidad genética de Aedes aegypti en algunas áreas del Perú usando Single Stranded Conformational Polymorphism (SSCP

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    Nélida Leiva G

    2004-07-01

    Full Text Available Aedes aegypti es el vector responsable de la transmisión del virus del dengue, su distribución geográfica se ha ampliado rápidamente debido principalmente a la intervención de los seres humanos. Objetivo: Analizar la variabilidad genética de este mosquito mediante la comparación del Segundo Espaciador Transcrito Interno (ITS 2 perteneciente al ADN ribosomal (rADN. Materiales y Métodos: Se analizaron muestras de ocho localidades (Jaén, Tingo María, Iquitos, Lambayeque, el distrito de El Rimac, Sullana y Zarumilla y uno de la provincia de Huaquillas (Ecuador. El análisis de la variabilidad se determinó usando la técnica conocida como SSCP (Single Stranded Conformation Polymorphism. Resultados: El estudio muestra que existe variabilidad genética entre las poblaciones analizadas, principalmente entre las muestras localizadas en la costa del Perú (Zarumilla, El Rímac, Sullana y Huaquillas y las muestras del nororiente (Tingo María, Iquitos, Jaén y Lambayeque Conclusión: Se determinaron dos variantes genéticas entre las poblaciones de Aedes aegypti: Costeña y Nororiental, que probablemente provienen de dos ancestros diferentes y cuyo ancestro común sufrió de aislamiento por distancia. Se observó que no existe relación entre las distancias genéticas y las distancias geográficas indicando que la migración de estas poblaciones es el resultado de la intervención de los seres humanos que diseminan al vector y no por la migración activa del mosquito. Se plantea el papel de la Cordillera de los Andes en la migración y separación de las poblaciones de Aedes.

  16. Mutaciones en genes modificadores de ARN ribosómico y la resistencia a aminoglucósidos: el caso del gen rsmG

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    Alfonso Benítez-Páez

    2014-04-01

    Full Text Available Introducción. Los aminoglucósidos son moléculas antibióticas capaces de inhibir la síntesis de proteínas bacterianas tras su unión al ribosoma procariota. La resistencia a aminoglucósidos está clásicamente asociada a mutaciones en genes estructurales del ribosoma bacteriano; sin embargo, varios estudios recientes han demostrado, de forma recurrente, la presencia de un nuevo mecanismo dependiente de mutación que no involucra genes estructurales. El gen rsmG es uno de ellos y se caracteriza por codificar una metiltransferasa que sintetiza el nucleósido m7G527 localizado en el loop 530 del ribosoma bacteriano, este último caracterizado como sitio preferencial al cual se une la estreptomicina. Objetivo. Partiendo de las recientes asociaciones clínicas entre las mutaciones en el gen rsmG y la resistencia a estreptomicina, este estudio se propuso la caracterización de nuevos puntos calientes de mutación en este gen que puedan causar resistencia a estreptomicina usando Escherichia coli como modelo de estudio. Materiales y métodos. Se indagó sobre el mecanismo genético y molecular por el cual se adquiere la resistencia a estreptomicina y su transición a la resistencia a altas dosis mediante mutagénesis dirigida del gen rsmG y genotipificación del gen rpsL. Resultados. Se encontró que la mutación N39A en rsmG inactiva la proteína y se reportó un nuevo conjunto de mutaciones en rpsL que confieren resistencia a altas dosis de estreptomicina. Conclusiones. Aunque los mecanismos genéticos subyacentes permanecen sin esclarecer, se concluyó que dichos patrones secuenciales de mutación podrían tener lugar en otros genes modificadores del ARN bacteriano debido a la conservación evolutiva y al papel crítico que juegan tales modificaciones en la síntesis de proteínas.

  17. Estructura genética del copépodo Acartia lilljeborgii en la costa del estado de Yucatán, México

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    Jorge Tello-Cetina

    2013-11-01

    Full Text Available Se determinó la estructura genética poblacional y sus implicancias dentro de la cadena trófica del copépodo Acartia lilljeborgii en la costa de Yucatán, mediante el uso de isoenzimas y su posterior determinación por electroforesis. Nueve sistemas se expresaron con un máximo de 30 loci. El polimorfismo y heterocigosis de las poblaciones estudiadas, al ser comparados con otras especies de copépodos, resultaron ser bajos y de los cuatro loci que presentaron variación, solo los loci EST2 y PGM1 se expresaron en todos los sitios de muestreo. La PGM1 presentó el mayor valor de heterocigosis (0,4728 y la GPI1 fue la de menor valor (0,3200. Ningún sistema se apartó de la condición de equilibrio de Hardy-Weinberg. Los valores de FST estuvieron entre los valores de -0,0798 para PGM1 y de 0,5899 para FBP1. Las tres poblaciones de A. lilljeborgii analizadas en la costa de Yucatán, presentaron una baja variabilidad y diferenciación genética entre las poblaciones, como lo indican los valores de distancia genética de 0,0585 que fue el mayor para las poblaciones de Chelem y de Río Lagartos, lo que sugiere que estas poblaciones están parcialmente aisladas. Sin embargo, debido a que A. lilljeborgii produce huevos diapáusicos o de reposo, que pueden ser transportados fuera o dentro de éstos cuerpos de agua, es probable que esta condición mantenga las frecuencias alélicas y genotípicas similares o muy cercanas entre sí. Los resultados mostraron la existencia de flujo genético, dado a través de una dispersión pasiva de los huevos diapáusicos que produce esta especie.

  18. Polimorfismo en el gen del factor de crecimiento vascular endotelial (VEGF y su asociación con la preeclampsia

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    José Pacheco-Romero

    2014-04-01

    Full Text Available Antecedentes: La preeclampsia (PE es la primera causa de muerte materna en el mundo y afecta alrededor de 10% de las gestantes en algunas regiones del Perú. Se ha determinado varios genes involucrados en el riesgo de PE, entre ellos el gen del factor de crecimiento endotelial vascular (VEGF. Objetivos: Estudiar el polimorfismo +936 CT en el gen VEGF y evaluar su asociación con la preeclampsia. Diseño: Estudio observacional, relacional (asociativo, tipo casos-control (no experimental. Institución: Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Participantes: Gestantes con y sin preeclampsia. Métodos: La muestra estuvo conformada por 94 gestantes (45 con PE y 49 controles sin PE atendidas en el hospital Docente Madre-Niño San Bartolomé. Previo consentimiento informado, se colectó de 3 a 5 mL de sangre de vena antecubital. El ADN fue aislado aplicando métodos estándares. Se evaluó el polimorfismo VEGF mediante técnica PCR-RFLP y electroforesis en geles de agarosa o poliacrilamida. Principales medidas de resultados: Asociación entre los genotipos y alelos VEGF con la preeclampsia. Resultados: Las distribuciones de los genotipos (CC, CT y TT en el grupo de Casos se encontraron en ‘desequilibrio de Hardy-Weinberg’ (existió un factor que estuvo influenciando esa distribución, mientras que los genotipos en el grupo de Controles se encontraron en equilibrio. Las frecuencias de los genotipos VEGF en los casos y controles mostraron diferencias no significativas, aunque en el límite de significancia (X2=5,630, p=0,060. El genotipo homocigoto TT fue más frecuente en los casos y los genotipos heterocigotos CT fueron más frecuentes en los controles. Las diferencias en las frecuencias de alelos C y T en los casos y controles no fueron significativas (X2=0,614, p=0,434. Conclusiones: Preliminarmente, se concluye que no existió asociación entre los genotipos (aunque en el límite de significancia y alelos VEGF con la

  19. El uso de alteraciones genéticas en la estratificación por riesgo del mieloma múltiple

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    Esteban Braggio

    2013-08-01

    Full Text Available Los estudios genéticos han alcanzado un papel central en el estudio del mieloma múltiple (MM, al convertirse en un componente crítico en la estratificación basada en el riesgo de la enfermedad. Se han hecho grandes esfuerzos para identificar cambios genéticos que puedan predecir el resultado clínico e incluirlos en la práctica clínica diaria. La hibridización in situ fluorescente (FISH es todavía la técnica genética más utilizada en la práctica clínica, mayormente debido a su sencilla implementación y su simplicidad para el análisis de datos. El advenimiento de la genómica (hibridización genómica comparativa, secuenciación exónica o genómica completa y del transcriptoma de alta resolución (perfiles de expresión de genes - GEP y secuenciación de ARNm proveen un análisis exhaustivo de los ya definidos factores pronósticos genéticos y son herramientas útiles para la identificación de potenciales nuevos marcadores pronósticos de enfermedad en el clon tumoral de MM. Más aún, GEP ha sido exitosamente implementado en MM como una herramienta de estratificación de riesgo, siendo la de mayor poder de discriminación de resultados. De todas maneras, algunos aspectos técnicos y logísticos complejos (necesidad de una elevada purificación del clon tumoral, costo de los ensayos y complejidad en los análisis de los datos deben ser considerados antes de la incorporación definitiva de estas tecnologías de alto rendimiento dentro de los ensayos clínicos de rutina. Hasta entonces, FISH continúa siendo la herramienta estándar para la detección de anormalidades genéticas y de valoración pronóstico de enfermedad.

  20. Efectos genéticos directos y maternos del peso al destete en una población de ganado Cebú de Cuba

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    Alejandro Palacios-Espinosa

    2010-01-01

    Full Text Available El objetivo de este estudio fue estimar los parámetros genéticos para peso al destete en ganado Cebú. Se utilizaron datos de 20,151 terneros nacidos entre 1988 y 2006 en la provincia de Camagüey, Cuba. Se aplicaron seis modelos estadísticos que tuvieron como efecto fijo en común al grupo de contemporáneas (año-hato-época-sexo y como covariables la edad al destete lineal y la edad de la madre al parto lineal y cuadrática. El efecto aleatorio del animal fue común a todos los modelos y se alternaron los efectos genético materno, del ambiente permanente y la covarianza genética entre los efectos directo y materno. De acuerdo con la prueba del logaritmo de la verosimilitud, el mejor modelo fue el que incluyó los efectos aleatorios del animal, maternos y del ambiente permanente, además, la covarianza entre los efectos directos y maternos. La heredabilidad de los efectos genéticos directo (0.06 a 0.34 y materno (0.06 a 0.19 varió entre los modelos. La correlación entre el efecto directo y materno varió entre -0.12 + 0.13 y -0.19 + 0.15. El efecto materno ambiental determinó un 13 % de la variabilidad total. Se concluyó que la heredabilidad del peso al destete en el ganado Cebú de la población estudiada puede ser sobre estimada cuando el modelo animal no incluye los efectos maternos; y no obstante que los valores de heredabilidad encontrados fueron bajos para los efectos directos y maternos, la ausencia relativa de antagonismo genético entre ellos podría permitir un mejoramiento genético moderado por selección.

  1. Estudio del gen WT1 en la leucemia mieloblástica aguda

    OpenAIRE

    Luna del Valle, Irene

    2016-01-01

    En los últimos años se ha producido un notable progreso en la elucidación de la patogénesis molecular de las Leucemias Mieloblásticas Agudas (LMA). Sin embargo, la mayoría de las alteraciones genéticas que subyacen en esta patología son todavía desconocidas. La LMA se caracteriza por la presencia de un “stop madurativo” de las células de la línea mieloide, que escapan de la inhibición de las señales anti-proliferativas y adquieren una capacidad indefinida de auto-renovación. Los posibles meca...

  2. Alteraciones del gen c-Myc en la oncogénesis = c-Myc gene alterations in oncogenesis

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    Ospina Pérez, Mariano

    2011-12-01

    Full Text Available La familia de protooncogenes MYC (c-Myc, N-Myc y L-Myc se relaciona con el origen de diversas neoplasias en seres humanos. Estos genes actúan como factores de transcripción y participan en la regulación del ciclo celular, la proliferación y diferenciación celulares, la apoptosis y la inmortalización. Los genes MYC se expresan en diferentes tejidos y responden a diversas señales internas y externas; codifican para la síntesis de factores de transcripción que se unen al ADN para regular la expresión de múltiples genes. El gen más ampliamente estudiado de esta familia es c-Myc, que se expresa en las células con mayor tasa de proli­feración. C-Myc se encuentra alterado en un gran número de tumores sólidos, leucemias y linfomas. Las alteraciones de c-Myc encontradas con mayor frecuencia en células cancero­sas son las amplificaciones, translocaciones, mutaciones y reordenamientos cromosómicos que involucran el locus de este gen y conducen a que se desregule su expresión en diversas neoplasias humanas. La amplificación de c-Myc es una alteración común en los cánceres de mama, pulmón, ovario y próstata, así como en leucemias y linfomas, mientras que la pérdida de su regulación es común en el cáncer de colon, en tumores ginecológicos y melanoma. En neoplasias con defectos de c-Myc los estudios actuales están dirigidos al desarrollo de nuevas estrategias terapéuticas.

  3. Análisis de la representación del contenido (ReCo a cerca del concepto de gen en un profesor en formación

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    Andres David García Melo

    2015-12-01

    Full Text Available Se presenta aquí un artículo   que evidencia los resultados obtenidos de un trabajo de investigación  sobre Conocimiento Didáctico del Contenido (CDC  durante  la práctica desarrollada en el espacio académico de Aula Experimental a través de la Representación del Contenido (ReCo sobre el concepto de Gen, de un estudiante de Licenciatura en Biología De la Universidad Distrital Francisco José de Caldas,se aplica un cuestionario semi-estructurado denominado Representación del Contenido (ReCo que consta de ocho preguntas  que permiten investigar el conocimiento didáctico que sobre esas ideas centrales tienen  la docente en formación  en torno al concepto de gen. Finalmente se puede concluir que La representación de contenido de gen asociada a las leyes de Mendel  en el caso particular del docente en formación, permite evidenciar la fragmentación que se da en torno al concepto de gen en el aula, ya que durante el (ReCo es repetitivo la necesidad de  asociar el concepto al contexto de los estudiantes para así llegar  a ser más aplicable  y fácil de entender.

  4. Detección de aneuploidías del cromosoma 17 y deleción del gen TP53 en una amplia variedad de tumores sólidos mediante hibridación in situ fluorescente bicolor

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    Juan Carlos Herrera

    2010-09-01

    Conclusiones. La aneuploidía del cromosoma 17 y la deleción en el locus 17p13.1 del gen TP53 son alteraciones muy frecuentes en los tumores sólidos. La técnica FISH-bicolor permite detectar simultáneamente alteraciones cromosómicas numéricas y estructurales en núcleos interfásicos.

  5. Aspectos genéticos del procesamiento de antígenos intracelulares

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    Beatriz Martínez

    1993-03-01

    Full Text Available La activación de los linfocitos T (LT, un aspecto fundamental en la generación de la respuesta inmune (RI, se produce mediante el contacto de sus receptores antigénicos (TCR con un complejo formado por un péptido derivado del antígeno y una molécula del complejo mayor de Histocompatibilidad (MHC, HLA en el humano sobre la superficie de una célula presentadora de antígenos (APC. El origen del péptido puede ser exógenooextracelular, como sucede con la mayoría de los antígenos presentados por las moléculas MHC clase II, o endógeno (intracelular, como es el caso de las proteínas virales. sintetizadas por la célula y presentadas por las moléculas MHC Clase.

  6. Enfermedades genéticas del ADN mitocondrial humano Genetic diseases of the mitochondrial DNA

    OpenAIRE

    Abelardo Solano; Ana Playán; López-Pérez, Manuel J.; Julio Montoya

    2001-01-01

    Las enfermedades mitocondriales son un grupo de trastornos que están producidos por un fallo en el sistema de fosforilación oxidativa (sistema Oxphos), la ruta final del metabolismo energético mitocondrial, con la consiguiente deficiencia en la biosíntesis del trifosfato de adenosina (ATP, por sus siglas en inglés). Parte de los polipéptidos que componen este sistema están codificados en el ácido desoxirribonucleico (DNA) mitocondrial y, en los últimos años, se han descrito mutaciones que se ...

  7. BÚSQUEDA DE LA MUTACIÓN Phe-809 EN EL GEN DEL SUSTRATO DEL RECEPTOR DE INSULINA -1 (IRS-1 EN RATAS DIABÉTICAS eSS

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    Stella Maris Daniele

    2010-01-01

    Full Text Available El gen del sustrato del receptor de insulina IRS-1 juega un rol clave en la transducción de señales de insulina en músculo esquelético. Diversos polimorfismos del gen IRS-1 han sido reportados en estados de insulinorresistencia como obesidad y diabetes tipo 2.Las ratas eSS desarrollan espontáneamente diabetes tipo 2 magra, con insulinoresistencia caracterizada por hiperglucemia e hiperinsulinemia. Durante el segundo año existe disminución progresiva de la insulinemia y agravamiento del síndrome. Nuestro propósito fue buscar la mutación Phe-809 en el gen IRS-1, que implica sustitución del aminoácido Ser por Phe en el codon 809; dicho sitio se halla conservado en la rata. Esta variante fue identificada en pacientes diabéticos tipo 2. El gen del IRS-1 consta de un solo exón.Se analizó un fragmento de 281pb del gen IRS-1, que posee 90% de homología con el mismo fragmento en humanos. Se purificó ADN de leucocitos de un pool de sangre de ratas machos eSS y controles Wistar. Se cuantificó y amplificó por PCR utilizando un par de primers para amplificar ese mismo fragmento en el gen IRS-1 en humanos. Se usó sangre humana como control de amplificación. Se empleó el método de Sanger en la secuenciación del fragmento obtenido por PCR, previa extracción del mismo de un gel de agarosa al 2%. Se observó que la rata eSS y las controles mantuvieron la lectura esperada para ese fragmento, no encontrándose la mutación investigada. Se descarta la mutación Phe-809 como origen de la insulinoresistencia de la rata eSS.

  8. Traducción independiente de la estructura 5´cap del ARN genómico del virus dengue

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    Mariela Pérez Dominguez

    Full Text Available Objetivos. Analizar la participación de la caperuza metil-guanosín-trifosfato (5´cap y de la región inicial del ARN genómico del virus dengue serotipo 2 (DENV-2 genotipo Americano en la traducción, utilizando un sistema libre de células obtenido de placenta humana. Materiales y métodos. Se preparó el plásmido recombinante pTZ18R-D2 conteniendo el ADN que codifica la 5´UTR y los primeros 201 nucleótidos de la cápside viral. Este plásmido se utilizó para transcribir el ARN correspondiente (ARN-D2, sin la 5´cap. El ARN-D2 fue traducido en un sistema constituido por la fracción posmitocondrial (S-30 de placenta humana y se evaluó la incorporación de [ 14C] aminoácidos en presencia del ARN-D2 y en su ausencia (control. Se diseñaron siete oligonucleótidos antisentido (OAs1-7 dirigidos contra secuencias de las estructuras SLA, SLB y cHP del ARN-D2 y se analizó el efecto de los mismos sobre la traducción ARN-D2. Resultados. El ARN-D2 produjo un incremento significativo (p<0,001 en la incorporación de [14C] aminoácidos, con estimulación del 75% de la actividad traduccional respecto al control. El análisis de los productos de traducción mostró un pico de incorporación correspondiente a péptidos con peso molecular aparente cercano al esperado (7,746 kDa. El OAs5, complementario a una secuencia de la estructura SLB del ARN-D2, inhibió completamente la traducción. Conclusiones. El ARN-D2 fue traducido de manera específica y eficiente, bajo condiciones semejantes a las intracelulares en humanos, por un mecanismo alternativo independiente de la 5´cap, que involucraría a la estructura SLB. Este mecanismo podría considerarse como blanco en el desarrollo de terapias antisentido para inhibir la reproducción del virus.

  9. Asociación del polimorfismo del codon 72 del gen p53 con el riesgo de cáncer gástrico en una población de alto riesgo de Costa Rica

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    Warner Alpízar-Alpízar

    2005-09-01

    Full Text Available El cáncer gástrico es la segunda causa de muerte por cáncer en el mundo. Varios factores han sido asociados con el riesgo de llegar a desarrollarlo, entre ellos la predisposición genética. El gen p53 presenta un polimorfismo en el codón 72, el cual ha sido asociado con un mayor riesgo de desarrollar varios tipos de cáncer entre ellos el gástrico. El objetivo de este estudio fue determinar la asociación del polimorfismo localizado en el codón 72 del gen p53 con el riesgo de cáncer gástrico y lesiones gástricas leves en una población de alto riesgo de Costa Rica. El análisis del polimorfismo se llevó a cabo mediante PCR-RFLP, en una muestra de 58 pacientes de cáncer gástrico, 99 personas controles y 41 individuos clasificados como grupos I y II de acuerdo con la clasificación histológica japonesa. No se determinó asociación del polimorfismo del codón 72 de p53 con el riesgo de cáncer gástrico, ni de lesiones gástricas leves en la muestra estudiada. Con base en este estudio y otros que han investigado el polimorfismo del codón 72 del gen p53, no está claro el papel que podría estar jugando dicho polimorfismo en el desarrollo de cáncer gástrico. Mutaciones de novo en el gen p53 producidas durante el desarrollo neoplásico de la enfermedad podrían tener un mayor efecto que polimorfismos de línea germinal de este mismo gen. Existen otros genes polimórficos que también se han asociado con el riesgo de desarrollar cáncer gástrico.Association of the p53 codon 72 polymorphism to gastric cancer risk in a hight risk population of Costa Rica. Gastric cancer is the second most common cancer associated death cause worldwide. Several factors have been associated with higher risk to develop gastric cancer, among them genetic predisposition. The p53 gene has a polymorphism located at codon 72, which has been associated with higher risk of several types of cancer, including gastric cancer. The aim of this study was to determine

  10. Conocimiento y actitudes de oftalmólogos mexicanos acerca del consejo genético para retinoblastoma: análisis bioético

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    Paula Morelos Herrera

    2016-11-01

    Resultados: Contestaron la encuesta 181 oftalmólogos. El 74% de los encuestados se ha visto en la necesidad de brindar este tipo de asesoramiento en alguna ocasión; sin embargo, una gran parte (73.5% no tiene conocimiento sobre los patrones de herencia del retinoblastoma, ni de los aspectos bioéticos relativos al asesoramiento genético.

  11. Aproximación a la filogenia de Spodoptera (Lepidoptera: Noctuidae con el uso de un fragmento del gen de la citocromo oxidasa I (COI

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    Clara Inés Saldamando

    2012-09-01

    Full Text Available En este trabajo se secuenció un fragmento de 451pb del gen mitocondrial de la citocromo oxidasa I (COI en 62 secuencias del género Spodoptera y una secuencia de Bombix mori (grupo externo. Los resultados mostraron gran diferenciación genética (distancia K2 entre los haplotipos de Spodoptera frugiperda de Colombia y Estados Unidos, según los estimadores de diversidad haplotípica, diversidad y polimorfismo nucleotídicos calculados. Un árbol de ML agrupó las especies con valores de bootstrap entre 73-99% en las ramas internas. No obstante algunas ramas presentaron bajos valores de bootstrap. Este árbol formó un grupo constituido por las especies del hemisferio oriental (S. littoralis y S. litura y también agrupó las especies localizadas en el hemisferio occidental (S. androgea, S. dolichos, S. eridania, S. exigua, S. frugiperda, S. latifascia, S. ornithogalli y S. pulchella. Esto demuestra que el árbol agrupó las especies con base en su origen geográfico. Contrariamente, el árbol no agrupó a S. frugiperda con S. ornithogalli, demostrando que a pesar de que ambas coexisten en el cultivo de algodón, no comparten un ancestro común reciente. En Colombia, estas especies forman parte del “complejo Spodoptera” del algodón, y nuestros resultados demuestran que la secuenciación de este gen permite diferenciarlas sin necesidad del uso de claves taxonómicas de sus estadios larvales. Este trabajo es una aproximación a la filogenia de este género, por lo cual la inclusión de más genes (mitocondriales y nucleares son necesarios para futuros trabajos.

  12. La Comunidad Andina frente al reto del acceso a los recursos genéticos y la distribución de beneficios

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    Martha Isabel Gómez Lee

    2012-11-01

    Full Text Available Este artículo estudia las medidas jurídicas y políticas que ha adoptado la Comunidad Andina (CAN sobre el acceso a los recursos genéticos y la distribución de beneficios a la luz de los estudios de equidad en la distribución de beneficios de Bram de Jonge y Niels Louwaar (2009. Según estos autores, el principio de Acceso y Distribución de Beneficios (ADB se justifica por tres asimetrías que están presentes en este asunto. Por un lado, la doble asimetría entre la asignación y la explotación de los recursos y, por otro, la asimetría entre los derechos de propiedad intelectual y los derechos legales de los recursos genéticos y los conocimientos tradicionales. En este contexto, la CAN ratifica los principios de soberanía de los recursos genéticos y de Acceso y Distribución de Beneficios del Convenio sobre Diversidad Biológica. Las principales respuestas que ha dado la CAN al reto del acceso a los recursos genéticos y distribución de beneficios son las Decisiones 391, 486 y 523. En este contexto, el Programa BIOCAN está trabajando en los temas de especial relevancia para la región, dentro de los cuales están los desafíos de asignarle valor a los recursos genéticos y el de la biopiratería.

  13. Caracterización de variantes genómicas. Aplicación de nuevas tecnologías al estudio del retraso mental.

    OpenAIRE

    Madrigal Bajo, Irene

    2008-01-01

    Estudios recientes han permitido estimar que aproximadamente un 5% del genoma consiste en duplicaciones segmentarias (DS), secuencias de entre 1-100 kb con un nivel de similitud de más del 95% (Eichler, 2001). Las regiones flanqueadas por duplicaciones segmentarias son susceptibles de sufrir reordenamientos mediante recombinación homóloga no alélica y se ha hipotetizado que estas regiones representan puntos calientes de inestabilidad genómica propensos a variación en número de copia (CNVs). E...

  14. Genética del Autismo: Caenorhabditis elegans como modelo experimental en el estudio de la función sináptica neuronal

    OpenAIRE

    Calahorro, Fernando

    2011-01-01

    Los trastornos del espectro autista son de etiología desconocida. Los datos epidemiológicos en los que se compara la incidencia de estas enfermedades en gemelos monocigóticos y dicigóticos demuestran que tienen un origen predominantemente genético. Diversos resultados experimentales recientes indican que en un número significativo de casos, estos trastornos se originan por alteraciones en la sinapsis neuronal, que durante el desarrollo del sistema nervioso podrían constituir la raíz de las an...

  15. Estimación mediante RAPD's de la diversidad genética en Guadua en el departamento del Cauca, Colombia

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    Palacio M. Juan Diego

    2006-06-01

    Full Text Available

    Mediante RAPD's se analizaron 120 muestras foliares de 12 biotipos de Guadua angustifolia Kunth clasificados morfológicamente, procedentes de la cuenca del río Cauca, en el departamento del Cauca, Colombia, para determinar diversidad genética. El ADN se extrajo mediante el protocolo modificado de Dellaporta (1983. Se emplearon los cebadores; OPF-12, OPG-19, OPN-19 y OPP-16 con mayor número de bandas polimórficas. El índice de Shannon (HT = 0.4556 ± 0.1849 señaló diversidad genética total alta y diversidad entre los biotipos y al interior de ellos. El Índice de estructura genética (Gst = 0.5200 e Indice de migración efectiva (Nm = 0.4615 definieron biotipos bien diferenciados. El análisis de similaridad conformó tres grupos a un coeficiente de 0.64. El grupo G1 incluyó los biotipos Curvado, Rayada frecuente, Amarilla Playón, Rayada ancha, Rayada escasa, Convexa, Amarilla, Hembra, Verde irregular y algunos individuos de verde alta. El grupo G2, Verde alta y Macho. El grupo G3, Rayada negra. El estudio molecular agrupó los individuos de forma similar al estudio morfológico, con excepción de los individuos del biotipo Hembra.

    Palabras claves: Guadua angustifolia, caracterización molecular, variación genética.

  16. Detección del gen codificante de la metalo-ß-lactamasa VIM-2 en un integrón de clase 1 asociado con el gen blaCTX-M-2 en un aislamiento clínico de Pseudomonas aeruginosa en el Uruguay: primera comunicación

    OpenAIRE

    Ingold, Ana J.; Mercedes Castro; Adriana Nabón; Graciela Borthagaray; Carolina Márquez

    2011-01-01

    Con el fin de analizar la presencia de metalo-ß-lactamasas en nuestro medio, se incluyeron en este estudio aislamientos de Pseudomonas aeruginosa causantes de infecciones nosocomiales en un centro hospitalario del Uruguay, en el período comprendido entre abril y setiembre de 2008. En un aislamiento se detectó la presencia del gen codificante de la metalo-ß-lactamasa VIM-2 asociado a un integrón de clase 1 y del gen codificante de una ß-lactamasa de espectro extendido CTX-M-2. Esta es la prime...

  17. Análisis del polimorfismo del gen APOE en la población de Barranquilla, Colombia

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    Martha Ruiz

    2016-03-01

    Conclusiones. Las frecuencias alélicas ε3 y el genotipo ε3/ε3 encontrados en la población estudiada, fueron similares a lo informado por la literatura científica en países como Brasil, México y Colombia, y en algunos grupos étnicos amerindios colombianos. No se encontró el genotipo ε2/ε2, resultado que coincide con otras poblaciones estudiadas a nivel mundial. La frecuencia del alelo ε4 y sus genotipos asociados en esta población, podría estar relacionada con la presencia de enfermedades como la hipercolesterolemia, el infarto de miocardio y la enfermedad de Alzheimer.

  18. Estimación de la varianza genética y ambiental en caracteres métricos del esqueleto humano

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    Varela, Héctor Hugo

    2003-01-01

    Full Text Available En la teoría evolutiva de rasgos cuantitativos el conocimiento de la varianza genética (VG es determinante para hacer inferencias acerca del parentesco. En muchos casos no es posible estimar dicha componente sin la información obtenida a partir de la correlación entre parientes o de experimentos de selección. Por esta razón, en ausencia de datos apropiados es posible lograr una aproximación mediante el análisis de la repetibilidad de caracteres cuantitativos. En este trabajo se estima la proporción de la varianza genética máxima (VGmax o repetibilidad de medidas del cráneo y del esqueleto postcraneal, empleando la información obtenida por la Dra. Silvia Quevedo en el grupo prehistórico de Punta Teatinos (Norte Semiárido de Chile. La VG es igual a la varianza fenotípica (VP menos la varianza ambiental (VE. Esta última se puede particionar en una varianza ambiental especial (VEe y en una varianza ambiental general (VEg. Como la VEe se puede conocer por la medición de caracteres simétricos del lado derecho e izquierdo del individuo, entonces es posible calcular la varianza genética máxima de la siguiente manera, VGmax=VP-VEe. La proporción de la VGmax se obtuvo para siete variables del esqueleto postcraneano en individuos femeninos (n=56, masculinos (n=55, de ambos sexos (n=115 e infantiles (n=66, y para nueve mediciones del cráneo en un único grupo (n=54. Los resultados indican que la proporción media de la VGmax es menor en el cráneo que en el esqueleto postcraneal sugiriendo una distribución diferencial del efecto ambiental desde el punto de vista topográfico. Además, dicha cantidad es mayor en individuos infantiles que en masculinos y femeninos posiblemente por la existencia en aquellos de una mayor influencia del efecto ambiental general confundido con la VGmax.

  19. Variabilidad genética del robalo común Centropomus undecimalis (Perciformes: Centropomidae en ambiente marino y ribereño interconectados

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    Ulises Hernández-Vidal

    2014-08-01

    Full Text Available El robalo común Centropomus undecimalis habita en áreas ribereñas y marinas del sur del Golfo de México donde es sujeto a explotación intensiva. Aunque la identificación de las poblaciones de peces representa una valiosa herramienta para el manejo de las poblaciones silvestres, no hay información disponible para identificar genéticamente las poblaciones de peces de esta especie en la región. El objetivo de este estudio fue determinar la relación genética entre C. undecimalis capturado en ambiente marino y dulceacuícola del Golfo de México y río San Pedro. Muestras de tejido muscular de 79 individuos fueron obtenidas en áreas separadas por más de 300km. El genotipo de cada individuo fue determinado usando siete pares de cebadores microsatélites. Cinco cebadores amplificaron eficientemente presentando entre seis y 28 alelos por locus. Altos niveles de heterocigosidad se observaron en las muestras de ambos ambientes. Se observó desviación del equilibrio HW debido a exceso de heterocigotos. Los valores de diferenciación genética indican ausencia de estructuración poblacional F ST (0.0075 y R ST (0.016, p=0.051 y similitud en las frecuencias alélicas definidas por el índice de Nei (0.805. Los datos mostraron elevado flujo genético debido al número de migrantes (Nm=18.7. Estos resultados sugieren que los individuos en estos ambientes provienen de la misma población genética. La información obtenida en este estudio, por lo tanto contribuirá con elementos que pueden ser considerados en el desarrollo de programas de manejo y protección de las poblaciones de peces silvestres.

  20. Aspectos genéticos da escoliose idiopática do adolescente Aspectos genéticos de la escoliosis idiopática del adolescente Genetic aspects of the adolescent idiopathic scoliosis

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    Marcelo Wajchenberg

    2012-09-01

    Full Text Available A escoliose idiopática do adolescente é uma doença frequente e sua etiologia permanece obscura. Várias hipóteses foram formuladas, entre elas a possibilidade da transmissão genética. Estudos na literatura procuraram analisar a prevalência da doença em determinadas populações, as possíveis formas de transmissão, a localização dos genes responsáveis e as variações de determinados genes (polimorfismos que podem influenciar o desenvolvimento da deformidade. O objetivo deste artigo é revisar e atualizar os conceitos sobre a influência genética na etiologia da escoliose idiopática do adolescente.La escoliosis idiopática del adolescente es una enfermedad frecuente y su etiología continúa siendo obscura. Varias hipótesis fueron elaboradas, entre ellas, la posibilidad de la transmisión genética. Los estudios en la literatura procuraron analizar la prevalencia de la enfermedad en determinadas poblaciones, las posibles formas de transmisión, la localización de los genes responsables y las variaciones de genes específicos (polimorfismos que pueden influenciar en el desarrollo de la deformidad. El objetivo de este artículo es revisar y actualizar los conceptos sobre la influencia genética en la etiología de la escoliosis idiopática del adolescente.The adolescent idiopathic scoliosis is a common disease and its etiology remains unclear. Several hypotheses have been devised, including the possibility of genetic transmission. Studies in the literature have examined the prevalence of the disease in certain populations, the possible modes of transmission, the location of genes and variations of certain genes (polymorphisms that may influence the development of the deformity. This article intends to review and update the concepts of genetic influence in the etiology of adolescent idiopathic scoliosis.

  1. Variabilidad genética de Hartón del Valle mediante RAM Genetic variability of Harton del Valle by RAM

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    Ana M Piedrahíta

    2008-01-01

    Full Text Available El Hartón del Valle (HV hace parte de las siete razas criollas de ganado bovino colombiano y de acuerdo con los criterios de la FAO está considerado como vulnerable. Para estudiar su variabilidad genética fueron muestreados 33 individuos HV y tres animales de la raza Holstein, como control externo. Se extrajo ADN utilizando el método de Salting Out y las muestras fueron analizadas mediante la técnica molecular RAM (Randon amplified microsatellites. Se utilizaron los cebadores CGA, CCA, TG, y CT. El valor promedio de heterocigosidad esperada fue de 0.26 y el F ST fue 0.39 ± 0.03. Con el índice de Dice-Nei Li y agrupando con el método UPGMA se distinguieron dos grupos: uno integrado por dos hatos de conservación y el otro por cuatro fincas que han compartido reproductores.Harton del Valle (HV breed belong to the seven Creole breeds of the Colombian bovine livestock, according to FAO criteria it is considered as vulnerable. To study its genetical variability, 33 HV animals and three and 3 animals of Holstein breed as a external control were sampled. Simples of DNA were isolated using the Salting Out method and RAM (Random amplified microsatellites technique was used. CGA, CCA, TG and CT primers were used. The mean value of expected heterocigozity was 0.26 and F ST fue 0.39 ± 0.03. Using Dice-Nei Li index and UPGMA clustering method, two groups were distinguished: the first one integrated for two conservation herds and other one by tour faros that have been sharing breeding bulls.

  2. Haplotipos del gen de la globina beta en portadores de hemoglobina S en Colombia

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    Claudia Liliana Durán

    2012-03-01

    Resultados. Los haplotipos de la hemoglobina S encontrados con mayor frecuencia en la muestra analizada son de origen africano y su orden de aparición fue mayor para el haplotipo Bantú (36,4 %, seguido por Senegal (30,3 %, Benín (21,2 % y Camerún (12,1 %. La electroforesis de hemoglobina confirmó el fenotipo AS; la dosificación de hemoglobina fetal mostró niveles por debajo de 1 % y los parámetros hematológicos analizados mostraron valores normales en el 100 % de los individuos. Conclusión. Los haplotipos de la HbS encontrados con mayor frecuencia en la muestra estudiada eran de origen africano y su distribución variaba de acuerdo con el lugar de prodedencia del individuo. La mayor frecuencia correspodió al haplotipo Bantú.   DOI: http://dx.doi.org/10.7705/biomedica.v32i1.600

  3. Diversidad genética de dos poblaciones del caracol Strombus gigas (Gastropoda: Strombidae en Yucatán, México, con microsatélite

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    Roberto Zamora-Bustillos

    2011-09-01

    Full Text Available El caracol rosado S. gigas, es una especie de gran importancia pesquera en la región del Caribe que incluye la Península de Yucatán, en la cual, se analizó la diversidad y estructura genética de dos poblaciones (Arrecife Alacranes y Banco Chinchorro mediante el uso de cinco marcadores moleculares del tipo microsatélites. Los resultados indican que las dos poblaciones analizadas se encuentran en el mismo rango de diversidad genética (He de 0.613 a 0.692. En ambas poblaciones también se observó una desviación significativa al equilibrio H-WE, la cual fue atribuida a factores como la endogamia a consecuencia de una sobre-explotación pesquera. Sin embargo otra explicación posible es que se deba a una mezcla de individuos de dos o más poblaciones, y la existencia de alelos nulos. Los niveles de estructura genética indican la existencia de una sola población homogénea en la península de Yucatán (F ST de 0.003, p=0.49 y el flujo genético fue significativo (2.3 individuos entre las dos poblaciones. Los resultados de este estudio aceptan la hipótesis de que las poblaciones S. gigas forman parte de una sola población panmíctica en la Península de Yucatán, por lo tanto, el recurso pesquero debe regularse de igual manera en ambas regiones.

  4. Distribución de tres polimorfismos del gen TSLP en población afrodescendiente de San Basilio de Palenque, Colombia

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    Luis Fang

    2013-06-01

    Full Text Available Introducción. La linfopoyetina tímica del estroma (Thymic Stromal Lymphopoietin, TSLP se ha vinculado como un gen de propensión al desarrollo de enfermedades alérgicas. Se sabe que la población de Cartagena es una mezcla triétnica, en la cual el componente de herencia africana se asoció con el riesgo de asma y altos niveles séricos de IgE total. Este componente provino de esclavos africanos que lograron organizarse en “palenques”, uno de ellos es San Basilio de Palenque, en la Costa Caribe colombiana. Objetivo. Determinar la distribución de los polimorfismos de nucleótido simple (Single Nucleotide Polymorphism, SNP rs1837253, rs17551370 y rs2289276 del gen TSLP en individuos afrodescendientes de San Basilio de Palenque. Materiales y métodos. Mediante PCR en tiempo real y sondas TaqMan SNP Genotyping™ segenotipificaron estos SNP en 80 individuos afrodescendientes entre los 5 y 18 años de edad. Resultados. El alelo de menor frecuencia para el polimorfismo rs1837253 fue el alelo T (41,9 %, para el rs17551370, el alelo A (14,3 %, y para el rs2289276, el alelo T (22,5 %. La distribución de los polimorfismos rs17551370 y rs2289276 se mantuvo en equilibrio genético de Hardy-Weinberg. Las frecuencias alélicas de cada SNP no mostraron diferencias significativas con las reportadas para poblaciones africanas. Conclusiones. Los tres polimorfismos analizados en el gen TSLP estuvieron presentes en la muestra de población de San Basilio de Palenque y su distribución es similar a la reportada para poblaciones africanas y para poblaciones americanas de ancestro africano. doi: http://dx.doi.org/10.7705/biomedica.v33i2.655

  5. Identificación de mutaciones puntuales del gen de la 21-hidroxilasa en pacientes afectados con hiperplasia suprarrenal congénita.

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    Dora Fonseca

    2005-06-01

    Full Text Available lntroducción. La hiperplasia suprarrenal congénita es un trastorno autosómico recesivo debido a la inadecuada secreción de cortisol. Mas del 95% de los casos de hiperplasia suprarrenal congénita son causados por defectos del gen de la 21 hidroxilasa, CYP21A2 . Las manifestaciones clínicas incluyen la forma clásica y la forma no clásica. Objetivos. Determinar la frecuencia de las mutaciones puntuales P30L, IVS2-12AIC-G, Del 8pb, I172N, cluster Ex 6, V281L, Q318X, R356W y P453S en pacientes con hiperplasia suprarrenal congénita. Materiales y métodos. Se estudiaron 58 pacientes, de los cuales, 48 fueron clásicos y 10 no clásicos. Mediante PCR alelo-especifica y ACRS (Amplified Creation Restriction Sites, se analizaron 9 mutaciones puntuales del gen CYP21A2 y se determinó la frecuencia en la población analizada. Resultados. Los alelos afectados se identificaron en el 82,8% de los cromosomas. Las mutaciones mas frecuentes fueron: IVS2-12AIC-G (26,7%, Q318X (21,5%, V281L (12,1% e I172N (12,1%. Conclusiones. Las mutaciones mas frecuentes en Colombia son similares a las de otros países del mundo, excepto para Q318X que presentó una mayor frecuencia, pero similar a la de otros países latinoamericanos. Este hallazgo y la existencia de 17,2% de alelos no identificados puede indicar diferencia entre el acervo genético de las poblaciones. En la forma clásica perdedora de sal predominaron las mutaciones Q318X e IVS2-12AIC-G; en la virilizante simple, IVS2-12AIC-G e I172N y en la no clásica , V281L, lo cual esta relacionado con el grado de actividad enzimática. En la forma no clásica, se encontraron alelos severos en el 66,7% de los casos, lo que determina el riesgo de tener hijos afectados con la forma grave virilizante simple o perdedora de sal. Los resultados reportados permiten ofrecer asesoramiento genético y diagnóstico prenatal.

  6. Identificación de mutaciones puntuales del gen de la 21-hidroxilasa en pacientes afectados con hiperplasia suprarrenal congénita.

    OpenAIRE

    Dora Fonseca; Andrés Gutiérrez; Claudia Silva; Mauricio Coll; Gustavo Malo; Camilo Orjuela; Alejandro Giraldo

    2005-01-01

    lntroducción. La hiperplasia suprarrenal congénita es un trastorno autosómico recesivo debido a la inadecuada secreción de cortisol. Mas del 95% de los casos de hiperplasia suprarrenal congénita son causados por defectos del gen de la 21 hidroxilasa, CYP21A2 . Las manifestaciones clínicas incluyen la forma clásica y la forma no clásica. Objetivos. Determinar la frecuencia de las mutaciones puntuales P30L, IVS2-12AIC-G, Del 8pb, I172N, cluster Ex 6, V281L, Q318X, R356W y P453S en pacientes con...

  7. Características de la hipoacusia en pacientes con la mutación a1555g del gen mtrnr1

    OpenAIRE

    Carrancho García, Andrea

    2016-01-01

    Introducción: La mutación A1555G del gen MTRNR1 del ADN mitocondrial es responsable del 20% de todos los casos familiares de hipoacusia neurosensorial bilateral no sindrómica en nuestro país, que se ve exacerbada por la exposición a aminoglucósidos. El objetivo de nuestro estudio fue determinar la prevalencia, las características clínicas de la hipoacusia causada por esta mutación y el papel de los aminoglucósidos en el desarrollo de la hipoacusia, así como describir las características clíni...

  8. La obra poética latina del humanista Juan de Iriarte: un enfoque crítico-genético

    OpenAIRE

    Ruiz Sánchez, María

    2016-01-01

    Este trabajo analiza las ventajas y los problemas de una edición crítico-genética de la poesía latina del humanista Juan de Iriarte. Este tipo de edición es necesaria por la complejidad textual del legado de Iriarte, especialmente en lo concerniente a los epigramas. La mayoría de los epigramas no fueron editados en vida del autor. La edición póstuma realizada por los sobrinos solo comprende una parte de los textos y altera la naturaleza de los materiales. This paper analyses the advantages...

  9. Filogenética Molecular de Peces del Complejo Midas Cichlidae que habitan lagos y lagunas de Nicaragua, utilizando el gen COI

    Directory of Open Access Journals (Sweden)

    Lucía Páiz-Medina

    2012-12-01

    Full Text Available Las lagunas cratéricas de Nicaragua se consideran verdaderos "laboratorios" naturales de investigación debido a que son geológicamente jóvenes y por su pequeña dimensión, lo que permite el estudio de procesos evolutivos y de especiación. En estas lagunas se encuentran especies endémicas (familia Cichlidae que representan recursos valiosos para estudios de especiación, incluyendo la velocidad y fuerzas con las que el aislamiento geográfico, la selección natural y sexual provocan la diversificación fenotípica y, finalmente, la especiación misma. Los peces de la familia Cichlidae han sido objeto de mucha controversia debido a que morfológicamente es difícil diferenciarlos y se requieren de nuevas herramientas moleculares para descifrar las diferencias a nivel genético y entender mejor los procesos de especiación de este fascinante grupo de peces. En este estudio se utilizó el gen Citocromo Oxidasa I, COI, para determinar las relaciones filogenéticas entre los peces del Complejo presente en lagos y lagunas de Nicaragua. El COI ha sido propuesto como "código de barras" genético y como técnica ha sido estandarizada para animales. Este trabajo es parte de una investigación más grande que se enmarca en el Proyecto "DNA Barcoding de la biodiversidad nicaragüense" y se realiza en el Centro de Biología Molecular de la Universidad Centroamericana. Con este estudio se ha logrado determinar que: (1 el gen COI discrimina entre especies de diferentes lagunas, (2 las relaciones entre las especies Midas Cichlidae son complejas y es necesario más de un gen para obtener resultados concluyentes, (3 las especies fundadoras de las lagunas cratéricas provienen del lago de Nicaragua, (4 en las lagunas habitan más de una especie del Complejo Midas Cichlidae y (5 se infiere que la especiación simpátrica es el mecanismo evolutivo que ha conducido a la creación de estas especies, confirmando la hipótesis de otros autores y aportando nuevos

  10. Molecular genetics of colorectal cancer Genética molecular del cáncer colorrectal

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    D. Cruz-Bustillo Clarens

    2004-01-01

    Full Text Available Colorectal tumours constitute an excellent system to study carcinogenesis and the molecular events implicated in the development of cancer. Attending to the way it is transmitted, colorectal cancer may appear in one of three forms: sporadic, familial, and hereditary. The sporadic form is most common and has no familial or hereditary associated factor thus far, while familial and hereditary forms show the same inheritance pattern. Hereditary colorectal cancers develop by means of defined stages that go from lesions in the crypt of the colon through adenomas to manifest cancer. They are characterised by the accumulation of multiple mutations in tumour suppressor genes and oncogenes that affect the balance between cell proliferation and apoptosis. The colorectal carcinogenesis pathway is not unique and there are probably several ways for the initiation, development and progression of colorectal tumours.Los tumores colorrectales constituyen un excelente sistema para estudiar la carcinogénesis y los eventos moleculares involucrados en el desarrollo de un tumor. El cáncer colorrectal puede presentarse en tres formas, según su forma de transmisión: esporádico, familiar y hereditario. La forma esporádica que es la mayoritaria, no tiene hasta el momento ningún factor familiar o hereditario asociado, mientras que las formas familiares y hereditarias siguen un patrón de herencia en la propensión familiar a padecerlo. Los cánceres colorrectales hereditarios se desarrollan mediante etapas definidas que van desde lesiones en la cripta del colon a través de adenomas hasta manifestar el cáncer y se caracterizan por la acumulación de múltiples mutaciones en genes supresores de tumor y oncogenes que afectan el balance entre la proliferación celular y la apoptosis. La vía de carcinogénesis colorrectal no es una sola y probablemente existan varios caminos para el inicio, desarrollo y progresión de un tumor colorrectal.

  11. Revalidacion de Bombax Ceiba L. como especie típica del genero Bombax L. y descripcion de Pseudobombax gen. nov

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    Dugand Armando

    1943-04-01

    Full Text Available En este trabajo se determina por razones históricas que Bombax Ceiba L. es la especie típica del genero Bombax L. y se tipifica dicha especie a su vez sobre Bombax quinatum Jacq. Refútase así la recomendación de B. malabaricum DC. como lectotipo de Bombax. Se propone una nueva definición, sensu maxime strictissimo, de Bombax L. y de B. Ceiba L. fundada en B. quinatum Jacq.; se mencionan los sinónimos conocidos y los ejemplares botánicos examinados. Esta tipificación causa una completa alteración del concepto genérico de Bombax por cuanto B. quinatum ha sido considerado generalmente como representativo de un género intermedio (Bombacopsis Pittier cuya definición sistemática resulta ahora justamente aplicable al genera linneano. Por consiguiente es necesario hacer un ajuste nomenclatural y se propone una nueva denominación genérica (Pseudobombax Dugand que abarca, por lo pronto, tres especies: septenatum Jacq. (como tipo , ellipticum HBK. y Palmeri S. Wats., antes considerados como verdaderos Bombax. La preparación de este estudio fue realizada en su mayor parte compilando numerosos datos históricos en las bibliotecas del Arnold Arboretum y del Gray Herbarium, merced a las prerrogativas que me fueron generosamente concedidas por la Universidad de Harvard al designarme Research Fellow del Arnold Arboretum durante la visita que hice recientemente a varias instituciones botanicas de los Estados Unidos como invitado del Comité de Relaciones Artísticas e Intelectuales Inter-Americanas.

  12. Determinación de mutaciones de un solo nucleótido en el gen 23S rRNA de Helicobacter pylori relacionadas con resistencia a claritromicina en una población del departamento del Cauca, Colombia

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    Claudia Patricia Acosta

    2014-04-01

    Full Text Available Introducción. La terapia antibiótica combinada para la erradicación de Helicobacter pylori debería basarse en los patrones locales de resistencia. Objetivo. Determinar la resistencia de H. pylori a claritromicina en una población del departamento del Cauca mediante la identificación de mutaciones en el gen 23S rRNA en ADN obtenido de biopsias gástricas. Materiales y métodos. Se incluyeron en el estudio 162 pacientes con dispepsia funcional. El gen 23S rRNA se amplificó por PCR y el patrón de mutaciones se identificó por secuenciación directa. Resultados. La frecuencia de resistencia a claritromicina fue de 4 %. La mutación A2143G del gen se encontró en cuatro pacientes (2,46 % y la mutación A2142G, en tres pacientes (1,85 %. Conclusiones. El estudio encontró que el genotipo más frecuente en los especímenes positivos para H. pylori fue 2143G, seguido por A2142G. La prevalencia observada de resistencia de H. pylori fue baja; por lo tanto, se considera que el tratamiento con claritromicina es una opción válida para la erradicación de H. pylori en la población objeto de estudio.

  13. Identificación de un polimorfismo del gen PAPP-A2 asociado a la fertilidad en vaquillas Romosinuano criadas en subtrópico

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    Pablo Luna-Nevárez

    2012-01-01

    Full Text Available El objetivo fue identificar polimorfismos de un solo nucleótido (SNP asociados a la fertilidad en hembras bovinas criadas en subtropico. La re-secuenciación de nueve genes relacionados al eje endocrino GH-IGF, localizados en los cromosomas 5, 16 y 20 del bovino, identificó 73 SNP útiles para estudios genéticos asociativos; sin embargo, sólo siete resultaron polimórficos y exclusivos de la raza Romosinuano. Muestras de ADN se extrajeron de 129 vaquillas Romosinuano y usadas para determinar los genotipos correspondientes a cada SNP. Un análisis de modelos mixtos identificó únicamente a un polimorfismo del gen PAPP-A2 (C/T, rs110490898 como predictor (P<0.05 del comportamiento reproductivo. El alelo T fue el más favorable (P<0.05 ya que éste se asoció a una reducción tanto en la edad al primer parto (-37.1 ± 14.4 días, como en la edad al segundo parto (-65.43 ± 30.8 días. En el análisis de contrastes el término lineal resultó significativo (P<0.05, pero no el quadrático, lo cual sugiere un efecto aditivo de los alelos. Los resultados proporcionan evidencia para proponer al gen PAPP-A2, como candidato asociado al comportamiento reproductivo en vaquillas y vacas primerizas de la raza Romosinuano.

  14. Estimación de la varianza genética y ambiental en caracteres métricos del esqueleto humano

    OpenAIRE

    Varela, Héctor Hugo; Cocilovo, José Alberto

    2003-01-01

    En la teoría evolutiva de rasgos cuantitativos el conocimiento de la varianza genética (VG) es determinante para hacer inferencias acerca del parentesco. En muchos casos no es posible estimar dicha componente sin la información obtenida a partir de la correlación entre parientes o de experimentos de selección. Por esta razón, en ausencia de datos apropiados es posible lograr una aproximación mediante el análisis de la repetibilidad de caracteres cuantitativos. En este trabajo se estima la pro...

  15. Genética y citogenética de la determinación del sexo en Diachasmimorpha longicaudata (Hymenoptera, Braconidae)

    OpenAIRE

    Carabajal Paladino, Leonela Z.

    2011-01-01

    El parasitoide bracónido Diachasmimorpha longicaudata es ampliamente utilizado como controlador biológico de moscas de los frutos; sin embargo, es escaso el conocimiento disponible sobre su genética. A fin de aportar información y mejorar su cría masiva, se estudió su sistema de determinación del sexo mediante la realización de cruzamientos de alta y baja endogamia, utilizando herramientas de citogenética para determinar el nivel de ploidía de la descendencia. Asimismo, se analizó su espermat...

  16. Mutaciones en genes modificadores de ARN ribosómico y la resistencia a aminoglucósidos: el caso del gen rsmG

    OpenAIRE

    Alfonso Benítez-Páez; Sonia Cárdenas-Brito; Mauricio Corredor; Magda Villarroya; María Eugenia Armengod

    2014-01-01

    Introducción. Los aminoglucósidos son moléculas antibióticas capaces de inhibir la síntesis de proteínas bacterianas tras su unión al ribosoma procariota. La resistencia a aminoglucósidos está clásicamente asociada a mutaciones en genes estructurales del ribosoma bacteriano; sin embargo, varios estudios recientes han demostrado, de forma recurrente, la presencia de un nuevo mecanismo dependiente de mutación que no involucra genes estructurales. El gen rsmG es uno de ellos y se caracteriza por...

  17. Frecuencia de siete mutaciones conocidas del gen de la beta globina en pacientes mestizos mexicanos con talasemia beta o delta beta

    OpenAIRE

    Laynes Decle, María del Carmen

    2007-01-01

    La talasemia ? es un padecimiento autosómico recesivo causado por más de 180 mutaciones diferentes del gen de la ?-globina que se caracteriza por la disminución en la síntesis (?+) o ausencia (?0) de las cadenas de ?-globina de la Hb A, lo que se manifiesta principalmente con anemia microcítica hipocrómica y niveles anormalmente incrementados de Hb A2 y Hb F. La presente investigación se realizó con el objetivo de determinar la frecuencia de siete mutaciones conocidas de...

  18. Paternidad extra pareja y variación genética individual: implicaciones en la eficacia biológica del papamoscas cerrojillo, Ficedula hypoleuca

    OpenAIRE

    Canal, David

    2012-01-01

    Las técnicas moleculares han revolucionado la forma de entender la ecología animal en general, y la de aves en particular. Su aplicación reveló la existencia de paternidad extra-pareja (EPP; de sus siglas en inglés) en aves, un descubrimiento considerado como el más importante en el campo de los sistemas de emparejamiento aviar de las últimas décadas. Hoy, se sabe que en más del 70% de las especies de aves estudiadas existe paternidad extra pareja (poligamia genética) pero los mecanismos que ...

  19. Genome dynamics, genetic complexity and macroevolution Dinámica del genoma, complejidad genética y macroevolución

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    MILTON GALLARDO

    2003-12-01

    duplicaciones génicas. Esta idea, desarrollada por Ohno (1968 permanece vigente en el estudio de varios organismos cuyos genomas se han secuenciado. El maíz, la levadura y los humanos contienen más paralogones que lo esperado por azar, apoyando así la idea que las familias génicas no se formaron de novo, sino por duplicaciones a gran escala del ADN. La hibridización de linajes emerge como un mecanismo eficiente y diseminado que crea novedades evolutivas por reclutamiento de genes redundantes hacia nuevos roles. La transferencia génica lateral indica una composición quimérica de los genomas de procariontes. Esta peculiar forma de herencia oscurece los límites de los linajes filogenéticos y sugiere anastomización y dicotomización en la forma del árbol de la vida. Las mutaciones adaptativas también han ensanchado el marco genético del pensamiento evolutivo al incorporar un nuevo mecanismo de formación de genes. Además, la biología del desarrollo ha entregado evidencias sólidas de la organización modular onto- y epigenética del organismo. Los cambios rápidos y drásticos generados por los genes del desarrollo han falseado la noción que la adaptación se logra exclusivamente por el reemplazo gradual de alelos, y que el cambio macroevolutivo es microevolución expandida. Con todo, la genómica comparada parece estar gestando una ampliación o un remodelamiento del marco genético en que comprendemos la filogenia y la evolución de la complejidad morfológica

  20. La divergencia genética entre poblaciones del Área Andina Centro Meridional evaluada mediante rasgos no métricos del cráneo

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    Cocilovo, José Alberto

    2009-01-01

    Full Text Available Durante más de 10.000 años el Area Andina Centro Meridional proporcionó un escenario ideal para el desarrollo de distintas poblaciones y entidades culturales, interactuando a través de una amplia red de intercambio y distribución de productos. A pesar de este nivel de interacción, la información métrica disponible (Bolivia, Norte de Chile y Noroeste Argentino, reveló un fuerte proceso de divergencia genética (FST = 0.195 entre subregiones (Varela et al., 2008. Esta evidencia es contrastada en el presente trabajo a partir del análisis de una muestra integrada por 1416 individuos de ambos sexos, cubriendo un intervalo de 4.500 años. Se emplearon 12 atributos (rasgos no métricos del cráneo registrados como presencia-ausencia. Las diferencias entre subáreas fueron evaluadas mediante la estadística MMDS y D2 de Mahalanobis calculada a partir de componentes principales. Ambas matrices de distancias fenotípicas presentaron una alta correlación, destacando una significativa diferenciación a nivel regional. La mayor distancia se registra entre el Noroeste Argentino y el Norte de Chile, ocupando Bolivia una posición equidistante entre ambas regiones. Dentro de cada región las muestras están más relacionadas entre si ((Cochabamba, (Puna, Quebrada, Valliserrana y Pampa Grande, (Arica, Pisagua, Norte Semiárido. Hay mayor vinculación entre Cochabamba y el Noroeste Argentino y mayor divergencia entre los grupos de Chile. Se confi rma un modelo de poblamiento a partir de la subdivisión de una población ancestral en dos ramas que ocuparon: una el Norte de Chile y otra el Noroeste Argentino. En cada una de ellas el proceso dispersivo originó varias líneas que se diferenciaron gradualmente hacia el sur, durante la exploración de nuevos ambientes cuya conquista y colonización garantizó la subsistencia de la población.

  1. Genetic variability of Harton del Valle by RAM Variabilidad genética de Hartón del Valle mediante RAM

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    Alvarez Franco Luz Angela

    2008-03-01

    Full Text Available Harton del Valle (HV breed belong to the seven Creole breeds of the Colombian bovine livestock, according to FAO criteria it is considered as vulnerable. To study its genetical variability, 33 HV animals and three and 3 animals of Holstein breed as a external control were sampled. Simples of DNA were isolated using the Salting Out method and RAM (Random amplified microsatellites technique was used. CGA, CCA, TG and CT primers were used. The mean value of expected heterocigozity was 0.26 and FST fue 0.39 ± 0.03. Using Dice–Nei Li index and UPGMA clustering method, two groups were distinguished: the first one integrated for two conservation herds and other one by tour faros that have been sharing breeding bulls.El Hartón del Valle (HV hace parte de las siete razas criollas de ganado bovino colombiano y de acuerdo con los criterios de la FAO está considerado como vulnerable. Para estudiar su variabilidad genética fueron muestreados 33 individuos HV y tres animales de la raza Holstein, como control externo. Se extrajo ADN utilizando el método de Salting Out y las muestras fueron analizadas mediante la técnica molecular RAM (Randon amplified microsatellites. Se utilizaron los cebadores CGA, CCA, TG, y CT. El valor promedio de heterocigosidad esperada fue de 0.26 y el FST fue 0.39 ± 0.03. Con el índice de Dice–Nei Li y agrupando con el método UPGMA se distinguieron dos grupos: uno integrado por dos hatos de conservación y el otro por cuatro fincas que han compartido reproductores.

  2. Polimorfismos del gen ApoE en individuos con síndrome de Down y sus progenitores en una población colombiana

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    Lucero Rengifo

    2012-06-01

    Full Text Available Introducción. Los polimorfismos en el gen ApoE se han examinado en el síndrome de Down debido a la relación existente de la isoforma E4 con la demencia de tipo Alzheimer que aparece en los individuos con síndrome de Down. Objetivos. Determinar los polimorfismos en el gen ApoE en individuos con síndrome de Down y sus progenitores, y buscar su asociación. Materiales y métodos. Mediante PCR-RFLP, se analizaron los polimorfismos del gen ApoE en 134 individuos jóvenes con síndrome de Down, 87 madres y 54 padres del eje cafetero, y se compararon con una población control de 525 individuos sanos. Resultados. El alelo APOEε3 y el genotipo ε3/ε3 fueron los más frecuentes en todas las poblaciones. La frecuencia alélica de APOEε2 es muy baja y ε2/ε2 está ausente en las poblaciones con síndrome de Down y sus progenitores. El alelo APOEε4 fue más frecuente en individuos con síndrome de Down que en el resto de poblaciones analizadas. Al comparar las frecuencias alélicas y genotípicas entre las poblaciones con síndrome de Down y los progenitores con la población control, mediante la χ2 de Pearson y los odds ratios por la prueba exacta de Fisher, no se encontraron diferencias estadísticamente significativas. Conclusiones. No se encontró asociación entre los polimorfismos del gen ApoE y el síndrome de Down. Es posible que el tamaño de la muestra o las influencias étnicas hubieran afectado estos resultados. Es necesario hacer otros estudios en poblaciones colombianas y evaluar la asociación con otros genes que se encuentran relacionados con la enfermedad de Alzheimer.   doi: http://dx.doi.org/10.7705/biomedica.v32i2.427

  3. Una variante del gen CAPN10 y los factores ambientales muestran asociación con el exceso de peso en jóvenes colombianos

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    Ana C. Orozco

    2014-12-01

    Full Text Available Introducción. La obesidad resulta de la interacción entre factores de riesgo genéticos y ambientales. Objetivo. Evaluar el efecto de tres variantes genéticas y factores ambientales en el exceso de peso en jóvenes de 10 a 18 años de Medellín, Colombia. Materiales y métodos. Se hizo un estudio transversal en 424 jóvenes divididos en tres grupos: 100 obesos, 112 jóvenes con sobrepeso, y, pareados con ellos, 212 jóvenes con peso adecuado, que conformaron el grupo de control. Se evaluó la asociación entre tres polimorfismos genéticos (UCP3-rs1800849, FTO-rs17817449 y CAPN10-rs3842570 y el exceso de peso, así como su interacción con antecedentes familiares de enfermedad, el tiempo dedicado a ver televisión y a jugar videojuegos y el consumo de alimentos. Resultados. Los antecedentes familiares de obesidad, la dedicación de más de dos horas al día a ver televisión y jugar videojuegos, la falta de lactancia materna, el bajo consumo de cereales, legumbres, frutas y verduras y el gran consumo de comidas rápidas fueron más frecuentes entre los obesos que en los controles. Se observó una asociación significativa entre el genotipo I/I (SNP19 del CAPN10 y el exceso de peso, incluso en los jóvenes que llevaban una vida activa. Además, se encontró una asociación significativa entre los genotipos C/C del UCP3 y G/G y T/T del FTO y el exceso de peso, pero solo en los jóvenes sedentarios. Conclusiones. En esta población, la alimentación inadecuada y el sedentarismo aumentaron el riesgo de exceso de peso. El genotipo I/I de SNP19 del CAPN10 se asoció significativamente con el exceso de peso. Algunas variantes del FTO y el UCP3 mostraron tener efecto solo en jóvenes sedentarios.

  4. La importancia del mundo virtual en la enseñanza y aprendizaje “AVA para el contenido de Genética”.

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    Alexander Afanador Castañeda

    2011-02-01

    Full Text Available El presente escrito describe la importancia y la necesidad de incorporar las TIC en los procesos de enseñanza y aprendizaje de las ciencias, además la utilización de ambientes virtuales de aprendizajes como alternativa innovadora y eficaz para la adquisición y comunicación del conocimiento científico, y hace referencia a la necesidad de incorporar la evaluación formativa en medios virtuales. Por último se presenta un ambiente virtual de aprendizaje como estrategia didáctica teniendo en cuenta la resolución de problemas para la apropiación del contenido conceptual en Genética con su respectivo guión pedagógico.

  5. Análisis de la biodiversidad genética del algodón peruano usando marcadores moleculares: Avances en el 2004

    OpenAIRE

    Olórtegui, José; Espinoza, Marco; Espinoza, José; Montoya,Ysabel

    2005-01-01

    Tres mini preparaciones de extracción de ADN de algodón fueron comparadas en términos de calidad y rendimiento. El método de extracción de ADN usando CTAB fue el más eficiente (30 ug) en comparación con un kit comercial de extracción (20 ug) a partir de 100 mg de hojas cotiledonarias. La óptima calidad del ADN fue evaluada con las enzimas de restricción EcoRI y MseI. El ADN preparado será usado para iniciar el análisis de la biodiversidad genética del algodón peruano, usando marcadores mole...

  6. Obtención de una sonda específica para evaluar la transcripción del gen STAT5b

    OpenAIRE

    Luis Eduardo Díaz; Blanca L. Ortiz; Myriam Sánchez de Gómez

    2001-01-01

    Se describe la estrategia empleada para clonar, en un vector de expresión, un fragmento de 306 pb del gen de STAT5b de rata, amplificado por la técnica de RT-PCR. Se amplificó una región en el terminal 3' donde se encuentra la mayor diferencia entre las secuencias del cADN de las isoformas STAT5a y STAT5b de rata. La clonación se logró utilizando el nuevo sistema TOPO-TA recomendado para productos de dificil clonación. El fragmento se subclonó en el vector pBlueScript II SK y se caracterizó m...

  7. Evaluación del potencial de mejoramiento genético en el crecimiento en altura de Acacia mangium Willd.

    Directory of Open Access Journals (Sweden)

    Iván Javier Pastrana-Vargas

    2012-04-01

    Full Text Available En el periodo 2009-2010, en Ayapel, Planeta Rica y Tierralta, departamento de Córdoba (Colombia se evaluó el desempeño en crecimiento en altura total de 90 familias de polinización abierta de Acacia mangium. En estos municipios el clima se clasifica, de acuerdo con Holdridge, como bosque seco tropical (Bs-T, excepto Tierralta que es bosque húmedo tropical (Bh-T. Durante el primer año de crecimiento, las plantas en cada familia fueron evaluadas en ensayos de progenie mediante un diseño experimental de bloques completos al azar, con seis bloques en cada una de las tres localidades. La parcela o unidad experimental consistió en seis plantas de polinización abierta por familia, distribuidas aleatoriamente en tres parejas espacialmente separadas dentro de cada bloque. La predicción de parámetros genéticos individuales y de familias se efectuó por medio del procedimiento BLUP y los componentes de varianza por medio del procedimiento REML utilizando el software SELEGEN. Las estimaciones de heredabilidad variaron entre <1 y 13%, y entre 6 y 68%, para heredabilidad individual en sentido estricto (h²a y heredabilidad media de familias (h²mp, respectivamente. El ranking genético en altura de las 15 mejores familias indica que las de mayor crecimiento fueron también las más estables y de mayor adaptabilidad a los ambientes. Los resultados sugieren un alto potencial de mejoramiento al nivel de familia en crecimiento y productividad de plantaciones de A. mangium en el departamento de Córdoba, Colombia. Son necesarios nuevos estudios a fin de lograr una mejor selección genética.

  8. Evaluación del potencial de mejoramiento genético en el crecimiento en altura de Acacia mangium Willd.

    Directory of Open Access Journals (Sweden)

    Pastrana Vargas Iván Javier

    2012-11-01

    Full Text Available

    En el periodo 2009-2010, en Ayapel, Planeta Rica y Tierralta, departamento de Córdoba (Colombia se evaluó el desempeño en crecimiento en altura total de 90 familias de polinización abierta de Acacia mangium. En estos municipios el clima se clasifica, de acuerdo con Holdridge, como bosque seco tro- pical (Bs-T, excepto Tierralta que es bosque húmedo tropical (Bh-T. Durante el primer año de creci- miento, las plantas en cada familia fueron evaluadas en ensayos de progenie mediante un diseño expe- rimental de bloques completos al azar, con seis bloques en cada una de las tres localidades. La parcela o unidad experimental consistió en seis plantas de polinización abierta por familia, distribuidas aleato- riamente en tres parejas espacialmente separadas dentro de cada bloque. La predicción de parámetros genéticos individuales y de familias se efectuó por medio del procedimiento BLUP y los componentes de varianza por medio del procedimiento REML utilizando el software SELEGEN. Las estimaciones de he- redabilidad variaron entre <1 y 13%, y entre 6 y 68%, para heredabilidad individual en sentido estricto (h2a y heredabilidad media de familias (h2mp, respectivamente. El ranking genético en altura de las

    15 mejores familias indica que las de mayor crecimiento fueron también las más estables y de mayor adaptabilidad a los ambientes. Los resultados sugieren un alto potencial de mejoramiento al nivel de familia en crecimiento y productividad de plantaciones de A. mangium en el departamento de Córdoba,

    #olombia. $on necesarios nuevos estudios a fin de lograr una me%or selección genética

  9. Paleogeoformas lacustres en los lagos Musters y Colhué huapí, su relación genética con un paleolago Sarmiento previo, centro-sur del Chubut

    OpenAIRE

    Emilio F González Díaz; Inés Di Tommaso

    2014-01-01

    El reconocimiento de paleogeoformas lacustres acrecionales y de erosión en la costa este del lago Musters, como así también, en la costa este del adyacente lago Colhué Huapí y fuera del ámbito lagunar al sur del cerro Puricelli en posiciones altimétricas similares, permitió relacionarlas genéticamente a nivel regional, con un cuerpo lagunar previo, aquí denominado Paleolago Sarmiento; generado por la inundación de la depresión preexistente del bajo de Sarmiento, luego de la captura y desvío d...

  10. Variación genética del mtDNA: De la genética poblacional a la farmacogenómica

    OpenAIRE

    Gómez Durán, Aurora; Ruiz Pesini, Eduardo

    2012-01-01

    El sistema de fosforilación oxidativa es la principal fuente celular de energía en forma de ATP y también de radicales libres de oxígeno. El estrés oxidativo es un factor determinante del envejecimiento y las enfermedades asociadas a la edad. Por ello, esta ruta metabólica parece adecuada para definir dianas farmacológicas aplicables en la terapéutica de estas patologías. Las enfermedades asociadas a la edad y la enfermedad mitocondrial de LHON son consideradas patologías multifactoriales, c...

  11. Frequency of MYO9B polymorphisms in celiac patients and controls Frecuencia de polimorfismos del gen MYO9B en pacientes celiacos y en sujetos controles

    Directory of Open Access Journals (Sweden)

    Tamara Loeff

    2012-12-01

    Full Text Available Introduction: the MYO9B gene contributes to the maintenance of the intestinal barrier and it has been postulated as a risk factor of celiac disease (CD. The objective of this study was to compare the frequency and association rs2305764, rs2305767and rs1457092 MYO09B polymorphisms in pediatric CD patients from Chile and Argentina. Patients and methods: the study was made in 104 CD pediatric patients (Chilean and Argentineans and 104 controls subjects. MYO9B gene polymorphisms were analyzed by Taqman allelic probes. We evaluated the Hardy-Weinberg equilibrium by means of Chi-square and compared the haplotypes distribution using Fisher test. Results: SNPs rs2305767 and rs1457092 were associated with celiac disease (CD; TT genotype in rs2305767 would be a protective factor (p Introducción: el gen miosina IX B (MYO9B participa en el mantenimiento de la barrera intestinal y se postula que puede aportar riesgo para desarrollar enfermedad celiaca (EC. El objetivo de este estudio fue comparar la frecuencia y la asociación de los polimorfismos rs 2305764, rs 2305767 y rs 1457092 del gen MYO9B en pacientes pediátricos con EC procedentes de Chile y Argentina. Pacientes y métodos: el estudio se realizó en 104 pacientes pediátricos con EC (chilenos y argentinos y en 104 sujetos controles. El análisis de los polimorfismos del gen MYO9B se realizó mediante ensayos Taqman de discriminación alélica. Se evalúo equilibrio de Hardy-Weinberg mediante Chi-cuadrado y comparación de haplotipos según prueba de Fisher. Resultados: los polimorfismos de un solo nucleótido (SNPs rs2305767 y rs1457092 mostraron asociación con la EC. El genotipo TT del rs2305767 sería un factor protector (p < 0,0001, OR = 0,19 IC 0,1-0,4 mientras que el genotipo CT sería un factor de riesgo (p < 0,0001, OR = 4,9 IC 2,2-11,3. En el rs1457092, el genotipo CC resultó también un factor protector frente a esta enfermedad (p < 0,0001, OR = 0,07 IC 0,0-0,3. Conclusión: nuestros

  12. Tesis doctoral: Estudio de las características contráctiles de la musculatura del tren inferior y de las distribuciones genotípicas del gen ACTN3 en voleibol de élite

    OpenAIRE

    Díez Vega, Ignacio

    2013-01-01

    El gen ACTN3 codifica la síntesis de la proteína intramuscular α-actinina-3. Esta proteína, ubicada en la línea Z del sarcómero muscular, tiene una función estructural que confiere a los elementos contráctiles de la fibra muscular una mayor estabilidad, que justificaría una mayor capacidad de transmisión de fuerzas. Sin embargo, esta proteína no está presente en todos los seres humanos, debido a una mutación acaecida en el gen ACTN3. Como consecuencia, aparecen dos alelos (R y X) que permiten...

  13. Origen y dinámica del poblamiento autóctono del Ecuador: diversidad genética de poblaciones de los Andes y de la Amazonía

    OpenAIRE

    Sáenz Ruales, Nancy

    2014-01-01

    En los últimos 15 años, la genética ha sido una de las disciplinas determinantes en la investigación arqueológica y antropológica. Sus alcances y aportes han permitido abrir nuevas discusiones sobre el asentamiento del Hombre moderno en los distintos continentes. La genética de poblaciones humanas está ligada a varias disciplinas científicas. Ella se apoya en datos y técnicas de análisis de la biología molecular y de la bioquímica, así como también en datos históriscos para comprender el rol...

  14. Eliminación del gen marcador de selección en plantas transplastómicas mediante la expresión transitoria de la recombinasa CRE

    OpenAIRE

    López López, Nahikari

    2011-01-01

    La formación de plantas transgénicas o transplastómicas requiere de la incorporación al genoma, ya sea al nuclear o al plastidial, del gen de interés acompañado de un gen marcador de selección que, generalmente, confiere resistencia a un antibiótico. Una vez que se ha obtenido la planta transgénica o transplastómica, es aconsejable eliminar el gen marcador de selección de la planta debido a la carga genética que supone para las células pero sobre todo al riesgo para la salud...

  15. Nuevos diseños de sistemas de control híbrido, genético-adaptativo, para la regulación de la eficiencia del bloque termoenergético de las empresas del níquel.

    Directory of Open Access Journals (Sweden)

    Antonio Muñoz

    2006-10-01

    Full Text Available El artículo muestra los resultados de la investigación del sistema de avanzado híbrido (genéticoadaptativo para la generación de vapor, a través de lazos de regulación para la reducción de la dispersión de las variables del régimen operacional del proceso, con la aplicación de nuevas estrategias de control óptimo con algoritmos genéticos del gasto de energía, sobre la desviación del régimen de trabajo de las calderas; todo lo cual contribuye a la reducción de las pérdidas de energía para generar vapor, permitiendo implementar sistemas control híbridos, resultantes de la integración de sistemas de control genético-adaptativos.

  16. Mejoramiento genético y taza de autofecundación del Camu Camu arbustivo en la Amazonía Peruana

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    Carlos Oliva Cruz

    2008-06-01

    Full Text Available El camu camu (Myrciaria dubia (H.B.K. MC VAUGH es una frutera silvestre conocida mundialmente como un excepcional productor de vitamina C. Su mejoramiento se encuentra en fase inicial. Este trabajo tuvo por objetivos estudiar el sistema reproductivo (taza de autofecundación, el efecto del origen del polen (autofecundación o polinización abierta en la producción de ácido ascórbico y porcentaje de germinación, la repetibilidad de caracteres productivos y sus implicaciones en el programa de mejoramiento. El sistema reproductivo del camu camu es mixto con variables tazas de autofecundación. No fue confirmada la existencia de efecto del origen del polen para el carácter de producción de ácido ascórbico. La repetibilidad individual de la producción fue de moderada magnitud (0.41; la repetibilidad del promedio de 5 cosechas de fruta fue de 0.77, propiciando exactitud selectiva de 0.88. Genotipos superiores pueden ser seleccionados con precisión y, por lo tanto, cinco a seis cosechas por planta es un número adecuado. La selección y clonación de los diez mejores individuos deberá propiciar una ganancia genética del 237.5 %, elevando la productividad media anual de frutas por planta de 7.75 para 26.17 kg/año.

  17. Bases genómicas del cáncer de mama: avances hacia la medicina personalizada Genomic basis for breast cancer: advances in personalized medicine

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    Alfredo Hidalgo-Miranda

    2009-01-01

    Full Text Available El análisis genómico del cáncer de mama ha permitido el desarrollo de nuevas herramientas de predicción de riesgo y respuesta al tratamiento en esta enfermedad. Los perfiles de expresión génica han generado una mejor clasificación de los tumores e identificado subgrupos tumorales con características clínicas particulares. También se han reconocido patrones de pérdida y ganancia de DNA y expresión de micro-RNA relacionados con la carcinogénesis mamaria, tras identificar nuevos blancos potenciales. Los estudios de asociación del genoma completo han identificado variantes genéticas vinculadas con un mayor riesgo a presentar esta enfermedad, lo que hará posible tomar decisiones de salud pública mejor fundamentadas. Asimismo, los avances en la tecnología de secuenciación de DNA permitirán obtener información acerca de todas las alteraciones genéticas en los tumores. En esta revisión se describe el estado que guarda la investigación genómica en el cáncer de mama, así como la transición de estos hallazgos a la práctica clínica y la creación de las bases para el desarrollo de la medicina personalizada.Genomic analysis of breast cancer has allowed the development of new tools for the prediction of recurrence and the response to treatment of this disease. Gene expression profiles allow better tumor classification, identifying tumor subgroups with particular clinical outcomes. New potential molecular targets involved in breast carcinogenesis have also been identified through the analysis of DNA copy number aberrations and microRNA expression patterns. Whole genome association studies have identified genetic variants associated with a higher risk to develop this tumor, providing more information for public health decisions. Progress in DNA sequencing methods will also allow for the analysis of all the genetic alterations present in a tumor. In this review, we describe the current state of genomic research in breast cancer as

  18. Trastornos generalizados del desarrollo: Aspectos clínicos y genéticos Pervasive developmental disorders: Clinical and genetics aspects

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    Víctor Ruggieri

    2007-01-01

    Full Text Available Los Trastornos Generalizados del Desarrollo se expresan con compromiso en la socialización, trastorno en el desarrollo del lenguaje (verbal y no verbal e intereses restringidos con conductas repetitivas. La frecuencia estimada en la población general es de 27.5/10.000. En nuestro trabajo analizamos los aspectos clínicos y genéticos de los TGD: Autismo, Síndrome de Asperger, TGD no Especificado, Síndrome de Rett y Trastorno desintegrativo de la niñez. Desde el punto de vista clínico jerarquizamos los aspectos conductuales para su reconocimiento. En los aspectos genéticos puntualizamos diversas entidades con las que se asocian consistentemente estos trastornos, denominados cuadros sindrómicos, (aproximadamente el 20% de los casos y las bases genéticas actualmente propuestas para el 80% restante o formas no sindrómicas. El reconocimiento temprano de estos trastornos del desarrollo y el diagnóstico de una entidad específica asociada permiten un temprano y adecuado abordaje terapéutico, un correcto asesoramiento genético y un control evolutivo específico previendo posibles complicaciones relacionadas a la entidad de base. Finalmente, si bien las bases genéticas del autismo no están identificadas se han propuesto diversos genes candidatos ubicados en los cromosomas: 15q, 2q, 17q, 7q, 12q, y los relacionados al X, entre otros, los que son analizados en este trabajo y permitirán en un futuro cercano comprender mejor estos trastornos.Pervasive developmental disorders (PDD encompass a heterogeneous group of children with deficits of verbal and non-verbal language, social communication, and with a restricted repertoire of activities or repetitive behaviours. The frequency in general population is considered 27.5/10,000. In this study, we analyzed the clinical and genetic aspects of Autism, Asperger Syndrome, PDD Not Otherwise Specified, Rett Syndrome and Childhood Disintegrative Disorder. We analyzed clinical, behavioural and

  19. La virtualización del cuerpo y la investigación genética

    OpenAIRE

    López, Daniel

    2002-01-01

    La presentación del primer borrador de la secuenciación del genoma humano presentada la semana del 12 de febrero del 2001 en Nature (por el Consorcio Público Internacional) y en Science (por Celera Genomics) supone la puesta en escena de algo que ya se comenzó a fraguar cuando Watson y Crick describieron la estructura helicoidal del DNA en 1953. La transformación que ha sufrido la biología molecular a partir de ese momento ha producido un cambio en nuestra concepción del cuerpo. En este artíc...

  20. Aspectos genéticos y clínicos del síndrome de usher Genetical and clinical aspects of Usher syndrome

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    Beatriz Dyce Gordon

    2000-12-01

    Full Text Available Con el objetivo de describir algunos aspectos genéticos y clínicos del Síndrome de Usher, se realizó un estudio descriptivo transversal en el Centro de Referencia Nacional de Retinosis Pigmentaria desde marzo de 1996 hasta junio de 1998, con 33 pacientes con diagnóstico de síndrome de Usher a través de la revisión de historias clínicas, entrevistas para interrogatorio y examen físico, así como para la confección e interpretación del árbol genealógico. La mayoría de los pacientes (60,60 % presentaron el síndrome de Usher tipo II. Se encontró consanguinidad en el 29,62 % de los casos y los antecedentes patológicos familiares se observaron en 12 familias. Las manifestaciones clínicas oftalmológicas tuvieron un inicio fundamentalmente juvenil, y las audiológicas tuvieron un inicio muy precoz (congénito en el tipo I y en la infancia, en el tipo II. En conclusión en el presente estudio, se pone de manifiesto la heterogeneidad clínica y genética del síndrome de Usher así como su carácter hereditario con patrón de herencia autosómico recesivo. Se hace necesario su diagnóstico precoz para ofrecer asesoramiento genético a los padres y poner tratamiento adecuado a las discapacidadesWith the aim of describe some genetic and clinical features of Usher´s syndrome, we performed a cross and descriptive study in National Center of Remission of Pigmentosa Retinitis from March 1996 o June 1998, where 33 patients were diagnosed of Usher´s syndrome through revision of medical records, interviews for interrogation and physical examination, as well as to drawing up and interpretation of genealogical tree. Most patients (60,60 % presenting with type II Usher´s syndrome. We found consanguinity in 29,62 % of cases and familial pathologic bacgrounds were observed in 12 families. Ophthalmologic and clinical manifestations had a youthful onset, and audiologies had a very early onset (congenital in type I, and in infancy in type II. In

  1. Duración del ciclo reproductivo y producción de semilla de dos materiales genéticos de cebadilla criolla (Bromus catharticus Vahl.) bajo distintos manejos del cultivo

    OpenAIRE

    Wolff, Renata Margarita S.; Vernengo, Eduardo Aníbal; Sánchez, S. P.; Spara, Fernanda

    2005-01-01

    p.233-246 El objetivo fue comparar la duración del ciclo reproductivo y la producción de semilla de un material experimental con baja tendencia al repanojado (NR) con el cultivar Martín Fierro MAG (MF), utilizando tres fechas de clausura y tres niveles de ferilización nitrogenada. Se usó un diseño en bloques con cuatro repeticiones, en parcelas subdivididas, siendo las parcelas principales las fechas de clausura, las subparcelas los materiales genéticos y las sub-subparcelas los niveles de...

  2. Estructura genética del sistema de asimilación de nitrato y regulación global de la asimilación de nitrógeno en la cianobacteria synechococcus sp.

    OpenAIRE

    Luque Romero, Ignacio

    1994-01-01

    Los objetivos de este trabajo han sido profundizar en el estudio de la estructura genética de los genes implicados en la asimilación de nitrato en Synechococcus sp. PCC 7942, y contribuir al esclarecimiento del mecanismo de regulación de dichos genes mediante la proteína NtcA.

  3. La fábrica de la empatía. Del determinismo genético al origen social de la moral

    Directory of Open Access Journals (Sweden)

    Hernández Castro, David

    2016-06-01

    Full Text Available Preston and De Waal have adopted a theoretical idea known as the “Perception-Action Model” (PAM, which suggests that empathy and morality have genetic and evolutionary roots. In this paper, the author proposes a critical reading of PAM and an alternative interpretation, “the empathy factory”, which reconsiders the “Perception-Action Hypothesis” and the discovery of mirror neurons in the light of Judith Butler’s concept of performativity and the social construction of emotions. The conclusion is that the origin of the moral impulse does not lie in genetic determinism but in social relationships, language and affective communication.Preston y De Waal han adoptado una idea teórica, el Mecanismo de Percepción-Acción (MPA, que sugiere que la empatía y la moral tienen raíces genéticas y evolutivas. En este artículo analizamos críticamente el MPA y proponemos una interpretación alternativa, la fábrica de la empatía, que reconsidera la “Hipótesis de la Percepción-Acción” y el descubrimiento de las neuronas espejo bajo la luz del concepto de performatividad de Judith Butler y la construcción social de las emociones. Frente al determinismo genético, nuestra investigación apunta a las relaciones sociales y el lenguaje.

  4. Epidemiología descriptiva y genética molecular del cáncer de mama hereditario en Costa Rica

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    Laura García-Jiménez

    2012-12-01

    Full Text Available El cáncer de mama ocupa el primer lugar en incidencia y mortalidad entre las mujeres costarricenses, para el año 2011, se tiene una proyección de 1 071 casos nuevos. Mediante selección directa se reclutaron 116 pacientes diagnosticadas con cáncer de mama y con antecedentes familiares de esta enfermedad. Se analizó la prevalencia de los factores de riesgo y de las mutaciones en los genes BRCA1 y BRCA2. Se encontró que la edad promedio de las mujeres portadoras de una mutación es menor que en mujeres no portadoras. Además, se identificaron seis pacientes (5.2% con una mutación en el gen BRCA2 y sólo una presentó una mutación en el gen BRCA1. Estos resultados y el aumento en la incidencia del cáncer de mama en los últimos años en Costa Rica deben promover un aumento en medidas de prevención y el establecimiento de métodos de detección más eficientes, que permitan realizar un diagnóstico temprano de la enfermedad.

  5. Análisis filogenético del virus del chikungunya en Colombia: evidencia de selección purificadora en el gen E1

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    Katherine Laiton-Donato

    2016-08-01

    Conclusiones. Se determinó la circulación del genotipo de Asia del virus del chikungunya como la causa de la primera epidemia en Colombia. Es necesario continuar con la vigilancia de genotipos, con el fin de detectar posibles cambios en la epidemiología, la eficacia (fitness viral y la patogenia del virus.

  6. Identificación de la secuencia del gen de la subunidad catalítica de la telomerasa en Plasmodium falciparum.

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    Claudia Consuelo Rubiano

    2005-03-01

    Full Text Available lntroducción. La enzima telomerasa participa en la regulación de la longitud de los telómeros al sintetizar nuevas repeticiones teloméricas que compensan las pérdidas en cada ronda de replicación del ADN. Por esta razón, el bloqueo de su actividad se plantea como un posible blanco de acción para detener el crecimiento de células con altas tasas de crecimiento. Tal es el caso de Plasmodium falciparum, parásito causante de la forma más grave de paludismo humano, en el cual se sabe que hay actividad de telomerasa pero no se tiene información sobre la enzima misma. Metodología. Para hacer un acercamiento al estudio de la telomerasa en P. falciparum, se realizó un alineamiento múltiple de las secuencias de la subunidad catalítica de la telomerasa disponibles en bases de datos y se obtuvo una secuencia consenso, la cual se comparó con las secuencias generadas en el proyecto de genoma de P. falciparum. Se encontró una secuencia que podría corresponder a parte del gen de la telomerasa de P. falciparum. Para comprobarlo, se diseñaron iniciadores que se utilizaron en ensayos de amplificación sobre el ADN y el ARN del parásito. Resultados. Se amplificaron fragmentos de ADN correspondientes a motivos conservados en las telomerasas y se detectó la presencia del ARNm mediante trascripción reversa y PCR sobre el ADNc generado. De esta manera, al combinar la utilización de herramientas de bioinformática y su posterior comprobación mediante técnicas de biología molecular, se obtuvo la secuencia del gen de la subunidad catalítica de la telomerasa en P. falciparum y se comprobó su presencia y trascripción en el parásito

  7. Relación del polimorfismo C-514T del gen de la lipasa hepática con indicadores nutricionales y lipoproteínas en una muestra poblacional peruana: una perspectiva nutrigenética

    Directory of Open Access Journals (Sweden)

    Doris Huerta

    2008-12-01

    Full Text Available Introducción: Las enfermedades cardiovasculares son una de las principales causas de muerte en todo el mundo. El promotor del gen de la lipasa hepática presenta un polimorfismo funcional C-514T que se relaciona con la actividad de la enzima, la variación de los niveles de lipoproteínas y un posible riesgo para desarrollar enfermedades cardiovasculares. Objetivos: Establecer la relación del polimorfismo C-514T del promotor del gen de la lipasa hepática con indicadores nutricionales y los niveles de lipoproteínas plasmáticas en una muestra de peruanos saludables. Diseño: Estudio descriptivo, transversal, asociativo. Lugar: Centro de Investigación de Bioquímica y Nutrición Alberto Guzmán Barrón, Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Participantes: Noventiuna personas sanas de ambos sexos, cuyas edades fluctuaban entre 18 y 58 años, voluntarios con consentimiento informado. Intervenciones: Extracción del ADN genómico a partir de muestras sanguíneas según metodología estándar. Toma de medidas antropométricas, estableciéndose los indicadores nutricionales, determinación del perfil lipídico por el método enzimático. Análisis del polimorfismo C-514T mediante la técnica de PCR/RFLP, con primers específicos y digestión con la enzima de restricción NlaIII, detectándose los fragmentos de RFLP por electroforesis en gel de poliacrilamida (PAGE y tinción con nitrato de plata. Principales medidas de resultados: Frecuencias genotípicas y alélicas del gen de la lipasa hepática y relación con parámetros lipídicos y nutricionales. Resultados: Se encontró las frecuencias genotípicas CC=0,143; CT=0,593 y TT = 0,264, siendo la distribución consistente con el equilibrio de Hardy-Weinberg (X2 =3,8024, g.l.=1, p = 0,086. Las frecuencias alélicas fueron alelo C = 0,4395 y el alelo T = 0,5605. Los niveles de colesterol, HDLc, LDLc, TG y los promedios de pliegue subcutáneo, el IMC y el porcentaje de

  8. Valoració del risc genètic en pacients amb oligoastenozoospèrmia en un programa de microinjecció intracitoplasmàtica

    OpenAIRE

    Aran Corbella, Begoña

    2006-01-01

    Consultable des del TDX Títol obtingut de la portada digitalitzada La microinjecció intracitoplasmàtica d'un espermatozoide (ICSI) ha estat el mètode d'elecció de l'esterilitat masculina severa des de que l'any 1992 Palermo i cols, publicaren el primer naixement obtingut mitjançant aquesta tècnica. El risc genètic de la ICSI ha sorgit al tractar factors masculins idiopàtics i severs (Meschede i cols, 1997), ja que el dany produït a l'oòcit mitjançant aquesta tècnica és mínim si s'utilit...

  9. Modelo para la generación de competencias genéricas a partir del e-learning fundamentado en aprendizaje autónomo

    OpenAIRE

    2011-01-01

    El objetivo de la presente investigación es el diseño de un modelo de formación-capacitación que permita la generación de competencias genéricas en el capital humano de la organización, en el marco del e-Learning y de los procesos de aprendizaje autónomo; el cual atiende no sólo a las necesidades de formación y capacitación al interior de la empresa, en términos coyunturales, sino además, a la urgencia de desarrollar un capital humano, capaz de ponerse a tono, por sí mismo, con las exigenc...

  10. Efecto del carácter multifoliolado sobre el rendimiento y sus componentes en generaciones tempranas de soya y determinación de parámetros genéticos en generación f3

    OpenAIRE

    Carvajal G., Héctor R.; Restrepo, J. Diego; Agudelo D., Orlando; Estrada, Edgar Iván

    2010-01-01

    Se realizó un experimento en soya, con el fin de indagar sobre el funcionamiento del modelo de herencia propuesto por Fehr (1972) para la condición genética hoja multifoliolada, al mismo tiempo conocer la posible influencia que podría tener su expresión en generaciones tempranas (F2 y F3) sobre un grupo de características agronómicas, entre ellas el rendimiento y sus componentes, cuando se compara con genotipos normales o trifolioladas. Se determinaron los parámetros genéticos en la generació...

  11. Relation of red blood cell\\\\\\'s folate and methylenetetrahedrofolate reductase C677T polymorphism to colorectal adenoma

    Directory of Open Access Journals (Sweden)

    Zohreh Mazloom

    2014-11-01

    Methods: In a case-control study conducted from January to October 2007 in Endoscopy-Colonoscopy ward of Shahid Faghihi Hospital, Shiraz. Participants were 177 case of colorectal adenoma who had pathologic-confirmed adenomatous polyps in full colonoscopy examination and 366 controls without polyps in full colonoscopy. Fasting venous blood were drawn from patients in order to determine RBC’s folate and to identify the MTHFR polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP technique. Results: Gender Distribution in the patient group were 57.6% male and 42.3% female and control group consisted of 55.1% male and 43.9% female. 50.2% of cases and 49.2% of controls were in the age group “45 years and above”. The T allele frequency was 56.6% in control group and 34.4% in colorectal adenoma patients. There was a significant association between T allele in -677 position of MTHFR gene and colorectal adenoma susceptibility (OR: 1.85, 95% CI: 0.76-4.24, P0.05 but mean concentration of RBC’s folate was the lowest in TT genotype compare with two other genotype. Odd's Ratio for low (<140ng/ml versus high level of RBC’s folate in participants with TT genotype was (OR: 2.08, 95% CI: 0.10-2.19, P<0.05 as compare with the CC ones. Conclusion: The result of this study suggested an inverse association between RBC's folate concentration and colorectal adenomas risk, which may be more relevant for those with the MTHFR TT genotype.

  12. Meta-analysis study to evaluate the association of MTHFR C677T polymorphism with risk of ischemic stroke

    OpenAIRE

    Abhinand, P.A.; Manikandan, M.; R.MAHALAKSHMI; Ragunath, P.K.

    2017-01-01

    Ischemic stroke is a condition characterized by reduced blood supply to part of the brain, initiating the ischemic cascade, leading to dysfunction of the brain tissue in that area. It is one of the leading causes of death and disability and is estimated to cause around 5.7 million deaths worldwide. Methyl tetra hydro-folate reductase (MTHFR) is a rate limiting enzyme in the methyl cycle which catalyzes the only biochemical reaction which produces 5, Methyl tetra hydro folate, the co-substrate...

  13. Aberrant DNA methylation associated with MTHFR C677T genetic polymorphism in cutaneous squamous cell carcinoma in renal transplant patients.

    LENUS (Irish Health Repository)

    Laing, M E

    2010-08-01

    Changes in genomic DNA methylation associated with cancer include global DNA hypomethylation and gene-specific hyper- or hypomethylation. We have previously identified a genetic variant in the MTHFR gene involved in the methylation pathway which confers risk for the development of squamous cell carcinoma (SCC) in renal transplant patients. This genetic variant has also been discovered to confer SCC risk in nontransplant patients with low folate status.

  14. Changes in lifestyle and total homocysteine in relation to MTHFR (C677T) genotype: the Inter99 study

    DEFF Research Database (Denmark)

    Husemoen, LL; Thomsen, TF; Fenger, M

    2006-01-01

    BACKGROUND: Reduction in total homocysteine (tHcy) may be clinically relevant in the prevention of cardiovascular disease (CVD) in the general population. OBJECTIVE: To examine the effects of changes in various lifestyle habits and lifestyle related biological CVD risk markers on changes in t...

  15. Methionine synthase A2756G polymorphism may predict ulcerative colitis and methylenetetrahydrofolate reductase C677T pancolitis, in Central China

    Directory of Open Access Journals (Sweden)

    Bronowicki Jean-Pierre

    2008-08-01

    Full Text Available Abstract Background The association of genetic polymorphisms related to metabolism of homocysteine with inflammatory bowel disease has been evidenced in Crohn disease and remains an open question in ulcerative colitis. We evaluated the association of the polymorphisms of MTHFR, MTR, MTRR and TCN2 genes with ulcerative colitis in Central China. Methods 168 patients were genotyped for these polymorphisms and compared to 219 matched controls. Results Methionine synthase 2756G allele frequency was higher in ulcerative colitis than in controls 0.15 (95% C.I. 0.11–0.19 vs 0.09 (95% C.I. 0.07 – 0.12, (P = 0.0137 and predicted ulcerative colitis risk in logistic regression, with an Odds ratio at 1.8 (95% C.I. 1.15–2.84. Methylenetetrahydrofolate reductase 677TT genotype was 2.7-fold more prevalent in individuals with pancolitis than in those with left colitis or proctitis, with respective percentages of 27.3 (95% C.I.16.4–42.0 and 10.5 (95% C.I. 6.3–17.1 (P = 0.0123. The carriage of 677TT or 677CT/1298AC genotypes of methylenetetrahydrofolate reductase was more frequent in cases with pancolitis than in subjects with left colitis or proctitis (P = 0.0048, with an Odds ratio adjusted by age and sex at 3.3 (95% C.I. 1.4–7.9, P = 0.0084 in logistic regression. Conclusion Methionine synthase and methylenetetrahydrofolate reductase are genes of vitamin B12 and folate cellular metabolism associated respectively with risk and extent of ulcerative colitis, at least in Central China. This finding may open new insights, particularly for the potential interest in treating patients carrying the 677TT MTHFR genetic trait and a deficit in folate.

  16. DEL GEN EGOISTA AL GEN ALTRUISTA

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    Oscar José Fernández Galíndez

    2010-06-01

    Full Text Available The Darwinian thought derived from the interpretations and / or rereadings done on Charles Darwin's work, they have generated many controversy. Even the same Darwin demonstrated in many occasions her, doubts on her, before raised ideas, of there that I dress the evolutionism as paradigm, it suggests a serious review in the frame of the emergent thought and in the most igalitarian search of a society and less fragmented.

  17. Medicina genómica: Aplicaciones del polimorfismo de un nucleótido y micromatrices de ADN Genomic Medicine: Polymorphisms and microarray applications

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    Monica P. Spalvieri

    2004-12-01

    Full Text Available Esta actualización tiene por objeto difundir un nuevo enfoque de las variaciones del ADN entre individuos y comentar las nuevas tecnologías para su detección. La secuenciación total del genoma humano es el comienzo para conocer la diversidad genética. La unidad de medida reconocida de esta variabilidad es el polimorfismo de un solo nucleótido (single nucleotide polymorphism o SNP. El estudio de los SNPs está restringido a la investigación pero las numerosas publicaciones sobre el tema hacen vislumbrar su entrada en la práctica clínica. Se presentan ejemplos del uso de SNPs como marcadores moleculares en la genotipificación étnica, la expresión génica de enfermedades y como potenciales blancos farmacológicos. Se comenta la técnica de las matrices (arrays que facilita el estudio de múltiples secuencias de genes mediante chips de diseño específico. Los métodos convencionales analizan hasta un máximo de 20 genes, mientras que una sola micromatriz provee información sobre decenas de miles de genes simultáneamente con una genotipificación rápida y exacta. Los avances de la biotecnología permitirán conocer, además de la secuencia de cada gen, la frecuencia y ubicación exacta de los SNPs y su influencia en los comportamientos celulares. Si bien la validez de los resultados y la eficiencia de las micromatrices son aún controvertidos, el conocimiento y caracterización del perfil genético de un paciente impulsará seguramente un cambio radical en la prevención, diagnóstico, pronóstico y tratamiento de las enfermedades humanas.This update shows new concepts related to the significance of DNA variations among individuals, as well as to their detection by using a new technology. The sequencing of the human genome is only the beginning of what will enable us to understand genetic diversity. The unit of DNA variability is the polymorphism of a single nucleotide (SNP. At present, studies on SNPs are restricted to basic research

  18. Identidad genética del hongo causante del primer caso de coccidioidomicosis descripto por Alejandro Posadas en 1892 Genetic characterization of the fungus involved in the first case of coccidioidomycosis described by Alejandro Posadas in 1892

    Directory of Open Access Journals (Sweden)

    Cristina E Canteros

    2009-04-01

    Full Text Available En 1892, Alejandro Posadas documentó el primer caso mundial de coccidioidomicosis en un paciente argentino de nombre Domingo Escurra. Con el objetivo de identificar la especie de Coccidioides involucrado en ese caso, analizamos una pieza de necropsia del paciente, conservada en el Museo de Patología de la Facultad de Medicina de la Universidad de Buenos Aires, Argentina. La porción del tejido con mayor número de endosporas del hongo libres e integras fue elegida utilizando una coloración inmunohistoquímica específica. El ADN fúngico fue amplificado usando una PCR anidada que reconoce un fragmento del gen Ag2/PRA cuyo polimorfismo diferencia Coccidioides immitis y C. posadasii. Se amplificó además, el ADN de dos cepas de referencia: C. immitis (M38-05 y C. posadasii (1-NL y de cuatro aislamientos de Coccidioides de pacientes argentinos. Los fragmentos amplificados fueron secuenciados en ambas hebras. Las secuencias fueron editadas, alineadas y comparadas con las depositadas en GenBank C. posadasii (Acceso N° AY536446, cepa Silveira y C. immitis (Acceso N° AY536445. Las secuencias del Coccidioides del caso Escurra, de los aislamientos argentinos y de la cepa 1-NL fueron idénticos entre sí y mostraron una mutación puntual de C→G en la posición 1228 en comparación con la secuencia de C. posadasii, cepa Silveira. Este es el primer trabajo donde se busca ADN de Coccidioides en una pieza anatómica de museo con más de 100 años de antigüedad. Los resultados confirman que el primer caso de coccidioidomicosis o enfermedad de Posadas documentado mundialmente fue producido por el recientemente descripto C. posadasii.In 1892 Alejandro Posadas described the first worldwide case of coccidioidomycosis in a patient named Domingo Escurra. A preserved necropsy piece from the patient's remains is conserved in the Museum of Pathology of the Medical School, Buenos Aires University. Paraffin-embedded specimens obtained from this piece served to

  19. Diversidad genética de dos poblaciones del caracol Strombus gigas (Gastropoda: Strombidae en Yucatán, México, con microsatélite

    Directory of Open Access Journals (Sweden)

    Roberto Zamora-Bustillos

    2011-09-01

    Full Text Available El caracol rosado S. gigas, es una especie de gran importancia pesquera en la región del Caribe que incluye la Península de Yucatán, en la cual, se analizó la diversidad y estructura genética de dos poblaciones (Arrecife Alacranes y Banco Chinchorro mediante el uso de cinco marcadores moleculares del tipo microsatélites. Los resultados indican que las dos poblaciones analizadas se encuentran en el mismo rango de diversidad genética (He de 0.613 a 0.692. En ambas poblaciones también se observó una desviación significativa al equilibrio H-WE, la cual fue atribuida a factores como la endogamia a consecuencia de una sobre-explotación pesquera. Sin embargo otra explicación posible es que se deba a una mezcla de individuos de dos o más poblaciones, y la existencia de alelos nulos. Los niveles de estructura genética indican la existencia de una sola población homogénea en la península de Yucatán (F ST de 0.003, p=0.49 y el flujo genético fue significativo (2.3 individuos entre las dos poblaciones. Los resultados de este estudio aceptan la hipótesis de que las poblaciones S. gigas forman parte de una sola población panmíctica en la Península de Yucatán, por lo tanto, el recurso pesquero debe regularse de igual manera en ambas regiones.Genetic diversity in two populations of the snail Strombus gigas (Gastropoda: Strombidae from Yucatan, Mexico, using microsatellite. The pink conch Strombus gigas is an important fisheries resource in the Caribbean region, including the Yucatán Peninsula. We analyzed the genetic diversity and genetic structure of two populations (Alacranes Reef and Chinchorro Bank with the use of five microsatellite molecular markers. The results indicate that the two populations are in the same rank of genetic diversity (He, from 0.613 to 0.692. Significant deviation from H-WE was observed in the both populations due to deficit to heterozygotes, this was attributed to inbreeding as a consequence of over- fishing

  20. Comunicar Conocimientos vs. Organizar el Conocimiento: la Gestión del Gen-preneur en el Aula.

    Directory of Open Access Journals (Sweden)

    Jose Manuel Comeche Martínez

    2014-08-01

    Full Text Available There have been countless tests made to confirm that creativity is a critical skill for entrepreneurs and their entrepreneurial training (Schmidt, J. et al. 2012, even more, practices on divergent thinking increases the entrepreneurial skills of students to generate a greater number and range of ideas, but not, their approaches to solve problems in a creative way. Our goal is to show that entrepreneurship is a facet of creativity and that the "hidden" entrepreneur in the learner, will need to observe and confirm the existence of sufficient external constraints -context and social network- to release its entrepreneurial attitude, furthermore it will be essential, that teachers adopt an innovative approach that enables a suitable context, in this way almost intuitively, and vocational - show student behaviors associated with entrepreneurial attitudes. In our study, we found out that the implementation of an innovative teaching contributes to facilitate the transmission of the entrepreneurial spirit and improves the use of gen-preneur in class.

  1. Composición Musical a Través del Uso de Algoritmos Genéticos

    Directory of Open Access Journals (Sweden)

    Ezequiel Moldaver

    2014-06-01

    Full Text Available Este trabajo se enfocará en el uso de los algoritmos genéticos (AAGG con el fin de mezclar armonías y melodías de forma que se genere una composición musical de buen sonido para el oído, lo que significa que el contexto de cada nota respaldará la sonoridad de la misma provocando que no se genere un efecto disonante de forma permanente, que se genere una disonancia momentánea es permisible ya que es parte de la misma música generar tensión a través de pequeños intervalos poco agradables al oído.

  2. Polimorfismos del gen Butirilcolinesterasa responsables de reacciones adversas en pacientes consumidores de “cocaína”

    OpenAIRE

    Estrada Serrato, Carlos

    2014-01-01

    La butirilcolinesterasa humana (BChE; EC 3.1.1.8) es una enzima polimórfica sintetizada en el hígado y en el tejido adiposo, ampliamente distribuida en el organismo y encargada de hidrolizar algunos ésteres de colina como la procaína, ésteres alifáticos como el ácido acetilsalicílico, fármacos como la metilprednisolona, el mivacurium y la succinilcolina y drogas de uso y/o abuso como la heroína y la cocaína. Es codificada por el gen BCHE (OMIM 177400), habiéndose identificado más de 100 varia...

  3. Feocromocitoma-paraganglioma: del diagnóstico bioquímico al genético

    Directory of Open Access Journals (Sweden)

    Marta Cano Megías

    2016-09-01

    Full Text Available Los feocromocitomas y paragangliomas son tumores derivados de células de la cresta neural, que pueden ser diagnosticados mediante la determinación bioquímica de metanefrinas y metoxitiramina. Los avances en la investigación genética han permitido identificar múltiples genes implicados en la fisiopatogenia de estos tumores, de forma que hasta el 35-45% podrían tener una mutación germinal subyacente. Estos genes tienen una firma biológica de transcripción característica y se pueden agrupar en 2 grandes grupos (o clusters, el grupo 1 (VHL y SHDx, con implicación de la vía de la angiogénesis e hipoxia; y el grupo 2 (MEN2 y NF1, implicados en la vía de señalización de la cinasa. A su vez estos genes se asocian a un fenotipo bioquímico (adrenérgicos y noradrenérgicos, y presentación clínica (localización, comportamiento biológico, edad de presentación… característicos en un número elevado de casos. Un diagnóstico precoz de estos tumores, acompañado de un correcto diagnóstico genético, debe ser una prioridad que permita un mejor tratamiento, la detección precoz de complicaciones, un correcto screening de familiares y de otros tumores relacionados, así como una mejoría en el pronóstico global de estos pacientes.

  4. Validación del cuaderno orientador para las clases teórico-prácticas y los seminarios de Genética Médica

    Directory of Open Access Journals (Sweden)

    Yeniseys Beltrán Blanes

    2017-07-01

    Full Text Available Objetivo: Validar el cuaderno orientador para las clases teórico-prácticas y los seminarios de Genética Médica en la Escuela Latinoamericana de Medicina. Método: Se realizó un estudio de intervención pedagógica. La muestra la constituyeron seis profesores del departamento docente y 324 estudiantes del segundo año de la Carrera de Medicina de La Habana, Cuba, durante el curso académico 2013-2014. Para la implementación se tuvo en cuenta la ejecución de talleres metodológicos, la asignación de tareas a los estudiantes y la evaluación del proceso de enseñanza-aprendizaje, midiéndose la utilidad del cuaderno orientador en el nivel de satisfacción de su uso y la contribución a la comprensión de conocimientos; para el procesamiento de los resultados se utilizaron métodos del nivel empírico y matemático. Resultados: Respecto a las evaluaciones frecuentes, se apreció que los resultados fueron satisfactorios. Se constató que la mayoría de las variables evaluadas se cumplieron en el 100% de las observaciones realizadas; 96% de los estudiantes consideraron que el cuaderno orientador contribuyó a la obtención de mejores calificaciones. Más del 90% de los estudiantes consideraron que el resumen teórico y los ejercicios de la orientación de la actividad fueron de gran utilidad. Los calificativos asignados al cuaderno más seleccionados fueron los de instructivo y asequible. Conclusiones: Se constató que el cuaderno orientador favorece la comprensión y el interés de los estudiantes por el estudio de la disciplina y contribuye a su futuro desarrollo profesional.

  5. ADAPTACI N AL ESPA OL DEL CUESTIONARIO VEC ET SANTE PER UE DE L ADOLESCENT (VSP-A: UNA MEDIDA GEN RICA DE CALIDAD DE VIDA PARA ADOLESCENTES

    Directory of Open Access Journals (Sweden)

    Vicky Serra-Sutton

    2002-01-01

    Full Text Available Fundamentos: En la última década se han desarrollado diversas medidas de calidad de vida relacionada con la salud para uso exclusivo en niños/as y adolescentes. No obstante, existen pocos instrumentos de estas características adaptados en España. El Vecú et Sante Perçue de l?adolescent (VSP-A es un instrumento genérico de calidad de vida relacionada con la salud para adolescentes de 11 a 17 años desarrollado en Francia. El objetivo de este estudio fue adaptar al español el VSP-A, como primera fase para la obtención del cuestionario. Métodos: Se adaptó la versión del VSP-A de 39 preguntas siguiendo la metodología de traducción directa e inversa incluyendo: 2 traducciones al español, puntuación del grado de dificultad (0 min-10 máx y clasificación de equivalencia semántica y cultural, 2 reuniones y discusión en paneles de adolescentes, así como reuniones de consenso del equipo de investigación. Finalmente se realizó una traducción inversa (retro-traducción al francés y se administró la versión final pre-test en la prueba piloto. Resultados: La mayoría de las preguntas se clasificaron como equivalentes (24 sobre 39. Tras las reuniones con adolescentes se modificaron algunas preguntas. Tras la retro-traducción, 3 preguntas necesitaron cambios menores. Conclusiones: La versión española del VSP-A parece semántica y culturalmente equivalente a la versión original en francés y adecuada para adolescentes en España. La sencillez de las preguntas, los comentarios de los adolescentes y la participación de los autores originales en el proceso de adaptación ha permitido obtener una versión pre-test adecuada. La siguiente fase del estudio es la comprobación de la fiabilidad y validez. Se espera que el VSP-A sea de utilidad para medir la calidad de vida relacionada con la salud en encuestas de salud o como instrumento de cribado en colegios o centros de atención primaria en nuestro medio.

  6. Caracterización de la diversidad genética en naranja y comparación del polimorfismo de microsatélites amplificados al azar (RAMs usando electroforesis de poliacrilamida y agarosa

    Directory of Open Access Journals (Sweden)

    Muñoz Flores Jaime Eduardo

    2009-12-01

    Full Text Available Se compararon las eficiencias de tres métodos de electroforesis en agarosa y poliacrilamida, usando la cámara pequeña de DNA Sequencing System y cámara grande OWL Sequi-Gen Sequencing Cell, en la detección del polimorfismo en 21 accesiones de naranja (Citrus sinensis con empleo del cebador CGA. El gel de poliacrilamida dio mejor resolución de los productos amplificados vía PCR producidos por RAMs. Este permitió una mejor detección de bandas de ADN polimórficas, lo que facilitó la identificación de la variabilidad genética. La electroforesis en agarosa puede ser más conveniente en otras aplicaciones, debido al bajo costo y fácil aplicación. El estudio de diversidad genética en naranja usando microsatélites RAMs diferenció 51 accesiones en siete grupos con 0.75 de similaridad y 0.25 de heterocigosidad, lo que revela bajo polimorfismo genético. La técnica RAMs permitió agrupar las accesiones en Comunes o Blancas, Navel y Pigmentadas o Sanguinas.

  7. La pesca indígena de autoconsumo en Veracruz. Papel en la dieta y división genérica del trabajo

    Directory of Open Access Journals (Sweden)

    Verónica Vázquez

    2004-01-01

    Full Text Available Los estudios sobre pesca en MÈxico indican la presencia de una estricta divisiÛn genÈrica del trabajo en esta actividad. Generalmente los hombres pescan en lagunas y mar, mientras las mujeres comercializan el producto o pescan en esteros, lagunas y rÌos para el autoconsumo. Sin embargo, desco- nocemos la importancia de estos alimentos para la dieta familiar, asÌ como las implicaciones derivadas de esta divisiÛn del trabajo, en tÈrminos del acceso por parte de mujeres y hombres, al recurso acu·tico. El presente trabajo contribuye a estos dos temas con un estudio de caso realizado en Ixhuapan, comu- nidad nahua de la Sierra de Santa Marta, Veracruz. Los datos fueron ob- tenidos mediante entrevistas grupales e individuales, una encuesta socioeconÛmica y cuatro frecuencias de consumo. Los resultados indican una reducciÛn en la variedad y tamaÒo de especies acu·ticas para el auto- consumo, el cual actualmente se limita a dos animales: camarÛn y mojarra. La construcciÛn de las artes de pesca como femeninas o mas- culinas determina el tipo de alimentos que mujeres y hombres pueden pescar. Las mujeres usan matayahual para atrapar camarÛn, los hombres atrapan peces con flechas y atarrayas y, en momentos determinados, tam- biÈn camarÛn con matayahual. Se concluye que el uso de determinado arte de pesca por parte de hombres o mujeres no depende de sus limi- taciones fÌsicas, sino m·s bien de prescripciones culturales que limitan el acceso de las mujeres a ciertos recursos alimenticios.

  8. La pesca indígena de autoconsumo en Veracruz. Papel en la dieta y división genérica del trabajo

    Directory of Open Access Journals (Sweden)

    Verónica Vázquez

    2004-01-01

    Full Text Available Los estudios sobre pesca en México indican la presencia de una estricta división genérica del trabajo en esta actividad. Generalmente los hombres pescan en lagunas y mar, mientras las mujeres comercializan el producto o pescan en esteros, lagunas y ríos para el autoconsumo. Sin embargo, desconocemos la importancia de estos alimentos para la dieta familiar, así como las implicaciones derivadas de esta división del trabajo, en términos del acceso por parte de mujeres y hombres, al recurso acuático. El presente trabajo contribuye a estos dos temas con un estudio de caso realizado en Ixhuapan, comunidad nahua de la Sierra de Santa Marta, Veracruz. Los datos fueron obtenidos mediante entrevistas grupales e individuales, una encuesta socioeconómica y cuatro frecuencias de consumo. Los resultados indican una reducción en la variedad y tamaño de especies acuáticas para el autoconsumo, el cual actualmente se limita a dos animales: camarón y mojarra. La construcción de las artes de pesca como femeninas o masculinas determina el tipo de alimentos que mujeres y hombres pueden pescar. Las mujeres usan matayahual para atrapar camarón, los hombres atrapan peces con flechas y atarrayas y, en momentos determinados, también camarón con matayahual. Se concluye que el uso de determinado arte de pesca por parte de hombres o mujeres no depende de sus limitaciones físicas, sino más bien de prescripciones culturales que limitan el acceso de las mujeres a ciertos recursos alimenticios.

  9. Papel del RNA en expresión genética y recombinación en Saccharomyces cerevisiae

    OpenAIRE

    Huertas Sánchez, Pablo

    2004-01-01

    La información necesaria para la supervivencia celular se encuentra codificada en el genoma. Cualquier proceso que conlleve la alteración de dicha información puede provocar la incapacidad del organismo para sobrevivir, la aparición de diversos síndromes La información necesaria para la supervivencia celular se encuentra codificada en el genoma. Cualquier proceso que conlleve la alteración de dicha información puede provocar la incapacidad del organismo para sobrevivir, la aparición de d...

  10. Variantes polimórficas Ala513Pro y Gly972Arg del gen IRS-1 no se asocian a la diabetes mellitus tipo 2 en un grupo de la población cubana The Ala513Pro and Gly972ARg polymorphous variants of IRS-1 gen are not associated with type diabetes mellitus in a group of the Cuban population

    Directory of Open Access Journals (Sweden)

    Luis Miguel Pérez

    2011-08-01

    Full Text Available Introducción: la diabetes mellitus tipo 2 es una enfermedad heterogénea y multifactorial, que está determinada por factores genéticos y no genéticos. El sustrato 1 del receptor de la insulina (IRS-1 cumple una función fundamental en la transmisión de la señal insulínica, por tanto sus variantes génicas constituyen blancos importantes en el estudio de la susceptibilidad genética a esta enfermedad en las diferentes poblaciones. Objetivo: explorar el papel de las variantes polimórficas Gly972Arg y Ala513Pro del gen IRS-1 en la susceptibilidad genética de la diabetes mellitus tipo 2 en un grupo de la población cubana. Métodos: se determinó la frecuencia de los polimorfismos Gly972Arg y Ala513Pro del IRS-1 en 499 ciudadanos cubanos, con un índice de masa corporal entre 22-30, con edades comprendidas entre los 40 y 70 años: de ellos 272 (54,5 % diabéticos y 227 (45,5 % no diabéticos. Resultados: la frecuencia del alelo Pro513 fue baja (1,2 % y similar para ambos grupos (1,1 % vs. 1,3 % para el grupo de diabéticos y el grupo control, respectivamente. La frecuencia del polimorfismo Gly972Arg fue de 16,2%, superior a la reportada para la mayoría de las poblaciones estudiadas. No se encontraron diferencias significativas en la frecuencia del alelo Arg972 entre el grupo de diabéticos y el grupo control (15,4 % vs. 17,3 %, ni cambios en los niveles de glucemia e insulinemia asociados a la presencia del alelo polimórfico Arg972. Conclusiones: en este grupo de sujetos de la población cubana, las variantes polimórficas Ala513Pro y Gly972Arg del gen IRS-1 no participan en la etiología de la diabetes mellitus tipo 2.Introduction: the type 2 diabetes mellitus is a heterogeneous and multifactor disease determined by genetic and no-genetic factors. The substrate 1 of insulin receptor (IRS-1 has a fundamental function in transmission of insulin signal, thus its genic variants are significant targets in study of genetic susceptibility to

  11. Alta conectividad genética y expansión poblacional de Scomber japonicus en en la parte norte del Sistema de Corriente de Humboldt reveladas por secuencias de la región control mitocondrial

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    Sergio Paolo Barahona Padilla

    2017-07-01

    Full Text Available La caballa, Scomber japonicus soporta una pesquería importante en el Pacífico Sudeste, sin embargo, su genética de poblaciones se desconoce actualmente. En el presente estudio se examinó la estructura genética, el flujo génico y la demografía histórica de esta especie en la parte norte del Sistema de la Corriente de Humboldt. Las muestras fueron colectadas en los veranos del 2013 y 2014 en tres puntos de desembarco de pesca (Paita, Ventanilla e Ilo cubriendo 12 grados de latitud frente a la costa peruana. Se secuenció un segmento de 532 pb de la región control mitocondrial en 72 individuos, el cual permitió detectar un total de 29 sitios polimórficos, 35 haplotipos, niveles moderados altos de diversidad haplotípica (0.793 – 0.969 y muy bajos niveles de diversidad nucleotídica (0.004 – 0.008. El análisis de flujo génico mostró altos niveles de conectividad entre las poblaciones en las áreas de muestreo. El análisis de varianza molecular (ФST = 0.00868, P = 0.1837, las comparaciones ФST a pares de poblaciones y las pruebas de diferenciación genética confirmaron la carencia de estructuración genética entre las tres localidades. Estos análisis sugieren que los sitios de muestreo analizados pueden ser considerados como un solo grupo genético. El comportamiento migratorio, el alto potencial de dispersión de los estadios tempranos de desarrollo y la ausencia de barreras oceanográficas pueden explicar su homogeneidad genética a lo largo del mar peruano. También se examinó la demografía histórica. Las pruebas de neutralidad, la distribución mismatch y el Bayesian Skyline Plot sugirieron un escenario de expansión poblacional que tuvo lugar durante el Pleistoceno Superior. Este estudio provee información nueva con respecto a la genética de poblaciones de la caballa en el Pacífico Sudeste.

  12. Papel de la metilación del ADN en el control del desarrollo y la estabilidad genómica en dos especies de peces anádromas (Petromyzon marinus y Salmo trutta)

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    Covelo Soto, Lara

    2015-01-01

    La epigenética es un campo en auge actualmente dentro de la investigación en Genética y Biología Molecular dada su gran importancia en el control de la expresión génica y mantenimiento estructural y funcional del genoma de muchos organismos. La modificación epigenética más estudiada es la metilación de ADN (5mC), consistente en la adicción de un grupo metilo a la posición 5' de un residuo de citosina. En vertebrados la metilación ocurre cuando la citosina está formando el dinucleótido CpG. Di...

  13. Hipercalcemia hipocalciúrica debida a una mutación de novo del gen del receptor sensor de calcio Hypocalciuric hypercalcemia due to de novo mutation of the calcium sensing receptor

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    Marcelo Sarli

    2004-08-01

    Full Text Available El objetivo de este trabajo es presentar el inusual caso clínico de una paciente de 34 años que consultó para establecer diagnóstico de certeza y conducta terapéutica ante una hipercalcemia asintomática, detectada en un examen bioquímico de rutina. La elevación de la calcemia en ausencia de inhibición de la secreción de parathormona orientó hacia una patología paratiroidea. La persistencia de la hipercalcemia concomitante con hipocalciuria y coincidente con una relación clearance de calcio/clearance de creatinina inferior a 0.01, hicieron sospechar el diagnóstico de hipercalcemia hipocalciúrica familiar. La falta de antecedentes familiares llevó a realizar un estudio molecular de la paciente y su grupo familiar. Los resultados de los estudios nos permitieron concluir que la paciente es portadora de una mutación de novo (inactivante del gen del receptor sensor del calcio. Se incluyen los datos del estudio molecular y una breve revisión bibliográfica del tema.The aim of this paper is to refer the unusual case of a 34 years old woman who consulted because of asymptomatic hypercalcemia, detected in a biochemical routine examination. The elevated values of serum calcium without blunted parathyroid hormone secretion suggested a parathyroid pathology. The concomitance of hypocalciuria with hypercalcemia and a calcium clearance/creatinine clearance ratio less than 0.01 reverted the diagnosis of familial hypocalciuric hypercalcemia, the first option. The absence of familial background led to the molecular study of the patient and her family. The latter confirmed the diagnosis of a de novo inactivating mutation of the calcium sensing receptor. Details on the molecular study and a brief review of this subject are included.

  14. Evaluación del daño genómico en células del cúmulus inducido por la hormona ghrelina

    OpenAIRE

    Sirini, Matías Ángel; Nikoloff, Noelia; Anchordoquy, Juan Patricio; Anchordoquy, Juan Mateo; Pascual, Adriana; Testa, Juan Alberto; Furnus, Cecilia

    2016-01-01

    Las células del cúmulus (CC), que rodean a los ovocitos durante la maduración, juegan un rol importante en su capacidad de desarrollo posterior hasta el estadio de blastocisto. Esto se debe a que las células se hallan unidas a través de uniones gap que conectan a las células del cúmulus entre sí y con el ovocito, interviniendo en el soporte metabólico del mismo.Si bien se ha demostrado, tanto en estudios in vivo como in vitro, que las células de la granulosa mueren a través del proceso activo...

  15. Polimorfismo en el gen COMT en una muestra de gestantes normales y con restricción del crecimiento intrauterino en un hospital de Lima

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    José Pacheco-Romero

    2013-04-01

    Full Text Available Antecedentes: Los procesos fisiopatológicos que ocurren a nivel celular y molecular en la restricción de crecimiento intrauterino (RCIU son aún desconocidos. La catecol-O-metiltransferasa (COMT es una enzima de fase II que inactiva los catecol estrógenos al transferir un grupo metílico. Se conoce un polimorfismo funcional Val158 Met en el gen COMT como un marcador susceptible para diversas enfermedades maternoperinatales, existiendo estudios que sugieren que el alelo que codifica una COMT de baja actividad puede ser un marcador susceptible para RCIU. Por lo tanto, el estudio del polimorfismo COMT ofrece una nueva estrategia para la evaluación de marcadores genéticos que pueden ser utilizados para la detección de ciertas alteraciones asociadas al embarazo. Objetivos: Establecer la asociación entre el polimorfismo Val158Met catecol-O-metiltransferasa (COMT y la restricción de crecimiento intrauterino. Institución: Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú. Diseño: Estudio tipo relacional (asociativo, con diseño observacional, tipo caso-control (no experimental. Materiales: Muestra de sangre materna de parturientas. Métodos: Durante el año 2011, se obtuvo 81 muestras para genotipaje del gen COMT. De ellas, 26 (32,1% correspondieron a parturientas con RCIU (casos y 55 (67,9% a muestras de madres de hijos sin RCIU (controles. La distribución de los genotipos fue evaluada usando la prueba de chi cuadrado. Se comprobó la distribución proporcional de los genotipos en los grupos con RCIU y sin RCIU con la hipótesis nula de Hardy-Weinberg. Las madres participantes firmaron un consentimiento informado. Principales medidas de resultados: Asociación entre los genotipos COMT y la RCIU, y entre los alelos COMT Val/Met y la RCIU. Resultados: Las distribuciones de los genotipos en los grupos con RCIU y sin RCIU estuvieron de acuerdo a la hipótesis nula de Hardy-Weinberg. Al relacionar los genotipos COMT Val

  16. Diagnóstico del tratamiento del género en los documentos de centro-, diseño y aplicación de la escala observacional Val-Gen

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    María Teresa PADILLA

    2009-11-01

    Full Text Available RESUMEN: Este artículo presenta el proceso de diseño y aplicación de la escala observacional Val-Gen, a través de la cual se pretende valorar en qué grado los diferentes documentos escolares (proyecto educativo, proyecto curricular, plan de orientación y acción tutorial, ROF, plan anual y memorias anuales recogen los valores de género e integran la educación para la igualdad de oportunidades. Se describe, por tanto, el marco conceptual a partir del cual se elaboró dicha escala, la estructura de ésta y el proceso a través del cual se confeccionó. Se discuten, asimismo, los resultados de una primera aplicación a los documentos escolares de dos centros de enseñanza en la que participaron 12 observadores/as.ABSTRACT: In this article, the process of design and application of the observational scale named Val-Gen is presented and described. This scale pretends to assess the extent which gender values and igual opportunities are integrated in several school papers (such as educational project, curriculum project, guidance programs, etc.. The scale conceptual framework, structure and process by means of which it has been designed, are described. Also, results from the scale application through two schools and by 12 observers are presented and discussed.RÉSUMÉ: Cet article présente le procès de dessin et application de l'escale Val- Gen, avec laquelle on prétende évaluer le degré avec lequel les différents documents écoliers (projet éducatif, projet du curriculum, plan d'orientation et action du tuteur, ROF, plan annuel et mémoires annuels recueillent les valeurs du genre, et composent l'éducation pour l'égalité des opportunités. On décri ainsi le marc conceptuelle, restructure et le procès de confection de l'escale, et en même temps les résultats d'une première aplication en deux centres d'enseignement avec la participation de 12 observateurs.

  17. Efecto del Polimorfismo del Intrón 6 del Gen LTF Bovino con Algunas Enfermedades de Alta Incidencia en la Producción Lechera Effect of the Polymorphism in the Intron 6 of the Bovine LTF Gene with Some Diseases of High Incidence in Dairy Production

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    Nancy Rodríguez Colorado

    2012-06-01

    Full Text Available Resumen. El objetivo de la investigación fue determinar la asociación del polimorfismo (C/T del intrón 6 del gen de la bLTF, con la incidencia de algunas enfermedades en ganado lechero. Para ello fueron observadas 482 vacas Holstein, durante al menos una lactancia, determinando la incidencia de algunas de las enfermedades mas importantes en la ganaderia de leche. La genotipificación para el polimorfismo de bLTF, se hizo usando la técnica de PCR-RFLP con DNA extraído de sangre periférica mediante la técnica de salting out. Para estudiar la asociación de los alelos del gen LTF, se utilizó el alelo B como control y se determinó el Odds Ratio (OR. Como resultados se obtiene que las frecuencias de los alelos A y B para el gen bLTF fueron 0,78 y 0,22 respectivamente. Las frecuencias genotípicas fueron 0,60, 0,36 y 0,04 para AA, AB y BB respectivamente. Una asociación altamente significativa (P≤0,001 fue hallada entre la incidencia de mastitis clínica y el polimorfismo del gen LTF. Los individuos portadores del alelo B tuvieron una probabilidad de incidencia de mastitis dos veces superior a los portadores del alelo A (OR=2.115 IC del 95%, 1.392-3.213. En el caso de la mastitis subclínica la probabilidad de incidencia fue de 1,6 veces más en los portadores del alelo B, con un OR=1.637 IC del 95% 1.184-2.264. Para la incidencia de enfermedades metabólicas, reproductivas, respiratorias, parasitarias, cáncer y cojeras, no se halló diferencia significativa (P>0,05 y se encontró asociación del alelo B del polimorfismo del intrón 6 del gen bLTF con la incidencia de mastitis clínica y subclínica.Abstract. The research objective was to determine the association of polymorphism (C/T of intron 6 bLTF gene, with the incidence of some diseases on dairy cattle. A total of 482 Holstein cows located in different herds in the department of Antioquia - Colombia, were used to follow the incidence of disease, for at least a full lactation

  18. Estructura genética e historia demográfica del Jaguar ( Panthera onca en Colombia: Contraste entre marcadores moleculares y datos craneométricos

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    M. Ruíz-García

    2001-07-01

    Full Text Available Se estudio la estructura genética de los jaguares en Colombia (n=49, e igualmente, se com-pararon los resultados moleculares obtenidos con otros 16 jaguares procedentes de Guatemala,Perú, Bolivia y zona central de la Amazonía brasileña. Para ello se emplearon 18 marcadores microsatélites (STRPs diseñados para gato doméstico. Estos marcadores fueron Fca 01, 08, 24,43, 45, 70, 94, 96, 126, 136, 176, 200, 225, 251, 290, 294, 391 y 506, localizados en losdiferentes cromosomas felinos. Mediante tests exactos utilizando cadenas de Markov y elmétodo de Fisher se determinó un fuerte exceso de homocigotos en todos los niveles jerárquicosanalizados, lo cual pone en evidencia la posible importancia del efecto Wahlund en esta especiey la no existencia de correspondencia con las subespecies morfológicamente propuestas en elpasado. Se calculó también el asignamiento poblacional de los jaguares analizados, a las dossubespecies de jaguares presentes en Colombia mediante el método de verosimilitud y con elmétodo basado en distancias con los procedimientos “as is” y “leave one out”.

  19. El cerdo cimarrón (Sus scrofa, Suidae) en la Isla del Coco, Costa Rica: Composición de su dieta, estado reproductivo y genética

    OpenAIRE

    Claudine Sierra

    2001-01-01

    Los cerdos cimarrones (Sus scrofa) provocan diferentes tipos de daños particularmente en islas oceánicas. En la Isla del Coco, Costa Rica, fueron introducidos en 1793 y se reprodujeron exitosamente. Para reunir datos sobre la ecología de los cerdos cimarrones y conocer su impacto sobre algunas comunidades de la Isla del Coco, analicé su dieta, estado reproductivo, genética y los efectos de la depredación. Estudié la dieta por medio de análisis estomacales en una época seca y otra húmeda. Dete...

  20. Caracterización epidemiológica, clínica y genética de la Neurofibromatosis 1 en la provincia Pinar del Río

    OpenAIRE

    Orraca Castillo, Miladys

    2014-01-01

    Con el objetivo de caracterizar la Neurofibromatosis 1 (NF1) se realizó un estudio analítico y transversal en Pinar del Río, desde 2004 hasta 2007. Para ello se utilizó como herramienta el registro informatizado de la enfermedad en la provincia, con 172 pacientes. Se obtuvo la prevalencia real de la enfermedad en niños entre 9 y 11 años. Se caracterizó clínica y genéticamente la misma. Cada criterio de la NF1 tuvo un comportamiento clínico acorde a la edad del paciente, aportando elementos de...

  1. Capítulo III: caracterización y evaluación de recursos genéticos del género Lycopersicon

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    Sierra Tulio Alberto

    1994-12-01

    Full Text Available

    Con el fin de determinar el potencial genético de 118 introducciones del género Lycopersicon se realizó la caracterización y evaluación, en el Centro Experimental de la Universidad Nacional Sede Palmira, utilizando los descriptores recomendados por el IBPGR (1981. Se utilizó el diseño experimental de Bloques al azar con dos repeticiones. La parcela experimental estuvo constituida por seis plantas. Se estudiaron nueve caracteres relacionados con la planta, diez caracteres relacionados con el fruto, componentes del rendimiento y  presencia o ausencia de plagas y enfermedades. Se encontró una gran variabilidad para la mayoría de los caracteres estudiados. Las variedades de la especie cultivada, L. esculentum, presentaron las mayores producciones por planta y el mayor tamaño de fruto, en comparación con las especies silvestres; sin embargo, estas últimas presentaron mayor resistencia a plagas y enfermedades. Se destacaron los siguientes variedades de L. esculentum por presentar altas producciones y tolerancia a plagas y enfermedades: ADB 18, ADB 400, 1600, 1604  y Río Fuego.

    118 accessions of the genus Lycopersicon were characterized and evaluated to determinate the genetic p