Developmental regression and mitochondrial dysfunction in a child with autism

J Child Neurol. 2006 Feb;21(2):170-2. doi: 10.1177/08830738060210021401.


Autistic spectrum disorders can be associated with mitochondrial dysfunction. We present a singleton case of developmental regression and oxidative phosphorylation disorder in a 19-month-old girl. Subtle abnormalities in the serum creatine kinase level, aspartate aminotransferase, and serum bicarbonate led us to perform a muscle biopsy, which showed type I myofiber atrophy, increased lipid content, and reduced cytochrome c oxidase activity. There were marked reductions in enzymatic activities for complex I and III. Complex IV (cytochrome c oxidase) activity was near the 5% confidence level. To determine the frequency of routine laboratory abnormalities in similar patients, we performed a retrospective study including 159 patients with autism (Diagnostic and Statistical Manual of Mental Disorders-IV and Childhood Autism Rating Scale) not previously diagnosed with metabolic disorders and 94 age-matched controls with other neurologic disorders. Aspartate aminotransferase was elevated in 38% of patients with autism compared with 15% of controls (P <.0001). The serum creatine kinase level also was abnormally elevated in 22 (47%) of 47 patients with autism. These data suggest that further metabolic evaluation is indicated in autistic patients and that defects of oxidative phosphorylation might be prevalent.

Publication types

  • Case Reports

MeSH terms

  • Aspartate Aminotransferases / blood
  • Autistic Disorder / diagnosis*
  • Autistic Disorder / enzymology
  • Biopsy
  • Child
  • Child, Preschool
  • Creatine Kinase / blood
  • Cytochrome-c Oxidase Deficiency
  • Developmental Disabilities / diagnosis*
  • Developmental Disabilities / enzymology
  • Diagnosis, Differential
  • Electron Transport Complex I / deficiency
  • Electron Transport Complex III / deficiency
  • Female
  • Follow-Up Studies
  • Humans
  • Infant
  • Infant, Newborn
  • Mitochondrial Diseases / diagnosis*
  • Mitochondrial Diseases / enzymology
  • Muscle, Skeletal / pathology
  • Muscular Atrophy / diagnosis
  • Muscular Atrophy / enzymology
  • Regression, Psychology*


  • Aspartate Aminotransferases
  • Creatine Kinase
  • Electron Transport Complex I
  • Electron Transport Complex III