Fatal lactic acidosis in infancy with a defect of complex III of the respiratory chain

Pediatr Res. 1989 May;25(5):553-9. doi: 10.1203/00006450-198905000-00025.


We report our studies on the metabolic defects which caused a newborn infant to present with a severe lactic acidemia (25 mM) and to die on the 3rd d after birth despite intensive supportive measures. The mitochondrial fractions prepared from skeletal muscle and liver oxidised NAD+-linked substrates and succinate slowly. Spectrophotometric assays for complexes I, II, and III of the respiratory chain demonstrate a specific defect of complex III in the skeletal muscle and liver mitochondrial fractions. The concentrations of cytochrome b were 75% lower in the skeletal muscle and heart mitochondria than in control preparations. The amount of non-heme iron sulphur protein of complex III was low in skeletal muscle, liver, and heart. This case differs from previous reports of complex III deficiency in three respects: the patient presented in the neonatal period, the defect was expressed in several tissues, and it was fatal.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acidosis, Lactic / etiology*
  • Cytochromes / analysis
  • Electron Transport
  • Electron Transport Complex III / analysis
  • Electron Transport Complex III / deficiency*
  • Humans
  • Infant, Low Birth Weight
  • Infant, Newborn
  • Male
  • Mitochondria / analysis*


  • Cytochromes
  • Electron Transport Complex III