PT  - JOURNAL ARTICLE
AU  - Antonio F. Pardiñas
AU  - Peter Holmans
AU  - Andrew J. Pocklington
AU  - Valentina Escott-Price
AU  - Stephan Ripke
AU  - Noa Carrera
AU  - Sophie E. Legge
AU  - Sophie Bishop
AU  - Darren Cameron
AU  - Marian L. Hamshere
AU  - Jun Han
AU  - Leon Hubbard
AU  - Amy Lynham
AU  - Kiran Mantripragada
AU  - Elliott Rees
AU  - James H. MacCabe
AU  - Steven A. McCarroll
AU  - Bernhard T. Baune
AU  - Gerome Breen
AU  - Enda M. Byrne
AU  - Udo Dannlowski
AU  - Thalia C. Eley
AU  - Caroline Hayward
AU  - Nicholas G. Martin
AU  - Andrew M. McIntosh
AU  - Robert Plomin
AU  - David J. Porteous
AU  - Naomi R. Wray
AU  - GERAD Consortium
AU  - David A. Collier
AU  - Dan Rujescu
AU  - George Kirov
AU  - Michael J. Owen
AU  - Michael C. O’Donovan
AU  - James T. R. Walters
TI  - Common schizophrenia alleles are enriched in mutation-intolerant genes and maintained by background selection
AID  - 10.1101/068593
DP  - 2016 Jan 01
TA  - bioRxiv
PG  - 068593
4099  - http://biorxiv.org/content/early/2016/08/09/068593.short
4100  - http://biorxiv.org/content/early/2016/08/09/068593.full
AB  - Schizophrenia is a debilitating psychiatric condition often associated with poor quality of life and decreased life expectancy. Lack of progress in improving treatment outcomes has been attributed to limited knowledge of the underlying biology, although large-scale genomic studies have begun to provide such insight. We report the largest single cohort genome-wide association study of schizophrenia (11,260 cases and 24,542 controls) and through meta-analysis with existing data we identify 50 novel GWAS loci. Using gene-wide association statistics we implicate an additional set of 22 novel associations that map onto a single gene. We show for the first time that the common variant association signal is highly enriched among genes that are intolerant to loss of function mutations and that variants in these genes persist in the population despite the low fecundity associated with the disorder through the process of background selection. Associations point to novel areas of biology (e.g. metabotropic GABA-B signalling and acetyl cholinesterase), reinforce those implicated in earlier GWAS studies (e.g. calcium channel function), converge with earlier rare variants studies (e.g. NRXN1, GABAergic signalling), identify novel overlaps with autism (e.g. RBFOX1, FOXP1, FOXG1), and support early controversial candidate gene hypotheses (e.g. ERBB4 implicating neuregulin signalling). We also demonstrate the involvement of six independent central nervous system functional gene sets in schizophrenia pathophysiology. These findings provide novel insights into the biology and genetic architecture of schizophrenia, highlight the importance of mutation intolerant genes and suggest a mechanism by which common risk variants are maintained in the population.