Congenital
hearing loss (
hearing loss that is present at birth) is one of the most prevalent
chronic conditions in children. In the majority of developed countries, neonatal hearing screening programmes enable early detection; early intervention will prevent delays in speech and language development and has long-lasting beneficial effects on social and emotional development and quality of life. A diagnosis of
hearing loss is usually followed by a search for an underlying aetiology. Congenital
hearing loss might be attributed to environmental and prenatal factors, which prevail in low-income settings; congenital
infections, particularly
cytomegalovirus infection, are also a common risk factor for
hearing loss. Genetic causes probably account for the majority of cases in developed countries; mutations can affect any component of the hearing pathway, in particular, inner ear homeostasis (endolymph production and maintenance) and mechano-electrical transduction (the conversion of a mechanical stimulus into electrochemical activity). Once the underlying cause of
hearing loss is established, it might direct therapeutic decision making and guide prevention and (genetic) counselling. Management options include specific antimicrobial
therapies, surgical treatment of
craniofacial abnormalities and implantable or non-implantable hearing devices. An improved understanding of the pathophysiology and molecular mechanisms that underlie
hearing loss and increased awareness of recent advances in genetic testing will promote the development of new treatment and screening strategies.