title: Asporin repeat polymorphism in rheumatoid arthritis.
abstract: BACKGROUND
  Asporin belongs to a family of proteins associated with the cartilage matrix.
  
  
  OBJECTIVE
  To investigate the role of the functional polymorphism consisting of an aspartic acid (D) repeat polymorphism located in the ASPN gene in the susceptibility to and clinical outcome of rheumatoid arthritis.
  
  
  METHODS
  A total of 803 Spanish Caucasian patients with rheumatoid arthritis and 904 controls of the same ethnic origin and matched for age and sex were included in the study. The asporin D repeat polymorphism was genotyped using polymerase chain reaction with a fluorescent primer.
  
  
  RESULTS
  No significant differences were detected in the distribution of the 10 alleles found in our population on comparing patients with rheumatoid arthritis with control groups. Nevertheless, individuals bearing D14 produced rheumatoid factor more often than the rest (85.7% v 72.1%, p = 0.006, odds ratio (OR) = 2.35, 95% confidence interval 1.21 to 4.50), and the mean (SD) onset age was higher in the group of individuals bearing D13 (50.09 (13.94)) compared with the rest (47.21 (14.31)), although the difference did not reach significance (p = 0.06).
  
  
  CONCLUSIONS
  The results do not support a major role for asporin D repeat polymorphism in the susceptibility to rheumatoid arthritis. Nevertheless, they support the influence of this gene on the outcome of the disease.
authors.affiliation: Servicio de Inmunología, Hospital Universitario Virgen del Rocío, Sevilla, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Torres
authors.forename: G
authors.initials: G
authors.lastname: Orozco
authors.forename: J R
authors.initials: JR
authors.lastname: García-Lozano
authors.forename: J
authors.initials: J
authors.lastname: Oliver
authors.forename: O
authors.initials: O
authors.lastname: Fernández
authors.forename: M A
authors.initials: MA
authors.lastname: González-Gay
authors.forename: A
authors.initials: A
authors.lastname: Balsa
authors.forename: A
authors.initials: A
authors.lastname: García
authors.forename: D
authors.initials: D
authors.lastname: Pascual-Salcedo
authors.forename: M A
authors.initials: MA
authors.lastname: López-Nevot
authors.forename: A
authors.initials: A
authors.lastname: Núñez-Roldán
authors.forename: J
authors.initials: J
authors.lastname: Martín
authors.forename: M F
authors.initials: MF
authors.lastname: González-Escribano
mesh_terms: D000328:Adult; D017668:Age of Onset; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000235:genetics*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D016326:Extracellular Matrix Proteins / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D018598:Minisatellite Repeats; D011110:Polymorphism, Genetic; D012217:Rheumatoid Factor / Q000032:analysis; D013030:Spain / Q000208:ethnology; D014481:United States
chemical_list: C439889:ASPN protein, human; D016326:Extracellular Matrix Proteins; D012217:Rheumatoid Factor