Development of in-house genetic screening for pediatric hearing loss

Objectives To evaluate the efficiency of in-house genetic testing for mutations causing the most common types of inherited, nonsyndromic, sensorineural hearing loss (SNHL). Methods Retrospective cohort study of 200 patients at a single, pediatric medical center with suspected or confirmed hearing loss who underwent either send out vs in-house genetic testing for mutations in GJB2/GJB6, SLC26A4, and MTRNR1. Primary outcome measure was the difference in mean turnaround time for send-out vs in-house genetic testing. Additional outcomes included associations between audiometric findings and genetic test results. Results One hundred four send-out tests were performed between October 2010 and June 2014, and 100 in-house tests were performed between November 2014 and November 2016. The mean turnaround time for send-out testing was 53.7 days. The mean turnaround time for in-house testing was 18.9 days. This difference was statistically significant (P < .001). The largest component of turnaround time was the amount of time elapsed between receipt of specimen in the lab and final test result. These intervals were 47.0 and 18.3 days for send-out and in-house tests, respectively. Notably, the longest turnaround time for in-house testing (43 days) was less than the average turnaround time for send-out testing. In addition, we identified two simple audiometric parameters (ie, bilateral newborn hearing screen referral and audiometry showing symmetric SNHL) that may increase diagnostic yield of genetic testing. Conclusions The development of in-house genetic testing programs for inherited SNHL can significantly reduce testing turnaround times. Newborn hearing screening and audiometry results can help clinicians identify patients most likely to benefit from genetic testing.