Autism is an incredibly complicated disorder that is thought to be caused by a complex set of genetic and environmental factors. In short, we’re not really sure what causes autism, but a new breakthrough might have just brought us one step closer. Researchers have discovered how a switch in one autism-linked gene mutation could cause the neurodevelopmental disorder in some children.
It was just last December that researchers first identified more than 1,000 gene mutations linked with autism. While these mutations were shown to increase the risk of autism, researchers weren’t exactly sure how. In a new study, published in the journal Cell, researchers have for the first time pinpointed how a mutation turns off a switch in one of the genes linked to autism.
Researchers from the University of North Carolina (UNC) found that an enzyme called UBE3A, which is important for brain development, is constantly switched on in children with autism. During normal brain development, a phosphate molecule is attached to UBE3A to switch it off. This process is tightly controlled, but an autism-linked mutation destroys this regulatory mechanism. As a result of being constantly switched on, UBE3A becomes hyperactive, which the researchers believe could lead to abnormal brain development and autism.
Currently, about 1 in 68 children are diagnosed with autism spectrum disorder (ASD) in the United States, according to estimates by the Centers for Disease Control and Prevention. ASD is five times more common among boys than girls. Those diagnosed with autism can suffer from a range of social, communication and behavioral challenges. As autism is on a spectrum, the severity of the disorder can differ greatly between those affected.
For the study, researchers sequenced genes from cell samples of autistic children and their parents. While the parents had no hyperactive UBE3A, the children did. When they introduced this mutation into a mouse model, researchers found that more door knob-like protrusions, called dendritic spines, formed on the neurons, which has previously been linked to autism.
The researchers believe it could be possible to decrease the hyperactivity of UBE3A and restore “normal levels of enzyme activity in the brain,” senior author Mark Zylka, from UNC Neuroscience Center, said in a statement.
“In fact, we tested known compounds and showed that two of them substantially reduced UBE3A activity in neurons.” But whether or not these could reduce symptoms is unknown at this stage.
There is currently no cure for autism, but there are a range of interventions that can help improve an autistic child’s development. These interventions range from talking therapy to support with how autistic children interact with others.