Testing revealed a pathogenic truncating PTEN mutation, c.388C>T, p.(Arg130*), confirming Cowden syndrome, as well as a pathogenic PMS2 frameshift variant, c.2192_2196del, p.(Leu731Cysfs*3), consistent with an increased risk for Lynch syndrome (hereditary non-polyposis colorectal cancer type 4). Here, PTEN is linked to Cowden disease.