Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

UNLABELLED: Folate deficiency and the presence of the 677C > T (CT) polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene have been implicated in the causation of malformations in the fetus (particularly cleft lip and palate and neural tube defects). These birth defects are also recognised complications of exposure to antiepileptic drugs (AEDs). In pregnant women with epilepsy, the use of AEDs has an added effect on the physiological reduction in folate levels, which may be enhanced further by the presence of the 677C > T polymorphism in the mother. We studied the MTHFR genotype and rate of major malformations (MM) in 187 mother-child pairs where the mothers had epilepsy and in 236 matched control pairs. Sodium valproate (VPA) was the most commonly used drug and was associated with the highest rate of malformations (9.6%). 49% of mothers, both in the cases and controls were heterozygotes for the 677C > T polymorphism. The rate of MM was increased in offspring of mothers who were heterozygous or homozygous for 677C > T genotype amongst AED-exposed cases, but more so in those exposed to VPA. The effect of the VPA on the rate of MM was much higher (OR 7.79, 95% CI (1.45-41.9)) than the effect of the maternal 677C > T genotype (OR 2.57, 95% CI (0.28-23.7)). There was no association between the child's MTHFR genotype and the rate of MM. CONCLUSION: This study indicates that although the maternal MTHFR genotype may confer susceptibility to the teratogenic effect of AEDs, particularly VPA, it is likely that the main teratogenic effects are mediated through other mechanisms.

Original publication

DOI

10.1016/j.ejmg.2007.08.002

Type

Journal article

Journal

Eur J Med Genet

Publication Date

11/2007

Volume

50

Pages

411 - 420

Keywords

Abnormalities, Drug-Induced, Anticonvulsants, Case-Control Studies, Child, Cohort Studies, Epilepsy, Female, Folic Acid, Genotype, Humans, Maternal Exposure, Methylenetetrahydrofolate Reductase (NADPH2), Pregnancy, Prenatal Exposure Delayed Effects, Prospective Studies, Risk Factors, Uterus, Valproic Acid