Pyruvate dehydrogenase (PDH) deficiency. E3 subunit deficiency (Dihydrolipoyl dehydrogenase (E3) deficiency)
Incidence
Less than 20 cases reported. AR disease.
Clinical Characteristics
Periodic lactic acidosis and MSUD-like crisis (keto-lactic acidosis) in an otherwise normal child. Symptoms usually start after age 2 years.
Precipitants
Infections, fasting.
Provocation Tests
L-Alanine loading (500 mg/kg or 1 g/kg) as an intravenous bolus rises blood glucose, which differentiates this disorder from pyruvate carboxylase deficiency.
Diagnostic Procedures
EB-F, EB-liver, EB-kidney, EB-brain, EB-heart, EB-muscle.