Barriers to Genetic Testing in Vascular Malformations.

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.

Prenatal phenotype of 47, XXY (Klinefelter syndrome).

OBJECTIVE: There is a paucity of knowledge regarding the prenatal presentation of Klinefelter syndrome, or 47, XXY. Accurate prenatal counseling is critical and in utero diagnosis is currently limited by a poor understanding of the prenatal phenotype of this condition. METHODS: This is a case series of fetuses with cytogenetically confirmed 47, XXY in the prenatal period or up to age 5 years, with prenatal records available for review from four academic institutions between 2006 and 2019. Ultrasound reports were reviewed in detail to assess for increased nuchal translucency and structural abnormalities. Additionally, we reviewed results of cell-free DNA and serum analyte testing when performed to inform our understanding of the detection of fetal 47, XXY through standard genetic screening tests. RESULTS: Forty-one cases with confirmed cytogenetic diagnosis of 47, XXY and prenatal records available for review were identified: 37 had a prenatal diagnosis and 4 had a postnatal diagnosis. Nuchal translucency was increased ≥3.0 mm in 23.1% (6/26) of cases with a documented measurement. In 29.2% (7/24) of cases with a second trimester anatomical ultrasound available for review, a fetal abnormality was identified (3 brain anomalies, 1 cardiac abnormality, 1 echogenic bowel, and 2 limb abnormalities). Among those who had cell-free DNA and serum analytes performed, 92.6% (25/27) and 36.3% (4/11) had an abnormal result respectively. CONCLUSION: This case series expands our knowledge of the prenatal presentation of 47, XXY by identifying first and second trimester fetal sonographic abnormalities. Prenatal identification of this condition enables accurate counseling, focused prenatal management, and early postnatal interventions to ameliorate some of the known complications.