Chromosomal Microarray Helps Doctors Determine Genetic Cause of Autism
Researchers and physicians at University of Iowa Children’s Hospital are working with new technology to help identify the cause of autism in about 10 percent of cases.
Using something called a chromosomal microarray, physicians are better able to find small changes in a person’s DNA, changes that include the addition of extra DNA into a chromosome or instances of missing DNA. While the changes aren’t always harmful, some may result in disease, including autism.
April is Autism Awareness Month and physicians and staff at UI Children’s Hospital along with UI Health Care are hoping to raise awareness of the disease by outlining new technologies and methods used in diagnosing and treating some patients.
In the chromosomal microarray test, a person with autism provides DNA, typically through a blood sample. The test finds all the small changes in that person’s DNA, which are then compared with large databases that identify which changes cause autism and which do not.
Compared to older technology, the microarray test more than triples the number of instances in which genetic causes of autism are identified. Those older tests could find a genetic cause only about 3 percent of the time. The microarray test is so effective, in fact, that medical specialty groups such as the American College of Medical Genetics, the American Academy of Neurology and the Child Neurology Society have recommended that it should be included in testing of any child with an autism spectrum disorder.
The benefits of such testing are many. For families and parents, finding a cause can provide welcome relief from the uncertainty of not knowing why their child developed autism. Finding a DNA change that is causing autism in one child can also help a family better understand the risk of autism for future children. For the person with an autism spectrum disorder, some DNA changes linked to autism also lead to medical problems for which a doctor can test.
Despite the benefits, however, access to the microarray test is limited. Many insurance companies don’t yet cover the testing and because of its sophistication, microarray technology isn’t available in a large number of hospitals and clinics.