Investigation of chromosome Y loss in men with schizophrenia

Abstract

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

Supplementary materials

Figure S1 Correlation between duration of illness and age in patients with schizophrenia. P-value and r values were calculated using Spearman’s rho test.

Table S1 Comparisons of demographic and clinical characteristics between participants with and without LOY in the schizophrenia group

Table S2 Logistic regression analysis of LOY in peripheral blood samples of patients with schizophrenia

Table S3 Smoking rates in Japanese men

Acknowledgments

This work was supported in part by the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant Numbers JP15K19727 and JP16K19765. We thank Yasuko Nagashima for providing technical assistance.

Disclosure

The authors report no conflict of interest in this work.