In many instances, genetic testing can guide the diagnosis and even treatment of autism. We at Center for Medical Genetics agree that such testing should always be done with the best interests of the child in mind. This test can be particularly useful for diagnosing older babies and children with developmental disorders such as autism. 

What is ASD?

Autism spectrum disorder (ASD) is a behavioral diagnosis. The range of symptoms in ASD vary and are generally characterized by an impaired ability to communicate and interact socially with other people. Sometimes children will not meet the diagnostic criteria for ASD but will have autistic-like features.

Why should I get a genetic test for autism?

There are many reasons you might find it beneficial to have your child tested.  Here are a few of them:

  1. If a genetic cause for your child’s ASD is identified, it might lead to changes in his/her medical management.  There might be recommendations for evaluation, testing or treatment that are specific to the genetic diagnosis, which you would only know about if your child were to have genetic testing.
  2. Because genetic conditions are often (though not always) inherited, the diagnosis might have implications for other family members, who might also need to pursue specific medical follow-up.
  3. Having a genetic diagnosis might give you more information about what to expect in terms of your child’s medical and developmental future.
  4. Having a genetic diagnosis might make it easier for you to connect with other parents or families of children with the same diagnosis. This type of support can be very valuable to families.
  5. Having a genetic diagnosis would end what some families and healthcare providers refer to as the “diagnostic odyssey” and might reduce the need for invasive procedures such as blood draws or lumbar punctures.
  6. A special genetic diagnosis might lead to opportunities to participate in clinical trials for new treatments, or other types of research.
  7. If you or other family members are planning a pregnancy, knowing the genetic diagnosis will make it possible to provide specific information about the likelihood that future children could have the same genetic condition.

It is important to keep in mind that at this time, genetic testing will not necessarily identify a genetic cause in every child with an ASD. In fact, for most children the results of genetic testing will be normal, even if they have the most comprehensive testing available.  It is also important to know that sometimes genetic testing may lead to information of unknown significance. This is because genetic information is relatively new and there may not always be enough clinical data to interpret laboratory results.  In some instances, a laboratory may request blood samples from parents or other family members in order to clarify results.

Relationship between ASD and Fragile X Syndrome

Whereas ASD is a behavioral diagnosis, FXS is a medical, or more accurately, a genetic diagnosis. When associated with FXS, ASD is caused by the genetic change or mutation in the Fragile X gene. . If a child is diagnosed with ASD and then diagnosed with FXS, he or she still has ASD. It is no different than someone with FXS also having ADHD or any other behavioral symptom of FXS.