Restless sleep marks autism disorders

Restless sleep marks autism disorders
Virginia Gewin 27 Mar 2008 2:46 PM
Clock wise: There may be molecular links
between circadian rhythms and synaptic activity.
For parents of children with autism, bedtime can be a boondoggle.

Some children with autism replay cartoons in their head or talk incessantly during the three to five hours it can take them to wind down and go to sleep1. In fact, up to 83% of parents report some type of sleep disruption among their autistic children — notably difficulty falling asleep or frequently waking in the middle of the night2.

Although the biological underpinnings of these sleep disorders are unknown, some studies — including ones on the growing number of animal models — indicate that the disruptions may hold molecular clues to the interconnected pathways involved in autism.

The best evidence for a biological link between sleep disruptions and autism comes from animal models of fragile X syndrome, a related disorder resulting from a single mutation in the FMR1 gene. The disorder accounts for between two and six percent of all autism cases.

In one model of the syndrome, for example, fruit flies lacking FMR1 are restless sleepers. “The first thing we found was a robust circadian defect,” says Thomas Jongens, a geneticist at the University of Pennsylvania.....................