Colon cancer, the second leading cause of cancer deaths in the United States, is responsible for more than 57 000 deaths annually. More than 150 000 new cases are reported each year. While environmental risk factors remain under investigation as potential triggers of DNA injury that underlies carcinogenesis, the nature of the DNA lesions has been a focus of molecular medicine. The uncontrolled cell growth that leads to the development of colon cancer is now believed to result from a series of inherited or acquired mutations in DNA repair genes, oncogenes, and tumor suppressor genes.
Hereditary nonpolyposis colon cancer, the most common form of inherited colon cancer, has been linked to a defective DNA repair gene that has been localized to the short arm of chromosome 2.1,2 The defective gene appears to be carried by one in every 200 persons and may be responsible for as much as 15%
Koff RS. Gastroenterology and Hepatology. JAMA. 1995;273(21):1679-1680. doi:10.1001/jama.1995.03520450049024