What are the major breast cancer susceptibility genes?

• A. BRCA1 and BRCA2
• B. TP53 and CHEK2
• C. HER2 and ESR1
• D. BRCA1 and APC

Answer: (A)

The major breast cancer susceptibility genes are BRCA1 and BRCA2. These two genes play a crucial role in the body's ability to repair DNA breaks, and mutations in these genes significantly increase the risk of developing breast and ovarian cancer. Individuals who inherit harmful mutations in either BRCA1 or BRCA2 have a much higher lifetime risk of breast cancer compared to the general population. This association has been well-established through extensive research, making these genes critical in understanding hereditary breast cancer syndromes and guiding genetic testing and risk assessment.

Other options, while they include important genes known to be associated with breast cancer, do not primarily represent the major susceptibility genes. For instance, TP53 and CHEK2 are involved in cancer risk but are considered less prominent than BRCA1 and BRCA2 in terms of hereditary breast cancer specifically. HER2 and ESR1 are involved in breast cancer more as receptors and pathways related to cancer progression rather than primary susceptibility genes. APC is more related to colorectal cancer, making it less relevant in the context of breast cancer susceptibility.