A recent issue of Emory Health magazine had an article describing the progress of clinical trials for fragile X syndrome, the most common inherited cause of intellectual disability. The article included interviews with the parents of a boy, Samuel McKinnon, who is participating in one of the phase III clinical trials here at Emory.

Last week, results for the phase II study for the same medication were published in Science Translational Medicine. The drug, called STX209 or arbaclofen, is one of the first designed to treat the molecular changes in the brain caused by fragile X syndrome. STX209 shows some promise in its ability to reduce social withdrawal, a key symptom of fragile X syndrome.

In one case, a boy was able to attend his birthday party for the first time in his life. In the past, he had been too shy and couldn’t tolerate hearing people sing Happy Birthday to You, the study’s lead author Elizabeth Berry-Kravis, MD, PhD from Rush University, told USA Today.

These results have generated excitement among autism researchers and specialists, because a fraction of individuals with fragile X mutations have autism and the same drug strategy may be able to address deficits in other forms of autism.

Some caveats:
1. Autism and fragile X are not the same thing.
2. This was a phase II study, the phase III results are yet to come.
3. The study authors are up front about saying that the “primary endpoint” (irritability) showed no difference between drug and placebo.

A team led by Emory genetics chair Steve Warren identified the gene responsible for fragile X in 1991, and Emory scientists have been important players in figuring out its effects on the brain.

Warren and colleague Mika Kinoshita are co-authors on a companion paper in STM on treatment of fragile X mice. A thoughtful review piece in the same issue of STM lays out current issues in developing therapies for “childhood disorders of the synapse.”