Juvenile polyposis syndrome (JPS) is a rare autosomal dominant disorder predisposing to gastrointestinal hamartomatous polyps and cancer with a pathogenic SMAD4 or BMPR1A germline mutation (1st-hit) being identified in about 40-50% of patients.
Alternatively, because simultaneous disruption of both the PTEN and TGF-β/SMAD4 pathways is associated with development of esophageal cancer in a mouse model and because SMAD4 mutations cause gastrointestinal hamartomas in juvenile polyposis syndrome, the SMAD7 mutation may represent an additional modifier of these individuals' PTEN-mutant phenotype.
Patients with juvenile polyposis syndrome and germline SMAD4 or BMPR1A mutations were identified from a prospectively maintained institutional registry.
Mutations in SMAD4 have been associated with juvenile polyposis syndrome and combined juvenile polyposis/hereditary hemorrhagic telangiectasia syndrome.SMAD4 is part of the SMAD gene family.
This study evaluated the differential impact of SMAD4 and BMPR1A gene mutations on cancer risk and oncological phenotype in patients with juvenile polyposis syndrome.
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 children with SMAD4 mutation and juvenile polyposis, this overlap syndrome needs to be considered in the differential diagnosis and prompt the clinician to look for telangiectasias on examination and consider surveillance imaging to look for arteriovenous malformations.
Juvenile polyposis syndrome (JPS) is a rare autosomal dominant disorder predisposing to gastrointestinal hamartomatous polyps and cancer with a pathogenic SMAD4 or BMPR1A germline mutation (1st-hit) being identified in about 40-50% of patients.
SMAD4 carriers should be managed for juvenile polyposis and hereditary hemorrhagic telangiectasia because symptoms of both conditions are likely yet unpredictable.
Genetic analysis of the CDC73 gene [for Hyperparathyroidism-jaw tumor (HPT-JT)], MEN1 for Multiple Endocrine Neoplasia Type1, CDKN1B for MEN4, SDHB and SDHD for Paraganglioma/Pheochromocytoma susceptibility, VHL for von Hippel-Lindau Syndrome, BMPR1A and SMAD4 for Juvenile Polyposis Syndrome (JPS) (sequencing and MLPA), karyotype and array CGH (44 K) were all normal.
In addition to this syndrome, gastric cancer risk is elevated in Lynch syndrome associated with germline mutations in DNA mismatch repair genes and microsatellite instability, in hereditary breast and ovarian cancer syndrome due to germline BRCA1 and BRCA2 mutations, in familial adenomatous polyposis caused by germline APC mutations, in Li-Fraumeni syndrome due to germline p53 mutations, in Peutz-Jeghers syndrome associated with germline STK11 mutations, and in juvenile polyposis syndrome associated with germline mutations in the SMAD4 and BMPR1A genes.
The vascular disorder Hereditary Hemorrhagic Telangiectasia (HHT) is in general an inherited disease caused by mutations in the TGF-β/BMP receptors endoglin or ALK1 or in rare cases by mutations of the TGF-β signal transducer protein Smad4 leading to the combined syndrome of juvenile polyposis and HHT.