While you might think your child is only at risk of a genetic disease if a certain condition runs in the family, genetic diseases can also be non-inherited. This means they can be caused by one or more random gene mutations (changes) that can occur during or before conception, and aren’t passed on from your genes. Furthermore, sometimes you need both parents to have a gene mutation for signs and symptoms to present.
In some cases, signs of a genetic condition are seen in a baby during pregnancy. Elizabeth Rowe learned that her third child, Jane, had a cystic hygroma (a fluid-filled bump on the neck) during a routine 12-week prenatal ultrasound appointment. Amniocentesis, a type of prenatal genetic test, revealed that Jane had Turner Syndrome, a congenital condition that occurs when one of two X chromosomes is missing partially or completely. “The thing about genetic testing is you get that definitive answer,” says Rowe. “It was really painful, but it was also like, okay, we know what’s going on.
More commonly, parents instead notice signs and symptoms in the first years after their child is born, that lead them to a doctor’s office. Many parents, and many pediatricians, may not immediately suspect an underlying genetic cause which could delay testing, and sometimes parental instincts can be dismissed or overlooked. If your child has unexplained developmental delays, genetic tests can be an invaluable tool to inform your family’s medical decisions and care, which can lead to better outcomes for your child’s development. If you have worries about your child, seek out a second opinion, such as with a behavioral pediatrician or a neurologist, and ask about genetic testing.
“Genetic testing is usually recommended when there are one or more notable health symptoms that prompt the need for more information,” says Malika Sud, MS, a licensed genetic counselor at Children’s Hospital of Boston.
Genetic results can help your family to navigate the path forward. For Rowe and her husband, this meant meeting with an endocrinologist and a cardiologist, who determined that Jane would need heart surgery immediately following birth. “As soon as she was born, she went over to Boston Children’s to be stabilized before surgery,” says Rowe.
What is genetic testing?
Genetic testing involves analyzing your child’s genes to identify mutations (sometimes called variants). “Our genes are like instruction manuals for our bodies to grow and develop,” says Sud. “When we do genetic testing, we are really trying to make a molecular diagnosis to understand the symptoms that we are seeing.” Everyone has variations in their genetic material. Some differences don’t have any health consequences, but some can lead to disease or risk for disease.
Genetic tests are usually ordered by a neurologist and performed by geneticists and genetic counselors using blood or saliva samples. During pregnancy, genetic tests are performed by your obstetrician. There are many different types of tests, which is where genetic counselors come in. They have specialized education and training and they work with doctors and families to decide the most appropriate testing for a family or individual.
What are the goals of genetic testing?
The goals of genetic testing vary, but results can provide a diagnosis that can help shape medical plans for your child. “One thing a genetic diagnosis really opens up is a kind of a roadmap for what might lie ahead to guide medical management and screening,” says Sud.
A genetic diagnosis can help your family understand your child’s symptoms and how to treat them. It can inform how to build your child’s care team, which might mean adding physical therapists, pulmonologists, gastroenterologists, dietitians, speech pathologists, or other specialists to your child’s medical roster. Tests may open up pathways to research studies as well as potential clinical trials.
Plus, a diagnosis can open the door to a community of parents who have children with the same diagnosis, who may offer insights from their experiences to help you care for your child and manage their condition.
In Rowe’s experience, genetic testing was useful for her family because, in addition to a diagnosis, it helped pinpoint her daughter’s specific mutation, Monosomy X. All rare diseases have variability. Knowing which type of mutation your child is living with may sometimes—although not always—help doctors customize care and therapies for your child.
In her practice, Sud has seen firsthand how knowledge of a genetic disease helps families and doctors. “Looking for other folks with the same specific genetic change and understanding what their road looked like can help you create a better picture of what your own road might look like,” says Sud.
Genetic testing during pregnancy
If your obstetrician notices an anomaly during a regularly scheduled ultrasound or a routine genetic screening test (usually cell-free prenatal testing, which involves analyzing placental DNA for common genetic disorders using a sample of Mom’s blood), you may be offered genetic testing. Other times, your obstetrician may ask if you have a family history of certain genetic conditions to determine if testing might be right for your family.
In either case, your obstetrician will discuss your options for genetic testing and will perform the test if you choose to move forward.
Parents can also request genetic testing if a sibling or family member is living with a genetic disease. These tests are generally not covered by insurance if the child does not have signs of a particular condition during pregnancy. Be sure to speak with your provider.
Testing procedures during pregnancy
Whether you choose to do the standard genetic tests offered during pregnancy, or your doctor orders more comprehensive genetic testing due to concerns, the procedures to retrieve genetic information are the same:
- Chorionic villus sampling (CVS), performed between 10 and 13 weeks, involves taking a sample of tissue from the placenta.
- Amniocentesis, performed between 16 and 20 weeks, where a thin needle takes a sample of amniotic fluid.
Genetic testing generally takes place prior to 20 weeks. In some cases, a doctor can perform testing later if required.
Genetic testing for children
Whether your doctor observes a congenital anomaly in your child at birth, or you notice that your child has signs of a neurological disorder, the first step is usually to see a neurologist for evaluation. Sometimes you may be referred directly to a genetic counselor. Otherwise, your neurologist determines if genetic testing is necessary and then refers your family to a genetic counselor.
What to expect from genetic counseling
Your initial appointment with a genetic counselor will cover the benefits, risks, and limitations of genetic testing. They might ask questions about the materials shared by your referring doctor or specialist (such as your child’s symptoms, medical history, data from tests that have already been performed, and the family’s history). Together, you’ll decide on a plan for which tests to use. “Usually, the testing plan is really individualized and tailored to what we’re seeing in the person,” says Sud.
Even if you schedule the genetic counseling session, you don’t need to decide anything at your initial appointment. However, if you’re sure you want to move forward, it can be often be performed the same day. Other times, a prescription for a blood draw is written, which you’ll take to a testing facility.
Genetic testing types for children
- Single gene tests: If your child has symptoms of a specific disease, genetic counselors might look for changes in a single gene to screen for that disease.
- Gene panel tests: If your child has symptoms that match a number of rare diseases, genetic counselors may look for changes in many genes.
- Epilepsy panel tests: If your child is having seizures, this panel covers most rare diseases that include seizures as a symptom
- Whole exome/genome tests: In rare cases, your child may have many different symptoms but none that are specific to any particular disease, or, other tests weren’t able to pinpoint the disease. In this case, more comprehensive testing may be used to look for mutations outside of the genes typically tested. This complex test is not available at every institution, requires more time and resources, and may only be used if your child meets certain criteria.
Turnaround time and results
The turnaround time for test results varies. Preliminary prenatal genetic tests results can sometimes arrive in a few days. In most cases, a full genetic testing panel takes around six weeks. Whole exome tests require more time, and results can take closer to three months. The genetic counselor or your child’s doctor will tell you when to expect the results.
If your child receives a result showing your child has a mutation known to cause a rare disease, genetic counselors, and often your neurologist, will schedule an appointment to review what the diagnosis means for your child’s health and the impact on your lives moving forward. “During that visit, it is often a time for emotional processing,” says Sud. Genetic counselors often give you literature and resources to read when you’re ready. She says that follow-up appointments are essential so that you’re able to ask more questions.
Rowe says the information and practical advice that her counselors provided was invaluable. “I think that one of the hardest things is getting a diagnosis and feeling like you had no power to control or fix that. To actually have practical information that you can take and advocate for your kid was helpful,” says Rowe.
How to afford genetic testing
If your unborn child has in-utero abnormalities that could be signs of a genetic disease, genetic testing is almost always covered by insurance companies. After your child is born, genetic testing is usually covered by insurance companies when signs and symptoms point to a genetic cause. Insurance companies generally require evaluation by a neurologist and/or genetic counselor.
If you’re having difficulties getting your insurer to cover genetic testing, or if you don’t have insurance or have additional questions, talk to your doctor or genetic counselor. “Another big part of genetic counseling is navigating insurance coverage, helping folks understand options financially, and seeking out support when it’s appropriate and available,” says Sud.
Finding connections through genetic testing
Genetic testing and a rare disease diagnosis can be a bridge to building connections. When you are ready, you can reach out to other caregivers, support groups, and advocacy organizations. “Often getting the result is thought of as kind of the final point, but it is a node on a tree that then opens up, and there are so many branches,” says Sud. “For families who are looking for answers, that genetic diagnosis opens up this world of folks who have walked the same road as you. I think that can be really special.”
When Rowe received her daughter’s rare disease diagnosis, she was not ready to reach out to the greater network of families. “I couldn’t do it. I couldn’t join the groups,” she says. “I kept myself a step removed because it was just too painful.”
When she made that initial outreach, she says, it changed her family’s experience. “I just have learned a lot from these women who have gone before me,” says Rowe. “To me, you need people who have gone ahead of you, who can point towards what you need at that time. Because it’s so overwhelming, especially if you have no medical background and you don’t know what to do.”
Today, Rowe is a volunteer with Turner Syndrome Global Alliance, and her daughter Jane is a fun-loving, outgoing 2-year-old who loves playing with her older siblings.
References and Further Reading