Individuals with the BRCA1 mutation have a substantially increased risk of developing Breast and Ovarian Cancer, often before the age of 50. 80% of the patients with a family history of Breast Cancer and/or Ovarian Cancer carry the BRCA1/2 mutation. However, early detection followed by preventive and prophylactic methods have been shown to reduce the risk by as much as 90%. Zentrogene a comprehensive test for Breast and Ovarian Cancers by covering 21 (including BRCA1/2) cancer-related genes, thereby allowing an accurate prediction of the disease risk.
FAP is caused by mutations of the APC gene while HNPCC is associated with mutations of MMR (MLH1, MSH2, MSH6, PMS2). Left untreated, an FAP patient has a 93% chance of developing CRC before the age of 50; and carriers of the MMR mutations have an 80% lifetime risk of CRC with an average onset age at 44 years. Genetic testing for Hereditary Colorectal Cancer detects mutations in 14 disease-related genes including APC and MMR, which enables early prediction of the disease risk and effective follow-up interventions.
A frameshift (c.335_335delA) was detected in the region of no.5 exon of, leading to protein synthesis termination ahead of time. This coding area is supposed to code 1863 amnio acid, however in this case, it only codes 117 amnio acid due to this frameshift, which eventually causes protein inactivation, losing its function in DNA damage repairmen, tumor suppression, and signal transmisson.
According to A’s family history, her mother and sister are also recommended to take validation of this mutation. The result shows that both of them carry the same frameshift mutation.
Finally, the real cause of cancer in this family is discovered and at the same time, test result prompts that her sister is at increased risk of developing breast/ovarian or related cancers.