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WHAT IS GENETIC TESTING?
Genetic testing usually means the direct examination of the DNA (it can sometimes mean RNA or the protein product of the DNA and RNA) in a gene associated with a particular disorder. The examination is usually made in order to enhance the understanding of symptoms (for example, to confirm a diagnosis of a muscular dystrophy), or to predict the occurrence of a genetic disorder in which symptoms haven't yet appeared.
Usually, only a blood sample is needed, but occasionally other tissues are used for the testing.
 Genetic counselors can help people make decisions about genetic testing and childbearing. |
Are there risks associated with genetic testing?
Yes. You hear a lot about genetic testing these days, not just in the MDA clinic or other medical settings, but in the newspaper and on TV, as gene after gene is discovered to be associated with everything from cancer or heart disease to rare disorders of metabolism or muscle function.
Privacy concerns are real. Some people are very concerned that genetic testing can interfere with privacy, insurance eligibility or even employment. Unfortunately, these fears aren't easily dismissed.
Laws protecting people who have had genetic testing from discrimination for insurance or em-ployment are unclear and vary from state to state. Even general privacy rights can't be strictly guaranteed.
However, you can minimize the risks by going to a qualified genetic counselor and discussing your concerns about privacy. In some situations, you may decide not to have a genetic test.
Mistakes can occur, and results can be unclear. Genetic tests, like any other tests, are subject to error. Accuracy in a qualified laboratory is high but never perfect. Also, the results of a test can sometimes be hard to interpret.
For example, testing may reveal a mutation the significance of which is unclear. Professionals may not know the effects of a previously undetected change in a gene. Not all changes are harmful.
Prenatal testing can prompt difficult examination of beliefs and values. Predictive, or presymptomatic, genetic tests are often done on fetuses in the womb or embryos created by in vitro (out of the body) fertilization. This is known as prenatal genetic testing.
A test result that suggests it's likely the baby will develop a serious genetic disorder makes parents face some very tough decisions. Genetic counseling, perhaps aided by psychological and spiritual counseling for both parents, can be of help.
Presymptomatic or carrier testing of children is controversial. Many professional organizations strongly discourage and some medical centers may forbid genetic testing of minors unless there is a compelling medical reason (such as treatment that can be started prior to symptoms) to do so.
Thoughtful professionals have reasoned that testing children or adolescents for a mutation that may cause an adult-onset disorder or confer carrier status may actually do more harm than good, and that people should be allowed to make the decision about testing for themselves when they reach adulthood. Genetic testing is so new that the legal, ethical and medical implications are far from clear. In the meantime, parents may elect to wait until their child is old enough to make an informed choice about genetic testing. Again, this is something to discuss with your physician or genetic counselor.
Testing of symptomatic, at-risk or carrier adults can have unintended consequences. Testing of adults who may have symptoms of a genetic disorder or a family history of a genetic disorder is perhaps the least controversial type of genetic testing. However, it, too, can have unintended consequences.
For example, test results on one person may suggest the genetic status of other family members, causing a dilemma about whether to inform the family or not.
Results may also cause anxiety or depression in the person being tested, particularly if there's no effective treatment for the condition or if it affects plans for having a family.
Test results demonstrating that a disorder came from one parent or the other can cause a strain in the parents' relationship or excessive guilt on the part of the parent whose gene was involved.
Again, help from a genetic counselor and other counselors is strongly recommended.
How much does genetic testing cost?
Costs range from about $100 to about $2,000, depending on the nature of the test. |
