Hereditary nonpolyposis colorectal cancer (HNPCC) is a hereditary predisposition to colon cancer. HNPCC includes (and was once synonymous with) Lynch syndrome, an autosomal dominant genetic condition that is associated with a high risk of colon cancer, endometrial cancer (second most common), ovary, stomach, small intestine, hepatobiliary tract, upper urinary tract, brain, and skin. The increased risk for these cancers is due to inherited genetic mutations that impair DNA mismatch repair. It is a type of cancer syndrome. Other HNPCC conditions include Lynch-like syndrome, polymerase proofreading-associated polyposis and familial colorectal cancer type X.

Reference
Wiki: Hereditary nonpolyposis colorectal neoplasms