Genetic testing can be very important for different moments in your life. It involves DNA examination and is done with the purpose of revealing gene mutations capable of causing diseases or illnesses. Although the procedure does have limitations, this test can offer very valuable information that will be used in preventing, treating, and diagnosing illness. Obviously, it should only be carried out by trained medical professionals.
There are situations in which genetic testing will not offer a diagnosis. If genetic causes for medical problems are still suspected, genome sequencing might be used. This is a process that analyzes DNA samples taken from blood.
It is important to note that every single person has their own genome. DNA is what makes up the genome. The complex testing procedure can prove to be invaluable when it comes to identifying several genetic variants. Genetic testing normally only analyzes the exome, which is the DNA’s protein-encoding parts.
Why Is Genetic Testing Done?
When you want to know if there are risks you will develop some diseases, genetic testing is highly useful, as it is for some medical treatments and for screening purposes. Some of the main reasons why the procedure is done include:
- Diagnostic testing – When a patient experiences symptoms that could be attributed to a genetic change, usually referred to as mutated genes, the doctor can use genetic testing. This will reveal whether or not the patient suffers from the disorder. As a very simple example, when the doctor suspects Huntington’s disease or cystic fibrosis, the test can help confirm the diagnosis.
- Carrier testing – This is very important when the family history shows specific genetic disorders like cystic fibrosis or sickle cell anemia. It is also very useful when being a part of a specific ethnic group with a higher risk of developing some genetic disorders. Usually, carrier testing is done before having children. Expanded screening tests are capable of detecting genes linked with several genetic mutations and diseases. This applies to both partners, which is important, especially for conditions where the condition is more likely to appear if this is the situation.
- Predictive testing – When your family has a history of one condition, the doctor can use genetic testing before symptoms appear. The test shows if you have a risk of ending up with that condition. As an example, the test is very useful for situations in which there is a family history of colorectal cancer.
- Prenatal testing – When pregnant, genetic testing will detect different possible baby gene abnormalities. The 2 specific genetic disorders doctors often discover are trisomy 18 syndrome and Down syndrome. Traditionally, the procedure involves analyzing blood markers but procedures that are more invasive can be used, like amniocentesis. Modern tests analyze the DNA of the baby through a mother’s blood test, a procedure called cell-free DNA testing.
- Preimplantation testing – This is also known as preimplantation genetic diagnosis. The test is useful if you want to have a child with in vitro fertilization. Genetic testing will screen the embryo so that no genetic abnormalities are present. During the actual procedure, only the embryos that do not have abnormalities are going to be implanted.
- Newborn screening – Out of all genetic testing options, this is the one that is very common. In the US alone, newborns have to be tested for some metabolic abnormalities and certain genetic abnormalities. Such genetic testing is very important since its results can show when a disorder like PKU (phenylketonuria), sickle cell disease, or congenital hypothyroidism will appear. Treatment and care will begin as fast as possible.
- Pharmacogenetics – When suffering from some diseases or health conditions, this test will determine the medication that is very effective and the dosage that is the very best.
Genetic Testing Risks
Some people are scared of potential risks associated with genetic tests but the truth is that there are few to even discuss. Check swab tests and blood tests have literally close to zero risk. But, in the event of going through prenatal testing, like chorionic villus sampling or amniocentesis, there is a risk of miscarriage (pregnancy loss).
We should also highlight that genetic testing has the possibility of having financial, social, and emotional risks. This is why it is so important to talk with the doctor about all the benefits and risks associated with the procedure. This can also be discussed with a genetic counselor or a medical geneticist, of course.
What Should You Expect?
What you can expect varies from one test type to another. But, you can expect an amniotic fluid, skin, or blood sample to be collected. Then, it is sent to a specialized lab for an analysis to be done.
Remember the following:
- Cheek swabs – The swab sample is going to be taken from the area inside the cheek. Then, the sample is used to perform the genetic tests.
- Blood samples – The sample can be taken by several health care professionals through a needle inserted in a vein, usually in the arm. If a newborn screening test is done, the blood sample will be taken from the heel of the baby.
- Chorionic villus samples – With this specific prenatal test, the doctor will use the placenta to obtain the tissue sample. Based on the situation you are in, this sample can be taken through a catheter (a tube) put inside the cervix. Alternatively, the genetic test is taken through the uterus and the abdominal wall. This is used with the use of a very thin needle.
- Amniocentesis – This is a type of prenatal genetic test. The doctor is going to insert a hollow, thin needle through the abdominal wall so it reaches the uterus. Then, amniotic fluid is collected for the tests to be done.
Genetic Counseling Needs
Genetic testing results can be good or bad. In both situations, it is very important to discuss with the genetic counselor, medical geneticist, or even the doctor. Ask all the questions you might have and make sure all concerns are addressed. If you do this, you will be able to fully understand what is happening.