title: The distribution of MICA alleles in an Austrian population: evidence for increasing polymorphism.
abstract: The Major Histocompatibility Complex Class I Chain-Related Gene A (MICA) is located 46.4 Kb centromeric to HLA-B locus on chromosome 6; 84 alleles have been described so far. To assess the distribution of MICA alleles in an Austrian population, 322 unrelated Austrian blood donors have been typed for MICA by direct sequencing of amplified exons 2-5; sequencing of exon 6 and separating alleles by haplotype specific primers or by cloning was performed to resolve ambiguities. HLA-B was typed at low level resolution and linkage disequilibrium was determined. We observed 20 already known and four novel MICA alleles. MICA*008:01/04 was the most frequent allele (42%), followed by MICA*002:01 (11%) and MICA*009:01 (9%), three alleles (MICA*029, *067 and *068) were observed only once. No deviation from the Hardy Weinberg equilibrium was observed. Linkage disequilibrium between MICA and HLA-B alleles was observed, most extensively between MICA*008:01/04 and HLA-B*07. Our population data are in agreement with other European populations. The fact that four novel alleles have been observed indicates that the polymorphism of MICA is larger than currently estimated.
authors.affiliation: Department of Blood Group Serology and Transfusion Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: Sabine
authors.initials: S
authors.lastname: Wenda
authors.forename: Ingrid
authors.initials: I
authors.lastname: Faé
authors.forename: Alicia
authors.initials: A
authors.lastname: Sanchez-Mazas
authors.forename: José M
authors.initials: JM
authors.lastname: Nunes
authors.forename: Wolfgang R
authors.initials: WR
authors.lastname: Mayr
authors.forename: Gottfried F
authors.initials: GF
authors.lastname: Fischer
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D001315:Australia; D005260:Female; D005787:Gene Frequency; D005828:Genetics, Population; D006239:Haplotypes; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006650:Histocompatibility Testing; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D055815:Young Adult
chemical_list: D015395:Histocompatibility Antigens Class I; C099187:MHC class I-related chain A