National Reyes Syndrome Foundation UK

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Inherited Metabolic Disorders Which Can Simulate Reye's Syndrome

Defects in Metabolism of Lipids



Defects in the ß-Oxidation Cycle

  • Medium-chain acyl-CoA dehydrogenase deficiency (MCADD)
  • Very long chain acyl-CoA dehydrogenase deficiency (VLCADD)
  • Long chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCADD) and Mitochondrial trifunctional protein deficiency
    see Note i
Defects in Electron Transfer Pathway

  • Multiple acyl-CoA dehydrogenase deficiency- severe and mild
  • Riboflavin responsive multiple acyl-CoA dehydrogenase deficiency
    see note ii
Defects in the Carnitine cycle

  • Carnitine palmitoyltransferase deficiency Types CPT(Ia) CPT1(liver) & CPT II

  • Carnitine-acylcarnitine translocase deficiency

  • Carnitine deficiency myopathic / systemic
       also known as:
       Primary carnitine deficiency
       Systemic carnitine deficiency
       Carnitine transporter deficiency
       OCTN2 transporter deficiency

Note i

Long chain 3-hydroxyacyl-CoA dehydrogenase and Mitochondrial trifunctional protein deficiency are rare conditions that prevent the body from converting certain fats to energy, particularly during periods without food (fasting) .  Further information about these disorders can be found by consulting "Genetics Home Reference".  See Resources & Reports shown opposite.

Note ii

Riboflavin responsive multiple acyl-CoA dehydrogenase deficiency is not listed on the CLIMB website.  This disorder is increasingly recognised as a cause of muscle weakness in adolescent girls in particular, but as well as the muscle problems some present with acute ketotic vomiting and decreased consciousness rather like a Reye’s-syndrome presentation.


Next review January 2020