Haplotype analysis of IL-10 gene polymorphism in couples with spontaneous abortions and aborted fetuses

Spontaneous abortion is the loss of pregnancy during an early gestational period. Interleukin-10 is an anti-inflammatory cytokine which plays an important role in successful pregnancy outcome. The aim of the study is to elucidate an association of IL-10 gene promoter polymorphisms (-1082G/A, -819 C/T, -592C/A) in spontaneous abortions from Telangana state of South India. The present population-based retrospective case-control triad study includes a total of 80 case families with spontaneous abortions and 100 control families with medically terminated pregnancies. Peripheral blood from all the couples and fetal tissues of < 20 weeks of gestation were collected. Genotype analysis was carried out by a standard amplification refractory mutation system-polymerase chain reaction followed by agarose gel electrophoresis. The strength of the association between IL-10 gene promoter polymorphisms and spontaneous abortions were measured by odd ratios and their respective 95% confidence intervals. Haplotype analysis was carried out for the three polymorphisms to establish an association of specific haplotypes with spontaneous abortions. The increased frequency of AA genotype and A allele of -1082G/A, TT genotype and T allele of -819C/T, and AA genotype and A allele of -592C/A was observed in case fetuses and case mothers compared to their respective controls. Haplotype analysis revealed that A-C-A, G-C-A haplotypes in fetuses and haplotypes A-C-C, G-T-C, A-T-A, and G-C-A in mothers were associated with increased risk of spontaneous abortions. IL-10 gene promoter polymorphisms may act as a major genetic regulator in the etiology of spontaneous abortions with maternal genome imprinting effects.