Interaction between GSTM1/GSTT1 Polymorphism and Blood Mercury on Birth Weight.

Background: Mercury (Hg) is toxic to both the reproductive and nervous systems. In addition,glutathione S-transferases (GSTs), which conjugate glutathione to a variety of electrophilic compounds,are involved in the detoxification of Hg.Objective: In this study we examined the association between prenatal exposure to Hg and birthweight as well as the influence of GST polymorphisms.Methods: The total Hg concentration in maternal and cord blood was measured from 417 Koreanwomen and newborns in the Mothers and Children's Environmental Health study from 2006 to2008. Information on birth weight was collected from the patients' medical records. The genotypingof glutathione S-transferase M1 (GSTM1) and glutathione S-transferase T1 (GSTT1) polymorphismswas carried out using polymerase chain reaction. Regression analysis was performed todetermine the association between the blood Hg concentration and birth weight in mothers withGSTM1 and GSTT1 polymorphisms.Results: The geometric mean levels of Hg in the maternal blood during late pregnancy and in cordblood were 3.30 μg/L and 5.53 μg/L, respectively. For mothers with the GSTT1 null genotype,elevated Hg levels in maternal blood during late pregnancy were associated with an increased risk oflower birth weight. For mothers with both GSTM1 and GSTT1 null genotype, both maternal andcord blood Hg levels were associated with lower birth weight.Conclusions: This study suggests that the interactions of Hg with GSTM1 and GSTT1 polymorphismsplay a role in reducing birth weight. [ABSTRACT FROM AUTHOR]