Immune related genetic polymorphisms and schizophrenia among the Chinese

Generic association studies were conducted among two independent cohorts of Chinese ethnicity. Thr samples consisted of cases and unrelated controls, ascertained from Guangzhou, China, and Singapore. The studies were prompted by our earlier report of an association between schizophrenia and HLA DQB1 alleles (HLA DQB1*0602 and HLA DQB1*0303) in the Singapore sample. Polymor phisms of HLA DQB1 and flanking markers on chromosome 6p21.3 were investiga ted in thr first part of the study. A significant negative association with HLA DQB1*0402 was detected in the Guangzhou sample (Odds ratio, OR 0.26, 9 5% confidence intervals, CI 0.1, 0.6; p < 0.02, corrected for multiple comp arisons). Additional analysis of the Guangzhou and Singapore samples reveal ed associations at three other anonymous markers flanking HLA DQB1. In che second part of che study, three polymorphisms at the Interleukin-1 gene clu ster (IL-1, chromosome 2q13-q21) were investigated in both cohort,, since a ssociations with schizophrenia have been reported in another sample. Persua sive evidence for an association at IL-1 was not detected in either sample. Our results suggest a susceptibility locus for schizophrenia in the HLA re gion among the Chinese, but further clarification is necessary. (C) America n Society fur Histocompatibility and Immunogenetics, 2001. Published by Els evier Science Inc.