Ideal sources for Wikipedia's health content are defined in the guideline Wikipedia:Identifying reliable sources (medicine) and are typically review articles. Here are links to possibly useful sources of information about Polymerase proofreading-associated polyposis.
PubMed provides review articles from the past five years (limit to free review articles)
The TRIP database provides clinical publications about evidence-based medicine.
Other potential sources include: Centre for Reviews and Dissemination and CDC