NEONATAL DETONI-DEBRE-FANCONI-SYNDROME DUE TO A DEFECT IN COMPLEX-IIIOF THE RESPIRATORY-CHAIN

A patient with neonatal expression of severe De Toni-Debre-Fanconi syn drome is presented, Because of early signs of renal tubulopathy togeth er with a large urinary excretion of lactate, 3-hydroxybutyrate and ci tric acid cycle intermediates, a mitochondrial disorder was suspected and muscle and liver biopsies were performed. Biochemical investigatio ns in both tissues revealed a defect in the respiratory chain at the l evel of complex III. In this patient renal dysfunction was the primary symptom, and hyperlactataemia, an important clue for a mitochondrial disorder, was lacking. Conclusion Complex III deficiency should be inc luded in the differential diagnosis of neonatal De Toni-Debre-Fanconi syndrome.