Rates, distribution and implications of postzygotic mosaic mutations in autism spectrum disorder

Elaine T Lim, Mohammed Uddin, Silvia De Rubeis, Yingleong Chan, Anne S Kamumbu, Xiaochang Zhang, Alissa M D'Gama, Sonia N Kim, Robert Sean Hill, Arthur P Goldberg, Christopher Poultney, Nancy J Minshew, Itaru Kushima, Branko Aleksic, Norio Ozaki, Mara Parellada, Celso Arango, Maria J Penzol, Angel Carracedo, Alexander Kolevzon, Christina M Hultman, Lauren A Weiss, Menachem Fromer, Andreas G Chiocchetti, Christine M Freitag, Autism Sequencing Consortium, George M Church, Stephen W Scherer, Joseph D Buxbaum, Christopher A Walsh

Index: 10.1038/nn.4598

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Abstract

We systematically analyzed postzygotic mutations (PZMs) in whole-exome sequences from the largest collection of trios (5,947) with autism spectrum disorder (ASD) available, including 282 unpublished trios, and performed resequencing using multiple independent technologies. We identified 7.5% of de novo mutations as PZMs, 83.3% of which were not described in previous studies. Damaging, nonsynonymous PZMs within critical exons of prenatally expressed genes were more common in ASD probands than controls (P < 1 × 10−6), and genes carrying these PZMs were enriched for expression in the amygdala (P = 5.4 × 10−3). Two genes (KLF16 and MSANTD2) were significantly enriched for PZMs genome-wide, and other PZMs involved genes (SCN2A, HNRNPU and SMARCA4) whose mutation is known to cause ASD or other neurodevelopmental disorders. PZMs constitute a significant proportion of de novo mutations and contribute importantly to ASD risk.