Diagnosis was established by using histological and genetic procedures (nerve biopsy, mtDNA molecular analysis in skeletal muscle and mutation screening in the _POLG_ gene). Results
Sural nerve biopsy showed marked loss of large myelinated fibers. Skeletal muscle analysis revealed multiple mtDNA deletions, a marked decrease in mtDNA copy number and pathogenic mutations in the _POLG_ gene.
Mitochondrial DNA depletion and polg mutations in a patient with sensory ataxia, dysarthria and ophthalmoplegia
 
  Keywords
 
 
  
   Sensory ataxic neuropathy
  
  
   
    dysarthria and ophthalmoplegia
   
  
 
 
  
   Mitochondrial deoxyribonucleic acid
  
 
 
  
   Multiple deletions
  
 
 
  
   Depletion
  
 
 
  
   POLG
  
 
Abstract
 Background and objetive
A broad spectrum of clinical disorders is produced by mutations in the DNA polymerase gamma mitochondrial ( _POLG_ ) gene which are associated with altered mitochondrial DNA (mtDNA) integrity.
The majority of disorders characterized by multiple mtDNA deletions present with progressive external ophthalmoplegia, though this feature is not usually found in syndromes caused by mtDNA depletion.
We report on a patient having the clinical triad of sensory ataxic neuropathy, <dis>dysarthria</dis> and ophthalmoplegia (SANDO), _POLG_ mutations and reduced muscle mtDNA content.
Patient and methods
The patient presented with sensory ataxic neuropathy, <dis>dysarthria</dis> and ophthalmoplegia.
Diagnosis was established by using histological and genetic procedures (nerve biopsy, mtDNA molecular analysis in skeletal muscle and mutation screening in the _POLG_ gene).
Results
Sural nerve biopsy showed marked loss of large myelinated fibers.
Skeletal muscle analysis revealed multiple mtDNA deletions, a marked decrease in mtDNA copy number and pathogenic mutations in the _POLG_ gene.
Conclusions
 _POLG_ mutations must be considered in all patients with the cardinal findings of the SANDO phenotype, without taking into account the type of abnormalities encountered in the mitochondrial genome.
Abstract
 Background and objetive
A broad spectrum of clinical disorders is produced by mutations in the DNA polymerase gamma mitochondrial ( _POLG_ ) gene which are associated with altered mitochondrial DNA (mtDNA) integrity.
The majority of disorders characterized by multiple mtDNA deletions present with progressive external ophthalmoplegia, though this feature is not usually found in syndromes caused by mtDNA depletion.
We report on a patient having the clinical triad of sensory ataxic neuropathy, dysarthria and ophthalmoplegia (SANDO), _POLG_ mutations and reduced muscle mtDNA content.
Patient and methods
The patient presented with sensory ataxic neuropathy, dysarthria and ophthalmoplegia.
Diagnosis was established by using histological and genetic procedures (nerve biopsy, mtDNA molecular analysis in skeletal muscle and mutation screening in the _POLG_ gene).
Results
Sural nerve biopsy showed marked loss of large myelinated fibers.
Skeletal muscle analysis revealed multiple mtDNA deletions, a marked decrease in mtDNA copy number and pathogenic mutations in the _POLG_ gene.
Conclusions
 _POLG_ mutations must be considered in all patients with the cardinal findings of the SANDO phenotype, without taking into account the type of abnormalities encountered in the mitochondrial genome.
Diagnosis was established by using histological and genetic procedures (nerve biopsy, mtDNA molecular analysis in skeletal muscle and mutation screening in the _POLG_ gene). Results
Sural nerve biopsy showed marked loss of large myelinated fibers. Skeletal muscle analysis revealed multiple mtDNA deletions, a marked decrease in mtDNA copy number and pathogenic mutations in the _POLG_ gene.