For patients suspected of having FAP, pathogenic variants in the APC gene were identified in only two patients (c.3183_3187del p.Lys1061_Gln1062insTer, and c.2016_2017del p.His672Ter), while another patient carried a frameshift variant (c.502_503del, p.Ile168SerTer11) in the PTEN gene, indicating Cowden Syndrome. Here, APC is linked to Cowden disease.