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How can genome sequencing help identify genes associated with cancer risk?
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human genome
The human genome is made up of approximately three billion base pairs of deoxyribonucleic acid (DNA). The bases of DNA are adenine (A), thymine (T), guanine (G), and cytosine (C).
Genome sequencing plays a critical role in identifying genes associated with cancer risk by enabling the detection of specific mutations that predispose individuals to the disease. By analyzing the human genome, researchers can identify "risk genes"āsuch as BRCA1 and BRCA2 for breast cancer or APC for colorectal cancerāthat, when mutated, significantly increase an individual's susceptibility to developing certain cancers.123
This process helps in several ways:
- Predictive Testing: Individuals with a family history of cancer can undergo genetic testing to determine if they carry inherited mutations. This allows for early, presymptomatic diagnosis and the implementation of heightened surveillance or preventive measures.425
- Tumor Profiling: Sequencing the genomes of tumor cells provides a "bar code" of genetic alterations unique to that cancer. This molecular evaluation allows physicians to classify tumors based on their specific defects and select targeted therapies designed to neutralize those mechanisms.6
- Understanding Mechanisms: Sequencing helps characterize the roles of tumor suppressor genes and oncogenes, revealing how successive mutations deregulate cell growth and lead to malignancy.31
While these advancements offer powerful tools for predictive medicine, they also raise important ethical considerations regarding privacy, insurance discrimination, and the psychological impact of receiving genetic risk information.42