Hereditary and Genetic Colorectal Conditions
The two most common hereditary syndromes linked to colorectal cancer are: familial adenomatous polyposis (FAP) and Lynch syndrome.
Familial adenomatous polyposis (FAP): FAP is an autosomal dominant genetic condition characterized by a mutation in the APC (adenomatous polyposis coli) gene, where an individual develops more than 100 adenomatous polyps usually at young adulthood between the ages of 20-35 years. If these polyps are left untreated, there is a very high likelihood of developing colorectal cancer.
Lynch Syndrome: Lynch syndrome is also known as hereditary non-polyposis colon cancer (HNPCC) due to a mutation in one of the DNA mismatch repair genes including MLH1, MSH2, MSH6 and PMS2. Patients with Lynch syndrome have an increased risk of developing colorectal cancers at a younger age and other cancers such as endometrial, ovarian, and stomach.
Young individuals with a strong family history of cancers, especially associated with a younger age at diagnosis, may be at risk of hereditary cancer syndromes. Symptoms such as blood in stools, abdominal cramps, unexplained weight loss, fatigue, nausea and vomiting, diarrhoea and irregular periods of constipation, may warrant further investigation.
The management of hereditary colorectal conditions is highly specialised and individualised, depending on factors such as the specific genetic mutation, age and health condition of the patient, and stage of disease. Surgery may be required to remove part or whole of the colon.