Association Analysis of the HLA-G Upstream Polymorphism Rs1736933 with the Recurrent Spontaneous Abortion

BACKGROUND AND OBJECTIVE: Studies have suggested that HLA-G is involved in protecting the fetus against the mother's immune system, and upstream polymorphisms of this gene may influence pregnancy success by effecting its expression. The aim of this study was to evaluate the association of upstream HLA-G gene polymorphism, rs1736933, with recurrent spontaneous abortion in East Azerbaijan women population. METHODS: This case-control study was performed on 80 women with at least one child and without any history of abortion, and 100 women with at least two recurrent spontaneous abortions which were diagnosed by gynecologist. 2 ml of blood was obtained from the participants and after DNA extraction, a segment of the HLA-G gene promoter was amplified by PCR and analyzed by agarose gel electrophoresis. PCR products were sequenced and genotyped. Allelic and genotypic frequencies of patient and control groups were compared. FINDINGS: Frequency of AA, CA, CC genotypes in the patient group were 8(8%), 37(37%), 55(55%) and in the control group were 16(20%), 33(41.25%), 31(38.75%) respectively. Comparison of genotypic frequencies between the two groups showed that CC homozygous genotype was associated with recurrent abortion (p= 0.015). Statistical analysis also showed a significant difference between the allelic frequencies of the two groups (p= 0.019). CONCLUSION: The results of this study showed that the upstream HLA-G gene polymorphism, rs1736933, is associated with the recurrent abortion in East Azerbaijan women population.