Impaired energy metabolism and abnormal muscle histology in mut- methylmalonic aciduria.
The authors report a 27-year-old man with B12-responsive mut- methylmalonic aciduria associated with pure muscle symptoms. Two mutations were found in the methylmalonyl-CoA mutase gene. An exercise test showed a reduced maximal workload and reduced oxygen uptake, and a muscle biopsy showed subsarcolemmal accumulation of mitochondria and normal respiratory chain enzyme activities. These findings may be caused by inhibition of mitochondrial energy metabolism by methylmalonate or its metabolites.
Østergaard
E
E
John F. Kennedy Institute, 2600 Glostrup, Denmark. els@kennedy.dk
Wibrand
F
F
Ørngreen
M C
MC
Vissing
J
J
Horn
N
N
D000328:Adult; D019069:Cell Respiration / Q000235:genetics; D004252:DNA Mutational Analysis; D004734:Energy Metabolism / Q000235:genetics*; D017079:Exercise Tolerance / Q000235:genetics; D006801:Humans; D008297:Male; D008661:Metabolism, Inborn Errors / Q000235:genetics*; D008764:Methylmalonic Acid / Q000378:metabolism; D008765:Methylmalonyl-CoA Mutase / Q000172:deficiency* / Q000235:genetics; D008928:Mitochondria / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D028361:Mitochondrial Diseases / Q000201:enzymology / Q000235:genetics; D017240:Mitochondrial Myopathies / Q000201:enzymology* / Q000235:genetics* / Q000503:physiopathology; D018908:Muscle Weakness / Q000201:enzymology / Q000235:genetics / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D009154:Mutation / Q000235:genetics; D012508:Sarcolemma / Q000201:enzymology / Q000473:pathology
D008764:Methylmalonic Acid; D008765:Methylmalonyl-CoA Mutase