Polymorphisms in factor V and antithrombin III gene in recurrent pregnancy loss: a case-control study in Indian population.

Recurrent pregnancy loss (RPL) can be caused due to diverse factors with thrombophilia being one of them. The association of various thrombophilic risk factors with RPL is inconsistent in different studies and the frequency of these risk factors in Indian population is obscure. Five hundred and eighty patients with either recurrent early miscarriage or a history of at least one late miscarriage were screened for deficiency of protein C (PC), protein S (PS), antithrombin III (AT), APC resistance and prothrombin 20210G > A mutation. APC resistance positive patients were typed for the factor V Leiden, factor V Hong Kong/Cambridge mutations, and HR2 haplotype. PstI and rs2227589 AT mutations were detected by direct sequencing. APC resistance (13.4 %) was detected to be most common in Indian RPL patients followed by PS (10.6 %), PC (9.8 %) and AT deficiency (4.31 %.). FV Leiden was shown to be associated with APC resistance while HR2 haplotype was not associated with APC resistance (p values: 0.0001 and 0.327 respectively) and the increased risk of RPL. PstI and rs2227589 polymorphisms were similar in patients and controls and not associated with AT deficiency in RPL. Our study emphasizes the presence of other contributory factors towards APC resistance rather than FV Leiden alone. This is the first Indian study where HR2 haplotype and rs2227589 are observed to be present in RPL population. Although not significant, occurrence of rs2227589 and FV HR2 in homozygous condition necessitates the study of these polymorphisms in a larger sample size.