Spinal and bulbar muscular atrophy: skeletal muscle pathology in male patients and heterozygous females

J Neurol Sci. 2008 Jan 15;264(1-2):100-5. doi: 10.1016/j.jns.2007.08.012. Epub 2007 Sep 12.


Spinal and bulbar muscular atrophy (SBMA) is an adult form of X-linked motor neuron disease caused by an expansion of a CAG repeat sequence in the first exon of the androgen receptor (AR) gene. Nuclear accumulation of mutant AR with expanded polyglutamines in motor neurons is a major pathogenic mechanism. To characterize muscle involvement in SBMA the skeletal muscle biopsies of 8 SBMA patients and 3 female carriers were studied. Six of 8 SBMA patients showed myogenic changes together with the neurogenic atrophy in their muscle biopsy. Myopathic abnormalities did not correlate with disease duration and were more prominent in the muscle of patients with an higher degree of disability. In all patients plasma CK levels were more elevated than what usually occurs in denervative diseases. Both neurogenic and myopathic changes were also observed in female carriers. Here we suggest that myopathic changes in SBMA muscle are not only related to denervation and that muscle satellite cells may have a role in the pathogenesis of muscle damage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biopsy
  • Creatine Kinase / blood
  • DNA Repeat Expansion / genetics
  • Disease Progression
  • Female
  • Genetic Predisposition to Disease / genetics*
  • Heterozygote*
  • Humans
  • Male
  • Middle Aged
  • Motor Neurons / metabolism
  • Motor Neurons / pathology
  • Muscle Fibers, Skeletal / metabolism
  • Muscle Fibers, Skeletal / pathology
  • Muscle, Skeletal / pathology*
  • Muscle, Skeletal / physiopathology
  • Muscular Atrophy, Spinal / genetics
  • Muscular Atrophy, Spinal / pathology*
  • Muscular Atrophy, Spinal / physiopathology
  • Nerve Degeneration / genetics
  • Nerve Degeneration / metabolism
  • Nerve Degeneration / physiopathology
  • Peptides / genetics
  • Receptors, Androgen / genetics
  • Satellite Cells, Skeletal Muscle / metabolism
  • Satellite Cells, Skeletal Muscle / pathology
  • Severity of Illness Index
  • Sex Characteristics


  • Peptides
  • Receptors, Androgen
  • polyglutamine
  • Creatine Kinase