Rare Structural Variants Disrupt Multiple Genes in Neurodevelopmental Pathways in Schizophrenia

Tom Walsh,^1* Jon M. McClellan,^2* Shane E. McCarthy,^3* Anjené M. Addington,^4* Sarah B. Pierce,¹ Greg M. Cooper,⁵ Alex S. Nord,⁵ Mary Kusenda,^3,6 Dheeraj Malhotra,³ Abhishek Bhandari,³ Sunday M. Stray,¹ Caitlin F. Rippey,⁵ Patricia Roccanova,³ Vlad Makarov,³ B. Lakshmi,³ Robert L. Findling,⁷ Linmarie Sikich,⁸ Thomas Stromberg,⁴ Barry Merriman,⁹ Nitin Gogtay,⁴ Philip Butler,⁴ Kristen Eckstrand,⁴ Laila Noory,⁴ Peter Gochman,⁴ Robert Long,⁴ Zugen Chen,⁹ Sean Davis,¹⁰ Carl Baker,⁵ Evan E. Eichler,⁵ Paul S. Meltzer,¹⁰ Stanley F. Nelson,⁹ Andrew B. Singleton,¹¹ Ming K. Lee,¹ Judith L. Rapoport,⁴ Mary-Claire King,^1,5 Jonathan Sebat³

Schizophrenia is a devastating neurodevelopmental disorder whose genetic influences remain elusive. We hypothesize that individually rare structural variants contribute to the illness. Microdeletions and microduplications >100 kilobases were identified by microarray comparative genomic hybridization of genomic DNA from 150 individuals with schizophrenia and 268 ancestry-matched controls. All variants were validated by high-resolution platforms. Novel deletions and duplications of genes were present in 5% of controls versus 15% of cases and 20% of young-onset cases, both highly significant differences. The association was independently replicated in patients with childhood-onset schizophrenia as compared with their parents. Mutations in cases disrupted genes disproportionately from signaling networks controlling neurodevelopment, including neuregulin and glutamate pathways. These results suggest that multiple, individually rare mutations altering genes in neurodevelopmental pathways contribute to schizophrenia.

¹ Department of Medicine, University of Washington, Seattle, WA 98195, USA.
² Department of Psychiatry, University of Washington, Seattle, WA 98195, USA.
³ Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
⁴ Child Psychiatry Branch, National Institute of Mental Health, National Institutes of Health (NIH), Bethesda, MD 20892, USA.
⁵ Department of Genome Sciences, University of Washington, Seattle, WA98195, USA.
⁶ Graduate Program in Genetics, State University of New York, Stony Brook, NY 11794, USA.
⁷ Department of Psychiatry, Case Medical Center, Cleveland, OH 44106, USA.
⁸ Department of Psychiatry, University of North Carolina, Chapel Hill, NC 27599, USA.
⁹ Department of Human Genetics, University of California, Los Angeles, CA 90095, USA.
¹⁰ Cancer Genetics Branch, National Cancer Institute, NIH, Bethesda, MD 20892, USA.
¹¹ Neurogenetics Laboratory, National Institute on Aging, NIH, Bethesda, MD20892, USA.

^* These authors contributed equally to this work.

To whom correspondence should be addressed. E-mail: drjack{at}u.washington.edu