Fatal lactic acidosis in infancy with a defect of complex III of the respiratory chain.
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.
Birch-Machin
M A
MA
Department of Neurology, University of Newcastle upon Tyne, U.K.
Shepherd
I M
IM
Watmough
N J
NJ
Sherratt
H S
HS
Bartlett
K
K
Darley-Usmar
V M
VM
Milligan
D W
DW
Welch
R J
RJ
Aynsley-Green
A
A
Turnbull
D M
DM
D000140:Acidosis, Lactic / Q000209:etiology*; D003580:Cytochromes / Q000032:analysis; D004579:Electron Transport; D014450:Electron Transport Complex III / Q000032:analysis / Q000172:deficiency*; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D008297:Male; D008928:Mitochondria / Q000032:analysis*
D003580:Cytochromes; D014450:Electron Transport Complex III