Objective: To investigate the frequencies of allele and genotype of HLA-DRB1 gene in Luoba ethnic group.
Methods: HLA-DRB1 genes from 92 individuals of Luoba ethnic group in Tibet Autonomous region were investigated, using PCR-SSO (polymerase chain reaction -sequence specific oligo-nucleotide) genotyping methods. We compared allele frequencies of Luoba population in HLA-DRB1 locus with that of various ethnic groups distributed worldwide, constructed the phylogenetic tree by UPGMA (unweighted pair group method with arithmetic mean), and counted genetic distance by Nei measure.
Results: Of the 11 DRB1 alleles detected, the two most common genes were DRBI * 04( gene frequency: 27.20% ) and DRB * 12 (25.50%) , which covered 52.70% of the total alleles detected from Luoba ethnic group. The frequencies of HLA-DRB1 * 14(15.20% ), DRB1 * 15(9.80% ) and DRB1 * 08(8.20% ) were more than 5%. Luoba was unique in the distribution of HLA alleles. The genetic distance between Luoba and Tibetan was closer than that with other population. A dendrogram based on the DRB1 genes by cluster analysis suggested that Luoba ethnic group might cluster with Tibetan firstly, then cluster with other population living in China (except Uygr) , and cluster with Caucasian and Black finally.
Conclusion: The HLA-DRBI gene frequency of Luoba individuals in Tibet Linzhi had some differences compared with that of other Chinese population. The kindred relation between Luoba and Tibetan was closer than that with other population, which was coincident with the results of ethnology, history and sociology.