genetic testing

A laboratory method that looks for changes in genes, gene expression, or chromosomes in a person’s cells or tissues. Genetic testing may be done to look for inherited changes in a person's genes that may be a sign that the person has an increased risk of developing a specific disease or condition or of having a child or other family member with the disease or condition. This type of genetic testing is called germline testing. Genetic testing is also done on tumor tissue to look for genetic changes in the cancer cells. These changes occur during a person’s lifetime and are not inherited from a parent. This type of genetic testing, called somatic testing, is done to learn more about the cancer, plan treatment, or find out how well treatment is working. Also called genetic analysis.