A Novel Germline Mutation in Exon 10 of the SMAD4 Gene in a Familial Juvenile Polyposis

Familial juvenile polyposis (FJP) is a rare autosomal dominant hereditary disorder that is characterized by the development of multiple distinct juvenile polyps in the gastrointestinal tract and an increased risk of cancer. Recently, germline mutations, including mutations in the SMAD4, BMPR1A, PTEN and, possibly, ENG genes, have been found in patients with juvenile polyps. We herein report a family with juvenile polyposis syndrome (JPS) with a novel germline mutation in the SMAD4 gene. A 21-year-old man presented with rectal bleeding and was found to have multiple polyps in his stomach, small bowel, and colon. His mother had a history of gastrectomy for multiple gastric polyps with anemia and a history of colectomy for colon cancer. A review of the histology of the polyps revealed juvenile polyps in both patients. Subsequently, mutation screening in DNA samples from the patients revealed a germline mutation in the SMAD4 gene. The pair had a novel mutation in exon 10 (stop codon at tyrosine 413). To our knowledge, this mutation has not been previously described. Careful family history collection and genetic screening in JPS patients are needed to identify FJP, and regular surveillance is recommended.

Juvenile polyposis syndrome / Síndrome de poliposis juvenil

Juvenile polyposis syndrome (JPS) is rare and is present when there are multiple juvenile polyps in the gastrointestinal tract, usually the colon. The importance of this condition is the association with the development of colorectal and upper gastrointestinal cancer at a young age. We report the case of a 21- year old male with a two-year history of intermittent rectal bleeding and anal protrusion. Colonoscopy revealed multiple pedunculated cherry red polyps mainly in the left colon. Histology confirmed juvenile polyps. Juvenile polyposis syndrome should be considered in young patients with colonic symptoms, especially rectal bleeding. It is important to distinguish between patients with JPS and patients with an isolated harmatomatous juvenile polyp.

El síndrome de poliposis juvenil (SPJ) es raro y se presenta en forma de pólipos juveniles múltiples en el tracto gastrointestinal, generalmente en el colon. La importancia de esta condición estriba en su asociación con el desarrollo del cáncer colorectal y el cáncer gastrointestinal superior en la edad juvenil. Reportamos el caso de un joven de 21 años con una historia de dos años de sangramiento rectal intermitente y protrusión anal. La colonoscopía reveló múltiples pólipos pedunculados de color rojocereza, principalmente en el colon izquierdo. La histología confirmó la presencia de pólipos juveniles. El síndrome del poliposis juvenil debe ser considerado en los pacientes jóvenes con síntomas colónicos, especialmente cundo hay sangramiento rectal. Es importante distinguir entre pacientes con SPJ y pacientes con un pólipo juvenil harmatomatoso aislado.