Genetic Counseling in Hereditary Nonpolyposis Colorectal Cancer
January 01, 1996ByFred H. Menko, MD, PhD|P. Meera Khan, MD, PhD|Hans F. A. Vasen, MD, PhD|M. H. Oosterwijk, PhD
Recent identification of gene mutations responsible for hereditary nonpolyposis colorectal cancer (HNPCC) has made possible the presymptomatic diagnosis of at-risk family members. If DNA testing shows that a family member is a gene carrier, that individual's lifetime cancer risk is approximately 90%. If the test is negative, the family member's cancer risk drops to that of the general population.