Investigation of chromosome Y loss in men with schizophrenia

Abstract

Takashi Hirata, Akitoyo Hishimoto, Ikuo Otsuka, Satoshi Okazaki, Shuken Boku, Atsushi Kimura, Tadasu Horai, Ichiro Sora Department of Psychiatry, Kobe University Graduate School of Medicine, Kusunoki-cho, Chuo-ku, Kobe, Japan Background: Life expectancy is 10–20 years lower in patients with schizophrenia than in the general population. In addition, men with schizophrenia have an earlier age at onset, more pronounced deficit symptoms, poorer course, and poorer response to antipsychotic medications than women. Recent studies have indicated that loss of chromosome Y (LOY) in peripheral blood is associated with an increased risk of all-cause mortality. In order to elucidate the pathophysiology of male-specific features, we investigated the association between LOY and schizophrenia. Materials and methods: The present study included 360 Japanese men (146 patients with schizophrenia vs 214 controls). The relative amount of Y chromosome was defined as the ratio of chromosome Y to chromosome X (Y/X ratio) based on the fluorescent signal of co-amplified short sequences from the Y-X homologous amelogenin genes (AMELY and AMELX). Results: There was no significant difference in the frequency of LOY between the schizophrenia and control groups. However, longer duration of illness was associated with LOY after controlling for age and smoking status in the schizophrenia group (P=0.007, OR =1.11 [95% CI =1.03–1.19]). Conclusion: According to our results, schizophrenia may not have a remarkable effect on blood LOY; however, LOY may be associated with disease course in patients with schizophrenia. Keywords: loss of chromosome Y, schizophrenia, disease duration

Keywords

• loss of chromosome Y
• schizophrenia
• disease duration