Pathogenic variants of the PTEN gene may include large deletions, small intragenic deletions/insertions and missense, nonsense, and splice site variants, and these have been described in all nine exons of the gene.2,6–8) Unlike other genes, virtually all germline PTEN missense mutations in the coding region are believed to be pathogenic.6,9) Furthermore, no clear genotype–phenotype correlation has been found in PHTS, although several studies have examined the correlation between CS phenotypes and PTEN gene variant sites.2,4,10,11). Here, PTEN is linked to Cowden syndrome 1.