ORIGINAL ARTICLE: A Prospective Case–Control Study Analyzes 12 Thrombophilic Gene Mutations in Turkish Couples with Recurrent Pregnancy Loss

Citation Yenicesu GI, Cetin M, Ozdemir O, Cetin A, Ozen F, Yenicesu C, Yildiz C, Kocak N. A prospective case–control study analyzes 12 thrombophilic gene mutations in Turkish couples with recurrent pregnancy loss. Am J Reprod Immunol 2010; 63: 126–136 Problem Recurrent pregnancy loss (RPL) is a heterogeneous disorder. The contribution of specific thrombophilic genes to the pathophysiology of RPL has remained controversial. We evaluated the prevalences of 12 thrombophilic gene mutations among homogenous Caucasian couples with RPL and fertiles. Method of study This was a prospective case–control study evaluating 272 women with RPL and 152 of their male partners, and a control group of 56 fertile couples. We investigated mutations including FV Leiden, factor V H1299R, factor II prothrombin G20210A, F XIII V34L, β‐fibrinogen ?455G>A, plasminogen activator inhibitor‐1, GPIIIa L33P (HPA‐1 a/b L33P), MTHFR C677T, MTHFR A1298C, ACE I/D, Apo B R3500Q, and Apo E. Results Overall, heterozygous mutations of FV Leiden, FXIII V34L, GPIIIa L33P, Apo E4, and prothrombin G20210A and homozygous mutations of PAI‐1and MTHFR C677T were associated with RPL. There was no meaningful association between RPL and other studied genes. Conclusion In contrast to the other mutations and polymorphisms, FV Leiden, FXIII V34L, GPIIIa L33P, Apo E, prothrombin G20210A, PAI‐1 and MTHFR C677T gene mutations may help to identify the couples at risk for recurrent pregnancy loss.     

Development of a high-throughput fluorescence assay for detecting SNPs in hemostasis and folate metabolism genes for clinical use

The genetic predisposition of an individual patient should be taken into account to choose the proper treatment. Doing this in clinical practice requires the development of rapid, high-throughput, and easy-to-do assays intended to detect single nucleotide polymorphisms. A detection kit intended to identify the hemostasis and folate cycle gene mutations G20210A FII, G1691A FV, G10976A FVII, G103T FXIII, C807T ITGA2, T1565C ITGB3, 5G(-675)4G PAI, G(-455)A FGB, C677T and A1298C MTHFR, A2756G MTR, and A66G MTRR is proposed in this work. The method is based on the polymerase chain reaction and subsequent melt curve analysis of complexes of amplicons with a specific probe. Three single-nucleotide polymorphisms can be identified in one tube using our detection kit, which increases the productivity of the analysis in clinical use. Different types of biological samples (buccal epithelium, saliva, plasma, serum, and urogenital swabs) can be used as the initial material for DNA isolation and further analysis by the method developed in the work.     

MTHFR C677T, MTHFR A1298C, and OPG A163G polymorphisms in Mexican patients with rheumatoid arthritis and osteoporosis

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.     

A haplotype of the methylenetetrahydrofolate reductase gene is protective against late-onset Alzheimer's disease

Epidemiological studies have shown that elevated plasma homocysteine (Hcy) levels play an important role in the pathogenesis of Alzheimer's disease (AD). In spite of the evidence that a C677T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene elevates plasma Hcy levels, the impact of the C677T polymorphism on the development of AD is controversial. Here, we performed a genetic case-control study in a Japanese population to investigate whether three polymorphisms of the MTHFR gene, C677T (Ala222Val), A1298C (Glu429Ala), and A1793G (Arg594Gln), are associated with the development of late-onset AD (LOAD). In our study, the MTHFR gene had four major regional haplotypes: Haplotype A (677C-1298A-1793G), Haplotype B (677T-1298A-1793G), Haplotype C (677C-1298C-1793G), and Haplotype D (677C-1298C-1793A). The frequency of Haplotype C in LOAD was significantly lower than that in control group. Furthermore, the benefit conferred by the presence of at least one Haplotype C was stronger in LOAD patients who lacked the ApoE 4 allele (OR=0.293; 95% CI=0.115-0.744; P=0.010). The results indicate that Haplotype C of the MTHFR gene is protective against the development of LOAD.     

MTHFR、MTRR基因多态性与反复流产的相关性分析

目的探讨叶酸代谢相关基因5,10-亚甲基四氢叶酸还原酶(MTHFR)、甲硫氨酸合成酶还原酶(MTRR)多态性与反复流产的关系,分析基因多态性对红细胞叶酸水平的影响。方法选取2016年12月至2018年6月来唐山市妇幼保健院遗传咨询门诊,要求进行常规孕前检查,汉族非妊娠健康女性424例为研究对象。依据不良孕产史分为两组,其中病例组216例和对照组218例。采集静脉血,提取DNA,荧光定量PCR法进行MTHFR、MTRR基因多态性检测。化学发光法进行红细胞叶酸定量检测。采用SPSS19.0软件进行统计学分析。比较两组MTHFR、MTRR基因多态性分布频率、不同基因类型红细胞叶酸水平。探讨基因多态性、红细胞叶酸水平与反复流产的关系。结果MTHFR A1298C和MTRR A66G两位点多态性在病例组和对照组间的分布,差异无统计学意义。MTHFR C677T位点多态性,在病例组中的分布频率明显高于对照组,差异具有统计学意义。病例组中MTHFR C667T位点TT型基因突变的患者红细胞叶酸水平远低于正常和杂合型。结论MTHFR C677T基因突变与反复流产的密切相关,MTHFR C667T位点TT型基因突变影响机体红细胞叶酸代谢水平。     

Hereditary thrombophilia, anti-beta2 glycoprotein 1 IgM, and anti-annexin V antibodies in recurrent pregnancy loss

Citation Karata S, Aydin Y, Ocer F, Buyru A, Balci H. Hereditary Thrombophilia, anti‐beta2 glycoprotein 1 IgM, and anti‐annexin V antibodies in recurrent pregnancy loss. Am J Reprod Immunol 2012; 67: 251–255 Problem We investigated the beta2‐glycoprotein I and anti‐annexin V antibodies as anti‐phospholipid–cofactor antibodies; and factor V G1691A Leiden, prothrombin G20210A, and methylenetetrahydrofolate reductase (MTHFR) C677T mutations as hereditary thrombophilia in recurrent pregnancy losses (RPL). Method of study Study group consisted of 84 women with recurrent pregnancy loss and control group consisted of 84 women having at least one live birth. Results Methylenetetrahydrofolate reductase C677T homozygous mutation was detected in 28.5% of the study group and in 14.2% of the controls, and the difference was highly significant (P < 0.001). Heterozygous mutation of this gene was found in 64.3% of the study population and in 38.1% of the controls, and difference in heterozygous mutation frequency was also significant (P < 0.001). Both homozygous and heterozygous mutations of PT G20210A and factor V G1691A were not different between the groups. There was no significant difference in anti‐annexin V levels and anti‐beta2‐gp 1 levels of the groups. Conclusion We concluded that both homozygous and heterozygous mutations of MTHFR C677T were related with RPL in Caucasian women.     

Polymorphisms in the CBS gene and homocysteine, folate and vitamin B12 levels: association with polymorphisms in the MTHFR and MTRR genes in Brazilian children

Polymorphisms in the methylenetetrahydrofolate reductase (MTHFR), methionine synthase reductase (MTRR) and cystathionine beta-synthase (CBS) genes, involved in the intracellular metabolism of homocysteine (Hcy), can result in hyperhomocysteinemia. The objective of this study was to evaluate prevalence estimates of CBS T833C, G919A and the insertion of 68-bp (844ins68) polymorphisms and their correlation with Hcy, folate and B(12) in 220 children previously genotyped for MTHFR C677T, A1298C, and MTRR A66G. The prevalence of heterozygote children for 844ins68 was 19.5%. The T833C CBS mutation was identified in association with 844ins68 in all the carriers of the insertion. Genotyping for CBS G919A mutation showed that all the children presented the GG genotype. Analysis of Hcy, B(12) and folate, according to the combination of the different genotypes of the C677T and A1298C MTHFR, A66G MTRR, and 844ins68 CBS showed that the 677TT/1298AA/68WW genotype is associated with an increase in Hcy, when compared to the 677CC/1298AC/68WW (P = 0.033) and the 677CT/1298AA/68WW genotypes (P = 0.034). Since B(12) and folate were not different between these groups, a genetic interaction between diverse polymorphisms probably influences Hcy. Our results emphasize the role of genetic interactions in Hcy levels.     

The clinical significance of methylenetetrahydrofolate reductase (MTHFR) polymorphisms in acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy. Genetic polymorphisms in the folate metabolic pathway may contribute to the susceptibility to childhood ALL because they affect the DNA synthesis, methylation, and repair. The most common polymorphisms are methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C. The current study aimed at detecting the frequency of these two genetic polymorphisms in de novo ALL patients, and to clarify their impact on the response to induction chemotherapy, as well as treatment toxicity. MTHFR C677T and A1298C polymorphisms were tested in 30 de novo ALL patients by restriction fragment length polymerase chain reaction technique. Thirty normal age- and sex-matched subjects were subjected to the same analysis as a control group. The frequency of MTHFR A1298C gene polymorphism was significantly lower in ALL patients than the controls thus showing a protective effect. The two polymorphisms had no effect on the response to induction chemotherapy. As regards the treatment toxicity, MTHFR C677T polymorphism was associated with marked thrombocytopenia, while A1298C polymorphism was associated with hepatic toxicity. Identifying predictors of methotrexate sensitivity may lead to the development of individualized treatment strategies with improved efficacy and reduced toxicity as well as adjusting the initial methotrexate dose.     

Association of total plasma homocysteine with methylenetetrahydrofolate reductase genotypes 677C>T, 1298A>C, and 1793G>A and the corresponding haplotypes in Swedish children and adolescents

We studied 692 Swedish children and adolescents (aged 9-10 or 15-16 years, respectively), in order to evaluate the effect of the methylenetetrahydrofolate reductase (MTHFR) 677C>T, 1298A>C, and 1793G>A polymorphisms on total plasma homocysteine concentrations (tHcy). Genotyping was performed with Pyrosequencing technology. The MTHFR 677C>T polymorphism was associated with increased tHcy concentrations in both the children and the adolescents (P<0.001 for both age groups) in both genders. The effect of MTHFR 1298A>C was studied separately in subjects with the 677CC and 677CT genotypes, and the 1298C allele was found to be associated with higher tHcy levels both when children were stratified according to 677C>T genotypes, and when using haplotype analyses and diplotype reconstructions. The 1793A allele was in complete linkage disequilibrium with the 1298C allele. It was still possible to show that the 1793A allele was associated with lower tHcy levels, statistically significant in the adolescents. In conclusion, a haplotype-based approach was slightly superior in explaining the genetic interaction on tHcy plasma levels in children and adolescents than a simple genotype based approach (R2 adj 0.44 vs. 0.40). The major genetic impact on tHcy concentrations is attributable to the MTHFR 677C>T polymorphism. The common 1298A>C polymorphism had a minor elevating effect on tHcy, whereas the 1793G>A polymorphism had a lowering effect on tHcy.     

The prevalence of inherited thrombophilias in a Caucasian Australian population

AIMS: To describe the prevalence of four inherited thrombophilias and their combinations for the first time in a large Caucasian Australian population. METHODS: Newborn screening cards of 883 Caucasian babies born in South Australia in 1986-1999 were de-identified and tested for the following inherited thrombophilic polymorphisms: factor V Leiden (G1691A), prothrombin gene mutation (G20210A), methylenetetrahydrofolate reductase gene (MTHFR) C677T and A1298C, as well as compound heterozygosity for the MTHFR polymorphisms. RESULTS: The birth prevalences of heterozygosity and homozygosity for the four thrombophilic polymorphisms were: factor V Leiden 9.5% and 0.7%, prothrombin gene 4.1% and 0.2%, MTHFR C677T 37.3% and 12.4%, and MTHFR A1298C 38.3% and 11.8%, respectively. Compound heterozygosity for MTHFR C677T and A1298C was seen in 16.6% of the population. Overall, 64.2% and 24.5% of the population studied were homozygous and heterozygous, respectively, for at least one of the four polymorphisms studied. CONCLUSION: Inherited thrombophilic polymorphisms are common in the Caucasian Australian population. Knowledge of the background prevalence of these polymorphisms will allow further study of their associations in future disease research.     

Increased frequency of combined methylenetetrahydrofolate reductase C677T and A1298C mutated alleles in spontaneously aborted embryos

The pathogenesis of spontaneous abortion is complex, presumably involving the interaction of several genetic and environmental factors. The methylenetetrahydrofolate reductase (MTHFR) gene C677T and A1298C polymorphisms are commonly associated with defects in folate dependent homocysteine metabolism and have been implicated as risk factors for recurrent embryo loss in early pregnancy. In the present study we have determined the prevalence of combined MTHFR C677T and A1298C polymorphisms in DNA samples from spontaneously aborted embryos (foetal death between sixth and twentieth week after conception) and adult controls using solid-phase minisequencing technique. There was a significant odds ratio of 14.2 (95% CI 1.78-113) in spontaneously aborted embryos comparing the prevalence of one or more 677T and 1298C alleles vs the wild type combined genotype (677CC/1298AA), indicating that the MTHFR polymorphisms may have a major impact on foetal survival. Combined 677CT/1298CC, 677TT/1298AC or 677TT/1298CC genotypes, which contain three or four mutant alleles, were not detected in any of the groups, suggesting complete linkage disequilibrium between the two polymorphisms. The present finding of high prevalence of mutated MTHFR genotypes in spontaneously aborted embryos emphasises the potential protective role of periconceptional folic acid supplementation.     

神经管畸形与MTHFRC677T、MTHFRA1298C、MSA2756G基因多态性的相关性研究

目的对MTHFRC677T、MTHFRA1298C、MSA2756G基因的多态性进行综合性分析,了解这3个基因多态性位点同神经管畸形发生的关系,明确神经管畸形发生的遗传学基础,为制定有效的预防及筛查方案提供依据.方法采用PCR-RFLP技术,对50例有两次或两次以上神经管畸形生育史的妇女及40例有正常生育史的妇女,MTHFRC677T、MTHFRA1298C、MSA2756G进行多态性研究.结果①MTHFRC677T及MTHFRA1298C基因型构成在病例组与对照组之间均存在显著性差异,而MSA2756G在两组之间无显著性差异.②MTHFR677TT、MTHFR1298CC和MS2756GGG中任意两种纯和突变并存时OR值明显增加.结论MTHFR677TT基因型和MTHFR1298CC基因型均可能是神经管畸形的危险因素;MS2756GG基因型虽不是独立危险因素,但与其它突变并存时会增加神经管畸形的危险性.     

MTHFR genetic polymorphism as a risk factor in Egyptian mothers with Down syndrome children

Recent reports linking Down syndrome (DS) to maternal polymorphisms at the methylenetetrahydrofolate reductase (MTHFR) gene locus have generated great interest among investigators in the field. The present study aimed at evaluation of MTHFR 677C/T and 1298A/C polymorphisms in the MTHFR gene as maternal risk factors for DS. Forty two mothers of proven DS outcomes and forty eight control mothers with normal offspring were included. Complete medical and nutritional histories for all mothers were taken with special emphasis on folate intake. Folic acid intake from food or vitamin supplements was significantly low (below the Recommended Daily Allowance) in the group of case mothers compared to control mothers. Frequencies of MTHFR 677T and MTHFR 1298C alleles were significantly higher among case mothers (32.1% and 57.1%, respectively) compared to control mothers (18.7% and 32.3%, respectively). Heterozygous and homozygous genotype frequencies of MTHFR at position 677 (CT and TT) were higher among case mothers than controls (40.5% versus 25% and 11.9% versus 6.2%, respectively) with an odds ratio of 2.34 (95% confidence interval [CI] 0.93-5.89) and 2.75 (95% CI 0.95-12.77), respectively. Interestingly, the homozygous genotype frequency (CC) at position 1298 was significantly higher in case mothers than in controls (33.3% versus 2.1% respectively) with an odds ratio of 31.5 (95% CI 3.51 to 282.33) indicating that this polymorphism may have more genetic impact than 677 polymorphism. Heterozygous genotype (AC) did not show significant difference between the two groups. We here report on the first pilot study of the possible genetic association between DS and MTHFR 1298A/C genotypes among Egyptians. Further extended studies are recommended to confirm the present work.     

Genotype and haplotype distributions of MTHFR677C>T and 1298A>C single nucleotide polymorphisms: a meta-analysis

Common single nucleotide polymorphisms (SNPs; 677C>T and 1298A>C) in the methylenetetrahydrofolate reductase gene ( MTHFR) decrease the activity of the enzyme, leading to hyperhomocysteinemia, particularly in folate-deficient states. We calculate herein the haplotype frequencies of the MTHFR 677 and 1298 polymorphisms in pooled general populations derived from published data. We selected 16 articles that provided reliable data on combined MTHFR genotypes in general populations ( n = 5389). The combined data comprised the following totals for each genotype at nucleotide positions 677 and 1298: 838 CC/AA (i.e., 677CC/1298AA), 1225 CC/AC, 489 CC/CC, 1120 CT/AA, 1093 CT/AC, 8 CT/CC, 606 TT/AA, 10 TT/AC, and 0 TT/CC. The estimated haplotype frequencies, and the fractional contribution of each, were 677C/1298A, 0.37; 677C/1298C, 0.31; 677T/1298A, 0.32; and 677T/1298C, 0.0023 to 0.0034. Thus, a vast majority of 677T alleles and 1298C alleles are associated with 1298A alleles and 677C alleles, respectively. There may be an increased frequency of the very rare cis 677T/1298C haplotype in some parts of the United Kingdom and Canada, possibly due to a founder effect. Further studies on both SNPs are needed to determine their exact role in various clinical settings.     

贵州三个民族亚甲基四氢叶酸还原酶基因的遗传多态性

目的研究贵州汉族、布依族、苗族亚甲基四氢叶酸还原酶(methylenetetrahydrofolate reductase，MTHFR)基因多态性，为贵州少数民族基因多态性数据库的建立提供相关数据。方法应用聚合酶链反应及限制性片段长度多态性检测贵州荔波汉族、布依族、雷山苗族MTHFR基因两个单核苷酸(677及1298位)多态位点的基因频率及基因型频率。结果汉族、布依族、苗族MTHFR677位T等位基因的分布频率分别是22．8％，16．1％，10．6％，MTHFR1298位C等位基因的分布频率分别是28．9％，39．1％，48．7％，677CT／1298AC双杂合子的分布频率分别是16．66％，22．7％，11．1％。在苗族还发现1例677TT／1298CC双纯合子。结论．MTHFR C677T和A1298C多态性存在群体差异；贵州雷山苗族、荔波布依族．MTHFR 1298位有较高的C等位基因频率，贵州雷山苗族MTHFR 1298位C等位基因频率是目前文献报道最高的民族。     

Which Thrombophilic Gene Mutations are Risk Factors for Recurrent Pregnancy Loss?

PROBLEM: Thrombophilia has been associated with poor obstetrical outcomes. To determine the association of specific inherited thrombophilias and recurrent pregnancy loss, 10 thrombophilic genes were investigated. METHOD OF STUDY: A total of 550 women with a history of recurrent pregnancy loss had buccal swabs taken for DNA analyses of the following gene mutations: factor V G1691A, factor V H1299R (R2), factor V Y1702C, factor II prothrombin G20210A, factor XIII V34L, beta-fibrinogen -455G>A, PAI-1 4G/5G, HPA1 a/b(L33P), methylenetetrahydrofolate reductase (MTHFR) C677T, MTHFR A1298C. The frequencies of these mutations were compared with controls published in the literature. RESULTS: When examined individually, PAI-1 4G/5G (P = 0.009), factor XIII V34L (P < 0.0001), and homozygous MTHFR C667T (P < 0.0001) correlated significantly with recurrent pregnancy loss compared with controls. The frequency of the factor V Y1702C mutation was extremely low in patients and controls; thus, this gene was removed from further calculations. The remaining six mutated genes, when analyzed cumulatively, also corresponded with recurrent pregnancy loss (P < 0.0001). CONCLUSION: A panel of thrombogenic gene mutations consisting of factor V G1691A, factor V H1299R (R2), factor II prothrombin G20210A, factor XIII V34L, beta-fibrinogen -455G>A, PAI-1 4G/5G, HPA1 a/b(L33P), MTHFR C677T, and MTHFR A1298C can identify individuals at risk for recurrent pregnancy loss.     

贵州荔波汉族与雷山苗族MTHFR基因多态性分布的比较

目的比较贵州汉族、苗族亚甲基四氢叶酸还原酶基因(MTHFR)多态性的分布情况,获取 MTHFR C677T和A1298C位点的群体遗传学数据.方法应用PCR-RLFP技术调查了贵州荔波汉族及雷山苗族MTHFR基因型的分布.结果汉族MTHFR 677位T等位基因频率为22.7%低于中国北方汉族,与苗族(10.64%)差异有显著性.苗族1298位C等位基因频率为48.66%高于有文献报道的种族和民族,与汉族(28.85%)差异有显著性.677TT/1298CC双杂合子的分布频率分别是16.66%,11.11%.在苗族还发现一例677TT/1298CC双纯合子.结论 MTHFR两个位点多态性在贵州汉族和苗族有民族差异;苗族A1298C位点C等位基因频率是有文献报道最高的民族.     

Folate gene polymorphisms and the risk of Down syndrome pregnancies in young Italian women

Maternal impairments in folate metabolism and elevated homocysteinemia are known risk factors for having a child with Down syndrome (DS) at a young age. The 80G>A polymorphism of the reduced folate carrier gene (RFC-1) has been recently demonstrated to affect plasma folate and homocysteine levels, alone or in combination with the 677C>T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene. We performed the present study on 80 Italian mothers of DS individuals, aged less than 35 at conception, and 111 Italian control mothers, to study the role of the RFC-1 80G>A, MTHFR 677C>T, and MTHFR 1298A>C genotypes to the risk of a DS offspring at a young maternal age. When polymorphisms were considered alone, both allele and genotype frequencies did not significantly differ between DS mothers and control mothers. However, the combined MTHFR677TT/RFC-1 80GG genotype was borderline associated with an increased risk (OR 6 (CI 95%: 1.0-35.9), P = 0.05), and to be MTHF1298AA/RFC-1 80(GA or AA) was inversely associated with the risk (OR 0.36 (CI 95%: 0.14-0.96), P = 0.04). Present results seem to indicate that none of the RFC-1 80G>A, MTHFR 677C>T, and MTHFR 1298A>C polymorphisms is an independent risk factor for a DS offspring at a young maternal age; however, a role for the combined MTHFR/RFC-1 genotypes in the risk of DS pregnancies among young Italian women cannot be excluded.     

Association of methylenetetrahydrofolate reductase C677T and A1298C polymorphisms with myocardial infarction in Tunisian young patients

Myocardial infarction (MI) is an important clinical problem because of its large contribution to mortality. The objective of this study is to assess whether two methylenetetrahydrofolate reductase (MTHFR) polymorphisms, C677T and A1298C, were associated with MI among Tunisian patients. One hundred young patients (<47 years old) with MI were recruited and compared with 200 control subjects with no history of MI. The most common MI risk factors were investigated. Fasting plasma homocysteine levels were measured. Genotypes of the MTHFR C677T and A1298 polymorphisms were studied by polymerase chain reaction. The mean plasma homocysteine level in the study group was raised when compared with the control group. Homozygous MTHFR C677T mutation was observed in 2 (2 %) patients and in 17 (8.5 %) control subjects, whereas heterozygous MTHFR C677T mutation was detected in 82 (82 %) patients versus only 79 (39.5 %) in control subjects. The mean total homocysteine concentrations were significantly higher in individuals with the 677TT and CT genotypes. Our results indicate that C677T and A1298C MTHFR mutations and hyperhomocysteinemia contributed to the risk factors for MI.     

MTHFD1 R653Q polymorphism is a maternal genetic risk factor for severe abruptio placentae

This study examined the relationship between folate/homocysteine-related genetic polymorphisms: MTHFD1 1958G --> A (R653Q), MTHFR 677C --> T (A222V), MTHFR 1298A --> C (E429A), and risk of severe abruptio placentae. We genotyped 62 women with a pregnancy history complicated by severe abruptio placentae and 184 control pregnancies. Analysis of the MTHFD1 1958G --> A (R653Q) polymorphism showed increased frequency of the 'QQ' homozygote genotype in pregnancies affected by severe abruptio placentae compared to control pregnancies (odds ratio 2.85 (1.47-5.53), P = 0.002). In contrast to previous reports, the MTHFR polymorphisms 677C --> T (A222V) and 1298A --> C (E429A) were not associated with abruptio placentae risk in our cohort, when analyzed either independently or in combination. We conclude that women who are 'QQ' homozygote for the MTHFD1 1258G --> A (R653Q) polymorphism are almost three times more likely to develop severe abruptio placentae during their pregnancy than women who are 'RQ' or 'RR.'