Genetic testing is a powerful tool that analyzes a person's DNA to identify changes or mutations in specific genes, chromosomes, or proteins. These changes can provide valuable information about a person's risk of developing certain genetic disorders, including hereditary cancers.
How genetic testing works:
- Sampling: A sample of the person's blood, saliva or tissue is collected. The choice of sample type depends on the specific test to be performed. At Eiira, we collect saliva samples to predict cancer risk.
- DNA extraction: The DNA is extracted from the sample and purified for testing.
- Analysis: The DNA is analyzed using various techniques, such as sequencing, to identify specific changes or mutations in the genes of interest.
- Interpretation: Genetic professionals interpret the results and determine their significance. They evaluate whether the identified changes are linked to an increased risk of developing a particular condition or disease, such as cancer.
- Reporting: The results are shared with the individual and/or their healthcare provider, who can then use the information to make informed decisions about prevention, screening, and treatment.
What genetic testing can reveal about a person's cancer risk: Genetic testing can help determine if an individual carries gene mutations associated with an increased risk of certain hereditary cancers. These tests can be particularly useful for people with a strong family history of cancer or those who have specific types of cancer that are more likely to be hereditary.
Some of the most common hereditary cancer syndromes include:
- Hereditary Breast and Ovarian Cancer (HBOC) Syndrome: Associated with mutations in the BRCA1 and BRCA2 genes, this syndrome increases the risk of breast, ovarian, and other types of cancer.
- Lynch syndrome: Lynch syndrome is caused by mutations in genes such as MLH1, MSH2, MSH6 and PMS2 and increases the risk of colorectal, endometrial and other cancer types.
- Familial Adenomatous Polyposis (FAP): Resulting from mutations in the APC gene, FAP significantly increases the risk of colorectal cancer and other malignancies.
It is important to remember that genetic tests can reveal an increased risk of hereditary cancer, but they do not guarantee that a person will develop cancer. The results help individuals and their healthcare providers to make informed decisions about prevention, lifestyle choices and expanded cancer screening to reduce risk and detect cancer early if it develops.
Genetic tests can also have limitations, as they do not always provide clear answers about a person's risk. Some genetic tests may reveal gene variants of uncertain significance, meaning their impact on cancer risk is unclear. Current practice among healthcare providers recommends not communicating such information to the patient until it becomes clear.
References:
- National Cancer Institute. (2021). Genetic Testing for Hereditary Cancer Syndromes.
- American Cancer Society (2021). Genetic Testing, Screening, and Prevention for People with a Strong Family History of Colorectal Cancer.
- Mayo Clinic. (2021). Genetic Testing.
