Disparities in Diagnostic Yield of Genetic Testing in Children and Adolescents With Vascular Malformations and/or Overgrowth: A Single Site Experience.

Genotyping in patients with vascular malformations and/or somatic overgrowth guides precision treatment and is often required for insurance approval of targeted medications. Despite commonly accepted guidelines, uniform implementation of genetic testing in this population is hindered by practical challenges in the clinical setting. Here we compare the molecular diagnostic yield as a function of biopsy source, specifics of genetic testing, and type of insurance. We conducted a retrospective chart review of patients who had genetic testing performed at various commercial or academic laboratories on a biopsy for vascular malformations and/or somatic overgrowth. Diagnostic yield was compared by specimen type, depth of coverage (DOC), and billing method. 70 genetic tests were reviewed for 56 patients. High DOC testing yielded a significantly higher diagnostic rate of 74.3% compared to 20.0% in low DOC testing (p < 0.001). Core biopsies (vs. skin punch) and tests utilizing private insurance/institutional billing (vs. Medicaid) also showed a higher diagnostic yield. In the clinical setting, patients reliant on low DOC commercial testing due to insurance barriers face significantly lower diagnostic rates, underscoring a clear inequity in diagnostic outcomes and demonstrating a need for improved testing access.