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 α (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 (Pallele= 0.008; P positivity 5× 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. © 2010 The Japan Society of Human Genetics. All rights reserved.