Scientists have developed a genome editing system that has successfully modified the DNA of mice with a mutation similar to that found in people with autism spectrum disorder (ASD), writes SCMP.
The article says special mice were bred for research with a mutation in the MEF2C gene, which they say is “strongly associated” with the disorder. Thus, mutations in this gene cause developmental disorders, speech problems, repetitive behavior and epilepsy, rbc.ru reports.
The developed system for editing the MEF2C gene was called AeCBE. As the study authors note, mice that received a special injection showed a decrease in behavior associated with ASD. The scientists emphasized that the potential treatment could be used not only for patients with ASD, but also for other genetic neurodevelopmental disorders.
A professor at East China Normal University told SCMP that this is the first effective treatment for mice with mutations associated with ASD. The injection would go directly into the mouse’s brain, he said, so scientists needed to learn how to safely interact with the blood-brain barrier, a group of cells that regulate the entry of foreign molecules into the brain. By studying mouse brain cells, the researchers found that AeCBE was able to “make repairs” throughout the brain with about 20% accuracy, which was enough to boost MEF2C protein levels, SCMP writes. “The treatment successfully restored MEF2C protein levels in several brain regions and reversed behavioral abnormalities in mice with the MEF2C mutation,” the paper states.
The exact cause of ASD is still unknown, but it is believed that 80–90% of cases are due to genetic predisposition. More than 100 genes have already been found that scientists associate with the occurrence of autism. But there are also environmental factors that can also contribute to the development of this disorder in a child. For example, inflammation in the mother’s body during pregnancy has been linked to an increased risk of ASD in the child. It can occur due to chronic diseases: arthritis, lupus or diabetes, and can also be triggered by obesity due to cytokines that penetrate the blood-brain barrier and attack neural networks.
Some people diagnosed with ASD as children outgrow it, achieving an “optimal outcome.” The term was coined by Deborah Fine, a professor of psychology at the University of Connecticut in Storrs. In 2013, she conducted research with 34 people diagnosed with autism. In 2016, scientists reviewed cases of “optimal outcomes” and concluded that it is possible to talk about loss of diagnosis only if it is made early. Timely, intensive behavioral intervention plays an equally important role. A large proportion of people with autism maintain symptoms consistent with the diagnosis and require therapy and support throughout their lives.