A new study has added to a growing body of evidence that autism is indeed a brain 'connectivity' disorder.
Senior investigator Mustafa Sahin, MD, PhD, of Children's Department of Neurology, Boston, and colleagues added to the findings suggesting rare disorder tuberous sclerosis complex (TSC), commonly associated with autism, is linked to defects in axon guidance.
The team gave evidence that mutations in one of the TSC's causative genes, known as TSC2, prevent growing nerve fibers (axons) from finding their proper destinations in the developing brain.
Sahin said: "People have started to look at autism as a developmental disconnection syndrome - there are either too many connections or too few connections between different parts of the brain.
"In the mouse models, we're seeing an exuberance of connections, consistent with the idea that autism may involve a sensory overload, and/or a lack of filtering of information."
Sahin continued: "Many of the genes implicated in autism may possibly converge on a few common pathways controlling the wiring of nerve cells.
"Rare genetic disorders like TSC are providing us with vital clues about brain mechanisms leading to autism spectrum disorders. Understanding the neurobiology of these disorders is likely to lead to new treatment options not only for TSC patients, but also for patients with other neurodevelopmental diseases caused by defective myelination and connectivity, such as autism, epilepsy and intellectual disability."
The findings were published online in Nature Neuroscience.