Genetic approaches to polydipsia in schizophrenia: A preliminary report of a family study and an association study of an angiotensin-converting enzyme gene polymorphism

✍ Scribed by Shinkai, Takahiro ;Ohmori, Osamu ;Hori, Hiroko ;Nakamura, Jun

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 69 KB
• Volume: 119B
• Category: Article
• ISSN: 0148-7299
• DOI: 10.1002/ajmg.b.10066

✦ Synopsis

Abstract

The pathophysiology of polydipsia in patients with schizophrenia is inadequately understood. This study aims to investigate the genetic influence on polydipsia in schizophrenia, and is comprised of a family study and an association study. First, we screened in‐patients in 14 psychiatric hospitals and found a total of 36 pairs of a proband and his/her first‐degree relative, both of whom were diagnosed with schizophrenia. Among these pairs, a significant familial concordance of polydipsia was found (Fisher's exact test, two‐sided, P = 0.0014; odds ratio, 88.20; 95% confidence interval, 7.31–1064.34). These results indicate that genetic factors may underlie the pathophysiology of polydipsia in patients with schizophrenia. Subsequently, we examined the genetic association between polydipsia/water intoxication and the angiotensin‐converting enzyme (ACE) insertion (I)/deletion (D) polymorphism in patients with chronic schizophrenia (polydipsics: n = 65; non‐polydipsics: n = 97) because several lines of evidence suggested that ACE might be involved in the development of polydipsia in schizophrenia. The D allele of ACE was found to be associated with a non‐significant trend toward an increased risk of polydipsia (P = 0.086). Furthermore, a significant allelic association was found between the D allele of ACE and water intoxication (P = 0.0392). This significance remained after the data were adjusted for confounding variables by regression analysis. These results suggest that the ACE D allele may be a risk factor for polydipsia/water intoxication in patients with schizophrenia. © 2003 Wiley‐Liss, Inc.