Factors influencing somatic genetic testing for vascular anomalies at 2 academic centers.

Vascular anomalies (VAs) are rare disorders with abnormal development of blood and lymphatic vasculature and surrounding tissues. Understanding the genetic etiology of VAs guides treatment with targeted inhibitors. This study compares patterns and outcomes of genetic testing in VA populations at 2 centers. Of 421 patients (mean age, 10 years; 55.6% female), 61.7% underwent prior authorization (PA) for genetic testing, 84% had their testing approved, 93% completed the testing. About 70% of the completed tests had pathogenic or likely pathogenic results. A positive result was not associated with sample type (skin biopsy vs surgical pathology; fresh vs archived). Greater odds of initiating PA were associated with presence of skin findings and male sex, whereas lower odds were associated with higher Area Deprivation Index at 1 center. This study highlights that genetic testing effectively finds causative variants, but not all patients can complete it and advocates for increased access to genetic testing.