Lipomatosis, proximal myopathy, and the mitochondrial 8344 mutation. A lipid storage myopathy?

Muscle Nerve. 2000 Apr;23(4):538-42. doi: 10.1002/(sici)1097-4598(200004)23:4<538::aid-mus12>;2-t.


Multiple symmetric lipomatosis (MSL) has been related in some cases to the 8344 point mutation of the tRNA-lysine gene of the mitochondrial DNA, mainly in the context of families with classic myoclonic epilepsy with ragged-red fibers (MERRF) and exceptionally in patients with proximal myopathy as the only manifestation of mitochondrial disease. We report on two families harboring the 8344 mutation. The patients presented with MSL and myopathy, expressed as limb girdle weakness in index cases and as exercise intolerance in the others. All muscle biopsies performed showed lipid storage apart from RRF and respiratory chain complexes deficiency. A possible explanation for both adipose proliferation and lipid storage myopathy in these cases is a disturbance in intermediary lipid metabolism secondary to mitochondrial respiratory chain deficiency that could be related via carnitine deficiency.

Publication types

  • Case Reports

MeSH terms

  • Adolescent
  • Adult
  • Cytochrome-c Oxidase Deficiency
  • Electron Transport Complex IV / analysis
  • Female
  • Humans
  • Lipids / analysis
  • Lipomatosis, Multiple Symmetrical / genetics*
  • Lipomatosis, Multiple Symmetrical / pathology*
  • MERRF Syndrome / genetics
  • MERRF Syndrome / pathology
  • Male
  • Middle Aged
  • Mitochondria, Muscle / genetics*
  • Muscle Fibers, Fast-Twitch / enzymology
  • Muscle Fibers, Fast-Twitch / pathology
  • Muscle, Skeletal / pathology*
  • Mutation*
  • Pedigree
  • Vacuoles / pathology


  • Lipids
  • Electron Transport Complex IV