Phenotype in 18 Danish subjects with genetically verified CHARGE syndrome

Abstract

CHARGE (coloboma of the eye, heart defects, choanal atresia, retarded growth and development, genital hypoplasia and ear anomalies and/or hearing loss) syndrome is a rare genetic, multiple-malformation syndrome. About 80% of patients with a clinical diagnose, have a mutation or a deletion in the gene encoding chromodomain helicase DNA-binding protein 7 (CHD7). Genotype-phenotype correlation is only partly known. In this nationwide study, phenotypic characteristics of 18 Danish CHD7 mutation positive CHARGE individuals (N = 18) are presented. We studied patient records, clinical photographs, computed tomography, and magnetic resonance imaging (MRI). Information was not available for all traits in all subjects. Therefore, the results are presented as fractions. The following prevalence of cardinal symptoms were found: coloboma, 16/17; heart defects, 14/18; choanal atresia, 7/17; retarded growth and development, 11/13; genital abnormalities, 5/18; ear anomalies, 15/17 and sensorineural hearing loss, 14/15. Vestibular dysfunction (10/13) and swallowing problems (12/15) were other frequent cranial nerve dysfunctions. Three-dimensional reconstructions of MRI scans showed temporal bone abnormalities in >85%. CHARGE syndrome present a broad phenotypic spectrum, although some clinical features are more frequently occurring than others. Here, we suggest that genetic testing for CHD7 mutation should be considered in neonates with a specific combination of several clinical symptoms.