Study Report

Reference	Chowdari, K. V.,2002 PMID: 12023979
Citation	Chowdari, K. V., K. Mirnics, et al. (2002). "Association and linkage analyses of RGS4 polymorphisms in schizophrenia." Hum Mol Genet 11(12): 1373-1380.
Disease Type	Bipolar Disorder & Schizophrenia
Study Design	family-based
Study Type	Candidate-gene association study
Sample Size	Pittsburgh schizophrenia cases and parents:Caucasian inpatients and outpatients with schizophrenia (n=55) or schizoaffective disorder (n=38);Pittsburgh bipolar I disorder cases:n=101;National Institute of Mental Health Collaborative Genetics Initiative (NIMH CGI) sample:39 cases, their parents and 30 affected sib-pairs were obtained.They comprised 25 families.Indian schizophrenia cases and parents:A total of 269 case-parent trio and 72 affected sib-pair families were analyzed.
SNP/Region/Marker Size	13 SNPs
Predominant Ethnicity
Population	American,Indian and NIMH collections

Sample Diagnosis	DSM
Technique	genotyping
Statistical Method	PEDCHECK software was used to check for Mendelian inconsistencies. X2 tests were employed for comparisons between cases and unrelated controls. We also used SNPEM software based on the EM algorithm to estimate and compare haplotype frequencies. We utilized GENEHUNTER software for TDT analysis of individual SNPs and haplotypes, as well as analysis of IBD among affected sib-pairs. We also used TRANSMIT for global tests of association involving multiple haplotypes . Linkage disequilibrium was estimated using published software.
Result Summary	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.