Genetic Testing for Pediatric Neurodevelopmental Disorders

Humans have about 20,000 genes. About 10,000 of these genes make proteins that help the brain develop and function. If those genes malfunction, it can cause a neurodevelopmental disorder.

Researchers at Children’s Health℠ and UT Southwestern are playing a key role in identifying which genes and genetic changes (mutations) are involved in autism spectrum disorder and other neurodevelopmental disorders. More of these genes are being identified every year. As a result, there are promising new therapies that can counteract some of these genes. This means, children are helped to live happier, healthier lives.

Genetic testing enables our doctors to identify which genes are involved in your child’s condition, so we can understand what’s causing their symptoms and match them with the best possible treatments.

Your child is a candidate for genetic testing if they’ve been diagnosed with autism spectrum disorder or a global development delay (a delay in two or more of these areas: language, social development, gross motor abilities or fine motor abilities).

There are three tiers of genetic testing:

• Tier 1: Our neurology team generally starts genetic testing with a screening called a chromosomal microarray analysis. This test looks for missing or extra pieces in the genetic code that cause neurodevelopmental disorders. As part of Tier 1 testing, the doctor may test your child for fragile X syndrome.
• Tier 2: If Tier 1 testing doesn’t find a confirmed genetic cause, the next step is to do more extensive, Tier 2 testing. Your doctor may order a "curated panel," where they look for specific genetic changes that are associated with specific genetic syndromes. Or they may order a whole exome sequencing test, which collects a large amount of genetic information to give doctors the best chance to understand what’s causing your child’s condition.
• Tier 3: Children’s Health and UT Southwestern conduct some of the nation’s most innovative research on neurodevelopmental disorders. This research includes a study on the genetics of neurodevelopmental disorders. Some children can participate in this study and gain access to Tier 3 genetic testing. This testing includes the most in-depth genetic testing available, called whole genome sequencing, which examines all your child’s DNA. Because whole genome sequencing is so extensive, it is mostly available through a research study and only rarely ordered by your doctor.

If testing confirms a genetic cause, your child may:

• Receive a more specific diagnosis
• Receive treatments and/or medications that are known to be effective for children whose disorders are caused by particular genes
• Connect with a community of other families with children who have the exact same condition
• Participate in clinical trials of new treatments tailored to the genes that cause their condition

Genetic testing can help families:

• Learn about the care your child may need in the future to live the highest quality of life
• Uncover any other conditions that your child may have that need treatment
• Understand your genetics and the likelihood than your future child might have a disorder

There are few risks to genetic testing. Sometimes we find information about a child's genetic make-up that we were not looking for. This can include, passing on the risk for a genetic disorder to a future child or reveal genetic information about a parent that you weren't expecting to find. Some tests require that we draw blood, which can be scary for some children. We can do some tests via a cheek swab, so we often choose that if it’s an option. If your child needs a blood draw, we make the process as easy on them as possible.

We can access specialists in our Child Life services, who can help distract your child and keep them as comfortable as possible while blood is drawn. If your child has an upcoming procedure that requires sedation, we can schedule the blood draw at that time. If your child is a patient of another department and has routine lab work scheduled, we’ll work with that department, so your child only needs blood drawn once.

Our expert pediatric neurology team is by your side through the entire genetic testing process. Here’s what to expect.

What to expect before genetic testing?

Our team will work with your insurance company to understand which genetic tests are covered. Insurance companies usually confirm that a test is covered within one to two weeks of submitting the request. Once we have approval, we schedule a blood draw or cheek swab.

You don’t need to do anything to prepare your child for a blood draw, but your child should not eat or drink anything 30 minutes before the cheek swab.

What to expect during genetic testing?

Your child will come in for a blood draw or cheek swab. If it’s a blood draw, we can work with our Child Life services to help make your child as comfortable as possible. Then, we’ll send the sample to labs for testing. Sometimes, we can coordinate for the cheek swab to be collected in your home.

What to expect after genetic testing?

Four to six weeks after a blood draw or cheek swab, your pediatric neurologist will receive results and review them with you. More in-depth tests like whole exome sequencing can take up to three months to generate results.

If testing identifies a genetic cause of the disorder, your doctor will recommend the next steps for customized treatment. Your child might have access to clinical trials for targeted medications specifically for their genetic condition. Or, doctors might change your child’s medication or treatment plan because they now have more information about how to effectively treat your child.

If the testing didn’t confirm a genetic cause of the disorder, your doctor might recommend further genetic testing to gain as much information as possible. Even if the test is negative, this information is still valuable in providing the best treatment for your child.

In some cases, genetic testing may uncover that your child has another condition or is at-risk for another condition because of their genetics. If that happens, our experts will provide advice and a treatment plan for those conditions. Identifying these conditions early helps doctors provide the best treatment to help your child live their happiest, healthiest life.