Table 1—

Clinical manifestation and classification of very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency

PhenotypeOnsetSymptoms and signsSeverityFrequency %Genotype
CardiomyopathicNeonatal or early infancyCardiomyopathy, pericardial effusion, hepatic dysfunction, mildly elevated serum ammonia, lactate and creatine kinase levelsSevere, usually fatal without treatment47Two null mutations with no residual VLCAD enzyme activity
HepaticLate infancy or childhoodRecurrent hypoketotic hypoglycaemia, hepatic dysfunctionIntermediate, may be life threatening if not diagnosed and treated33
MyopathicAdolescence to adulthoodIsolated skeletal muscle involvement with episodic muscle weakness, myalgia and rhabdomyolysis triggered by exercise or fastingMild20Two missense mutations or single amino acid deletions with residual enzyme activity
  • Arrow represents the shift from two null mutations through to two missense mutations.