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Genome-wide copy number variation analysis of a Branchio-Oto-Renal syndrome cohort identifies a recombination hotspot and implicates new candidate genes
Journal article   Open access   Peer reviewed

Genome-wide copy number variation analysis of a Branchio-Oto-Renal syndrome cohort identifies a recombination hotspot and implicates new candidate genes

Patrick D Brophy, Fatemeh Alasti, Benjamin W Darbro, Jason Clarke, Carla Nishimura, Bryan Cobb, Richard J Smith and J. Robert Manak
Human genetics, Vol.132(12), pp.1339-1350
12/2013
DOI: 10.1007/s00439-013-1338-8
PMCID: PMC3830662
PMID: 23851940
url
http://doi.org/10.1007/s00439-013-1338-8View
Open Access

Abstract

Branchio-oto-renal (BOR) syndrome is an autosomal dominant disorder characterized by branchial arch anomalies, hearing loss and renal dysmorphology. Although haploinsufficiency of EYA1 and SIX1 are known to cause BOR, copy number variation analysis has only been performed on a limited number of BOR patients. In this study, we used high-resolution array-based comparative genomic hybridization (aCGH) on 32 BOR probands negative for coding-sequence and splice-site mutations in known BOR-causing genes to identify potential disease-causing genomic rearrangements. Of the >1,000 rare and novel copy number variants (CNVs) we identified, four were heterozygous deletions of EYA1 and several downstream genes that had nearly identical breakpoints associated with retroviral sequence blocks, suggesting that non-allelic homologous recombination seeded by this recombination hotspot is important in the pathogenesis of BOR. A different heterozygous deletion removing the last exon of EYA1 was identified in an additional proband. Thus in total 5 probands (14%) had deletions of all or part of EYA1. Using a novel disease-gene prioritization strategy that includes network analysis of genes associated with other deletions suggests that SHARPIN (Sipl1) , FGF3 and the HOXA gene cluster may contribute to the pathogenesis of BOR.
array CGH EYA1 copy number variation birth defects Branchio-oto-renal syndrome

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