P-203: Investigating Association of HLA-G Gene Polymorphisms and Failed Implantation in Human Embryos

Background: HLA-G is a non-classical human leukocyte antigen expressed primarily in fetal tissues at the maternal-fetal interface. The unique structure of HLA-G molecule permits a restricted peptide presentation and allows the modulation of the immune system. There is now general agreement that HLA-G is an important immunotolerant molecule with the capability of inhibiting immune cell functions, such as those of natural killer (NK) cells, T lymphocytes and dendritic cell. Recently, 44 HLA-G alleles have been described which encode 14 distinct functional proteins. Materials and Methods: To investigate whether HLA-G gene polymorphism is associated with failed implantation, we used polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) for exon 4 of HLA-G gene in 100 couples with failed assisted reproductive technology (ART), such as IVF/ICSI, in their history and 100 couples with normal fertility in their history from Roy an institute DNA bank. PCR products of exon 4 were digested with three restriction endonucleases (MspI, TspRI and NspI) that have restriction site for HLA-G 010404, 0108 and 0106 alleles. Therefore digested fragments of the PCR products were separated by 2% agarose gel and detected by ethidium bromide staining. Results: The obtained results indicate that HLA-G 0106 alleles in failed ART group were significantly higher than control group (p<0.05). In the other hand, the data have shown numbers of cases with HLA-G 010404 polymorphism in the two groups had no significant difference. Also HLA-G 0108 polymorphism was not seen in the groups. Conclusion: The significant genotype-specific risk in failed ART group suggested that allelic variation in α3 domain of HLA-G have associated to failed implantation.