Background: HLA genes are highly polymorphic and certain alleles are frequent only in specific populations. Therefore, HLA is a unique tool for studying the genetic relationship between different populations. Iranians are ethnically diverse people and one of the major ethnic groups in Iran is Lur population inhabiting along the central and southern parts of Zagros Chain Mountain.
Objectives: Genetic relationship among three Lur subpopulations was investigated based on HLA class II profiles.
Methods: HLA typing was performed using PCR/RFLP and PCR/SSP methods in 154 individuals from three Lur subpopulation living in Luristan, Kohkiloyeh/ Boyerahmad, and Chahar-Mahal/ Bakhtiari.
Results: The most common DRB1 allele in Lurs of Luristan and Kohkiloyeh/ Boyerahmad was *1103=4 while DRB1*0701 was the most common allele in Bakhtiaris. DQA1*0501 and DQB1*0301 were the most frequent alleles and DRB1*1103=04-DQA1*0501-DQB1*0301 was the predominant haplotype in the three studied subpopulations. Neighbor-joining tree based on Nei's genetic distances and correspondence analysis according to DRB1, DQA1, and DQB1 allele frequencies showed a close genetic relationship between Lurs of Luristan and Lurs of Kohkiloye/ Boyerahmad and they were well separated from Bakhtiaris. The results of AMOVA revealed no significant difference between the three studied groups of Lurs and other major ethnic groups of Iran.
Conclusion: The results of this study revealed that Bakhtiaris were genetically far from the two other Lur subpopulations. Despite a probable common ancestor, this genetic difference might be explained by Bakhtiaris admixture with other Zagros inhabitants due to their nomadic life style.