Genetic Evaluation and Counseling in the Context of Early Hearing Detection and Intervention

ABSTRACT

Hearing loss (HL) is an extremely common sensory deficit with heterogeneous etiologies, including genetic and environmental causes. Advances in health care and development of vaccines has resulted in a decline in some of the traditional environmental etiologies for HL such as bacterial meningitis and rubella. However, prematurity and congenital cytomegalovirus (CMV) infections remain in the forefront as environmental causes. Genetic causes account for nearly 60% of all sensorineural HL, which can be associated with other systemic findings in 30% of individuals (syndromic HL) but more often (in 70%) presents as the only clinical finding. Rapid advances in our understanding of the molecular mechanisms for hearing have resulted in the identification and characterization of dozens of genes, mutations of which result in syndromic or nonsyndromic SNHL. Certain genetic changes are more common than others among those with HL, and offering testing for these changes has become the standard of care in clinical practice. The institution of universal audiologic newborn hearing screening nationally allows early identification of HL in infants. It is important for audiologists to be familiar with some of the clinical features often associated with syndromic and nonsyndromic forms of HL, as well as with the process of genetic evaluation and counseling for a child with HL and the child's family.

KEYWORDS

Clinical evaluation - genetic counseling - molecular testing

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