Fragile X Imaging Study Results Show Differences in Infant Brains

Using MRIs and computer models, researchers from the University of North Carolina (UNC) School of Medicine were able to prove for the first time that babies who develop the fragile X syndrome have less white matter circuitry than infants who did not develop the neurodevelopmental condition.

Data for the study was collected from 2008 to 2016, and funding was provided by the National Institutes of Health (NIH) and the Simons Foundation. Results were published in JAMA Psychiatry this morning and showed that there are brain differences related to the disorder established well before a diagnosis, which is typically made at 3 years of age or later.

With this information and the ability to image various sections of white matter from different angles, researchers can focus on the underlying brain circuitry essential to proper communications between neurons.

To date, no clinical trial or drug in development has demonstrated the ability to change treatment targets in individuals with Fragile X, and a big reason is that there hasn’t been success in identifying good treatment outcome measures or biomarkers that show responses to interventions. This morning, the U.S. Food and Drug Administration (FDA) granted orphan drug designation to BPN14770, which is in development by Tetra Discovery Partners. The therapy, however, has still yet to even enter a Phase 2.

“It’s our hope that earlier diagnosis and intervention will help children with fragile X and their families,” said co-first author Meghan Swanson, PhD, postdoctoral research fellow at the Carolina Institute for Developmental Disabilities at the UNC School of Medicine in a press release. “We also hope that this knowledge might inform drug development research.”

For the study, Swanson, along with co-senior author, Heather C. Hazlett, PhD, assistant professor of psychiatry at the UNC School of Medicine, and colleagues imaged the brains of 27 infants who went on to be diagnosed with fragile X .Seventy-three never developed the condition.

The researchers focused on 19 white matter fiber tracts in the brain, or bundles of axons, responsible for connecting various parts of the brain so that neurons can rapidly communicate with each other. Imaging and analytical analysis showed significant differences in the development of 12 out of 19 fiber tracts in babies with fragile X from as early as 6 months of age.

The babies who wound up being diagnosed with fragile X had significantly less-developed fiber tracts throughout the brain. “One of the exciting things about our findings is that the white matter differences we observe could be used as an objective marker for treatment effectiveness,” said Hazlett.

“These results substantiate what other researchers have shown in rodents — the essential role of fragile X gene expression on early development of white matter in babies,” said co-first author, Jason Wolff, PhD, former postdoctoral fellow at UNC-Chapel Hill and now assistant professor of educational psychology at the University of Minnesota. “Our work highlights that white matter circuitry is a potentially promising and measurable target for early intervention. However, achieving the goal of infant intervention for fragile X would likely require expanded newborn screening efforts.”

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