title: Association of HLA haplotype with alopecia areata in Chinese Hans.
abstract: BACKGROUND
  Some studies have shown discrepancies in human leucocyte antigen (HLA) associated with alopecia areata (AA) between different ethnic populations.
  
  
  OBJECTIVE
  To investigate whether HLA-I, -DQA1 and -DQB1 alleles and the HLA haplotype are associated with AA, and the correlation between the HLA haplotype profile, age of onset and severity of AA in Chinese Hans.
  
  
  METHODS
  The polymerase chain reaction-sequence specific primer (PCR-SSP) method was used to analyse the frequencies of HLA class I, -DQA1 and -DQB1 alleles in 192 patients with AA and 252 controls in Chinese Hans. The linkage disequilibrium was calculated using the 2 x 2 table.
  
  
  RESULTS
  The 24 two-locus haplotypes [including A*02-B*18, A*02-B*27, A*02-B*52, A*02-Cw*0704, A*02-DQA1*0104, A*02-DQB1*0604, A*02-DQB1*0606, B*18-Cw*0704, B*18-DQA1*0104, B*18-DQA1*0302, B*18-DQB1*0606, B*27-Cw*0704, B*27-DQA1*0104, B*27-DQA1*0302, B*52-Cw*0704, B*52-DQA1*0104, B*52-DQA1*0302, B52-DQB1*0606, Cw*0704-DQA1*0104, Cw*0704-DQA1*0302, Cw*0704-DQB1*0606, DQA1*0104-DQB1*0604, DQA1*0104-DQB1*0606, DQA1*0302-DQB1*0606 (P<0.05)] were associated with AA, while eight extended haplotypes (A*02-B*18-DQA1*0104, A*02-B*27-DQA1*0104, A*02-B*52-DQA1*0104, A*02-B*52-DQA1*0302, A*02-B*52-DQB1*0606, B*52-Cw*0704-DQA1*0104, B*52-Cw*0704-DQA1*0302, A*02-B*52-DQA1*0302-DQB1*0606) were found to be related to AA in Chinese Hans. Through stratified analysis, we found that the extended haplotype B*52-Cw*0704-DQA1*0302 was related to early onset of AA, and no haplotype was only associated with severe AA.
  
  
  CONCLUSIONS
  This is the first detailed report to elucidate HLA haplotypes associated with AA and that demonstrates the significant HLA haplotypes in Chinese Hans AA. The haplotype B*52-Cw*0704-DQA1*0302 was identified to be related to early onset of AA. Our results provide some information for future research on predisposing genes in HLA regions in Chinese Hans.
authors.affiliation: Insititute of Dermatology, Anhui Medical University, Department of Dermatology, No. 1 Hospital, Hefei, China.
authors.forename: F-L
authors.initials: FL
authors.lastname: Xiao
authors.forename: D-Q
authors.initials: DQ
authors.lastname: Ye
authors.forename: S
authors.initials: S
authors.lastname: Yang
authors.forename: F-S
authors.initials: FS
authors.lastname: Zhou
authors.forename: S-M
authors.initials: SM
authors.lastname: Zhou
authors.forename: Y-G
authors.initials: YG
authors.lastname: Zhu
authors.forename: Y-H
authors.initials: YH
authors.lastname: Liang
authors.forename: Y-Q
authors.initials: YQ
authors.lastname: Ren
authors.forename: X-J
authors.initials: XJ
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000506:Alopecia Areata / Q000208:ethnology* / Q000235:genetics*; D044466:Asian People / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006680:HLA Antigens / Q000235:genetics*; D006683:HLA-DQ Antigens / Q000235:genetics; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; D006239:Haplotypes; D015395:Histocompatibility Antigens Class I / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index
chemical_list: D006680:HLA Antigens; D006683:HLA-DQ Antigens; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; C069050:HLA-DQA1 antigen; C069051:HLA-DQB1 antigen; D015395:Histocompatibility Antigens Class I