Familial adenomatous polyposis at the Tel Aviv Medical Center: demographic and clinical features

Familial adenomatous polyposis (FAP) is an uncommon, but widespread genetic disorder that develops multiple colonic adenomatous polyps and, if untreated, can lead to large bowel cancer. Little is known about its occurrence and characteristics in the Israeli population.

To evaluate FAP prevalence, phenotypic manifestations and compliance for diagnosis and follow-up in our registry.

Since 1993 approximately one-half of FAP patients in Israel have been seen and followed-up by us before and/or after colectomy. They and their families were encouraged to have mutation analysis, genetic and/or endoscopic screening.

37 pedigrees were identified, including 2 non-Jewish. The Jewish ethnic distribution was similar to that of the general population and the point prevalence rate estimated as 28.4/one million Jewish inhabitants. There were 461 first-degree relatives at-risk for FAP. Genetic screening was completed and successful in 28 pedigrees (87.5%), and 73 FAP patients entered the registry. Marked intra- familial phenotypic variations with minimal disease manifestation were noted in 11 patients belonging to 4 pedigrees. Cancer occurred in 15.1% (11 patients), in 10 before FAP diagnosis or during follow- up elsewhere, but one non-compliant patient developed duodenal cancer. One other patient died from a massive, neglected, intra- abdominal desmoid. Compliance for evaluation and follow-up of pedigree members and individual FAP patients was inadequate in 29% and 27%, respectively.

FAP occurs in the Israeli Jewish population at the expected rate, but is inadequately recognized in non-Jews. The inadequate compliance for screening and post-surgical follow-up needs to be addressed by educating the public, health care workers and Health Insurers.