Absence of immunoreactive enzyme protein in short-chain acylcoenzyme A dehydrogenase deficiency

Defects of short-chain acylcoenzyme A dehydrogenase (SCAD) may cause a severe metabolic illness in children or a lipid storage myopathy in adults. The childhood form is associated with low enzyme activity, but the synthesis of a normal-size enzyme protein in cultured skin fibroblasts. We report further biochemical studies on the original patient described with myopathic SCAD deficiency. We show an absence of enzyme protein in skeletal muscle, which both confirms the original diagnosis and suggests that the two forms of SCAD deficiency have a different molecular basis.