Partial block of glycolysis in late-onset phosphofructokinase deficiency myopathy

R. Massa, R. Lodi, B. Barbiroli, S. Servidei, G. Sancesario, G. Manfredi, P. Zaniol, G. Bernardi

Research output: Contribution to journalArticle

Abstract

A late-onset, myopathic variant of phosphofructokinase (PFK) deficiency has been previously described in two patients of Ashkenazic descent. We report here on a non-Ashkenazic woman with the onset, at the age of 48 years, of a progressive limb girdle myopathy that was not preceded by a history of exercise intolerance. Muscle biopsy findings at the age of 58 years showed deposition of amylopectin-like material in muscle fibers and the absence of histochemical PFK activity. Enzymatic PFK activity in vitro was only 4% of normal. Since the forearm ischemic exercise test induced a sub-normal production of serum lactate, the patient underwent phosphorus magnetic resonance spectroscopy (31P-MRS), a noninvasive method that allows in vivo assessment of the functional status of the glycolytic pathway and mitochondrial oxidative metabolism by measuring the high-energy phosphates and cytosolic pH. In vivo, 31P-MRS disclosed a residual glycolytic flux and a normal rate of ATP production both at rest and during exercise. These results suggest that, in some patients, muscle PFK deficiency may be partial in vivo, and more severe in vitro, possibly due to protein or mRNA instability rather than absence. The presence of these findings in a patient with the late-onset myopathic form is compatible with a distinct pathogenetic mechanism, relying on progressive polysaccha- ride accumulation, rather than on acute energetic shortage in muscle fibers.

Original languageEnglish
Pages (from-to)322-329
Number of pages8
JournalActa Neuropathologica
Volume91
Issue number3
Publication statusPublished - 1996

Keywords

  • Glycogenosis type VII
  • In vivo phosphorus magnetic resonance spectroscopy
  • Muscle energy metabolism
  • Myopathy
  • Phosphofructokinase

ASJC Scopus subject areas

  • Clinical Neurology
  • Pathology and Forensic Medicine
  • Neuroscience(all)

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    Massa, R., Lodi, R., Barbiroli, B., Servidei, S., Sancesario, G., Manfredi, G., Zaniol, P., & Bernardi, G. (1996). Partial block of glycolysis in late-onset phosphofructokinase deficiency myopathy. Acta Neuropathologica, 91(3), 322-329.