Amyotrophic lateral sclerosis with ragged-red fibers.
BACKGROUND
Motor neuron diseases (amyotrophic lateral sclerosis [ALS] and spinal muscular atrophy [SMA]) have been rarely associated with mitochondrial respiratory chain defects.


OBJECTIVE
To describe a patient with typical ALS and the finding of ragged-red fibers in muscle biopsy specimens and to review the literature on respiratory chain defects in ALS and SMA.


METHODS
Case report and review of the literature.


METHODS
Collaboration between tertiary care academic hospitals.


METHODS
A 65-year-old man with typical ALS.


METHODS
The patient had 10% ragged-red fibers and 3% cytochrome-c oxidase-negative fibers in muscle biopsy specimens but no biochemical defects of respiratory chain enzymes or alterations of mitochondrial DNA (mtDNA).


RESULTS
Amyotrophic lateral sclerosis with ragged-red fibers has been reported in 5 families and is associated with mtDNA mutations in some subjects. Spinal muscular atrophy without mutations in the survival motor neuron gene (SMN; OMIM 600354) has been associated with mtDNA depletion or with mutations in the cytochrome-c oxidase assembly gene (SCO2; OMIM 604377).


CONCLUSIONS
Respiratory chain defects can mimic ALS or SMA and should be considered in the differential diagnosis.
Hirano
Michio
M
Department of Neurology, Columbia University Medical Center, 3-317 Russ Berrie Medical Science Pavilion, 1150 St Nicholas Ave, New York, NY 10032, USA. mh29@columbia.edu
Angelini
Corrado
C
Montagna
Pasquale
P
Hays
Arthur P
AP
Tanji
Kurenai
K
Mitsumoto
Hiroshi
H
Gordon
Paul H
PH
Naini
Ali B
AB
DiMauro
Salvatore
S
Rowland
Lewis P
LP
D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics / Q000473:pathology*; D001706:Biopsy / Q000379:methods; D002352:Carrier Proteins; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics; D030401:Cytochrome-c Oxidase Deficiency / Q000150:complications; D004252:DNA Mutational Analysis / Q000379:methods; D004272:DNA, Mitochondrial; D003576:Electron Transport Complex IV / Q000378:metabolism; D017353:Gene Deletion; D006801:Humans; D008297:Male; D024101:Mitochondrial Proteins; D018832:Molecular Chaperones; D018656:Muscle Fibers, Fast-Twitch / Q000473:pathology*; D009154:Mutation / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics; D055532:SMN Complex Proteins
D002352:Carrier Proteins; D017362:Cyclic AMP Response Element-Binding Protein; D004272:DNA, Mitochondrial; D024101:Mitochondrial Proteins; D018832:Molecular Chaperones; D009419:Nerve Tissue Proteins; D016601:RNA-Binding Proteins; C400285:SCO2 protein, human; D055532:SMN Complex Proteins; D003576:Electron Transport Complex IV