August 30, 2013. Momentum is building in the largest experiment ever in schizophrenia research: Thirteen more regions in the human gene code, or genome, have been implicated in the most recent report from genomewide association studies (GWAS). An international team led by Patrick Sullivan of the University of North Carolina, Chapel Hill, combined a large group of DNA samples from their Swedish collaborators with previous GWAS data, creating a study of more than 20,000 schizophrenia subjects and bringing the total of published genomic suspects in the disorder to over 20.
More work will have to be done to drill down and figure out what the "hits" from this study represent. In their paper, published August 25, 2013, in the journal Nature Genetics, Sullivan and his co-authors highlight two of them: There seems to be good evidence for involvement of molecules that move the element calcium into cells and for a molecule called microRNA-137 that regulates the production of various proteins.
Although the new results represent progress, they are not the end goal, according to Sullivan. The number of genetic suspects that can be found in GWAS increases with the number of study subjects, and the international Psychiatric GWAS Consortium has gathered, but not yet published, genetic data (called genotypes) from over 30,000 people. "We hope to genotype 100,000 people above and beyond what we have right now," said Sullivan. (For more details, see the related news story.)—Hakon Heimer.