Types of Genetic Tests
Types of Genetic Tests
- Single-Gene Tests: Focus on one specific gene, often BRCA1 or BRCA2.
- Panel Testing: Examines multiple genes associated with breast and other cancers.
- Whole-Exome or Whole-Genome Sequencing (WES/WGS): Rarely used but may identify novel mutations.
Key Genes Tested for Breast Cancer Risk
1. BRCA1 and BRCA2
- Mutations in these genes significantly increase the risk of breast, ovarian, and other cancers.
- Lifetime Risk with Mutations:
- Breast cancer: 45-85%.
- Ovarian cancer: 15-45%.
- Also associated with increased risks of pancreatic and prostate cancers.
2. PALB2
- Mutations increase breast cancer risk (33-58% lifetime risk).
- Associated with other cancers like pancreatic cancer.
3. TP53
- Mutation causes Li-Fraumeni syndrome, linked to a high risk of various cancers, including early-onset breast cancer.
4. CHEK2
- Mutations confer a moderate risk of breast cancer and possibly other cancers.
5. PTEN
- Mutation causes Cowden syndrome, associated with breast, thyroid, and other cancers.
6. ATM
- Mutations increase the risk of breast cancer and are linked to ataxia-telangiectasia.
7. Other Genes
- CDH1: Linked to lobular breast cancer and gastric cancer.
- STK11: Causes Peutz-Jeghers syndrome, increasing the risk of breast and other cancers.
- NBN, RAD51C, RAD51D: Moderate risk genes with a role in DNA repair.
