Phenotypic expression and polymorphism of Glutathione S Transferase gene in materno-fetal dyads with idiopathic fetal growth restriction

Abstract

Introduction

Incidence of fetal growth restriction (FGR) in India is quite high, and FGR has been found to be associated with various non-infectious diseases including coronary artery disease, diabetes mellitus and metabolic syndrome. Moreover, 40% of FGR is termed idiopathic (IFGR) for which cause is not known. Oxidative stress, which is postulated to have a role in FGR, is modulated by polymorphism of antioxidant genes. This study aims to examine association of GST polymorphism and enzymatic activity with incidence of FGR.

Materials and methods

150 unrelated live births participated as dyads (mother and neonate). 75 consecutive IFGR materno-fetal dyads (referred subsequently as IFGR mother and IFGR neonate) were recruited as cases. Polymorphic analysis of GSTT1 and GSTM1 were carried out by multiplex PCR. Glutathione-S-transferase activity in serum was measured using 1-chloro-2, 4-dinitrobenzene (CDNB) as substrate.

Results

Incidence of GSTT1 null type is significantly higher in IFGR fetus and their mothers (p < 0.01). Incidence of GSTM1 null type is significantly higher in IFGR fetus (p = 0.001). GST activity levels in mothers giving birth to IFGR babies was about 50% of the values found in the control group (p < 0.001). The GST activity levels in control group was found to be 50% higher than the FGR babies (p = 0.001).

Conclusion

Our results show that there is definite association between polymorphism of GST genes and incidence of IFGR. Simultaneously, our study also found a correlation between maternal GST activity and fetal weight.