Genetic Testing/Counseling
Genetic tests are tests on blood and other tissue to find genetic disorders. About 900 such tests are available. Doctors use genetic tests for several reasons. These include
- Finding possible 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
- Confirming a diagnosis in a person who has disease symptoms
A positive test result means that you have the mutation you’ve been tested for. If you have a positive test result, it means you may be more likely to get a particular disease than most people, but it doesn’t mean you will definitely get the disease.
What does a negative test result mean?
A negative test result means that you don’t have that particular mutation. This may mean that the disease doesn’t run in your family. A negative result doesn’t mean you won’t get the disease. It only means that you’re not more likely to get the disease than other people are.
Who should be tested?
By looking at your family history, your doctor can tell if you’re likely to have a gene mutation that may contribute to disease. A disease might run in your family if a blood relative developed the disease at a young age, if several family members have the disease or if the condition is rare. People from certain ethnic groups may also be more likely to get certain diseases. If one of your family members already has the disease, that person should be tested first. This helps show which genes, if any, are associated with the disease.
How do I decide if I should get tested?
If you think you may be at high risk for an inherited disease, talk to your family doctor. Your doctor will ask you questions about your health and the health of your blood relatives. This information will help your doctor find out what your risks might be. The information your doctor gives you about your risks can help you decide whether you want to be tested.
There are two important questions you should think about before you go through genetic testing:
1. What can I gain by being tested?
Here are some reasons you might want genetic disease testing:
- You might not be so worried about getting a disease.
- You might be able to change your lifestyle to reduce your risk of getting a disease.
- Your doctor will know how often to check you to see if a disease is developing.
- You might be able to take medicine to prevent the disease.
Here are some reasons you might not want to know that you could be at risk for a certain disease:
- Testing may make you more worried about getting sick.
- Testing may give you stress, make you feel guilty or strain your family relationships.
- Testing could lead to problems with employers or insurance companies.
If you are expecting a baby or planning to have a baby, your doctor can run many tests to help assess the health of both you and your baby. Your doctor may also refer you for genetic counseling. Genetic counseling provides information and support to people who have, or may be at risk for, genetic disorders. A genetics professional meets with you to discuss genetic risks. You may follow up with genetic testing.
There are many reasons to seek genetic counseling. You may consider it if you
- Have or are concerned you have an inherited disorder
- Are pregnant or planning to be pregnant after age 35
- Already have a child with a genetic disorder or birth defect
- Have had two or more pregnancy losses or a baby who died
- Have had ultrasound or screening tests that suggest a possible problem
Genetic counselors are professionals who have completed a master's program in medical genetics and counseling skills. They then pass a certification exam administered by the American Board of Genetic Counseling.
Genetic counselors can help identify and interpret the risks of an inherited disorder, explain inheritance patterns, suggest testing, and lay out possible scenarios. (They refer you to a doctor or a laboratory for the actual tests.) They will explain the meaning of the medical science involved, provide support, and address any emotional issues raised by the results of the genetic testing.
After Counseling
Genetic counselors can help you understand your options and adjust to any uncertainties you face, but you and your family will have to decide what to do next.
If you've learned prior to conception that you and/or your partner are at high risk for having a child with a severe or fatal defect, your options might include:
- pre-implantation diagnosis — when eggs that have been fertilized in vitro (in a laboratory, outside of the womb) are tested for defects at the 8-cell (blastocyst) stage, and only nonaffected blastocysts are implanted in the uterus to establish a pregnancy
- using donor sperm or donor eggs
- adoption
- preparing yourself for the challenges you'll face when you have your baby
- fetal surgery to repair the defect before birth (surgery can only be used to treat some defects, such as spina bifida or congenital diaphragmatic hernia, a hole in the diaphragm that can cause severely underdeveloped lungs. Most defects cannot be surgically repaired.)
- ending the pregnancy
Genetic counselors can share the experiences they've had with other families in your situation. But they will not suggest a particular course of action. A good genetic counselor understands that what is right for one family may not be right for another.
Genetic counselors can, however, refer you to specialists for further help. For instance, many babies with Down syndrome are born with heart defects. Your counselor might encourage you to meet with a cardiologist to discuss heart surgery, and a neonatologist to discuss the care of a post-operative newborn. Genetic counselors can also refer you to social workers, support groups, or mental health professionals to help you adjust to and prepare for your complex new reality.