Schizophrenia and the HLA-DRB1 gene in the Japanese population

Objective: Small Japanese studies have suggested that patients with schizop hrenia have higher rates of the HLA-DR1 gene than normal subjects. The auth ors' goal in the present study was to confirm this finding in a larger numb er of Japanese subjects. They also investigated the rate of DR4 in Japanese patients with schizophrenia because it has been reported that Caucasian pa tients with schizophrenia have higher rates of DR4. Method: They studied th e occurrence of the HLA-DRB1 gene in 233 unrelated Japanese patients with s chizophrenia compared with the occurrence of the gene in a group of 493 hea lthy Japanese volunteers. Results: A larger proportion of the patients with schizophrenia (15.9%) than the comparison subjects (10.5%) were found to h ave DR1 (DRB1*0101). The proportion of patients (36.9%) and comparison subj ects (40.6%) with DR4 did not differ significantly. Conclusions: Consistent with the findings of three other Japanese studies, the findings of the pre sent study suggest that the rate of HLA-DR1 may be higher in Japanese patie nts with schizophrenia than in normal Japanese subjects. No evidence for an association between schizophrenia and the rate of DR4 was obtained in this study, although the combined data from the present study and other Japanes e studies support the finding of lower rates of DR4 among patients with sch izophrenia.