The effect of sample type on genetic testing completion in pediatric congenital hearing loss patients

Congenital pediatric hearing loss can be linked to a genetic cause in about 60% of cases. Genetic testing (GT) for this condition can be complicated by the availability of blood draw services and the patient's amenability to this procedure. The primary objective of this study was to assess whether GT sample collection method influences the percentage of completed tests in pediatric patients with congenital, non-syndromic sensorineural hearing loss. This was a retrospective chart review of patients at a tertiary pediatric otolaryngology clinic who had GT ordered through blood draw from May 2022-April 2023 and patients who had GT ordered through buccal swab from June 2023-May 2024. Patients were offered a testing method based on availability at our institution during the time period studied. The primary endpoint was completion of GT. Additional data collected included demographic patient characteristics, average turnaround time for GT completion, and GT results. Each cohort had a GT completion percentage of approximately 93%. Almost twice as many patients had GT ordered via buccal swab (148/227) than blood sample (79/227: p < 0.05). There was no difference in GT results between cohorts. The observed similarities in GT completion of the cohorts in this study suggests that barriers to GT completion may not be the sample type alone, but rather a more complex set of factors that may affect family decision-making.