Fragile X syndrome is one of those genetic disorders we learn vaguely about in our Introductory Biology course during freshman year, but most people tend not to know the specifics of what fragile X is and how it impacts those afflicted with the disorder. In fact, fragile X syndrome is the most common inherited cause of intellectual disability in males. Symptoms include intellectual disabilities, problems with social interaction, delayed speech, hyperactivity, repetitive behaviors and speech. Not to mention, about ten percent of those with fragile X experience seizures and about one third meet the diagnostic criteria for autism spectrum disorder. So clearly fragile X syndrome can have significant and detrimental consequences to those inflicted with the genetic disorder. Yet until now, not much was previously known about the physicalities underlying fragile X.
This recently-published study that delves into the neural signatures underlying fragile X syndrome was performed by researchers at UNC School of Medicine. The researchers used MRI techniques to image the brains of 100 infants, 27 of which were later diagnosed with fragile X and 73 who did not develop the condition. This study focused on 19 white matter fiber tracts in the brain (pictured below). Fiber tracts are bundles of myelinated axons- the long parts of neurons that extend across the brain or throughout the nervous system. Like bundles of cables, these bundles of axons connect various parts of the brain so that neurons can rapidly communicate with each other. Such communication is essential, especially for proper neurodevelopment during infancy.
The imaging processes and analytical analysis utilized in this study found significant differences in the development of 12 of the 19 fiber tracts in babies with fragile X from as early as six months. In general, the infants who ended up being diagnosed with fragile X had significantly less-developed fiber tracts in various parts of the brain compared to infants who were not later diagnosed with the condition. These results corroborate the results found in previous research with rodents- that the role of fragile X gene expression is essential in the early development of white matter in infants.
So why are these results significant? Co-senior author Heather C. Hazlett, Ph.D., explains that “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.” That is, white matter circuitry is a potentially promising and measurable target for early intervention in the treatment of fragile X syndrome. Who knows, maybe with further, more extensive research, we will one day be able to develop a course of treatment that focuses on correcting this difference in the white matter fiber tracts. Such a discovery could potentially lead to a significant decrease in the number of individuals affected by the condition, as well as potentially lessen the severity of the syndrome in some individuals.
University of North Carolina Health Care. "Fragile X imaging study reveals differences in infant brains." ScienceDaily. ScienceDaily, 4 April 2018.
Meghan R. Swanson et al. Development of White Matter Circuitry in Infants With Fragile X Syndrome. JAMA Psychiatry, 2018 DOI: 10.1001/jamapsychiatry.2018.0180
- Posted by Nicole Ayres (1)