Amanda Moccia, Anshika Srivastava, Jennifer M. Skidmore, John A. Bernat, Marsha Wheeler, University of Washington Center for Mendelian Genomics, Jessica X.Chong, Deborah Nickerson, Michael Bamshad, Margaret A. Hefner, Donna M. Martin, Stephanie L. Bielas

PurposeCHARGE syndrome is an autosomal-dominant, multiple congenital anomaly condition characterized by vision and hearing loss, congenital heart disease, and malformations of craniofacial and other structures. Pathogenic variants in CHD7, encoding adenosine triphosphate-dependent chromodomain helicase DNA binding protein 7, are present in the majority of affected individuals. However, no causal variant can be found in 5-30% (depending on the cohort) of individuals with a clinical diagnosis of CHARGE syndrome.MethodsWe performed whole-exome sequencing (WES) on 28 families from which at least one individual presented with features highly suggestive of CHARGE syndrome.ResultsPathogenic variants in CHD7 were present in 15 of 28 individuals (53.6%), whereas 4 (14.3%) individuals had pathogenic variants in other genes (RERE, KMT2D, EP300, or PUF60). A variant of uncertain clinical significance in KDM6A was identified in one (3.5%) individual. The remaining eight (28.6%) individuals were not found to have pathogenic variants by WES.ConclusionThese results demonstrate that the phenotypic features of CHARGE syndrome overlap with multiple other rare single-gene syndromes. Additionally, they implicate a shared molecular pathology that disrupts epigenetic regulation of multiple-organ development.GENETICS in MEDICINE advance online publication, 4 January 2018; doi:10.1038/gim.2017.233.