The Clinical Spectrum of Mutations.

is a tumor suppressor gene that classically dampens the PI3K/AKT/mTOR growth-promoting signaling cascade. dysfunction causes dysregulation of this and other pathways, resulting in overgrowth. Cowden syndrome, a hereditary cancer predisposition and overgrowth disorder, was the first Mendelian condition associated with germline mutations. Since then, significant advances by the research and medical communities have elucidated how clinical phenotypic manifestations result from the underlying germline mutations. With time, it became evident that mutations can result in a broad phenotypic spectrum, causing seemingly disparate disorders from cancer to autism. Hence, the umbrella term of hamartoma tumor syndrome (PHTS) was coined. Timely diagnosis and understanding the natural history of PHTS are vital because early recognition enables gene-informed management, particularly as related to high-risk cancer surveillance and addressing the neurodevelopmental symptoms.