Cowden disease is a genetic disorder associated with a mutation of the PTEN gene and is known to be easily complicated by generalized vascular malformations and malignant tumors.
Along with previous reports, this case suggests that acral plexiform PENs may be an early, highly specific finding in CS and highlights the importance of screening these patients for PTEN mutation.
Here we report that a missense mutation in PTEN, PTEN-G129E, which is observed in two Cowden disease kindreds, specifically ablates the ability of PTEN to recognize inositol phospholipids as a substrate, suggesting that loss of the lipid phosphatase activity is responsible for the etiology of the disease.
Germline mutations in PTEN can predispose people to Cowden syndrome (CS) and Bannayan-Ruvalcaba-Riley (BRR) syndrome, rare, autosomal dominantly inherited neoplastic disorders.
Due to the chromosome 10 deletion involving contiguous portions of BMPR1A and PTEN in our patient, he may be at risk for CS associated cancers and features, in addition to the polyps associated with JPS.
In addition, PTEN was identified as the susceptibility gene for two hamartoma syndromes: Cowden disease (CD; MIM 158350) and Bannayan-Zonana (BZS) or Ruvalcaba-Riley-Smith syndrome (MIM 153480).
Here, we describe a novel PTEN splicing site mutation in a family with classical Cowden disease and we studied benign skin lesions typical for Cowden disease for loss of heterozygosity.
Phosphatase and tensin homolog (PTEN) hamartoma tumor syndrome (PHTS) encompasses several rare disorders linked to mutations of the PTEN gene, including Cowden disease (CD) and Bannayan-Riley-Ruvalcaba syndrome (BRRS).
A PTEN mutation, c.1003C>T p.(Arg335Ter), was subsequently identified as the cause of Cowden syndrome in another family member (a nephew) with dysplastic gangliocytoma of the cerebellum (Lhermitte-Duclos disease), and genetic testing in the proband's daughter indicated that he was an obligate carrier of the mutation.
Caveolin-1 is of particular functional interest because it has been shown to interact with PTEN, the tumor suppressor gene mutated in Cowden syndrome, an inherited multiple hamartoma syndrome that includes predisposition to FTC.
These results support the notion that PTEN haploinsufficiency plays a causal role in CD, LDD and BZS pathogenesis, and demonstrate that Pten is a tumour suppressor essential for embryonic development.
Germline mutations of PTEN give rise to Cowden Disease (CD), an autosomal dominantly-inherited cancer syndrome which predisposes to increased risk of developing breast and thyroid tumors.
The diagnosis of Cowden syndrome with PTEN gene mutation, linked to higher risk of neoplasia and occurrence of hamartomatous lesions characteristic of the Lhermitte-Duclos disease (LDD), was confirmed by genetic investigation.