title: Wide distribution of the MICA-MICB null haplotype in East Asians.
abstract: Stress-inducible MICA (MHC class I chain-related A) is known to bind to NKG2D, which is one of the natural killer (NK) cell receptors, and plays a role in immune surveillance. We have reported that a MICA-MICB null haplotype is in linkage disequilibrium with HLA-B*4801 in the Japanese population. In the haplotype, an approximately 100-kb deletion, including the entire MICA gene, was observed and MICB possessed a premature stop codon. In this study, a multiplex polymerase chain reaction (PCR) method was developed for detecting the MICA deletion. MICB alleles were typed by PCR-single-strand conformation polymorphism (SSCP) method and direct sequencing. The frequency of the MICA-MICB null haplotype was 3.7% on the average, and was strongly associated with HLA-B48 in seven East Asian populations. It was presumed that the stop codon of MICB gene generated after the large-scale deletion. The wide distribution of the null haplotype at polymorphic frequencies suggests that the haplotype has been conservatively maintained because of some selective advantage.
authors.affiliation: Department of Human Genetics, Graduate School of Medicine, The University of Tokyo, 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: C
authors.initials: C
authors.lastname: Leelayuwat
authors.forename: K
authors.initials: K
authors.lastname: Kashiwase
authors.forename: H
authors.initials: H
authors.lastname: Tanaka
authors.forename: S
authors.initials: S
authors.lastname: Moriyama
authors.forename: F
authors.initials: F
authors.lastname: Nakajima
authors.forename: M H
authors.initials: MH
authors.lastname: Park
authors.forename: G J
authors.initials: GJ
authors.lastname: Jia
authors.forename: N O
authors.initials: NO
authors.lastname: Chimge
authors.forename: E W
authors.initials: EW
authors.lastname: Sideltseva
authors.forename: T
authors.initials: T
authors.lastname: Juji
mesh_terms: D000483:Alleles; D044466:Asian People / Q000235:genetics; D005202:Asia, Eastern; D017353:Gene Deletion; D005787:Gene Frequency; D005805:Genes, MHC Class I; D015235:HLA-B Antigens / Q000235:genetics; D006239:Haplotypes / Q000235:genetics*; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006650:Histocompatibility Testing; D006801:Humans; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational
chemical_list: D015235:HLA-B Antigens; D015395:Histocompatibility Antigens Class I; C099187:MHC class I-related chain A; C098080:MICB antigen