Neurodevelopmental disease genes implicated by de novo mutation and CNV morbidity

Abstract

We combined de novo mutation (DNM) data from 10,927 cases of developmental delay and autism to identify 301 candidate neurodevelopmental disease genes showing an excess of missense and/or likely gene-disruptive (LGD) mutations. 164 genes were predicted by two different DNM models, including 116 genes with an excess of LGD mutations. Among the 301 genes, 76% show DNM in both autism and intellectual disability/developmental delay cohorts where they occur in 10.3% and 28.4% of the cases, respectively. Intersecting these results with copy number variation (CNV) morbidity data identifies a significant enrichment for the intersection of our gene set and genomic disorder regions (36/301, LR+ 2.53, p=0.0005). This analysis confirms many recurrent LGD genes and CNV deletion syndromes (e.g., KANSL1, PAFAH1B1, RA1, etc.), consistent with a model of haploinsufficiency. We also identify genes with an excess of missense DNMs overlapping deletion syndromes (e.g., KIF1A and the 2q37 deletion) as well as duplication syndromes, such as recurrent MAPK3 missense mutations within the chromosome 16p11.2 duplication, recurrent CHD4 missense DNMs in the 12p13 duplication region, and recurrent WDFY4 missense DNMs in the 10q11.23 duplication region. Finally, we also identify pathogenic CNVs overlapping more than one recurrently mutated gene (e.g., Sotos and Kleefstra syndromes) raising the possibility that multiple gene-dosage imbalances may contribute to phenotypic complexity of these disorders. Network analyses of genes showing an excess of DNMs confirm previous well-known enrichments but also highlight new functional networks, including cell-specific enrichments in the D1+ and D2+ spiny neurons of the striatum for both recurrently mutated genes and genes where missense mutations cluster.