Over the past decade, the genes that underlie the development of many human diseases have been identified and the diseases causing mutations within these genes have been unveiled. Many genetic alterations responsible for a variety of human disorders have been characterized. These alterations range from simple Mendelian inherited syndromes to more complex traits such as cancers that involve multiple genetic and environmental factors. Identification and characterization of disease-causing mutations has practical as well as biological implications. As our understanding of these alterations advances, the potential for developing molecular genetic markers with clinical applications increases. This improved understanding also opens new avenues for advances in diagnostic testing, prognostication, and design of preventative strategies or therapeutic interventions. Indeed, direct genetic testing for an inherited colorectal cancer predisposition syndromes, Familial Adenomatous Polyposis (FAP) is currently available to the medical community with appropriate genetic counseling (1 ).
