Pyruvate dehydrogenase (PDH) deficiency. E1 subunit deficiency (childhood form) Also called pyruvate decarboxylase deficiency or PDC deficiency
Incidence
rare (6 pts). Affects only boys.
Clinical Characteristics
Much milder than infantile form. Usually asymptomatic with mild ataxia only when having a high carbohydrate diet. They may have post-exercise fatigue, transient paraparesis, thiamine responsivenes and normal mental and motor development.
Precipitants
High carbohydrate diet
Provocation Tests
Glucose loading (1 g/kg IV) or L-Alanine loading (110 to 200 mg/kg IV) leads to sustained hyperlactic acidemia.
Diagnostic Procedures
EB-F, EB-muscle, EB-liver, EB-brain, EB-kidney, OB-F, DB-F.