Barriers to Genetic Testing in Vascular Malformations

Abstract

Importance: Vascular malformations (VMs) are rare disorders of vasculogenesis associated with substantial morbidity. Improved understanding of their genetic basis is increasingly guiding management, but logistical barriers to obtaining genetic testing in patients with VM may constrain treatment options.

Objectives: To examine the institutional mechanisms for and obstacles to obtaining genetic testing for VM.

Design, setting, and participants: This survey study invited members of the Pediatric Hematology-Oncology Vascular Anomalies Interest Group, representing 81 vascular anomaly centers (VACs) serving individuals up to 18 years of age, to complete an electronic survey. Respondents were mostly pediatric hematologists-oncologists (PHOs) but included geneticists, genetic counselors, clinic administrators, and nurse practitioners. Responses that were received between March 1 and September 30, 2022, were analyzed with descriptive methods. Requirements for genetic testing by several genetics laboratories were also reviewed. Results were stratified by size of the VAC.

Main outcomes and measures: Vascular anomaly center and associated clinician characteristics and practice patterns for ordering and obtaining insurance approval for genetic testing for VMs were collected.

Results: Responses were received from 55 of 81 clinicians, for a response rate of 67.9%. Most respondents were PHOs (50 [90.9%]). Most respondents (32 of 55 respondents [58.2%]) replied that they order genetic testing on 5 to 50 patients per year and reported a genetic testing volume increase of 2- to 10-fold over the past 3 years (38 of 53 respondents [71.7%]). Most testing was ordered by PHOs (35 of 53 respondents [66.0%]), followed by geneticists (28 [52.8%]) and genetic counselors (24 [45.3%]). In-house clinical testing was more common at large and medium-sized VACs. Small VACs were more likely to use oncology-based platforms, which potentially miss low-frequency allelic variants in VM. Logistics and barriers varied by size of the VAC. Obtaining prior authorization was the duty shared among PHOs, nurses, and administrative staff, but the burden of insurance denials and appeals were on PHOs (35 of 53 respondents [66.0%]). Lack of administrative support; unclear institutional, insurance, and laboratory requirements; and lack of clinician education were barriers to genetic testing at VACs of all sizes. The effort to obtain genetic testing for patients with VM, compared with patients with cancer, was perceived as excessive, despite genetic testing being considered standard of care for this population.

Conclusions and relevance: Results of this survey study showed the barriers to genetic testing for VM across VACs, described differences between VACs based on size, and proposed multiple interventions to support clinicians ordering genetic testing for VM. The results and recommendations should have broader application to clinicians caring for patients for whom molecular diagnosis is important to medical management.

Figure.. Reference Laboratories for Genetic Testing in Vascular Malformations

Dark blue bars represent where a tissue specimen was sent for somatic testing, and light blue bars represent where peripheral blood samples were sent for germline testing. Other less frequently used laboratories included Prevention Genetics, GeneDx, ARUP, Ambry Genetics, Mayo Medical Laboratories, Blueprint Genetics, Caris, and Cincinnati Children’s Molecular Genetics Laboratory.