A Case Control Study of Gene Environment Interaction in Pre-Eclampsia with Special Reference to Organochlorine Pesticides

Objectives: To study and compare the frequency of GSTM1 & T1 gene polymorphism in cases (Pre-eclampsia) and controls (normal pregnancy), to estimate and compare serum levels of Glutathione-S-Transferase enzyme in cases and controls, to quantify and compare Organochlorine pesticides levels in maternal blood of cases and controls and to evaluate the correlation; if any; amongst GSTM1 & T1 gene polymorphism, GST activity and Organochlorine pesticides levels in cases.

Methodology: Maternal blood samples of 66 Pre-eclampsia cases and equal number of matched control were collected. Samples were analyzed for OCPs levels, GST activity and GST M1 and T1 gene polymorphism.

Results: β-HCH, Heptachlor, Dieldrin, Endosulphan-I levels were found in higher amounts in cases as compared to controls. GSTT1-/GSTM1- (double null polymorphism) was significantly high in cases as compared to controls. GSTT1-(null) genotype was exclusively associated with severe pre-eclampsia. When GST activity was correlated with genotypic variation of GSTT1/M1 gene, null genotypes significantly downregulated GST activity, lowest being with double null genotype.

Conclusions: There is a possible role of gene-environment interaction in the pathogenesis of pre-eclampsia. An interaction of increased levels of pesticides with GST polymorphisms (null type) causes low levels of GST enzyme levels (an anti-oxidant) resulting in increased oxidative stress causing pre-eclampsia.