Emily Chan
“We found the larger the embryonic brain cortical organoid size, the more severe the child’s later autism social symptoms,” said Eric Courchesne, the lead author of the study and the co-director of the Autism Center of Excellence in the neuroscience department at UC San Diego.
“Toddlers who had profound autism, which is the most severe type of autism, had the largest brain cortical organoid overgrowth during embryonic development,” he continued. “Those with mild autism social symptoms had only mild overgrowth.”
The mini brains grown from the stem cells of children with autism were about 40 percent larger than the brains of neurotypical children.
This indicates that dramatically large brain growth during the first trimester of pregnancy could be an early sign of autism.
Brain overgrowth may be caused by lower levels of a protein called NDEL1. It is known for the regulation of brain growth during embryonic development.
In the study, the team of scientists discovered that in the brain organoids of children with autism, levels of the protein were lower compared to those of the neurotypical children. The lower the protein levels were, the larger the mini brains grew.
The new study was published in the journal Molecular Autism.
