Dioxin-metabolizing genes in relation to effects of prenatal dioxin levels and reduced birth size: The Hokkaido study

Abstract

Objectives We investigated the effects of maternal polymorphisms in 3 genes encoding dioxin-metabolizing enzymes in relation to prenatal dioxin levels on infant birth size in Japan. Methods We examined the relationship between dioxin exposure and birth size in relation to the polymorphisms in the genes encoding aromatic hydrocarbon receptor (AHR [G > A, Arg554Lys]), cytochrome P450 (CYP) 1A1 (T6235C), and glutathione S-transferase mu 1 (GSTM1; Non-null/null) in 421 participants using multiple linear regression models. Results In mothers carrying the GSTM1 null genotype, a ten-fold increase in total dioxin toxic equivalency was correlated with a decrease in birth weight of −345 g (95% confidence interval: −584, −105). Conclusions We observed adverse effects of maternal GSTM1 null genotype on birth weight in the presence of dioxins exposure during pregnancy.