title: Polymorphism located in TCRA locus confers susceptibility to essential hypersomnia with HLA-DRB1*1501-DQB1*0602 haplotype.
abstract: Essential hypersomnia (EHS) exhibits excessive daytime sleepiness without cataplexy and is associated with the HLA-DRB1*1501-DQB1*0602 haplotype, similar to narcolepsy with cataplexy. Single-nucleotide polymorphism (SNP) rs1154155 located in the T-cell receptor alpha (TCRA) locus has been recently identified as a novel genetic marker of susceptibility for narcolepsy with cataplexy. We investigated whether the SNP was associated with EHS in the Japanese population. We found a significant association with EHS patients possessing the HLA-DRB1*1501-DQB1*0602 haplotype, compared with HLA-matched healthy individuals (P(allele)=0.008; P(positivity)=5 x 10(-4)), whereas no significant association was observed for EHS patients without this haplotype. Thus, TCRA is a plausible candidate for susceptibility to EHS patients positive for the HLA-DRB1*1501-DQB1*0602 haplotype.
authors.affiliation: Department of Human Genetics, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan. taku@jn2.so-net.ne.jp
authors.forename: Taku
authors.initials: T
authors.lastname: Miyagawa
authors.forename: Makoto
authors.initials: M
authors.lastname: Honda
authors.forename: Minae
authors.initials: M
authors.lastname: Kawashima
authors.forename: Mihoko
authors.initials: M
authors.lastname: Shimada
authors.forename: Susumu
authors.initials: S
authors.lastname: Tanaka
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Honda
authors.forename: Katsushi
authors.initials: K
authors.lastname: Tokunaga
mesh_terms: D016022:Case-Control Studies; D006970:Disorders of Excessive Somnolence / Q000235:genetics*; D005819:Genetic Markers; D020022:Genetic Predisposition to Disease; D006683:HLA-DQ Antigens / Q000235:genetics*; D059866:HLA-DQ beta-Chains; D006684:HLA-DR Antigens / Q000235:genetics*; D059811:HLA-DRB1 Chains; D006239:Haplotypes; D006801:Humans; D007564:Japan; D020641:Polymorphism, Single Nucleotide; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics*
chemical_list: D005819:Genetic Markers; D006683:HLA-DQ Antigens; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D016693:Receptors, Antigen, T-Cell, alpha-beta