Germline PTEN Mutation Analysis for PTEN Hamartoma Tumor Syndrome.

Clinically, deregulation of PTEN function resulting in reduced PTEN expression and/or activity is implicated in human disease. Cowden syndrome (CS) is an autosomal dominant disorder characterized by benign and malignant tumors. CS-related individual features occur commonly in the general population. Approximately 25 % of patients diagnosed with CS have pathogenic germline PTEN mutations, which increase lifetime risks of breast, thyroid, uterine, renal, and other cancers. PTEN testing and intensive cancer surveillance allow for early detection and treatment of these cancers for mutation-positive patients and their relatives. In this methods chapter, we highlight our protocol for identifying patients at risk of harboring a germline PTEN mutation.