Prospective evaluation of the risk conferred by factor V Leiden and thermolabile methylenetetrahydrofolate reductase polymorphisms in pregnancy.

Department of Clinical Pharmacology, Royal College of Surgeons in Ireland.
Arteriosclerosis Thrombosis and Vascular Biology (Impact Factor: 5.53). 02/2000; 20(1):266-70. DOI: 10.1161/01.ATV.20.1.266
Source: PubMed

ABSTRACT Factor V (FV) Leiden and thermolabile methylenetetrahydrofolate reductase (MTHFR) are 2 common polymorphisms that have been implicated in vascular thrombosis. We determined whether these mutations predicted an adverse outcome in pregnancy. Second, we looked for an interaction between these 2 mutations in patients with recurrent fetal loss or thrombosis in pregnancy. Primigravid subjects at their booking visit to the National Maternity Hospital (Holles Street, Dublin, Ireland) were screened for the polymorphisms. Thermolabile MTHFR and FV Leiden genotypes were detected by either restriction fragment length polymorphism or heteroduplex capillary chromatography. The carrier frequency of FV Leiden in the screened primigravid population was 2.7% (allele frequency 1.36%), all being heterozygous for the mutation. This value was lower than expected from previous studies in European populations. Forty-nine percent of the screened population (289 of 584) were heterozygous for thermolabile MTHFR, and 10.6% were homozygous (62 of 584). The frequency of the 2 polymorphisms was no higher in those who subsequently developed preeclampsia (n=12) or intrauterine growth retardation (n=9), and none of the screened population developed thrombosis. However, the frequency of FV Leiden was higher in patients who subsequently miscarried after the first trimester of pregnancy (allele frequency of 5.5%, P=0.0356). Among those positive for FV Leiden, 3 of 27 miscarried, compared with 24 of 572 of FV Leiden-negative patients (11% versus 4.2%). No interaction was found between the 2 mutations in the control or patient populations. In patients with a prior history of venous thrombosis, the carrier rate of FV Leiden was increased (4 of 33, allele frequency of 7.6%, P=0. 0115). In contrast, the carrier frequency for thermolabile MTHFR was no higher, and there was no interaction between the 2 mutations. Neither mutation occurred at a significantly higher frequency in patients with a prior history of recurrent fetal loss. In conclusion, FV Leiden is a risk factor for thrombosis in pregnancy and possibly for second-trimester miscarriage independent of thermolabile MTHFR. However, prospective analysis suggests that the risk conferred by FV Leiden is low in a primigravid population. The thermolabile MTHFR genotype was not implicated in any adverse outcome.

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    ABSTRACT: The aim of this study was to examine the association of factor V Leiden, prothrombin and methylenetetrahydrofolate reductase (MTHFR) polymorphisms and preeclampsia (PE) in Southeast of Iran. This case-control study was performed on 192 preeclamptic and 196 normotensive pregnant women. Single nucleotide polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and Tetra ARMS methods. No significant differences were observed in distribution of MTHFR C677T and FVL polymorphisms between two groups. There was a significant difference in frequency of 1298AC genotype in PE pregnant women compared to controls (P = 0.03). No 20210A allele of prothrombin gene was observed in this population. The analysis of MTHFR and factor V Leiden polymorphisms between early-onset PE (EOPE) and late-onset PE (LOPE) showed significant differences in MTHFR A1298C polymorphism (AC and CC vs AA, P = 0.012 and P = 0.006, respectively) and G1691A polymorphism of FVL(GA vs GG, P = 0.03). Moreover, the analysis of three SNPs between EOPE and controls showed significant differences in MTHFR C677T (CT + TT vs CC, P = 0.035) and MTHFR A1298C (AC and CC vs AA, P = 0.001 and P = 0.006, respectively) polymorphisms. The synergic effect of MTHFR A1298C and C677T polymorphisms showed increased risk of EOPE. MTHFR A1298C polymorphism was associated with PE. Although MTHFR C677T and FVL polymorphisms did not differ between PE patients and controls, significant differences in MTHFR A1298C, C677T and FVL polymorphisms between EOPE and LOPE/controls were observed. The synergic effect of MTHFR variants could increase PE and EOPE risk.
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    ABSTRACT: Preeclampsia is one of the common complications during pregnancy with considerable maternal and fetal mortality and morbidity. Hypercoagulability due to thrombophilic factors is discussed as the etiology involved in this disease. The aim of this study was to evaluate selected thrombotic factors among pregnant women with preeclampsia and normal pregnant women. This case-control study was performed on 200 pregnant women at third trimester of pregnancy between 2012 and 2013. 100 pregnant women admitted to Qaem and Imam Reza hospitals of Mashhad, due to preeclampsia, were selected as case group and 100 pregnant women without preeclampsia referred to OB/GYN clinic of these hospitals as control group. Blood samples were taken from two groups for evaluation of the coagulation factors including factor V Leiden, protein C, protein S, antithrombin III, anti-cardiolipin antibodies, and lupus anticoagulant antibodies. Two groups were not significantly different in terms of maternal age and parity (p>0.05). Levels of factor V Leiden, protein C, protein S, antithrombin III, anti-cardiolipin antibodies and lupus anticoagulant antibodies were compared between two groups. The number of patients with abnormal factor V Leiden and protein C was significantly higher in case group than in the control group (p<0.01 respectively), but other factors were not significant different between two groups. Thrombophilia disorders were significantly more in case group compared to control (p<0.001). The risk of thrombophilia disorders is higher in preeclamptic patients than normal pregnant women.
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