Atypical CHARGE Syndrome with Auditory Neuropathy and Vestibulocochlear Nerve Aplasia: A Case Report

Abstract

The CHARGE syndrome represents a rare congenital disorder characterised by a constellation of ocular, auditory, vestibular, craniofacial, and developmental anomalies, most commonly linked to pathogenic variants in the CHD7 gene. The phenotypic spectrum is notably wide, and advances in molecular diagnostics have increasingly revealed incomplete and atypical presentations. This report describes a 17-month-old male child presenting with developmental delay, ocular coloboma, inner ear malformations, vestibulocochlear nerve aplasia, and Auditory Neuropathy Spectrum Disorder (ANSD), alongside absence of choanal atresia, cardiac, or renal anomalies. Whole exome sequencing identified a pathogenic CHD7 mutation, confirming atypical CHARGE syndrome. This case is notable for the rare coexistence of ANSD with unilateral vestibulocochlear nerve aplasia in genetically confirmed atypical CHARGE syndrome. The absence of classical features such as choanal atresia, cardiac, and renal anomalies further emphasises the expanding phenotypic spectrum. Radiological-audiological discordance underscores the importance of detailed neuroimaging in children with unexplained hearing loss. This report highlights the critical role of whole exome sequencing in diagnosing incomplete presentations of CHARGE syndrome and guiding multidisciplinary management.