Genetic tests are tests on blood and other tissue to find genetic disorders. Over 2000 tests are available. Doctors use genetic tests for several reasons. These include
Finding genetic diseases in unborn babies
Finding out if people carry a gene for a disease and might pass it on to their
children
Screening embryos for disease
Testing for genetic diseases in adults before they cause symptoms
Making a diagnosis in a person who has disease symptoms
Figuring out the type or dose of a medicine that is best for a certain person
People have many different reasons for being tested or not being tested. For some, it is important to know whether a disease can be prevented or treated if a test is positive. In some cases, there is no treatment. But test results might help a person make life decisions, such as family planning or insurance coverage. A genetic counselor can provide information about the pros and cons of testing.
NIH: National Human Genome Research Institute