title: Polymorphic insertions in 5 Alu loci within the major histocompatibility complex class I region and their linkage disequilibria with HLA alleles in four distinct populations in mainland China.
abstract: In this study, we investigated the five polymorphic Alu loci located within human major histocompatibility complex (MHC) class I region in 445 individuals from four distinct Chinese populations: Hunan Han, Inner Mongolia Han, Inner Mongolia Mongol and Guangdong Han populations, with an emphasis on the linkage disequilibrium (LD) between Alu insertions and human leukocyte antigen (HLA)-A, Cw and B loci in a southern (Hunan Province) and a northern (Inner Mongolia Autonomous Region) Chinese Han population. Our data showed that (a) the allele and haplotype frequencies of Alu and HLA-A loci did not differ significantly between the two southern Chinese Han populations and showed remarkable homogeneity in the two northern Chinese populations; (b) AluyHG had the highest insertion rate and HLA-A*02 harboring the single AluyHG insertion was most frequent among Alu insertion-bearing haplotypes in all four populations; (c) haplotypes AluyHF insertion-HLA-A*26, AluyHG insertion-HLA-A*02 and AluyHJ insertion-HLA-A*24 were in significant LD across the four groups and (d) haplotype AluyMICB insertion-HLA-Cw*06 was in significant LD in both populations, while significant LD of haplotypes AluyMICB insertion-HLA-B*54 and AluyMICB insertion-HLA-B*48 was only observed in the Hunan Han population and the Inner Mongolia Han population, respectively. Haplotype HLA-B*48-MICA gene deletion-AluyMICB insertion was observed at a frequency of about 3.85% in the latter population. Our data, together with previous reports on several Asian-Oceanian populations suggest the identity by descent of several common HLA-A allelic lineages in these modern human populations. The novel population-specific LD patterns uncovered in this study also shed new insight into HLA evolution and haplotype origin.
authors.affiliation: Immunogenetics Research Group, Department of Immunology, College of Basic Medical Sciences, Central South University, Changsha, Hunan, China. tianwei2@yahoo.com
authors.forename: W
authors.initials: W
authors.lastname: Tian
authors.forename: F
authors.initials: F
authors.lastname: Wang
authors.forename: J H
authors.initials: JH
authors.lastname: Cai
authors.forename: L X
authors.initials: LX
authors.lastname: Li
mesh_terms: D000483:Alleles; D020087:Alu Elements / Q000235:genetics*; D002681:China; D005787:Gene Frequency; D005838:Genotype; D015234:HLA-A Antigens / Q000235:genetics*; D015235:HLA-B Antigens / Q000235:genetics*; D015236:HLA-C Antigens / Q000235:genetics*; D006239:Haplotypes / Q000235:genetics*; D006801:Humans; D015810:Linkage Disequilibrium / Q000235:genetics*; D011110:Polymorphism, Genetic; D011153:Population / Q000235:genetics
chemical_list: D015234:HLA-A Antigens; D015235:HLA-B Antigens; D015236:HLA-C Antigens