Brca1

Definition

BRCA1 is a gene that produces a protein responsible for repairing DNA damage and maintaining genomic stability. Mutations in the BRCA1 gene significantly increase an individual's risk of developing breast and ovarian cancers, as this gene is classified as a tumor suppressor that plays a critical role in cellular processes related to tumor formation.

5 Must Know Facts For Your Next Test

1. BRCA1 is located on chromosome 17 and works closely with BRCA2 to repair DNA double-strand breaks through homologous recombination.
2. Women with harmful mutations in the BRCA1 gene have a significantly increased risk of developing breast cancer, estimated at 55-72% by age 70.
3. In addition to breast and ovarian cancer, BRCA1 mutations have been linked to increased risks of pancreatic and prostate cancers.
4. Individuals with BRCA1 mutations can undergo genetic testing to determine their risk of developing related cancers, which can inform proactive measures such as enhanced screening or preventive surgeries.
5. The discovery of the BRCA1 gene in the early 1990s has revolutionized our understanding of hereditary cancer syndromes and led to targeted therapies for patients with these mutations.

Review Questions

• How does the BRCA1 gene function as a tumor suppressor, and what are the consequences of its mutations?
  • BRCA1 functions as a tumor suppressor by encoding a protein that repairs DNA damage, specifically double-strand breaks. When mutations occur in the BRCA1 gene, the protein may be dysfunctional or absent, leading to an accumulation of DNA errors. This failure in DNA repair increases the risk of cells becoming cancerous, particularly in breast and ovarian tissues.
• Discuss the role of BRCA1 in DNA repair mechanisms and how its malfunction contributes to cancer development.
  • BRCA1 plays a vital role in homologous recombination, a key DNA repair mechanism that fixes double-strand breaks. When BRCA1 is functioning properly, it helps ensure genetic integrity during cell division. However, when BRCA1 is mutated, this repair process becomes compromised, leading to genomic instability and an increased likelihood of tumorigenesis, particularly in breast and ovarian tissues where these repairs are essential.
• Evaluate the implications of BRCA1 genetic testing for individuals at risk of hereditary breast and ovarian cancers.
  • Genetic testing for BRCA1 mutations has significant implications for individuals with a family history of breast or ovarian cancer. It allows for early identification of those at higher risk, enabling informed decisions regarding preventive measures such as increased surveillance or prophylactic surgeries. Moreover, understanding one’s BRCA1 status can guide treatment options and strategies, particularly with advancements in targeted therapies aimed at patients with specific genetic profiles.

Related terms

Tumor Suppressor Gene: A gene that regulates cell division, repairs DNA mistakes, and prevents the formation of tumors. When these genes are mutated, they can lead to uncontrolled cell growth.

Oncogene: A mutated form of a proto-oncogene that promotes cancerous growth. Unlike tumor suppressor genes, which inhibit cell division, oncogenes encourage it.

DNA Repair Mechanism: The processes by which a cell identifies and corrects damage to its DNA molecules that encode its genome, crucial for maintaining genetic integrity.