title: HLA class 2 genes in Singaporean Chinese rheumatoid arthritis.
abstract: This study analysed HLA class 1 and 2 allele associations in Singaporean Chinese patients with RA. Seventy patients (ARA definite or classical) and 80 controls were typed for HLA class 1 alleles by serology and class 2 alleles by serology and the PCR/SSO method. RA patients had higher frequencies of DRB1*0405 (40 vs 12.5%; corrected probability value (PC) < 0.02, relative risk (RR) = 4.7, 95% confidence limit (CL) 2.1-10.6), DRB1*1001 (14.3 vs 1.3%; PC = 0.06, RR = 13.2, 95% CL 1.6-105.7), DQB1*0401 (38.6 vs 12.5%; P = 0.006, RR = 4.4, 95% CL 1.9-10.0) and DQB1*0501 (20 vs 5%; PC = 0.048, RR = 4.8, 95% CL 1.5-15.2). It is concluded that Chinese RA is associated primarily with HLA DRB1*0405 and DRB1*1001 which share common amino acid sequences in the third hypervariable region of the DR beta chains shown to be associated with RA in other ethnic groups. Patients without DRB1*0405 and *1001 had a higher frequency of DRB1*0901, which is in linkage disequilibrium with HLA B46 in the Chinese.
authors.affiliation: Department of Microbiology, Faculty of Medicine, National University of Singapore.
authors.forename: S H
authors.initials: SH
authors.lastname: Chan
authors.forename: Y N
authors.initials: YN
authors.lastname: Lin
authors.forename: G B
authors.initials: GB
authors.lastname: Wee
authors.forename: W H
authors.initials: WH
authors.lastname: Koh
authors.forename: M L
authors.initials: ML
authors.lastname: Boey
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D001172:Arthritis, Rheumatoid / Q000208:ethnology / Q000235:genetics*; D002648:Child; D002681:China / Q000208:ethnology; D005260:Female; D005787:Gene Frequency; D005805:Genes, MHC Class I; D005802:Genes, MHC Class II; D006683:HLA-DQ Antigens / Q000235:genetics; D059866:HLA-DQ beta-Chains; D006684:HLA-DR Antigens / Q000235:genetics; D059811:HLA-DRB1 Chains; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012846:Singapore
chemical_list: D006683:HLA-DQ Antigens; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D000949:Histocompatibility Antigens Class II