HLA-G allele and haplotype frequencies in a healthy population of Iran.

The human leukocyte antigen (HLA)-G molecule is expressed in cytotrophoblast cells, adult thymic epithelial cells, erythroblasts, pancreatic islets and mesenchymal stem  cells. Although, HLA-G expression in allotransplanted patients is correlated with a better allograft acceptance, it is associated with an advanced grade of the tumor in cancer. In addition to the role on the immune system, HLA-G is also involved in successful pregnancy through the embryo implantation, fetal survival and the initial steps of hematopoiesis and angiogenesis. The  aim of  this  study was determination  of  HLA-G  allele frequencies in a healthy population of Iran. In this research, we selected 100 samples from healthy Iranian individuals and henceforth, we used polymerase chain reaction (PCR) followed by sequencing technique for exon 2, 3, 4 and intron 2 of the gene for evaluating the HLA-G  alleles frequencies. Investigation of intronic (intron 2) variation is the  novelty of our study. The obtained results indicated thirteen alleles of HLA-G in Iranian individuals including G*01:01:01:01, G*01:06, G*01:01:01:06, G*01:01:02, G*01:01:03, G*01:01:05, G*01:01:06, G*01:01:07, G*01:01:08, G*01:03, G*01:04:01, G*01:04:03, and G*01:04:04. According to this study, the most prevalent alleles in the Iranian population were G*01:01:01:01 (52.5%), G*01:01:02  (16%)  and  G*01:04:03  (14.5%) and  also  the  lowest  alleles regarding  the frequency were G*01:01:01:06 (0.5%) and G*01:03 (0.5%). The results of G*01:01:01:01 and G*01:04:01 frequencies showed some similarities with the  polish population.  Our  results were similar to  the  north  Indian  population  for  the frequencies of G*01:06 and G*01:01:02.