Molecular analysis of HLA allelic frequencies and haplotypes in Jordaniansand comparison with other related populations

Twenty alleles for the locus human leukocyte antigen (HLA-A) and 46 for the HLA-B locus were detected in Jordanians. This indicates the existence of h igh polymorphism in this area. The most frequent HLA class I alleles found were A*0201 (0-1344), B*0713 (0.1724), and C*0502 (0.1793). Twenty-six diff erent alleles in the Jordanian population were identified for the DRB1 locu s being the DRB1*0704 (0.2552), DRBI*0401 (0.1965), and DRBI*1501 (0.0896) the most frequent. Common DQA1 alleles were DQAI*0201 (0.2690), DQA1*0301 ( 0.2-414), and DQA1*0501 (0.1724). Three-loci haplotype heterogeneity was co mmon: 38 HLA class II haplotypes were identified, of which the most frequen tly observed was DRB1*0401-DQA1*0301-DQB1*0302 (0.1793). In addition, as ex pected, 220 different five-loci haplotypes with several unusual allelic com binations were observed, although many of them are pan-European haplotypes. The most frequent five-loci haplotype was the A30-B7-DRB1*03-DQA1*0501-DQB 1*0201 (0.0138). It seems that the specific Jordanian haplotypes are the fo llowing: the A31-B7-DRB1*04/07-DQA1*0301/0201-DQB1*0302/0202 haplotypes (0- 0103) and the A1-B7-DRB1*07-DQA1*0201-DQB1*0202, A2-B7-DRB1*04-DQA1*0301-DQ B1*0302, A11-B7-DRB1*07-DQA1* 0201-DQB1*0201 haplotypes but at lower freque ncies (0.007). A tree analysis of HLA class I and class II alleles were mad e for several Caucasian populations and individual genetic distances calcul ated. The haplotype frequencies, genetic distances, and dendrograms do not reveal great differences as compared with those in other Mediterranean coun tries and Western Europeans populations. Our results suggest that both HLA class I and class II polymorphism (but especially the former) of the Jordan ian population demonstrates considerable heterogeneity, which reflects anci ent and recent admixture with neighboring populations, and important human migratory trends throughout the history. Human Immunology 62, 901-909 (2001 ), (C) American Society for Histocompatibility and Immunogenetics, 2001. Pu blished by Elsevier Science Inc.