The One Question Most Would-Be Parents Forget to Ask
Thinking about having a baby? If so, you and your partner can easily find plenty of information to help you decide if you’re ready for this life-changing event. But there’s one important question most would-be parents forget to ask:
Are we at risk of passing down a genetic disease or major birth defect to our child?
Most people are unaware that they are carriers for a genetic disorder until they have an affected child. Knowing this before your child is born can help you prepare for the future and make the reproductive choices that are right for you and your family. A genetic screening procedure such as the Panorama test can provide this information.
According to NetWellness, about 3–4 percent of all newborns have a genetic disease or major birth defect, and 1 percent has a chromosomal abnormality. The National Organization for Rare Disorders (NORD) reports that nearly one in ten Americans lives with a rare disease, and two thirds of them are children.
Fortunately, advances in genetic testing have made it much easier for parents to find out if they are carriers of genetic diseases. If you’re considering a first-time adventure in parenthood, or if you’re adding another child to your family, here are some facts you should know about genetic testing and the risks for genetic diseases. Knowing these facts can help inform your decisions.
How Does Genetic Testing Work?
Genetic screening tests can tell prospective or expecting parents whether they have abnormal genes that can lead to certain diseases in their baby. Most of these diseases are recessive disorders, which means that the child can only be affected if both parents have a specific recessive gene.
Some diseases are carried on the X chromosome (for example, Duchenne Muscular Dystrophy and Fragile X). If the mother is a carrier of an X-linked disorder, she has a 50 percent chance of passing the affected X chromosome to her child. Men generally are affected with the disease if their mothers passed on the X chromosome that carried the disease. Most people are carriers of at least one recessive or X-linked genetic condition.
Genetic screening tests can be conducted at a physician’s office or at a nearby lab simply by providing a sample of one parent’s blood or saliva. Most patients receive their results within about two weeks. If no genetic issues are apparent from the test, the other partner usually doesn’t need to be tested.
Who Should Consider Genetic Screenings?
Both men and women (including egg and sperm donors) are eligible for genetic screening tests like Horizon, which can tell individuals and couples whether they are carriers for hundreds of possible genetic diseases.
Non invasive prenatal screening tests (NIPTs) are simple blood tests conducted in the early stages of pregnancy (as early as nine weeks gestation) that screen women for chromosomal abnormalities. NIPTs like the Panorama test can also determine the baby’s gender as early as nine weeks.
The Panorama test is the only NIPT that uses single-nucleotide polymorphsims (SNPs) to differentiate between and analyze both the maternal and fetal DNA. This method produces highly accurate risk results with a lower incidence of false positives and false negatives.
Other NIPTs rely on quantitative methods—that is, they only use the mother’s blood sample to count the total number of chromosomes. These approaches may produce inconsistent results, since they do not separate out the baby’s DNA, and instead only analyze the mother’s DNA against a reference chromosome.
NIPTs like the Panorama test offer an easy, accurate, and non-invasive way to obtain important health information about the fetus. If the screening results indicate your fetus may be at risk for a genetic disease, your doctor may recommend a confirmatory test such as a CVS (chorionic villi sampling) or amniocentesis.
The American College of Obstetricians and Gynecologists (ACOG) and Society for Maternal Fetal Medicine (SMFM) Committee recently updated their published opinion to state that all women, regardless of their risk status, can choose non-invasive prenatal testing.
What Do the Test Results Mean?
A genetic screening test does not provide a diagnosis, but its results can give you a clear idea of your risk for passing along certain genes. If either you or your partner does not carry a recessive gene, your child will most likely not inherit the condition. If you are both carriers, your child has a 1 in 4 chance of being affected, and a 1 in 2 chance of being a carrier.
It’s important to discuss screening test results with your doctor before making decisions. Your doctor also may be able to recommend a genetic counselor, or you can find one through the National Society of Genetic Counselors or the American Board of Genetic Counseling. A genetic counselors can further discuss test results with a patient, and provide additional information and support to families that may be at risk for a variety of inherited conditions.
What Are The Benefits of Taking a Genetic Screening Test?
Genetic testing can arm couples with important knowledge about their genetic health, and possibly that of their unborn baby. This can peace of mind for many prospective parents, and help others who may be at risk for a genetic condition to better prepare.
For more information on genetic and prenatal tests, please go to www.natera.com.
Dr. Hechtman is an OB/GYN and the Medical Director of Tampa, Florida’s leading medical center for women, Tampa Obstetrics.