Frequency of rare HLA-A allelic groups in Gilak, Lor, Kurdish and Arab ethnic groups of Iran

Histocompatibility antigens (HLAs) have high genetic diversity and their frequency can be diverse in different ethnicities. Therefore, the determination of these antigens in different ethnicities can provide data used in the expansion of centers for the registration of stem cell donors.

In this descriptive study, donor DNA was extracted and qualified. Then, the allele groups of HLA-A were determined at low resolution level by PCR-SSP method. Ethnic and HLA information of Gilak (n= 150), Lor (n= 465), Kurdish (n = 719) and Arab (n = 370) were analyzed and the relationship between the allele and ethnicity was examined and a significant relationship between the frequencies of alleles in the studied ethnicities were evaluated by chisquare statistical method. In this study, a statistically significant level of 0.05 was considered. In order to determine in which of the ethnicities the frequency of the studied alleles was higher than the expected values under the assumption of independence, the standardized residual values were determined.

Allelic frequencies in the studied ethnic groups were obtained for HLA-A*23 and HLA-A*31, <3% . In allelic groups of HLA-A*25, HLA-A*34, HLA-A*36, HLA-A*43, HLA-A*66, HLA-A*69 and HLA-A*74, this frequency was less than 1 %. The frequency of rare HLA-A allelic groups, including HLA-A*34, HLA-A*69 and HLA-A*74, showed a significant difference in the ethnic groups (p-value less than 0.05).

Identifying the frequency of HLA alleles in different ethnicities can identify similarities and differences in allelic groups in those ethnicities.