Cancer genetics

Cancer genetics is the study of genetics in relation to cancer. It focuses on the role of genetic mutations in the development and progression of cancer. Understanding the genetic basis of cancer can lead to improved diagnosis, treatment, and prevention strategies.

Overview

Cancer is a complex disease characterized by uncontrolled cell growth. It is caused by mutations in the DNA of cells, which can be inherited or acquired. These mutations can affect various genes, including oncogenes, tumor suppressor genes, and DNA repair genes.

Types of Genetic Mutations

Genetic mutations in cancer can be broadly classified into two categories:

• Germline mutations: These are inherited mutations present in the germ cells (sperm or egg) and can be passed on to offspring. Individuals with germline mutations have a higher risk of developing certain types of cancer.
• Somatic mutations: These are acquired mutations that occur in individual cells during a person's lifetime. They are not inherited and cannot be passed on to offspring.

Key Genes Involved in Cancer

Several key genes are commonly associated with cancer:

• Oncogenes: These genes promote cell growth and division. When mutated, they can become overactive and lead to uncontrolled cell proliferation. Examples include the RAS and MYC genes.
• Tumor suppressor genes: These genes regulate cell growth and division, preventing the formation of tumors. Mutations in these genes can lead to a loss of function, allowing cells to grow uncontrollably. Examples include the TP53 and RB1 genes.
• DNA repair genes: These genes are involved in repairing damaged DNA. Mutations in these genes can lead to an accumulation of genetic errors, increasing the risk of cancer. Examples include the BRCA1 and BRCA2 genes.

Hereditary Cancer Syndromes

Certain inherited genetic mutations can lead to hereditary cancer syndromes, which are conditions that increase an individual's risk of developing specific types of cancer. Examples include:

• Lynch syndrome: Caused by mutations in DNA mismatch repair genes, leading to an increased risk of colorectal cancer and other cancers.
• Hereditary breast and ovarian cancer syndrome: Caused by mutations in the BRCA1 and BRCA2 genes, leading to an increased risk of breast cancer and ovarian cancer.
• Li-Fraumeni syndrome: Caused by mutations in the TP53 gene, leading to an increased risk of various cancers, including sarcomas, breast cancer, and brain tumors.

Genetic Testing and Counseling

Genetic testing can identify individuals with inherited mutations that increase their risk of cancer. This information can be used to guide screening and prevention strategies. Genetic counseling is an important component of the testing process, providing individuals with information about their risk and options for managing it.

Research and Future Directions

Ongoing research in cancer genetics aims to identify new genetic mutations associated with cancer, understand their mechanisms, and develop targeted therapies. Advances in genomics and bioinformatics are driving this research, leading to more personalized approaches to cancer treatment.

See Also

• Oncology
• Genomics
• Precision medicine
• Tumor marker
• Carcinogenesis