Insertional polymorphism of endogenous retrovirus HERV-K115 in schizophrenia

Retroviruses are implicated in the pathogenesis of schizophrenia. Human endogenous retrovirus type KI 15 (HERV-KI 15) is a full-length, potentially transcriptional retrovirus and is also polymorphic. We investigated the frequency of HERV-KI 15 in Japanese schizophrenia patients and healthy controls. No difference was found in the frequency between patients and controls (8.4% versus 9.4%, respectively). However, a marginal difference was observed in age at onset between the HERV-K positive and negative patients (p = 0.057). The HERV-KI 15 insertion appeared to be more frequent in patients with younger onset than those with later onset. These results preliminarily suggest that HERV-KI 15 may not be associated with schizophrenia in general, but that it could play a partial role in early precipitation of the disease. (c) 2006 Elsevier Ireland Ltd. All rights reserved.