Clinical aspects of mitochondrial dysfunction in autism spectrum disorder (ASD) include unusual neurodevelopmental regression, especially if triggered by an inflammatory event, gastrointestinal symptoms, seizures, motor delays, fatigue and lethargy.

Many genetic abnormalities have been associated with mitochondrial dysfunction in ASD, including chromosomal abnormalities, mitochondrial DNA mutation and large-scale deletions, and mutations in both mitochondrial and non-mitochondrial nuclear genes.

Several environmental factors, including toxicants, microbiome metabolites and an oxidized microenvironment have been shown to modulate mitochondrial function in ASD tissues.