Identifying Genetic Mutations in Vascular Anomalies Using a Sequencing Panel for Childhood Cancers: A Pilot Study

Abstract

Introduction: Genetic mutations have been identified in the pathogenesis of vascular anomalies. Due to overlaps in genetic variants causing vascular anomalies and cancer, we used a next-generation sequencing panel for genomic profiling of childhood cancers to detect somatic mutations in children with vascular anomalies. We aim to review the utility of an oncology panel for the molecular diagnosis of vascular anomalies. Methods: Nine patients with histologically confirmed vascular anomalies were included. DNA was extracted from formalin-fixed paraffin-embedded tissue specimens obtained from affected tissue following diagnostic punch biopsies of the skin and core biopsies of the vascular malformation or tumor during sclerotherapy or surgical excision. Molecular analysis of the tissue samples was performed using AmpliSeq for Childhood Cancer DNA Assay Panel. Results: Two patients had antenatally detected vascular anomalies. The median age at diagnosis for the remaining patients was 7.0 years (IQR, 0.6–10.0 years). Seven were diagnosed with vascular malformations, while 2 had vascular tumors. Pathological somatic mutations were identified in 4 patients, leading to a diagnostic yield of 44.4%. Two different PIK3CA mutations were identified in 3 cases: 1 in a case of macrocystic lymphatic malformation, the other in a case of Congenital Lipomatous Overgrowth, Vascular malformations, Epidermal nevus, Spinal/Skeletal anomalies syndrome and Klippel–Trenaunay syndrome. BRAF mutation was identified in a patient with a veno-lymphatic malformation. Conclusion: An oncology next-generation sequencing panel can be used for genetic profiling of vascular anomalies. However, a more customized and sensitive panel may be of better diagnostic yield, as detection of somatic mutations in vascular anomalies is challenging due to tissue mosaicism, low-abundant genetic variants, and specimen limitations.