title: CAG repeat polymorphism in the androgen receptor gene in women with rheumatoid arthritis.
abstract: OBJECTIVE
  Rheumatoid arthritis (RA) is the most common chronic, autoimmune, inflammatory disease, with a genetic and hormonal background. The prevalence of women among patients with RA suggests the important role of sex hormones in the pathogenesis of RA. We examined the association between CAG repeat polymorphism in the androgen receptor (AR) gene and susceptibility to RA and its clinical features in white women.
  
  
  METHODS
  The study groups consisted of 325 female patients with RA and 238 female controls. CAG repeat polymorphism was determined using polymerase chain reaction and subsequent fragment analysis by capillary electrophoresis.
  
  
  RESULTS
  The number of CAG repeats in patients did not differ from that of controls (22.1 ± 2.9 vs 21.9 ± 2.9, respectively; p = 0.26), but the presence of articular erosions was associated with a lower number of repeats in the shorter allele of patients with RA (20.4 ± 2.2 vs 21.2 ± 2.4; p = 0.031). When alleles with < 22 CAG were classified as short (S) and those with ≥ 22 CAG as long (L), the age at diagnosis of RA was lower in women with S-S genotype in comparison to combined S-L + L-L genotypes (43.0 ± 14.6 yrs vs 47.6 ± 12.5 yrs; p = 0.021). In patients with the L-L genotype, the frequency of erosive disease (OR 0.45, 95% CI 0.25-0.80, p = 0.0085) and extraarticular manifestations (OR 0.50, 95% CI 0.26-0.98, p = 0.047) was lower in comparison to carriers of the S allele. In multivariate analysis, the L-L genotype was an independent factor associated with a lower risk of erosions (OR 0.44, 95% CI 0.22-0.90, p = 0.024).
  
  
  CONCLUSIONS
  The results suggest the association of short AR (CAG)(n) alleles with earlier onset and a more aggressive course of RA.
authors.affiliation: Department of Pharmacology, Pomeranian Medical University, Powstancow Wlkp. 72, 70-111 Szczecin, Poland.
authors.forename: Violetta
authors.initials: V
authors.lastname: Dziedziejko
authors.forename: Mateusz
authors.initials: M
authors.lastname: Kurzawski
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Safranow
authors.forename: Andrzej
authors.initials: A
authors.lastname: Ossowski
authors.forename: Jaroslaw
authors.initials: J
authors.lastname: Piatek
authors.forename: Miroslaw
authors.initials: M
authors.lastname: Parafiniuk
authors.forename: Dariusz
authors.initials: D
authors.lastname: Chlubek
authors.forename: Andrzej
authors.initials: A
authors.lastname: Pawlik
mesh_terms: D000483:Alleles; D001172:Arthritis, Rheumatoid / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology; D016022:Case-Control Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D011944:Receptors, Androgen / Q000235:genetics*; D018911:Trinucleotide Repeats / Q000235:genetics*
chemical_list: D011944:Receptors, Androgen