Cowden Syndrome (CS) and Bannayan–Riley–Ruvalcaba syndrome (BRRS) are associated to PTEN gene mutations, but also Proteus/Proteus-like syndrome, autism spectrum disorders with macrocephaly, Lhermitte–Duclos syndrome, and juvenile polyposis of infancy have been linked to PTEN gene mutations. Here, PTEN is linked to Cowden disease.