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.
We report on a patient with a contiguous interstitial germline deletion of chromosome 10q23, encompassing BMPR1A and PTEN, with clinical manifestations of juvenile polyposis and minor symptoms of Cowden syndrome (CS) and Bannayan-Riley-Ruvalcaba syndrome (BRRS).
However, the mutation analysis in the PTEN gene and the two other genes involved in juvenile polyposis, namely BMPR1A and MADH4 (SMAD4), in the Cowden syndrome patient failed to show any pathogenic mutation.
This opens up a new mode of regulating PTEN activity to be investigated further and may explain why BMPR1A can act as a minor susceptibility gene for PTEN mutation negative Cowden syndrome.
Thus, germline BMPR1A mutations cause a significant proportion of cases of JPS and might define a small subset of cases of CS/BRRS with specific colonic phenotype.
Thus, germline BMPR1A mutations cause a significant proportion of cases of JPS and might define a small subset of cases of CS/BRRS with specific colonic phenotype.