Electrophysiological findings in a Danish family with Machado-Joseph disease

Muscle Nerve. 1996 Jun;19(6):743-50. doi: 10.1002/(SICI)1097-4598(199606)19:6<743::AID-MUS9>3.0.CO;2-A.


Machado-Joseph disease (MJD) is a neurodegenerative disorder with autosomal dominant inheritance, We have carried out electrophysiological studies in 8 individuals belonging to a Danish family with several affected members. Five had an expanded trinucleotide (CAG) repeat sequence in the MJD1 gene on chromosome 14 indicating MJD, while 3 unaffected individuals had normal repeat lengths. Three individuals with repeat expansion had clinical symptoms and signs of the Machado or "type III" phenotype, whereas 2 had slight symptoms and signs only, Electrophysiological evaluation included visual, somatosensory, and auditory brain stem evoked potentials, quantitative electromyography, and nerve conduction studies. In the patients with clinical MJD, evoked potential studies showed multimodal abnormalities, electromyography showed neurogenic changes, and nerve conduction studies showed signs of severe loss of motor and sensory nerve fibers. Of the 2 patients with slight symptoms and signs, 1 had evidence of peripheral and central affection, while the other had slight signs of a central affection. This study provides insight into the distribution and character of electrophysiological abnormalities in MJD of putative importance for an understanding of the pathogenesis of the disease, and for monitoring disease progress, or the outcome of a possible treatment.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Aged
  • Ataxin-3
  • Brain Stem / physiopathology
  • Chromosome Mapping
  • Chromosomes, Human, Pair 14
  • Denmark
  • Electromyography
  • Electrophysiology
  • Evoked Potentials, Auditory
  • Evoked Potentials, Somatosensory
  • Evoked Potentials, Visual
  • Female
  • Humans
  • Machado-Joseph Disease / genetics*
  • Machado-Joseph Disease / physiopathology*
  • Male
  • Middle Aged
  • Motor Neurons / physiology
  • Nerve Fibers / physiology
  • Nerve Tissue Proteins*
  • Neural Conduction
  • Neurons, Afferent / physiology
  • Nuclear Proteins
  • Pedigree
  • Phenotype
  • Polymerase Chain Reaction
  • Proteins / genetics
  • Repetitive Sequences, Nucleic Acid*
  • Repressor Proteins


  • Nerve Tissue Proteins
  • Nuclear Proteins
  • Proteins
  • Repressor Proteins
  • ATXN3 protein, human
  • Ataxin-3