Factsheet
Condition:
Cowden syndrome (PTEN hamartoma syndrome)
Inheritance:
Autosomal dominant
Genetic Etiology:
The PTEN hamartoma syndrome is a group of related disorders, including Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome, as well as a proportion of cases of Proteus syndrome or a Proteus-like syndrome, all due to mutations in the PTEN gene (encodes phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase). Most pathogenic mutations involve loss of function.
Frequency:
1/200,000 (may be underdiagnosed)
Clinical features:
The PTEN hamartoma syndromes are a group of closely related hamartoneoplastic disorders. Features of Cowden syndrome include a set of lesions on the skin and mucous membranes, including facial tricholemmomas, acral keratoses, and papillomas; macrocephaly; intestinal polyps; breast, thyroid, and endometrial cancers. Bannayan-Riley-Ruvalcaba syndrome includes macrocephaly, large birth weight; gastrointestinal polyps; lipomas; developmental delay. Proteus syndrome includes epidermal nevi, connective tissue overgrowth; oseomas.
Management:
Symptomatic treatment and surveillance for development of cancer.
Genetic counseling:
Recurrence risk of Cowden or Bannayan-Riley-Ruvalcaba syndrome is according to autosomal dominant inheritance. Cases occur both within families and sporadically. Most cases of Proteus syndrome are sporadic. Genetic testing for PTEN mutation is available.