title: HLA-A, -B, -C, -DRB1 allele and haplotype frequencies in an African American population.
abstract: Sequence-based typing was used to identify human leukocyte antigen (HLA)-A, -B, -C, and -DRB1 alleles from 564 consecutively recruited African American volunteers for an unrelated hematopoietic stem cell registry. The number of known alleles identified at each locus was 42 for HLA-A, HLA-B 67, HLA-C 33, and HLA-DRB1 44. Six novel alleles (A*260104, A*7411, Cw*0813, Cw*1608, Cw*1704, and DRB1*130502) not observed in the initial sequence-specific oligonucleotide probe testing were characterized. The action of balancing selection, shaping more 'even' than expected allele frequency distributions, was inferred for all four loci and significantly so for the HLA-A and DRB1 loci. Two-, three-, and four-locus haplotypes were estimated using the expectation maximization algorithm. Comparisons with other populations from Africa and Europe suggest that the degree of European admixture in the African American population described here is lower than that in other African American populations previously reported, although HLA-A:B haplotype frequencies similar to those in previous studies of African American individuals were also noted.
authors.affiliation: CW Bill Young Marrow Donor Recruitment and Research Program, Department of Pediatrics, Georgetown University, Washington, DC 20057, USA.
authors.forename: B
authors.initials: B
authors.lastname: Tu
authors.forename: S J
authors.initials: SJ
authors.lastname: Mack
authors.forename: A
authors.initials: A
authors.lastname: Lazaro
authors.forename: A
authors.initials: A
authors.lastname: Lancaster
authors.forename: G
authors.initials: G
authors.lastname: Thomson
authors.forename: K
authors.initials: K
authors.lastname: Cao
authors.forename: M
authors.initials: M
authors.lastname: Chen
authors.forename: G
authors.initials: G
authors.lastname: Ling
authors.forename: R
authors.initials: R
authors.lastname: Hartzman
authors.forename: J
authors.initials: J
authors.lastname: Ng
authors.forename: C K
authors.initials: CK
authors.lastname: Hurley
mesh_terms: D001741:Black or African American / Q000235:genetics*; D005787:Gene Frequency; D015234:HLA-A Antigens / Q000235:genetics; D015235:HLA-B Antigens / Q000235:genetics; D015236:HLA-C Antigens / Q000235:genetics; D006684:HLA-DR Antigens / Q000235:genetics*; D059811:HLA-DRB1 Chains; D006239:Haplotypes / Q000235:genetics*; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans
chemical_list: D015234:HLA-A Antigens; D015235:HLA-B Antigens; D015236:HLA-C Antigens; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D015395:Histocompatibility Antigens Class I