Fragile X expert Dr. Randi Hagerman was recently interviewed by SF Gate writer and autism advocate, Laura Shumaker. In the interview, Dr. Hagerman talks about Fragile X-associated Disorders, the important link between Fragile X syndrome and autism, and the development of new treatments for both conditions.
Yes. Whereas autism is a behavioral diagnosis, Fragile X syndrome (FXS) is a medical or more accurately, a genetic diagnosis. When associated with FXS, the autism is caused by the genetic change or mutation in the Fragile X gene. This is similar to other conditions such as Down syndrome. Individuals with Down syndrome can also have other conditions, including autism, hearing loss, diabetes and other behavioral and medical conditions. If a child is diagnosed with autism and then diagnosed with FXS, he or she still has autism, it is just that the cause of their autism is known. It is no different than someone with FXS also having ADHD or any other behavioral symptom of FXS.
Many studies have evaluated the FXS-autism link over the past decade. These studies have shown the percentage of children with FXS who have autism varying from 15 to 33 percent. This range may be due to the fact that the diagnostic criteria for autism have varied and the diagnostic tools used have changed.
Since many children with FXS are interested in social interactions, they may not meet the diagnostic criteria for autism, even as they exhibit autistic-like features such as poor eye contact, shyness, social anxiety, hand-flapping and sensory issues. Autism is much more common in boys with FXS than in girls with FXS.
Approximately 2-6 percent of children with autism are diagnosed with FXS. Given the possibility of a link, it is recommended that all children with autism, both male and female, be referred for genetic evaluation and testing for FXS and any other genetic cause of autism.
Studies show that individuals with FXS who have autism can have a more significant intellectual disability (lower IQ) than those with FXS who do not have autism.
Should all individuals have pre-marital screening for Fragile X carrier state, given how common the carrier state is?
There are three general circumstances in which Fragile X testing should be considered:
- Clinical symptoms that suggest Fragile X syndrome, FXTAS or infertility/FXPOI.
- A family history of Fragile X syndrome, FXTAS, intellectual or learning disabilities or autism of unknown cause, or infertility.
- Family or personal history of a Fragile X genetics and inheritance (carrier).
You’ll be talking at the UCSF Conference about your recent research of targeted treatment for Fragile X, autism and other neurodevelopmental disorders. Are there hopeful treatments on the horizon?
Yes. Elizabeth Berry-Kravis of Rush University Medical Center and I led the first in-patient drug trial examining the effects of the compound STX 209, also known by the name arbaclofen, on individuals with Fragile X-associated disorders. This study showed that STX 209 could become an important part of the treatment for Fragile X syndrome, because it appeared to improve symptoms in those with significant social deficits or autism, as well as Fragile X syndrome. Additional studies also are suggesting that STX 209 could be helpful for autism without Fragile X syndrome. Until now, there have been no targeted treatments available for autism. This appears to be the first.