title: HLA-DQA1*03:02/DQB1*03:03:02 is strongly associated with susceptibility to childhood-onset ocular myasthenia gravis in Southern Han Chinese.
abstract: OBJECTIVE
  Our aim was to investigate the correlation between onset age, clinical features and HLA-DQA1/DQB1 genetic variability in myasthenia gravis (MG) patients in Southern Han Chinese.
  
  
  METHODS
  205 MG patients and 100 controls were genotyped for HLA-DQA1 and -DQB1 using sequence-based typing (SBT) and analyzed for haplotype frequencies. Anti-acetylcholine receptor (AChR) autoantibodies were measured in all, and muscle-specific tyrosine kinase (MuSK) antibodies were tested in AChR antibody negative patients.
  
  
  RESULTS
  HLA-DQA1/DQB1 haplotypes showed association only with childhood-onset MG. Haplotype DQA1*03:02/DQB1*03:03:02 (DQ9) was positively associated with the childhood-onset MG, while haplotype DQA1*02:01/DQB1*02:02 and DQA1*05:01:01/DQB1*02:01:01 (DQ2) were negatively associated with this group. Childhood-onset ocular MG patients had an extremely high phenotype frequency of DQ9 haplotype (90.1% of patients, 34.0% of controls, p≤0.0001, OR=17.8).
  
  
  CONCLUSIONS
  The childhood-onset ocular MG in Southern Han Chinese may present a particular subgroup of distinct genetic background. Its correlation to the HLA haplotype DQA1*03:02/DQB1*03:03:02 might explain the phenotypic difference of MG between Han Chinese and Caucasians.
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, 12 Middle Wulumuqi Road, Shanghai, China.
authors.forename: Wen-Hua
authors.initials: WH
authors.lastname: Zhu
authors.forename: Jia-Hong
authors.initials: JH
authors.lastname: Lu
authors.forename: Jie
authors.initials: J
authors.lastname: Lin
authors.forename: Jian-Ying
authors.initials: JY
authors.lastname: Xi
authors.forename: Jun
authors.initials: J
authors.lastname: Lu
authors.forename: Su-Shan
authors.initials: SS
authors.lastname: Luo
authors.forename: Kai
authors.initials: K
authors.lastname: Qiao
authors.forename: Bao-Guo
authors.initials: BG
authors.lastname: Xiao
authors.forename: Chuan-Zhen
authors.initials: CZ
authors.lastname: Lu
authors.forename: Chong-Bo
authors.initials: CB
authors.lastname: Zhao
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D044466:Asian People / Q000208:ethnology; D002681:China / Q000453:epidemiology / Q000208:ethnology; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D005838:Genotype; D059848:HLA-DQ alpha-Chains / Q000235:genetics*; D059866:HLA-DQ beta-Chains / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000208:ethnology* / Q000235:genetics*; D011110:Polymorphism, Genetic; D020794:Receptor Protein-Tyrosine Kinases / Q000276:immunology; D011950:Receptors, Cholinergic / Q000276:immunology
chemical_list: D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; C069050:HLA-DQA1 antigen; C069051:HLA-DQB1 antigen; D011950:Receptors, Cholinergic; C095714:MUSK protein, human; D020794:Receptor Protein-Tyrosine Kinases