Prenatal Prediction of Risk of the Fetal Hydantoin Syndrome

Abstract

Abstract The well-known teratogenicity of several anticonvulsant medications is associated with an elevated level of oxidative metabolites that are normally eliminated by the enzyme epoxide hydrolase. In this study, we attempted to determine whether infants who are at risk for congenital malformations could be identified prenatally by the measurement of epoxide hydrolase activity. Before fetuses at risk could be identified, it was necessary to measure epoxide hydrolase activity in a randomly selected sample of amniocytes from 100 pregnant women. According to a thin-layer Chromatographic ssay, the randomly selected sample population had an apparently trimodal distribution, suggestive of an enzyme regulated by a single gene with two allelic forms. Fetuses homozygous for the recessive allele would have low epoxide hydrolase activity and would therefore be at risk if exposed to anticonvulsant drugs during gestation. In a prospective study of 19 pregnancies monitored by amniocentesis, an adverse outcome was pr...