Genetic markers in late paraphrenia: a study of HLA antigens.

Patients with late paraphrenia were typed for HLA-A, -B and -C. Increased frequencies of BW55 (P = 0.036), B37 (P = 0.008) and CW6 (P = 0.056) were found relative to controls. Unlike findings in paranoid schizophrenia, there was no HLA-A9 association, suggesting that paraphrenics may be genetically distinct from schizophrenics. The primary association seems to be with B37, which has the lowest corrected P value and highest relative risk; if this were replicated, it would make possession of this antigen a strong risk factor for developing the disorder.