title: The association of HLA with young-onset keratoconus in Japan.
abstract: OBJECTIVE
  To report the association of HLA antigens with keratoconus in Japanese patients.
  
  
  METHODS
  Observational consecutive case series.
  
  
  METHODS
  In 90 consecutive Japanese keratoconus patients, HLA class I (HLA-A, -B, -C) and class II (HLA-DR, -DQ) were analyzed.
  
  
  RESULTS
  Compared with control frequencies, based on mean gene frequencies for the Japanese population, higher frequencies of HLA-A26, B40, and DR9 antigens were found in patients whose conditions were diagnosed before 20 years of age (chi(2) = 6.45, P =.01; chi(2) = 6.78, P =.01; chi(2) =3.99, P =.05, respectively), but were not found in patients whose conditions were diagnosed later in life. Men were significantly younger at diagnosis than were women. No obvious relation was found between HLA antigens and other clinical data.
  
  
  CONCLUSIONS
  HLA-A26, B40, and DR9, which were found relatively frequently in the ancient Japanese population, seem to be associated with keratoconus in younger individuals.
authors.affiliation: Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kawaramachi, Hirokoji, Kamigyo-ku, Kyoto, Japan. wadachi@ophth.kpu-m.ac.jp
authors.forename: Wakako
authors.initials: W
authors.lastname: Adachi
authors.forename: Yoko
authors.initials: Y
authors.lastname: Mitsuishi
authors.forename: Kazuto
authors.initials: K
authors.lastname: Terai
authors.forename: Chisato
authors.initials: C
authors.lastname: Nakayama
authors.forename: Yoko
authors.initials: Y
authors.lastname: Hyakutake
authors.forename: Junko
authors.initials: J
authors.lastname: Yokoyama
authors.forename: Chikako
authors.initials: C
authors.lastname: Mochida
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kinoshita
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D002648:Child; D005260:Female; D005787:Gene Frequency; D005805:Genes, MHC Class I; D005802:Genes, MHC Class II; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007640:Keratoconus / Q000208:ethnology / Q000235:genetics*; D008297:Male; D008875:Middle Aged
chemical_list: D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II