NEW YORK, N.Y. (December 1, 2010) A new study published in the Journal of the American Medical Association (JAMA) and partially funded by Autism Speaks, found that children with autism have more trouble fueling the energy demands of their cells due to dysfunctional mitochondria. These new findings from UC Davis reveal several different types of mitochondrial dysfunction and suggest a novel way of screening for these deficits using blood samples.
Mitochondria, the "powerhouses" of cells, provide energy for cell functions through a cascade of enzyme complexes. Together, those enzyme complexes create energy through a process called oxidative phosphorylation. Previous studies have shown that mitochondrial dysfunction can lead to a host of disorders particularly affecting brain cells which are characterized by high energy demands. Although mitochondrial dysfunction has previously been suspected in some individuals with autism spectrum disorders, the evaluation was difficult, and typically required a sample from muscle cells.
For the study, blood samples were taken from ten children with autism and ten unrelated typically developing children, all aged 2-5 years. The researchers analyzed mitochondria in children's white blood cells. Mitochondria in the samples from children with autism were less efficient at creating energy through oxidative phosphorylation. In some, there was a genetic mutation that affected mitochondrial function. In others, the researchers observed that one or more enzyme complexes were dysfunctional. In most of the children with autism, there were many extra copies of mitochondria, which may partially compensate for each one not working optimally.
"It is remarkable that evidence of mitochondrial dysfunction and changes in mitochondrial DNA were detected in the blood of these young children with autism," said Geraldine Dawson, Ph.D., Autism Speaks chief science officer. "We look forward to seeing oth
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