Association of CYP1A1 gene polymorphism with recurrent pregnancy loss in the South Indian population

Background: We investigated the relationship between idiopathic recurrent pregnancy loss (RPL) and genetic polymorphisms in phase I and phase II detoxification genes which include CYP1A1, CYP2D6, GSTM1, GSTP1 and GSTT1. Method: A case-control study comprised 160 females with RPL and 63 healthy controls with a successful reproductive history. Results: The CYP1A1 variant allele was present at frequencies of 0.61 and 0.44 in cases and controls, respectively (odds ratio = 1.93; P=0.023, 95% confidence interval 1.10-3.38). The CYP2D6 variant allele was present at a frequency of 0.17 in females with RPL, while in the control population the frequency was 0.16. The GSTM1 and GSTT1 null genotypes were present at frequencies of 0.39 and 0.26 in RPL cases, whereas in controls the frequencies were 0.37 and 0.17, respectively. The mutant GSTP1 frequencies in case and control women were 0.38 and 0.40, respectively. We report a significant association of the CYP1A1*2A allele with RPL which is confirmed by logistic regression analysis. No association was observed for the other polymorphisms or in their combinations studied. Conclusions: The present study suggests the occurrence of the CYP1A1*2A allele as a probable risk factor in idiopathic recurrent miscarriages.