Sleep Problems In Autism May Stem From Leaky Brain Barrier
Could a leaky brain barrier be the key to causing sleep issues for people with autism?
If you aren’t getting enough sleep, you are at risk of developing serious medical conditions, including heart disease, obesity, and diabetes. Besides that, not getting regular amounts of sleep can leave you feeling tired, stressed, moody, and unable to concentrate on simple tasks.
Many people with neurodevelopmental disorders such as autism often suffer from sleep issues that can exasperate their condition even more. Until now, the underlying cause of these sleep issues was unclear, but a new study into fruit flies may have provided us with an important breakthrough.
Published in the journal Science Advances, the study titled ‘The CHD8/CHD7/Kismet family links blood-brain barrier glia and serotonin to ASD-associated sleep defects’ was led by researchers at Radboudumc University Medical Center.
“Sleep disturbances in autism and neurodevelopmental disorders are common and adversely affect patient’s quality of life, yet the underlying mechanisms are understudied,” wrote the authors of the study. “We found that individuals with mutations in CHD8, among the highest-confidence autism risk genes, or CHD7 suffer from disturbed sleep maintenance. These defects are recapitulated in Drosophila mutants affecting kismet, the sole CHD8/CHD7 ortholog. We show that kismet is required in glia for early developmental and adult sleep architecture.”
“We first looked very closely at the sleep problems in two specific patient groups with neurodevelopmental disorders,” noted Annette Schenck, Ph.D., a professor at Radboudumc. “They have mutations in the CHD8 gene, a leading genetic cause of autism, or in a closely related gene, CHD7, giving raise to CHARGE syndrome.”
“We see that the bad sleep in these disorders particularly comes from problems falling and staying asleep, which causes night awakenings and low sleep quality. We call this problem sleep fragmentation. It is frequent in autism in general but even more frequent in individuals with mutations in CHD8 or CHD7. According to affected families, these sleep problems are one of their biggest problems in daily life management. This motivated us to study sleep disturbances, in context of these genes and disorders further.”
In fruit flies, CHD8 and CHD7 are represented by a single gene that is called kismet. Fruit flies were used for the study because mutations in kismet in the fly can be mimicked by human genes.
“We see that flies with mutations in kismet have problems staying asleep, waking up during night extremely frequently. They show the same characteristics that we see in people with mutations in CHD8 and CHD7.” So said Mireia Coll-Tané, a researcher in Schenck’s group and lead author of the study.
Sleep Problems In Autism May Stem From Leaky Brain Barrier – Conclusion
While the results look extremely promising, more research is need before it can be studied effectively in humans.
“We have already shown in our article that CHD7 and CHD8 are expressed in the human blood-brain barrier, both during development and adulthood,” said Professor Tjitske Kleefstra, a clinical geneticist at Radboudumc University Medical Center. “Now, we aim to collect further clinical data and apply SRT to these patients, in close collaboration with the expert sleep clinic Kempenhaeghe in Heeze. Together, we are expanding our ‘human-to-fruit-fly-and-back’ strategy to a number of other disorders.”
References
https://science.sciencemag.org/
https://science.sciencemag.org/content/372/6546/eabe9124
https://www.radboudumc.nl/en/people/annette-schenck
