Relative carnitine deficiency in autism

J Autism Dev Disord. 2004 Dec;34(6):615-23. doi: 10.1007/s10803-004-5283-1.


A random retrospective chart review was conducted to document serum carnitine levels on 100 children with autism. Concurrently drawn serum pyruvate, lactate, ammonia, and alanine levels were also available in many of these children. Values of free and total carnitine (p < 0.001), and pyruvate (p = 0.006) were significantly reduced while ammonia and alanine levels were considerably elevated (p < 0.001) in our autistic subjects. The relative carnitine deficiency in these patients, accompanied by slight elevations in lactate and significant elevations in alanine and ammonia levels, is suggestive of mild mitochondrial dysfunction. It is hypothesized that a mitochondrial defect may be the origin of the carnitine deficiency in these autistic children.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Alanine / blood
  • Autistic Disorder / diagnosis
  • Autistic Disorder / metabolism*
  • Carnitine / blood
  • Carnitine / deficiency*
  • Child
  • Child, Preschool
  • Diagnostic and Statistical Manual of Mental Disorders
  • Female
  • Humans
  • Hyperammonemia / blood
  • Lactic Acid / blood
  • Male
  • Pyruvic Acid / blood
  • Retrospective Studies


  • Lactic Acid
  • Pyruvic Acid
  • Alanine
  • Carnitine