Hereditary colorectal cancer: keeping it in the family--the bowel cancer story.

Up to 20% of colorectal cancers are thought to have a genetic component. Several familial syndromes are known to confer an increased risk for colorectal cancer. Advances in our understanding of these syndromes has improved the care delivered to, and the overall survival of, these patients. Genetic testing has great potential to further improve detection and direct subsequent preventative measures. The diagnosis, management and surveillance issues relating to some of the more commonly encountered syndromes - in particular Familial Adenomatous Polyposis and Hereditary Non-Polyposis Colorectal Cancer - are reviewed.