Polymerase proofreading-associated polyposis

Polymerase proofreading-associated polyposis (PPAP) is an autosomal dominant hereditary cancer syndrome, which is characterized by numerous polyps in the colon and an increased risk of colorectal cancer.^[1] It is caused by germline mutations in DNA polymerase ε (POLE) and δ (POLD1).^[1] Affected individuals develop numerous polyps called colorectal adenomas. Compared with other polyposis syndromes, Polymerase proofreading-associated polyposis is rare. Genetic testing can help exclude similar syndromes, such as Familial adenomatous polyposis and MUTYH-associated polyposis. Endometrial cancer, duodenal polyps and duodenal cancer may also occur.^[2]

Polymerase proofreading-associated polyposis
Other names	PPAP
Specialty	Medical genetics, gastroenterology
Symptoms	Asymptomatic, often develop multiple colorectal adenomas
Complications	Colorectal, duodenal, & endometrial cancer
Diagnostic method	Colonoscopy
Differential diagnosis	Familial adenomatous polyposis, MUTYH-associated polyposis
Treatment	Colonoscopy Polypectomy
Frequency	Rare

Genetics

PPAP is an autosomal dominant syndrome caused by germline mutations in DNA polymerase ε (POLE) and δ (POLD1).^[1] The penetrance of the condition appears high.^[3]