TBX6 and Cowden syndrome 1: The 16p11.2 microdeletion was found to be associated with CS [13], and recent studies demonstrated that a compound inheritance of a TBX6-containing 16p11.2 microdeletion and a TBX6 mutation or hypomorphic haplotype accounted for 5–10% of patients with CS in different populations [14,15,16,17].