Genetic Testing for Congenital Bilateral Hearing Loss in the Context of Targeted Cytomegalovirus Screening

Objectives/Hypothesis To determine the prevalence of children with genetic hearing loss who are cytomegalovirus (CMV) positive at birth and the relative proportion of genetic and CMV etiology among children with congenital bilateral hearing loss. Study Design Database review. Methods We performed a review of clinical test results for patients undergoing comprehensive genetic testing for all known hearing loss-associated genes from January 2012 to January 2019. This population was reviewed for reported CMV status and genetic causes of congenital bilateral hearing loss. Results In the OtoSCOPE database, 61/4,282 patients were found to have a documented CMV status, and 661/4282 had documented bilateral congenital hearing loss. Two patients were identified who had both a positive CMV result and a genetic cause for their hearing loss. Forty-eight percent of patients with bilateral congenital hearing loss (320/661) were found to have a genetic etiology. In 62% (198/320), the hearing loss was associated with pathogenic variants in GJB2, STRC, SLC26A4 or an Usher syndrome-associated gene. Conclusions We estimate that similar to 2% of CMV-positive newborns with hearing loss have a known genetic variant as a cause. The subcohort of CMV-positive newborns with symmetric mild-to-moderate bilateral hearing loss will have at least a 7% chance of having pathogenic gene variants associated with hearing loss. In a CMV-positive neonate who failed their newborn hearing screen bilaterally, genetic screening needs to be considered for accurate diagnosis and possible deferment of antiviral treatment.