title: MIC-A polymorphism in Japanese and a MIC-A-MIC-B null haplotype.
abstract: A polymorphic gene, MIC-A, is one of the MIC family of genes which is composed of a group of homologous genes interspersed in the class III and class I regions of the major histocompatibility complex. MIC-A is located 46 kilobases (kb) centromeric of HLA-B, and is preferentially expressed in the epithelial cells and intestinal mucosa. Recently, MIC-A and the closely related MIC-B were reported as the molecules that conferred specificity in the recognition by the Vdelta1gammadeltaT cells. In the present study, polymorphic exons 2, 3, and 4 of the MIC-A gene were analyzed using the polymerase chain reaction-single-strand conformation polymorphism method. The number of patterns found in exons 2, 3, and 4 were 5, 6, and 4, respectively, in 114 healthy Japanese subjects. Eight MIC-A alleles were observed in Japanese individuals, among which one, tentatively named MIC-AMW, has not previously been reported. There was a strong linkage disequilibrium between MIC-A and HLA-B loci: each MIC-A allele showed strong association with a particular HLA-B group. In contrast, B*3901 showed association with multiple MIC-A alleles. Furthermore, the existence of a MIC-A-MIC-B null haplotype, which is associated with HLA-B*4801, was identified. In this haplotype, a large-scale deletion (of approximately 100 kb) including the entire MIC-A gene was indicated and the MIC-B gene possessed a stop codon.
authors.affiliation: Department of Human Genetics, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Komatsu-Wakui
authors.forename: K
authors.initials: K
authors.lastname: Tokunaga
authors.forename: Y
authors.initials: Y
authors.lastname: Ishikawa
authors.forename: K
authors.initials: K
authors.lastname: Kashiwase
authors.forename: S
authors.initials: S
authors.lastname: Moriyama
authors.forename: N
authors.initials: N
authors.lastname: Tsuchiya
authors.forename: H
authors.initials: H
authors.lastname: Ando
authors.forename: T
authors.initials: T
authors.lastname: Shiina
authors.forename: D E
authors.initials: DE
authors.lastname: Geraghty
authors.forename: H
authors.initials: H
authors.lastname: Inoko
authors.forename: T
authors.initials: T
authors.lastname: Juji
mesh_terms: D000483:Alleles; D001483:Base Sequence; D018076:DNA, Complementary; D005091:Exons; D005787:Gene Frequency; D015235:HLA-B Antigens / Q000235:genetics; D006239:Haplotypes; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans; D007564:Japan; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods; D011110:Polymorphism, Genetic; D018807:Polymorphism, Single-Stranded Conformational; D017384:Sequence Deletion
chemical_list: D018076:DNA, Complementary; D015235:HLA-B Antigens; D015395:Histocompatibility Antigens Class I; C099187:MHC class I-related chain A; C098080:MICB antigen