(hu-RED-i-tare-ee non-pah-li-PO-sis) An inherited condition in which carriers develop a few (not thousands like those familial polyposis) colon polyps at a younger age than do people without the mutation. Since there is an 80-percent likelihood that a carrier will develop an intestinal tumor during his or her lifetime, people with family history of the disease should undergo regular colonoscopies and abdominal imaging to aid in early detection of polyps. Women with HNPCC have a significantly higher risk of developing cancer of the endometrium, the upper lining of the uterus.

HNPCC. An inherited disorder in which affected individuals have a higher-than-normal chance of developing colorectal cancer and certain other types of cancer, often before the age of 50. Also called Lynch syndrome.