title: The association between Interleukin (IL)-4 gene intron 3 VNTR polymorphism and alopecia areata (AA) in Turkish population.
abstract: OBJECTIVE
  Alopecia areata (AA) is hypothesized to be an organ-specific autoimmune disease of hair follicles mediated by T cells. As immunological and genetic factors have been implicated in the pathogenesis of AA, the purpose of the present study was to investigate possible associations between the functional Interleukin (IL)-4 gene intron 3 VNTR polymorphism and AA susceptibility and disease progression in Turkish population.
  
  
  METHODS
  The study group consisted of 116 unrelated patients with AA and 125 unrelated healthy controls. Genomic DNA was isolated and IL-4 gene 70 bp VNTR polymorphism determined by using polymerase chain reaction (PCR) with specific primers.
  
  
  RESULTS
  No association was observed between AA patients and controls according to genotype distribution (p=0.051). The allele distribution of IL-4 gene intron 3 VNTR polymorphism was statistically different between AA patients and control group (p=0.026). The frequency of P1 allele in patients was significantly higher than that in the control group. When the P2P2 genotype was compared with P1P2+P1P1 genotypes, a statistically significant difference was observed between patients and controls (p=0.036). Intron 3 VNTR polymorphism in the IL-4 gene was found to be associated with AA susceptibility in Turkish population.
  
  
  CONCLUSIONS
  The results suggest that IL-4 VNTR polymorphism in the intron 3 region may be a risk factor for the development of AA among Turkish population. This is the first to report that intron 3 VNTR polymorphism in the IL-4 gene is associated with AA susceptibility.
authors.affiliation: Gaziosmanpasa University, School of Medicine, Department of Dermatology, Tokat, Turkey. goknurkalkan@yahoo.com
authors.forename: Göknur
authors.initials: G
authors.lastname: Kalkan
authors.forename: Nevin
authors.initials: N
authors.lastname: Karakus
authors.forename: Yalçın
authors.initials: Y
authors.lastname: Baş
authors.forename: Zennure
authors.initials: Z
authors.lastname: Takçı
authors.forename: Pınar
authors.initials: P
authors.lastname: Ozuğuz
authors.forename: Omer
authors.initials: O
authors.lastname: Ateş
authors.forename: Serbulent
authors.initials: S
authors.lastname: Yigit
mesh_terms: D000328:Adult; D000506:Alopecia Areata / Q000235:genetics*; D005260:Female; D006801:Humans; D015847:Interleukin-4 / Q000235:genetics*; D007438:Introns; D008297:Male; D008875:Middle Aged; D018598:Minisatellite Repeats; D011110:Polymorphism, Genetic; D014421:Turkey
chemical_list: D015847:Interleukin-4
keywords: AA; ANOVA; AT; AU; Alopecia; Alopecia areata; CI; ESRD; Genetic skin disorders; HLA; IL; IL-4; MS; NK; OR; PCR; Polymorphism; RA; SD; SLE; SNPs; SPSS; Statistical Package for the Social Sciences; T helper cells; TC cells; TNF; Th cells; VNTR; alopecia totalis; alopecia universalis; analysis of variance; confidence interval; cytotoxic T cells; end-stage renal disease; human leukocyte antigen; interleukin; multiple sclerosis; natural killer; odds ratio; polymerase chain reaction; rheumatoid arthritis; single-nucleotide polymorphisms; standard deviation; systemic lupus erythematosus; tumor necrosis factors alpha; variable number of tandem repeat