Cytochrome P450 gene polymorphisms and risk of low birth weight.

This study investigated the association between polymorphisms in cytochrome P450 genes (CYP1A1MspI, CYP1A1HincII, and CYP2E1) and low birth weight. Between July 1999 and June 2002, we conducted a study using infant-parents triads in Anqing, China. The analyses included the families of 248 normal birth weight, full-term infants, and 248 low-birth-weight infants. Genotyping was performed for the polymorphisms of cytochrome P450 genes using standard techniques. We used log-linear modeling to analyze the association of CYP1A1 and CYP2E1 gene polymorphisms with the risk of low birth weight. In the analysis of children's genotypes, the relative risk was 1.92 (95% confidence interval: 1.05, 3.52, p=0.034) for CYP1A1MspI C/C6235 compared with CYP1A1 MspI T/T6235. In the analysis of mothers' genotypes, an association was also seen for maternal CYP1A1MspI C/C6235 compared with CYP1A1MspI T/T6235 (relative risk: 1.68, 95% confidence interval: 1.06, 2.68, p=0.029). We did not observe a joint effect between mother's and children's genotypes. Analysis of control triads suggests Mendelian transmissions of the variant alleles of CYP1A1MspI, CYP1A1HincII, and CYP2E1. In conclusion, both infant and maternal CYP1A1MspI C/C6235 genotypes were associated with increased risk of low birth weight in our study population. This suggests a possible role for human cytochrome P450 variability in the etiology of low birth weight. Genet. Epidemiol. 2005. © 2005 Wiley-Liss, Inc.