An association study of RGS4 polymorphisms with clinical phenotypes of schizophrenia in a Chinese population

The regulator of G-protein signaling 4 (RGS4) has been suggested as a candidate gene for schizophrenia. However, following an initial positive report, subsequent association studies between RGS4 and schizophrenia have yielded inconclusive results. Also, few studies have investigated the association of RGS4 polymorphisms with the phenotypic subgroups of schizophrenia. To further clarify the role of RGS4 in this disease, we performed a case-control study (504 cases and 531 controls of Han Chinese descent) to examine the association of RGS4 with schizophrenia and with clinical and neurocognitive profiles. The four markers (SNPs 1, 4, 7, and 18) implicated in the original association study were genotyped. We detected significant association of four-marker haplotypes with schizophrenia (UNPHASED: global P = 0.037; PHASE: global P = 0.048). The haplotype G-G-G-G, which was implicated in at least three previous studies, was the major risk haplotype (UNPHASED: P = 0.019; PHASE: P = 0.010). Regarding the clinical phenotypes, the Wechsler Adult Intelligence Test (WAIS) information subtest score was associated with SNP4 genotypes (P = 0.001). PANSS total and global psychopathology scores were also associated with SNP4, but may not reliably reflect the general severity of disease as the scores may be affected by confounders like medication response. Our study provides further support for a role of RGS4 in the pathogenesis of schizophrenia. We identified G-G-G-G as the risk haplotype in our Chinese sample. The association with information subtest score suggests an effect of RGS4 on premorbid functioning, which may be related to neurodevelopmental processes. Further independent studies are required to verify our findings. © 2007 Wiley-Liss, Inc.link_to_subscribed_fulltex

Examining gender difference in adult-onset psychosis in Hong Kong

Aim: Gender-specific treatment strategies for psychosis have been suggested in recent years. Data on gender difference were largely consistent regarding premorbid functioning, age of onset and negative symptoms; however, results regarding neurocognitive function and duration of untreated psychosis were mixed and inconclusive. In this study, we aimed at a thorough examination on the gender differences in 360 Chinese patients with first-episode psychosis in Hong Kong. Methods: From June 2009 to August 2011, participants were consecutively recruited from a population-based territory-wide study of early psychosis targeting first-episode psychosis in Hong Kong. Comprehensive data on basic demographics, premorbid functioning and schizoid and schizotypal traits, clinical, functioning, medication side effects and a battery of neurocognitive measures were collected upon entry into the service. Results: In 360 patients with first-episode psychosis aged between 26 and 55 years, 43.6% (n=157) were male and 56.4% (n=203) were female. Males had poorer premorbid functioning and adjustment, earlier age of onset, more negative symptoms and poorer functioning in terms of work productivity, independent living and immediate social network relationships at presentation of first-episode psychosis. Interestingly, our data indicate that males tend to be more educated, and also characterized by higher IQ, better neurocognitive performance on visual domain compared with females. Duration of untreated psychosis was not different between the two genders. Conclusion: Data from this homogeneous cohort of Chinese populations enabled tailored and culturally sensitive recommendation on gender-specific treatment strategies, hence improving patients' care and facilitate better diagnostic and interventional decisions for patients with psychosis. © 2014 Wiley Publishing Asia Pty Ltd.link_to_subscribed_fulltex