HNPCC, also known as hereditary nonpolyposis colorectal cancer, is a genetic disorder characterized by an increased risk of developing colorectal and other types of cancers. HNPCC is an inherited condition that is passed down through families in an autosomal dominant pattern, meaning that an affected individual has a 50% chance of passing on the condition to each of their children.
Individuals with HNPCC have a higher predisposition to developing colorectal cancer, as well as other types of cancer including endometrial, ovarian, stomach, urinary tract, pancreatic, and small intestine. The risk of developing these cancers is often younger compared to the general population.
The condition is primarily caused by mutations in specific genes responsible for DNA repair within the cells. Mutations in genes such as MLH1, MSH2, MSH6, PMS2, and EPCAM have been associated with HNPCC. These genes normally help repair errors that occur during DNA replication. However, in individuals with HNPCC, mutations in these genes impair the DNA repair process, leading to an accumulation of genetic changes that can eventually lead to the development of cancer.
Diagnosis of HNPCC is usually made based on family history, with specific diagnostic criteria outlined by medical organizations. Genetic testing for mutations in the associated genes can confirm the diagnosis in some cases.
Management of HNPCC typically involves regular cancer screening, such as colonoscopies and endometrial biopsies, to detect any abnormalities at an early stage. Surgical interventions, such as prophylactic removal of the colon or uterus, may be considered in individuals with a high risk of developing cancer. Additionally, genetic counseling and testing are recommended for individuals with a family history of HNPCC.
