Figure 2.

Urine organic acids chromatograms in mitochondrial cytopathies. (a) Control patient. The other panels show the urine chromatograms of their patients with a mitochondrial cytopathy presenting with a generalized tubular defect (b), with De Toni-Debré-Fanconi syndrome (c), or with congenital nephritic syndrome (d). Note the marked increase in lactate (L) excretion in all 3 patients, which was associated with increased urinary excretion of 3-OH-butyrate (B) and 5-oxoproline (O). Other metabolites such as pyruvate (P), succinate (S), and fumarate (F) may also be found in excess.