Abnormal H-Tfam in a patient harboring a single mtDNA deletion.
We report on a patient suffering from a progressive mitochondrial disorder characterized by ocular myopathy, exercise intolerance, and muscle wasting. Morphological examination of muscle biopsy showed increased variability in fiber size and scattered ragged-red fibers. Analysis of muscle mitochondrial DNA by Southern blot and PCR revealed a heteroplasmic single deletion of 4100 base pairs, located between nucleotide positions 8300 and 12,400. Western blot analysis showed high levels of the human mitochondrial transcription factor A (Tfam). Interestingly, we also detected an additional Tfam product, of approximately 22 kDa. This is the first case in which a qualitatively abnormal Tfam has been found to be associated with a mitochondrial disorder in humans.
Tessa
A
A
Department of Neurosciences, Institute of Neurology, University of Pisa.
Manca
M L
ML
Mancuso
M
M
Renna
M R
MR
Murri
L
L
Martini
B
B
Santorelli
F M
FM
Siciliano
G
G
D001706:Biopsy; D015139:Blotting, Southern / Q000379:methods; D017931:DNA Primers / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics*; D004268:DNA-Binding Proteins; D005260:Female; D017353:Gene Deletion; D006801:Humans; D008875:Middle Aged; D024101:Mitochondrial Proteins; D018482:Muscle, Skeletal / Q000473:pathology; D009687:Nuclear Proteins / Q000235:genetics*; D017246:Ophthalmoplegia, Chronic Progressive External / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology*; D017354:Point Mutation / Q000235:genetics; D016133:Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics*
D017931:DNA Primers; D004272:DNA, Mitochondrial; D004268:DNA-Binding Proteins; D024101:Mitochondrial Proteins; D009687:Nuclear Proteins; C499631:TFAM protein, human; D014157:Transcription Factors; C422562:mitochondrial transcription factor A