Fig. 1.

Clinical algorithm for patients with exercise intolerance in whom a metabolic myopathy is suspected. CK—creatine kinase; COX—cytochrome c oxidase; CPT—carnitine palmitoyl transferase; cyt b—cytochrome b; mtDNA—mitochondrial DNA; nDNA—nuclear DNA; PFK—phosphofructokinase; PGAM—phosphoglycerate mutase; PGK—phosphoglycerate kinase; PPL—myophosphorylase; RRF—ragged red fibers; TFP—trifunctional protein deficiency; VLCAD—very long-chain acyl-coenzyme A dehydrogenase