Familial adenomatous polyposis: Discovery of a family and its management in a Cancer Genetics Clinic

BACKGROUND. Familial adenomatosis polyposis (FAP) is a prototype model for hereditary cancer. The adenomatous polyposis coli (APC) germline mutation, when identified within an FAP family, provides a powerful basis for early diagnosis. Indeed, the location of intragenic mutations in this large APC gene may distinguish the attenuated FAP variant (mutations proximal to 5') from classic FAP (mutations distal to 5'). METHODS. The authors describe a family with classic FAP that was evaluated at the authors' Hereditary Cancer Prevention Clinic (HCPC). RESULTS. The family history was extended from the original 10 to 32 family members. Medical records confirmed that six were affected with FAP and an additional 10 were reported by family members to be affected. CONCLUSIONS. HCPC clinics provide an invaluable support system for the physician and patient community in which genetic counseling, DNA testing when appropriate, and highly targeted surveillance and management options can be provided to all available members of the extended kindred. Because there are >200 differing hereditary cancer-prone syndromes, most of which will not involve such striking premonitory physical signs as in FAP, such clinics can provide an invaluable service to high risk patients.