Gene–environment interactions between air pollution and biotransformation enzymes and risk of birth defects

Abstract

Genetic and environmental factors have been observed to influence risks for birth defects, though few studies have investigated gene–environment interactions. Our aim was to examine the interaction terms of gene variants in biotransformation enzyme pathways and air pollution exposures in relation to risk of several structural birth defects. We evaluated the role of ambient air pollutant exposure (nitrogen dioxide [NO2], nitrogen oxide, carbon monoxide, particulate matter <10 [PM10] and <2.5 [PM2.5] microns) during pregnancy and 104 gene variants of biotransformation enzymes from infant bloodspots or buccal cells in a California population-based case–control study in 1997–2006. Cases included cleft lip with or without cleft palate (N = 206), gastroschisis (N = 94), tetralogy of Fallot (N = 69), and dextro-transposition of the great arteries (d-TGA; N = 40) and were compared to 208 nonmalformed controls. Overall, the results were not consistent, though did highlight some associations for further investigation as indicated by Wald chi-square test p value