Multiple Recurrent De Novo CNVs, Including Duplications of the 7q11.23 Williams Syndrome Region, Are Strongly Associated with Autism

Abstract

Summary Given prior evidence for the contribution of rare copy number variations (CNVs) to autism spectrum disorders (ASD), we studied these events in 4,457 individuals from 1,174 simplex families, composed of parents, a proband and, in most kindreds, an unaffected sibling. We find significant association of ASD with de novo duplications of 7q11.23, where the reciprocal deletion causes Williams-Beuren syndrome, featuring a highly social personality. We identify rare recurrent de novo CNVs at five additional regions including two novel ASD loci, 16p13.2 (including the genes USP7 and C16orf72) and Cadherin13, and implement a rigorous new approach to evaluating the statistical significance of these observations. Overall, we find large de novo CNVs carry substantial risk (OR=3.55; CI =2.16-7.46, p=6.9 × 10−6); estimate the presence of 130-234 distinct ASD-related CNV intervals across the genome; and, based on data from multiple studies, present compelling evidence for the association of rare de novo events at 7q11.23, 15q11.2-13.1, 16p11.2, and Neurexin1.

1q21.1 Microduplication expression in adults

“…The 76 probands (including adults and children) comprised 70 subjects ascertained because of major clinical features, five reported in nonoverlapping control populations, 2,5,6 and one parent of a child with autism spectrum disorder where the child did not have a 1q21.1 duplication. 22 The majority were referred from centers in Europe or the United States. Of the 70 clinically ascertained probands, 15 (21.4%) were ascertained with autism spectrum disorder, 12 (17.1%) with congenital heart disease, 10 (14.3%) with schizophrenia, two (2.9%) with bipolar disorder, and one (1.4%) with recurrent depressive disorder.…”

“…[17][18][19][20] Other citations involving 1q21.1 duplication cases were also assessed. [21][22][23][24][25][26][27][28][29][30][31][32][33][34] Cases of 1q21.1 duplication in GeneReviews (http://www.ncbi.nlm. nih.gov/books/NBK52787) and the four references provided therein 1,2,10,25 were reviewed as well, but no new subjects or phenotypic data were identified.…”

“…3,35 We systematically reviewed 28 primary reports identified and their accompanying supplemental materials to identify unique individuals and abstract as much information as possible on each subject. 1,2,[5][6][7][8][9][10][11][12][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] Any subjects with 1q21.1 duplications that were not 1.0-5.0 Mb (Figure 1) in size were excluded, 12,31 allowing us to include atypical variants that were larger or smaller than the standard duplication classes used in our analyses. We documented the ascertainment criteria, country of origin, authors, and the demographic, clinical, and genotypic characteristics of subjects in different studies, and used these variables to attempt to identify duplicate cases reported in two or more papers.…”

“…Four studies were excluded because the sources of subjects overlapped with those of other reports and/or the origin of cases was not specified. 17,18,32,34 We compiled data for 107 subjects from the remaining 22 studies 1,2,[5][6][7][8][9][10][11][19][20][21][22][23][24][25][26][27][28][29][30]33 for the main analyses in this report.…”

Autism throughout genetics: Perusal of the implication of ion channels

“…Thanks to the comparative genomic hybridization (CGH) technique or SNPs array, CNVs were also found in multiple chromosomal regions at 1q21.1, 16p11.2, 17q12, and 22q11.2 (Jacquemont et al., 2006; Marshall et al., 2008; Matsunami et al., 2013; O'Roak et al., 2012; Pinto et al., 2010; Sebat et al., 2007). Further studies supported the association with ASD of two recurrent de novo CNVs at 16p11.2 (duplication and deletion) and 7q11.23 (duplication; Levy et al., 2011; Sanders Stephan et al., 2011). The chromosomal deletion found at 7q11.23 has been linked to William's syndrome, which includes intellectual disabilities, facial dysmorphic features, congenital heart defect, and transient hypercalcemia.…”