The Tyr113His polymorphism in exon 3 of the microsomal epoxide hydrolase gene is a risk factor for perinatal mortality.

Abstract

A genetic predisposition to impaired detoxification of oxidative or chemical stress could play a role in the etiology of perinatal mortality. In this pilot study we investigated the risk of perinatal mortality in relation to genetic polymorphism in microsomal epoxide hydrolase (EPHX) and glutathione S-transferase P1 (GSTP1) in women who experienced perinatal mortality caused by placental pathology, congenital disorders and complications of premature delivery and their male partners. Genomic DNA of couples (72 females and 46 males) with a history of perinatal mortality and control couples (71 females and 66 males) with no complications in their obstetric history were analyzed for the presence of the polymorphisms in exon 3 of EPHX (Tyr113His) and GSTP1 (Ile105Val). A similar distribution of the GSTP1 polymorphism was found in all subjects investigated. In women who experienced perinatal mortality, we demonstrated a higher prevalence of the EPHX His113/His113 genotype, which could result in a lower enzyme activity, compared with controls (25% vs. 9%; chi2 = 5.7 and p < 0.02), with an odds ratio (95% confidence interval) of 3.5 (1.1-12.7). Our results suggest that the maternal Tyr113His polymorphism in EPHX may be a risk factor for perinatal mortality. However, more research is needed to determine the implication of this finding.