Hundreds of mutations have been connected to autism spectrum disorder (ASD), and a new study finds further evidence that suggests a possible cause of this spectrum of conditions
Neuroscience News recently published an article announcing a finding by researchers at Philadelphia’s Children’s Hospital. The researchers have now shown that defects in the mitochondria of brain cells could cause ASD based on the fact that mitochondria are considered the cell’s “batteries”. Their primary function is to create energy. In fact, they generate a major portion of energy in the body.
Therefore, the researchers reasoned that variants in mitochondrial DNA (mtDNA) could cause ASD.
About Autism Spectrum Disorder
The National Institute of Mental Health defines ASD as a developmental disorder as the first symptoms generally occur in the first or second year of life. ASD presents challenges in social and behavioral skills and communication.
Symptoms vary widely between affected individuals, as they all fall somewhere different on the spectrum. It is important to personalize any treatment for each affected individual.
About the Research
The research team put this hypothesis into action by introducing mtDNA mutations into mice similar to mutations in patients. Their rationale was that if mitochondrial defects are suspected of causing ASD, then a mouse model that is introduced to mtDNA mutations should develop the same traits. The traits that were similar to those seen in patients with ASD were neurophysiological, biochemical, and behavioral.
The team introduced a mutation in the mtDNA ND6 gene into a mouse strain. As a result, the mouse showed increased repetitive behaviors, anxiety, and lack of social interactions. The same features that are associated with ASD.
In addition, the team found deviations in EEGs, seizures, and defects on mitochondrial functions in the brain but no change in the anatomy of the brain. Therefore, the findings lend credence to the original suggestions that energy defects in mitochondria are enough to cause autism.
Dr. Douglas Wallace, Director of the Epigenomic and Mitochondrial Center, said that the study indicates that mild mitochondrial variants can cause ASD but may not cause neuroanatomical deficiencies. Dr. Wallace went on to say that the ASD mutations cause tissue-specific defects in the brain. After suggesting the need for additional studies, Dr. Wallace said their current findings may result in improved diagnosis and treatments for autism patients.
