GENETIC-MAPPING OF A 2ND LOCUS PREDISPOSING TO HEREDITARY NONPOLYPOSIS COLON-CANCER

Hereditary colon cancer is caused by mutations in several different loci. The APC gene on chromosome 5 causing adenomatous polyposis coli represents a minority of the inherited colon cancer cases, while hereditary-non polyposis colon cancer (HNPCC) may cause five percent of all human colon cancer. One gene causing HNPCC was recently mapped to chromosome 2 but the same study also showed that at least one additional locus may cause HNPCC. We now present tight linkage between a polymorphic marker on the short arm of chromosome 3 and the disease locus, and find that these families also manifest signs of a general DNA replication disorder.