Gene expression analyses of postmortem cerebral cortex suggest that transcription of the regulator of G-protein signaling 4 (RGS4) is decreased in a diagnosis-specific manner in subjects with schizophrenia. To evaluate the possible role of RGS4 in the pathogenesis of schizophrenia, we conducted genetic association and linkage studies using samples ascertained independently in Pittsburgh and New Delhi and by the NIMH Collaborative Genetics Initiative. Using the transmission disequilibrium test, significant transmission distortion was observed in the Pittsburgh and NIMH samples. Among single-nucleotide polymorphisms (SNPs) spanning approximately 300 kb, significant associations involved four SNPs localized to a 10 kb region at RGS4, but the associated haplotypes differed. A trend for transmission distortion was also present in the Indian sample for haplotypes incorporating the same SNPs. Consistent with the linkage/association observed from the family-based tests, samples with affected siblings (NIMH, India) showed higher levels of allele sharing, identical by descent, at RGS4. When the US patients were contrasted to two population-based control samples, however, no significant differences were observed. To check the specificity of the transmission bias, we therefore examined US families with bipolar I disorder (BD1) probands. This sample also showed a trend for transmission distortion, and differed significantly from the population-based controls for the four-SNP haplotypes tested in the other samples. The transmission distortion is unlikely to be due to chance, but its mechanism and specificity require further study. Our results illustrate the potential power of combining gene expression profiling and genomic analyses to identify susceptibility genes for genetically complex disorders.

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Understanding the pharmacogenetic basis of developing iatrogenic disorders such as Tardive Dyskinesia (TD) has significant clinical implications. CYP1A2, an inducible gene of the cytochrome P450 family of genes, has been suggested to contribute to the metabolism of typical antipsychotics in subjects with schizophrenia on long-term treatment, and has been considered as a potential candidate gene for development of TD. In this study, we have investigated the significance of CYP1A2 gene polymorphisms in TD susceptibility among chronic schizophrenia sufferers (n ¼ 335) from north India. TD was diagnosed in B29% (96/335) of these subjects. Of the 96 TD positives, 28 had been treated with typical antipsychotics alone, 23 with atypical antipsychotics alone and 45 patients had received both classes of drugs during the course of their illness. Out of the six SNPs tested, CYP1A2*2, *4, *5, *6 were found to be monomorphic in our population. CYP1A2*1C and CYP1A2*1F were polymorphic and were analyzed in the study sample. Since these two allelic variants lead to lesser inducibility among smokers, the smoking status of TD patients was also considered for all subsequent analysis. We observed increased severity of TD among TD-Y smokers, who were carriers of CYP1A2*1C (G4A) variant allele and had received only typical antipsychotic drugs (F(1,8) ¼ 9.203, P ¼ 0.016). No significant association of CYP1A2*1F with TD was observed irrespective of the class of drug they received or their smoking status. However, we found a significant association of CYP1A2*1F with schizophrenia (w 2 ¼ 6.572, df ¼ 2, P ¼ 0.037).

The validity of a Hindi version of the Diagnostic Interview for Genetic Studies (DIGS) was investigated. The original English version was initially translated into Hindi. The Hindi version was then back-translated and compared with the original. Next, a group of psychiatric inpatients and outpatients were interviewed using the Hindi version. The resultant diagnoses were compared with those obtained for the same patients using a Hindi version of the Present State Examination (PSE), and the clinical diagnoses given by the treating psychiatrists. The DIGS diagnoses were significantly correlated with both the PSE diagnoses (Cohen's kappa = 0.80) and the clinical diagnoses (kappa = 0.56). Interrater reliability between three interviewers for diagnoses obtained using the Hindi version of the DIGS varied (kappa = 0.45-1.00). Possible causes for this variability are discussed. The Hindi version of the DIGS fulfills the need for a current comprehensive interview schedule not only for psychiatric genetic research in India, but also for nongenetic research.

Background Yoga therapy (YT) improves cognitive function in healthy individuals, but its impact on cognitive function among persons with schizophrenia (SZ) has not been investigated. Aims Evaluate adjunctive YT for cognitive domains impaired in SZ. Methods Patients with SZ received YT or treatment as usual (TAU; n = 65, n = 23, respectively). Accuracy and speed for seven cognitive domains were assessed using a computerized neurocognitive battery (CNB), thus minimizing observer bias. Separately, YT was evaluated among patients with Bipolar I disorder (n = 40), Major Depressive Disorder (n = 37), and cardiology outpatients (n = 68). All patients also received routine pharmacotherapy. Patients were not randomized to YT or TAU. Results Compared with the SZ/TAU group, the SZ/YT group showed significantly greater improvement with regard to measures of attention following corrections for multiple comparisons; the changes were more prominent among the men. In the other diagnostic groups, differing patterns of improvements were noted with small to medium effect sizes. Conclusions Our initial analyses suggest nominally significant improvement in cognitive function in schizophrenia with adjunctive therapies such as YT. The magnitude of the change varies by cognitive domain and may also vary by diagnostic group.

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Background Neuregulin-1 (NRG1) gene polymorphisms have been proposed as risk factors for several common disorders. Associations with cognitive variation have also been tested. With regard to Schizophrenia (SZ) risk, studies of Caucasian ancestry samples indicate associations more consistently than East Asian samples, suggesting heterogeneity. To exploit the differences in linkage disequilibrium (LD) structure across ethnic groups, we conducted a SZ case-control study (that included cognitive evaluations) in a sample from the north Indian population. Methods NRG1 variants (n= 35 SNPs, three microsatellite markers) were initially analyzed among cases (DSM IV criteria, n = 1007) and controls (n=1019, drawn from two groups) who were drawn from the same geographical region in North India. Nominally significant associations with SZ were next analyzed in relation to neurocognitive measures estimated with a computerized neurocognitive battery in a subset of the sample (n=116 cases, n=170 controls). Results Three variants and one microsatellite showed allelic association with SZ (rs35753505, rs4733263, rs6994992, and microsatellite 420 M9-1395, p ≤ 0.05 uncorrected for multiple comparisons). A six marker haplotype 221121 (rs35753505-rs6994992-rs1354336-rs10093107-rs3924999-rs11780123) showed (p=0.0004) association after Bonferroni corrections. Regression analyses with the neurocognitive measures showed nominal (uncorrected) associations with emotion processing and attention at rs35753505 and rs6994992, respectively. Conclusions Suggestive associations with SZ and SZ-related neurocognitive measures were detected with two SNPs from the NRG1 promoter region in a north Indian cohort. The functional role of the alleles merits further investigation.