Identification of aggressive Gardner syndrome phenotype associated with a de novo APC variant, c.4666dup

Identification of aggressive Gardner syndrome phenotype associated with a de novo APC variant, c.4666dup COLD SPRING HARBOR MOLECULAR CASE STUDIES Kiessling, P., Dowling, E., Huang, Y., Ho, M., Balakrishnan, K., Weigel, B. J., Highsmith, W., Niu, Z., Schimmenti, L. A. 2019; 5 (2)

Abstract

Gardner syndrome describes a variant phenotype of familial adenomatous polyposis (FAP), primarily characterized by extracolonic lesions including osteomas, dental abnormalities, epidermal cysts, and soft tissue tumors. We describe a 2-yr-old boy presenting with a 2-cm soft tissue mass of the forehead. Pathologic evaluation revealed a nuchal-type/Gardner-associated fibroma. Sequencing of the APC gene revealed a pathologic variant c.4666dupA. Parental sequencing of both blood and buccal tissue supported the de novo occurrence of this pathologic variant. Further imaging revealed a number of additional lesions including a large lumbar paraspinal desmoid, a 1-cm palpable lesion posterior to the left knee, firm lesions on bilateral heels, and multiple subdermal lesions. Colonoscopy was negative. This case illustrates a genetic variant of Gardner syndrome resulting in an aggressive early childhood phenotype and highlights the need for an individualized approach to treatment.

View details for DOI 10.1101/mcs.a003640

View details for Web of Science ID 000462938400004

View details for PubMedID 30696621

View details for PubMedCentralID PMC6549566