Abstract
Two brothers, aged 11 and 13 years, have seizures, growth and developmental delay and intellectual regression. Physical findings include mild facial coarseness, bilateral ptosis, sensorineural hearing loss, hypotonia, weakness, incoordination, and hyporeflexia. Their mother has late onset sensorineural hearing loss but is otherwise normal. Abnormal laboratory results include elevated plasma and CSF alanine and lactate (4-6mM), low dibasic and neutral amino acids and mild cerebral atrophy; muscle from the younger boy contains ragged red fibers. Lactate to pyruvate ratios in fibroblasts incubated with glucose were normal (Dr. Brian Robinson). Dr. Thomas Perry of Vancouver has ruled out lysinuric protein intolerance or renal tubular dysfunction. In the younger boy's fibroblast mitochondria, ATP synthesis with pyruvate and malate was undetectable (<1% of control) and with succinate, 70% of control, suggesting deficient activity of Complex I of the electron transport chain. In another child with hypotonia, necrotic lesions of the cerebral cortex, hepatomegaly with severe fatty change, lactic acidosis and early death, we found Complex I activity to be 20% of control, as did Dr. Robinson. These patients demonstrate the clinical and biochemical heterogeneity of disorders involving the electron transport chain in man and the utility of mitochondrial studies in fibroblasts.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Rhead, W., Amendt, B., Greenberg, C. et al. MITOCHONDRIAL NADH-CoQ OXIDOREDUCTASE (COMPLEX I) DEFICIENCY IN MAN. Pediatr Res 21 (Suppl 4), 345 (1987). https://doi.org/10.1203/00006450-198704010-01069
Issue Date:
DOI: https://doi.org/10.1203/00006450-198704010-01069