A new study in mice suggests that a single genetic mutation could be at the root of autism-causing brain development disorder.
Could the single mutation of a gene contribute to the development of Autism Spectrum Disorder (ASD)?
While still today, scientists are struggling to identify all the factors determining the development of this neurological disorder affecting 1 in 160 children worldwide, new work being done by the University of Carolina's Faculty of Medicine. North (UNC) suggest that a unique genetic mutation could play a key role in the development of autism. The results have just been published in the journal Neuron.
A disorder of brain development
Still considered, erroneously, as a psychiatric illness, autism is actually an early disorder of brain development including the formation of neuronal connections.
A gene, identified in mice but also present in humans, has particularly caught the attention of researchers: the gene MEMO1, whose mutation could disrupt the formation and organization of glial cells. These cells, which play a role in supporting and protecting nerve tissue, are present in the cerebral cortex, the part of the brain that regulates higher order functions such as speech, consciousness, and memory.
"This finding suggests that autism spectrum disorders can be caused by disruptions that occur very early when the cerebral cortex is just beginning to build," says lead author Eva Anton.
A mutation that disrupts brain cells
To reach this conclusion, the researchers started by removing the MEM01 gene in an early phase of the development of the cerebral cortex. They then observed disturbances in the formation of glial cells, which branched excessively, which led to disorganization of the brain cells. The researchers concluded that these glial cells were stabilized by the MEMO1 protein produced by the gene of the same name.
Based on these results and previous studies, they then analyzed mutations of the MEMO1 gene in autistic individuals with characteristic behaviors and also with intellectual disabilities. They then discovered that this mutation resulted in a "functional loss of MEMO1" and had an impact on the development of glial cells. In addition, when the researchers re-examined genetically modified mice, they found that rodents displayed some typical behaviors of autism, such as lack of interest in exploration.
Ultimately, this discovery could provide better support for some features of ASD, including behavioral problems. However, the researchers acknowledge, this work is only preliminary, and it is still too early to hope to detect or correct this genetic mutation in utero.