Now a possible treatment is in sight. Emory is participating, along with four other medical centers, in a Phase II clinical trial testing targeted drug therapy for fragile X syndrome.
Fragile X syndrome affects approximately 1 in 4,000 males and 1 in 8,000 females in the United States, in addition to many more carriers of the mutation. A premutation of the gene is present in 1 in 800 males and 1 in 260 females.
The randomized, double-blind, placebo-controlled clinical study is being conducted in 32 adult participants, ages 18 to 50, with fragile X syndrome. A second study will continue testing the most effective dose against a placebo in 28 participants. In addition to Emory, the study sites are Rush Medical Center, Indiana University Medical Center, Vanderbilt University Medical Center, and the University of California, Davis, Medical Center.
Warren and others have learned that the genetic mutation inhibits the production of a protein, FMRP, which regulates the amount of other proteins produced in the brain. Scientists have since discovered that the absence of this protein leads to the over production of synaptic proteins triggered by mGluR5 activity, a glutamate receptor that is part of the brain’s signaling mechanism. This results in the complex learning and behavior problems of fragile X syndrome.
“The drug we are testing is an mGluR5 antagonist, which puts a brake on the mGluR5 activity and may improve learning and cognition,” says Emory geneticist Jeannie Visootsak, MD, principal investigator of the study. “In mouse and fruit fly models, we were able to improve cognition with an mGluR5 antagonist.”
A phase I trial of the drug was conducted last year in adults without fragile X syndrome, and no serious adverse events were noted. The current trial will assess safety as well as efficacy.
The clinical trial is sponsored by Roche Pharmaceuticals. More information about the trial is available at the Fragile X Clinical Trials Unit, Division of Medical Genetics, Emory University, 404-778-8478 or 8479.
The Robert W. Woodruff Health Sciences Center of Emory University is an academic health science and service center focused on missions of teaching, research, health care and public service. Its components include the Emory University School of Medicine, Nell Hodgson Woodruff School of Nursing, and Rollins School of Public Health; Yerkes National Primate Research Center; Emory Winship Cancer Institute; and Emory Healthcare, the largest, most comprehensive health system in Georgia. Emory Healthcare includes: The Emory Clinic, Emory-Children’s Center, Emory University Hospital, Emory University Hospital Midtown, Wesley Woods Center, and Emory University Orthopaedics & Spine Hospital. The Woodruff Health Sciences Center has a $2.5 billion budget, 17,600 employees, 2,500 full-time and 1,500 affiliated faculty, 4,700 students and trainees, and a $5.7 billion economic impact on metro Atlanta.