Indian Case Control (ICC) Study

Since 2008, we have been working with colleagues in Chennai, India, to recruit a large schizophrenia case-control cohort from Tamil Nadu. Combined with our existing family cohorts, the planned 2000 cases and 3000 controls will provide the largest resource for genetic studies of schizophrenia in India, including primary genome-wide association studies (GWAS) and replication studies for findings from our earlier studies and those of recent large international GWAS consortia. To date, we have recruited 567 cases and 1776 controls, across ~ 50 different caste groups. We have performed genome-wide genotyping of > 700,000 single nucleotide polymorphisms (SNPs) in a total of 200 individuals from ~ 40 castes. Analysis of these data indicates that genetic distances between caste groups are sufficiently small that the entire cohort can be considered a single ethnically homogeneous sample for genetic studies.