Making Sense of Genetic Testing for Autism Spectrum Disorders

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GENETIC ALLIANCE BY LAUREN LICHTEN, MS CGC

Although it is a routine recommendation to offer genetic testing to all children who have a diagnosis of an autism spectrum disorder (ASD), the thought of genetic testing can be unsettling to many parents. It also can be very difficult for families and doctors to obtain clear and accurate information about genetic testing for ASDs in an age where our knowledge of genetics is growing at a rapid pace.

“ASD Gene-Link” is a project that aims to demystify genetic testing for autism spectrum disorders. This project, supported by the National Genetics Education and Consumer Network (NGECN), is collaboration between Boston University School of Public Health researchers and the Boston Medical Center Autism Program that aims to improve patient and provider knowledge, awareness, and understanding of genetic testing for ASDs and to facilitate access to genetic services. As part of this project, educational materials were developed for both families and providers. One goal of the parent information booklet was to answer some common questions parents might have about genetic testing for autism spectrum disorders, which are highlighted below.

1. WHAT CAUSES AUTISM SPECTRUM DISORDERS?
There is a lot of research being done to understand why ASDs happen, but we know there is nothing parents can do to cause their child to have an ASD. ASDs can sometimes be caused by a change in the genetic information. Our genetic information, or DNA, is stored inside the cells of our body and grouped into genes along the chromosomes. Changes in chromosomes or genes can cause health or developmental problems and there are many genetic changes associated with ASDs. Some genetic changes can cause autism in addition to other health problems.

2. NOBODY ELSE IN MY FAMILY HAS AN AUTISM SPECTRUM DISORDER. HOW CAN IT BE GENETIC?
We are learning more each day about the role genetics plays in the development of autism spectrum disorders. Currently, doctors can find a genetic explanation for a child’s ASD 30 to 40 percent of the time. Many different genetic changes can lead to a child developing an ASD. Sometimes, parents pass down these genetic changes to the child. Other times, the genetic changes are new and occur only in the child. This may explain why a child developed an ASD even though no ASDs have appeared in that family before.

3. WHAT KINDS OF GENETIC TESTS ARE RECOMMENDED FOR CHILDREN WITH AN AUTISM SPECTRUM DISORDER?
There are many different genetic tests available, but most of the time, genetic testing for ASD involves a blood test. Doctors typically recommend two tests for children with autism spectrum disorder: fragile X testing and chromosome microarray, or CMA. Fragile X syndrome is a relatively common genetic condition that can cause autism spectrum disorder, particularly in boys. CMA looks for extra or missing pieces of chromosome material, which are common changes that can lead to ASD. Doctors may also recommend other tests, depending on your child’s development, medical history, and family history.

4. WHAT ARE THE POSSIBLE RESULTS OF GENETIC TESTING?
There are three possible results of genetic testing: positive, negative, and variant of uncertain significance. A positive result means that a genetic change has been identified that is known to cause medical and/or developmental problems. A positive result is a genetic diagnosis. A negative result means that no genetic changes have been identified. A negative result does not rule out a genetic diagnosis as no single genetic test can test for every genetic condition. A variant of uncertain significance means that a genetic change has been identified, but more information is needed to determine if the change can cause health problems or if the change is a normal variation. We all have genetic variations and not all of these changes cause health problems.

5. I’M NOT PLANNING ON HAVING MORE CHILDREN. IS THERE ANY POINT OF HAVING GENETIC TESTING?
Genetic testing can help determine the chances that other family members, including future children, will develop ASD. However, the main benefit of genetic testing is that it may provide an explanation of why your child developed ASD. If a genetic cause is identified, it may help determine the types of services that your child may benefit from. Knowledge of a genetic cause may also help identify other health issues in your child. For example, if a genetic cause was identified that is associated with an increased risk for vision problems, more frequent eye exams would be recommended.

6. WILL GENETIC TESTING TELL ME HOW WELL TREATMENTS WILL WORK?
There are things genetic testing can and cannot tell you. Genetic testing cannot tell you how your child will develop or how well treatments will work for your child. However, if a genetic cause was identified, it can be helpful to know what treatments worked for other children with the same genetic change.

7. DOES INSURANCE COVER GENETIC TESTING? CAN I LOSE MY HEALTH INSURANCE BECAUSE OF THE RESULTS?
Many insurance companies cover routine genetic testing, such as fragile X testing and CMA. However, it is important to talk to your insurance company and doctor prior to having testing so that you understand if there will be any out of pocket cost to you. There are federal laws in place that prevent you from losing your health insurance based upon the results of genetic testing. For more information on the Genetic Information Nondiscrimination Act (GINA) visit ginahelp.org.

8. DO I HAVE TO GET GENETIC TESTING FOR MY CHILD?
It is your choice to have genetic testing done for your child. Receiving a diagnosis of ASD can be overwhelming and some parents are not ready for genetic testing at that time. It is not necessary to have genetic testing done right away as your child’s DNA is not going to change. You can work with your child’s doctor to determine the right time for genetic testing.

9. WHO CAN I TALK TO IF I HAVE MORE QUESTIONS?
Genetic testing raises many questions and concerns for parents. A genetics team can be very helpful in determining which genetic tests are best for your family, explaining the advantages and disadvantages of genetic testing, and interpreting the results of genetic testing. A genetics team is usually made up of a genetics doctor (a geneticist) and a genetic counselor, who both have specialized training in genetics. To find a genetic counselor near you, you can use the “find a genetic counselor” tool on the National Society of Genetic Counselors’ website: www.nsgc.org.
The goal with the ASD Gene-Link project is to ultimately facilitate access to genetic services for ASDs. For more information about the project, or to receive a copy of the parent information booklet, please contact the Autism Program at BMC: bmcautismprogram@gmail.com •

This project was funded by an Impact Award from the Genetic Alliance/National Genetics Education and Consumer Network – PIs:Catharine Wang & Emily Feinberg.

ABOUT THE AUTHOR:
Lauren Lichten is a Licensed Genetic Counselor and clinical instructor at Boston University School of Medicine.

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