title: Interleukin-4 -590 T>C and interleukin-4 receptor Q551R A>G gene polymorphisms in Saudi cases with alopecia areata.
abstract: OBJECTIVE
  Immunogenetic factors are known to play a role in the pathogenesis of alopecia areata (AA). This study aimed at investigating the association between AA with the polymorphisms of interleukin-4 (IL-4) promoter and receptor (IL-4R) genes.
  
  
  METHODS
  This work is a case-control study that was conducted on 76 AA patients from Qassim region, Saudi Arabia. Patients were compared with 93 normal healthy controls from the same locality. Genomic DNA was extracted and processed using real-time PCR amplification for characterization of IL-4 -590 T>C and IL-4R Q551R A>G gene polymorphisms.
  
  
  RESULTS
  Cases of AA showed a higher frequency of the IL-4 -590 CC homozygous genotype compared with controls (63.2 vs. 53.8%, P>0.05) with a lower frequency of the TT genotype (5.3 vs. 10.8%); yet, both were statistically nonsignificant (P>0.05). Regarding the IL-4R Q551R A>G polymorphism, cases and controls showed nearly equal frequencies of all variants, that is, with no significant difference. Although the frequency of the IL-4 C and the IL-4R A alleles was higher among cases than among controls (78.9 vs. 71.5% and 78.8 vs. 72.6%, respectively), this was also statistically nonsignificant (P>0.05). Comparing case subgroups in terms of their age of onset, sex, disease severity, consanguinity, and family history showed no statistically significant difference regarding the studied genetic variant.
  
  
  CONCLUSIONS
  IL-4 -590 and IL-4R Q551R gene polymorphisms are not associated with the susceptibility and the clinical pattern of AA in Saudi patients. We recommend further research studies involving the estimation of cytokines both in the serum and in the local skin lesions or in cultured skin cells to figure out whether Th1 or Th2 pathways play a specific role in the pathogenesis of AA.
authors: aDermatology Department bResearch Center, College of Medicine, Qassim University cDermatology Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors: Abdullateef A
authors: AA
authors: Alzolibani
authors: Ahmad A
authors: AA
authors: Al Robaee
authors: Hani A
authors: HA
authors: Al Shobaili
authors: Ghada
authors: G
authors: Bin Saif
authors: Fahad
authors: F
authors: Al-Saif
authors: Ahmed
authors: A
authors: Ali
authors: Ahmad
authors: A
authors: Settin
mesh_terms: D000293:Adolescent; D000328:Adult; D000506:Alopecia Areata / Q000235:genetics* / Q000276:immunology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D015847:Interleukin-4 / Q000235:genetics* / Q000276:immunology; D053662:Interleukin-4 Receptor alpha Subunit / Q000235:genetics* / Q000276:immunology; D008297:Male; D010865:Pilot Projects; D011110:Polymorphism, Genetic; D012529:Saudi Arabia; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology
chemical_list: C508598:IL4 protein, human; C504000:IL4R protein, human; D053662:Interleukin-4 Receptor alpha Subunit; D015847:Interleukin-4