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Ann Rheum Dis 73:1240-1245 doi:10.1136/annrheumdis-2012-202675
  • Basic and translational research
  • Extended report

Ethnic specificity of lupus-associated loci identified in a genome-wide association study in Korean women

  1. Sang-Cheol Bae1
  1. 1Department of Rheumatology, Hanyang University Hospital for Rheumatic Diseases, Seoul, Korea
  2. 2Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Korea
  3. 3Department of Microbiology, Integrated Research Center for Genome Polymorphism, The Catholic University of Korea, College of Medicine, Seoul, Korea
  4. 4Department of Life Science, Sogang University, and SNP Genetics, Inc., Seoul, Korea
  5. 5Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea
  6. 6Division of Rheumatology, Daejeon Rheumatoid & Degenerative Arthritis Center, Chungnam National University Hospital, Daejeon, Korea
  7. 7Department of Rheumatology, Ajou University School of Medicine, Suwon, Korea
  8. 8Department of Internal Medicine, Institute for Immunology and Immunological Diseases, Yonsei University College of Medicine, Seoul, Korea
  9. 9Department of Family Medicine, Chungnam National University Hospital, Daejeon, Korea
  1. Correspondence to Professor Changwon Kang, Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea; ckang{at}kaist.ac.kr or Sang-Cheol Bae, Department of Rheumatology, Hanyang University Hospital for Rheumatic Diseases, Seoul 133-792, Korea; scbae{at}hanyang.ac.kr
  • Accepted 5 May 2013
  • Published Online First 5 June 2013

Abstract

Objectives To identify novel genetic candidates for systemic lupus erythematosus (SLE) in the Korean population, and to validate the risk loci for SLE identified in previous genome-wide association studies (GWAS).

Methods We performed a GWAS in 400 Korean female SLE patients and 445 controls. Selected single-nucleotide polymorphisms (SNP) were then replicated in an independent cohort of 385 SLE patients and 583 controls (replication cohort 1), and in a further 811 SLE patients and 1502 controls (replication cohort 2).

Results In the GWAS phase, rs9275428 located near HLA-DQB1 showed the strongest association with SLE (OR 0.50, false discovery rate (FDR) p=3.07×10−6). Although no loci reached genome-wide significance outside major histocompatibility complex (MHC), C8orf13-BLK, STAT4, CSMD1, DIAPH3, GLDC and TNFSF4 showed FDR p < 0.05. Our results suggest that STAT4, BLK, IRF5, PTTG1-miR-146a, UBE2L3 and TNFAIP3 are shared susceptibility loci among Caucasians and Asians, while ETS1, IKZF1, SLC15A4 are likely to be Asian-specific loci. In a combined analysis of 1596 SLE patients and 2540 controls for selected 22 candidate SNP, STAT4 and BLK as positive controls showed a strong association with SLE (FDR p=9.85×10−13 and 2.28×10−8, respectively). Of these, 16 candidates (PEX5L, TRAJ50, MYO18B, SOS1, ARHGAP26, SMURF1, CADPS, HAND1, FAM78B, DIAPH3, TBL1XR1, CSMD1, ZBTB20, C3orf21, HIPK1 and AP001042.1) showed only nominal significance (7.05×10−4≤FDR p≤4.38×10−2).

Conclusions There are similarities and differences in genetic susceptibility for SLE between Caucasian and Asian ethnic groups. Although 16 putative novel loci for SLE have been suggested in the Korean population, further research on a larger sample is required to discriminate truth from error.