There are many types of genetic tests
There are thousands of genetic tests, meaning we can test for many of these genetic mutations. But there are also many mutations that we don’t have tests for.
Whether or not to have genetic testing is complicated. What will it tell you? What will you do about it once you get the results? Will having that information help you or not? That’s why the insight and guidance provided by a genetic counselor is invaluable. A genetic counselor can explain the different types of tests available and what they may – and may not – tell you as well as how they may or may not help you.
Genetic tests are generally performed as part of your clinical care. However, there are times when you may be offered one or more genetic tests as part of a research study. If this is the case, the genetic counselor or study staff will review the study in detail so that you can decide whether or not to participate
Currently, a number of different types of testing are available
- Diagnostic testing – This type of test is used to determine whether you have a specific genetic condition. It may be recommended to confirm a diagnosis if you have signs and symptoms of a condition. While this test can be performed for someone of any age (infants through seniors), it is currently not available for all genetic conditions.
- Carrier testing – All of our genes come in pairs. We inherit one copy from our biological mother and one copy from our biological father. One of the quirks of genetics is that you might inherit a copy of a gene mutation from one parent but not the other. This can mean you will not get the genetic condition, but you can pass it on to your children. This test may be recommended if you have a family history of a genetic disorder. It’s also often suggested for people planning to have a family or people of certain ethnic groups who are at increased risk for specific genetic conditions.
- Prenatal testing – Pregnant women may have prenatal testing if the pregnancy is at increased risk for having a genetic or chromosome disorder, or if they want additional information about the health of their pregnancy. For example, prenatal testing may be recommended if the woman is 35 or older if screening tests are abnormal, or if there is a family history of a genetic disorder. Common prenatal tests include amniocentesis and chorionic villus sampling. It is important to know however, that prenatal testing can’t identify all inherited disorders or birth defects.
- Preimplantation testing – Preimplantation testing may be an option for families who wish to have a child but are concerned because of a maternal age or a family history of a genetic disorder. It is used to test embryos created using assisted reproduction to determine if the embryos have inherited the specific genetic disorder(s). Only embryos that don’t test positive for the genetic disorder are implanted in the uterus with the hope of leading to a pregnancy.
- Predictive testing – This testing can detect some genetic variants that may not be apparent right away. For example, you can be tested for the BRCA mutation that indicates an increased risk of breast and ovarian cancer, or variants of the APOE gene that indicate increased risk for Alzheimer’s disease.
- Newborn screening – All states automatically screen infants right after they are born to see if they could have one of about 30 genetic disorders. If detected, some of these disorders can be treated so they don’t cause problems. For example, all states test for phenylketonuria (PKU). When the test is positive, the child can follow a special diet to avoid brain damage and developmental delay.
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