The Uses of Genetic Tests
Uses of Genetic Testing
Genetic tests can be used for different purposes, each of which may carry different medical, psychological, financial, legal, or family implications.
The purpose for genetic testing can be categorised in the following way:
Diagnostic testing refers to genetic tests that diagnose whether a person is affected with disease. In many ways, this is the same as many other pathology tests used to make a diagnosis. However a genetic test may identify a genetic abnormality (mutation) that is inherited, indicating that unaffected family members may be at increased risk of developing that disease. It can be helpful to use a consent form to guide doctor-patient discussions about such a test.
Reproductive testing refers to tests used to predict the risk of a couple having a baby with a serious medical disorder. This may involve testing a couple prior to them conceiving to determine this risk, or testing during pregnancy to determine if the developing fetus is affected. This type of testing can raise significant medical and ethical issues during the pregnancy, and careful documentation of doctor-patient discussions (with or without the use of a consent form) is recommended. Some reproductive tests require the use of a special request form which incorporates a consent form for the patient to sign.
Predictive Testing involves testing an unaffected person to determine their risk of developing a serious disease that is running in the family. In addition to the medical issues that need to be addressed, this type of testing raises significant psychological, legal, ethical and family issues. National regulations require that such testing be performed after counselling by a genetics professional (clinical geneticist or genetic counsellor) and with written consent from the patient. Sonic Genetics may not provide such testing without evidence that this requirement has been met.
Pharmacogenetic testing refers to tests that are used to assist in the selection and dose of medications for a patient. These tests may identify a familial tendency to have an adverse reaction to a particular drug or dose, but this is only relevant if a relative is also going to be exposed to that medication. In practice, these tests do not have significant ethical considerations, and special pre-test counselling and written consent are not required.
Oncology testing refers to the testing of a tumour to assist in diagnosis, or to guide decisions about cancer therapy. The abnormalities identified in these tests are usually restricted to the tumour tissue, and are not inherited. For this reason, these tests do not raise special issues that require written consent.
There is a group of tests that can confirm or exclude the supposed relationship between two people. This is often referred to as paternity testing, but it has a broader role and can be useful in many situations. Relationship testing is a non-medical test and frequently does not require the involvement of a medical practitioner. However, there may be specific issues of consent and sample collection associated with this type of testing. Relationship testing is provided by a specific laboratory in Sonic Genetics and details of testing, together with consent and collection forms, are available.