The percent of children with autism spectrum disorder (ASD) that experience sleep problems are up to 80 percent. It has been a mystery to get to the root of these problems as well as the exact causes of ADS, which scientists are still working to unravel.
But a group of neuroscientists at Washington State University has made a new study which has brought scientists closer to identifying the causes of disturbed sleep in autism, which could shed more lights to future treatment that would bring relief to children with autism and their caregivers. The scientists published their research in the open access journal eLife.
The senior author and the principal investigator of the study, Lucia Peixoto, an assistant professor in the WSU Elson S. Floyd College of Medicine, said that poor sleep is not only a problem for people with autism but is also one of the top concerns among caregivers. Also, there is a clear connection between sleep problems and severity of core autism symptoms including social and communication challenges and repetitive behaviors. If scientists can get to the root of these sleep issues, this could potentially help ease other autism symptoms as well.
The results of the study suggest that sleep problems in patients with autism spectrum disorder may be connected to a mutation in the gene SHANK3 that in return regulates the genes of the body's 24-hour day and night cycle. The research revealed that individuals who were missing the SHANK3 gene and mice that lacked part of the gene had difficulty falling asleep. Their study in mice also strongly supported one possible explanation as to why people with autism have trouble falling asleep. It is not that they are not asleep; they are sleepy but cannot fall asleep.
The team took a step further in their study by firstly analyzed sleep data from patients with Phelan-McDermid syndrome (PMS), a genetic disorder that often goes hand in hand with autism and is thought to be related to the SHANK3 gene. They discovered that PMS patients who are missing the SHANKS3 gene have trouble falling asleep and wake up multiple times during the night, starting at age five.
The first author of the study and a postdoctoral research associate, Hannah Schoch said that many kids with Phelan-McDermid syndrome sleep less than six hours a night, and their sleep is abysmal their lifespan, so it's an ongoing source of difficulty for them.
A postdoctoral research associate Ashley Ingiosi and Schoch did much of the hands-on work for the study. Next, Ingiosi studies sleep in a mouse model of PMS, which used mice that are missing a part of the Shank3 gene and wild-type control mice.
When they kept mice on a light-dark cycle of 12 hours each and allowed to sleep usually, mice with Shank3 mutation spent more time awake at the end of the dark period when nocturnal mice would typically take a nap. The data also suggested a reduction in the quality of their sleep.
Peixoto concluded that if scientists can understand the molecular mechanisms underlying the sleep problem in Shank3 mutant mice, they expect that this will also strongly relate to sleep problems in autism in general and that would suggest new points of intervention.
