What are some of the advantages of genetic testing?
Whether the results of genetic testing are positive or negative for a gene mutation, there are possible benefits. Genetic test results might bring a sense of relief from uncertainty and assist people in making educated health-care decisions. In some situations, a negative result, for example, can reduce the need for unneeded checkups and screening tests.
A positive outcome can point a person in the direction of available preventative, monitoring, and treatment choices. Some test results can also aid in the decision-making process when it comes to having children. Genetic diseases can be identified early in life through newborn screening, allowing therapy to begin as soon as feasible.
The color of a baby’s eyes and hair can be influenced by genetics, but it can also influence the development of certain birth abnormalities or genetic illnesses. That’s why, during the first and second trimesters of pregnancy, women are frequently offered a variety of genetic screening tests to assess the risk of these potential disorders in their unborn child.
Screening tests can help establish whether a newborn is more or less likely to acquire certain birth abnormalities or genetic illnesses
The probabilities that the fetus will be born with Down syndrome, cystic fibrosis, Tay-Sachs disease, or sickle cell anemia are calculated using screening findings and additional risk factors such as a woman’s age, a couple’s ethnic origin, and a family history of genetic disorders.
According to the Centers for Disease Control and Prevention, birth abnormalities afflict one out of every 33 newborns born in the United States each year, or about 3% of all babies (CDC). According to the CDC, birth abnormalities can develop at any time during pregnancy, but the majority occur during the first trimester, while the baby’s organs are maturing.
Dr. Andrea Greiner, a maternal and fetal medicine specialist at the University of Iowa Hospitals and Clinics, said genetic screening is offered to all pregnant women and is normally discussed during the first prenatal visit. “It’s a nice touch, but it’s not essential.”
According to Greiner, most women obtain prenatal genetic testing to find out what their risk is before their baby is born. They’d rather know the facts during pregnancy than after the baby is born, she noted, so they can make preparations and decisions ahead of time or learn more.
Genetic screening’s benefits and drawbacks
Greiner told, “Every woman wants to believe that her pregnancy is normal and uncomplicated.” If a pregnant woman chooses to undertake genetic screening, there’s a chance the results could be abnormal, so she should consider how this information will effect her, she said.
However, not all genetic testing takes place when a woman is pregnant. It may be possible to do it before becoming pregnant in some cases. Carrier testing, for example, can be performed during pre-conception genetic screening to detect whether the mother or father carries a gene for genetic illnesses that may run in families, such as cystic fibrosis and sickle cell anemia, and may be passed on to the pair if they conceive.
As a result, pregnant women should not terminate a pregnancy based solely on a positive screening result without first having a diagnostic test to confirm or rule out a diagnosis.
Diagnostic testing versus. screening
Diagnostic tests and genetic screening tests are not the same thing. According to Greiner, genetic screening determines the fetus’s risk of genetic disorders.
Screening tests determine the likelihood that the fetus will be born with some common birth abnormalities. According to the American College of Obstetricians and Gynecologists, however, they can’t be sure if the infant has the condition.
Between the 10th and 13th weeks of pregnancy, first trimester screening tests are routinely performed. One frequent screening test assesses the risk of Down syndrome and other chromosomal disorders by measuring the quantity of certain chemicals in the mother’s blood. Another first-trimester screening test, known as “nuchal translucency,” uses ultrasound to look for increased fluid or thickening at the back of the fetus’s neck, which could suggest a risk for Down syndrome.
“The research is still very new, and patients should proceed with caution,” Greiner said, adding it’s crucial for women to understand that cell-free fetal DNA isn’t a substitute for diagnostic testing if a positive result is obtained.
During the second trimester, some genetic screening tests are possible. One of them is the “quad screen,” which detects genetic abnormalities such as Down syndrome by measuring four particular chemicals in the mother’s blood. The quad screen can also detect neural tube anomalies, such as spina bifida, which are birth disorders of the brain and spinal cord.
A second ultrasound, usually performed between the 18th and 22nd weeks of pregnancy, can detect structural abnormalities in the growing fetus, such as cleft lip and heart deformities, as well as genetic illnesses like Down syndrome.
Although the screening tests are not thought to be dangerous to the mother or the fetus, positive screening results do not guarantee a diagnosis. If a screening test yields a positive result, a woman should talk to her doctor about her options, including if she wants to pursue diagnostic tests, which are more accurate and reliable than genetic screening alone.
Many genetic disorders are caused by flaws in a gene or chromosome, and diagnostic tests can discover them. They can generally notify prospective parents whether their fetus has a specific genetic condition. Some diagnostic tests provide a risk to a woman, such as a small chance of miscarriage.
Genetic diagnostic tests: advantages and disadvantages
Some of Greiner’s patients ask why they should perform prenatal genetic testing because if a positive result is found, the genetic defect detected in the baby cannot be modified, rectified, or treated, according to Greiner.
To this question, she responds by assuring her patients that no one enjoys surprises. Knowing positive test results ahead of time might assist expecting parents in planning and preparing themselves and their home for a newborn with special needs.
According to Greiner, women should consider whether a positive diagnostic test result would give them concern if they choose to prolong the pregnancy, or whether these genetic results would provide reassurance if they chose to terminate the pregnancy due to the diagnosis.
Who should have their DNA tested?
The key elements that decide whether or not genetic testing is good for you are your ethnic origin and family history. Because the diseases for which genetic testing is currently available are more common in specific ethnic groups, this is the case.
Here’s an example of a group that has a higher risk of developing specific hereditary diseases:
- Cystic fibrosis is more common in European Caucasians and Eastern European Jews.
- Tay-Sachs, Canavan, and familial dysautonomia are all illnesses that are more common among Eastern European Jews.
- Sickle cell anemia and thalassemia are more common in African Americans and persons of Mediterranean heritage (Greeks, Turks, and Italians). Thalassemia is also more common in people of Southeast Asian heritage.
- Tay-Sachs disease and cystic fibrosis are more common in French Canadians.
Many other recessive genetic illnesses are not regularly screened for because they are either extremely rare or the appropriate tests have not yet been developed.