Negative association of schizophrenia with HLA DQB1*0602: evidence from a second African-American cohort.

The authors attempted a replication of an earlier study of African-Americans, in which they detected a negative association of schizophrenia with HLA DQB1*0602. Patients with schizophrenia (n = 75, DSM-III-R criteria) and screened adult controls of African-American ethnicity (n = 66) were genotyped with respect to HLA DQB1*0602 using a combination of two polymerase chain reaction (PCR) based assays: amplification with sequence specific primers and a dot blot assay. A significant negative association with HLA DQB1 was not noted overall, but was present among women (female patients vs. female controls: odds ratio, OR = 0.42, 95% confidence intervals, CI = 0.32, 0.55). Reanalysis of the earlier study also revealed a gender related association. When the present and earlier samples from both genders were combined, the association persisted (OR 0.48; 95% CI: 0.12, 0.52). The present findings support and association between schizophrenia and the HLA DQB1 gene locus among African-Americans.