Final answer:
BRCA1 and BRCA2 gene mutations lead to poor DNA repair and an increased risk of breast and ovarian cancers. Testing for these mutations is crucial for guiding medical care and cancer screening for those with a family history of inherited cancer. While inheriting the mutation significantly raises cancer risk, it does not guarantee cancer will develop.
Step-by-step explanation:
The BRCA1 and BRCA2 genes play a crucial role in repairing DNA and maintaining the stability of a cell's genetic information. When these genes are mutated, their ability to repair DNA is compromised, leading to an increased risk of developing certain cancers, particularly breast and ovarian cancer. These mutations are inherited and can increase an individual's cancer risk significantly.
Testing for BRCA mutations can provide definitive results on whether someone carries these genetic alterations. If a mutation is present, it implies a higher risk of developing cancer and thus necessitates more rigorous and frequent screenings. An individual's personal or family history of cancer can suggest the presence of these mutations, hence the importance of genetic counselling and cancer screening for those at risk.
It's important to note that inheriting the mutation does not guarantee the development of cancer; it only increases the likelihood. Environmental factors also contribute to cancer risk, and not everyone with the mutation will develop cancer. However, knowledge about the presence of a BRCA mutation can guide in taking preventative measures, such as increased monitoring and potentially prophylactic surgeries.
Rebecca's family history highlights the variability in mutation inheritance and expression. Despite a family history of cancer, Rebecca's mother did not develop the disease, which is possible due to the nature of genetic inheritance and expression. Understanding why certain mutations are more prevalent in some ethnic groups can assist in targeting cancer prevention strategies.