[1H and 31P magnetic resonance spectroscopy study of a case of phosphoglycerate kinase deficiency].

Magnetic resonance spectroscopy (MRS) is a useful tool for detecting in vivo metabolic status and in vitro analysis of chemical metabolites. We performed MRS on a 15 year-old mentally retarded male patient with recurrent myoglobinuria due to phosphoglycerate kinase (PGK) deficiency. Muscle histochemistry was normal, although electron microscopy showed a significant increase in glycogen content. Biochemical analysis using muscle specimens revealed profound reduction of PGK activity to 4.4% of the control mean. In vivo MRS using 31P revealed a significant accumulation of sugar phosphates after ischemic forearm exercise, although no significant rise of inorganic phosphate was demonstrated during exercise. 1H MRS using the perchloric acid extracts of the blood taken at the ischemic forearm test, revealed no rise of venous lactate but a significant reduction of alanine levels. These data suggest that, unlike the patients with a glycogenolytic block, our patient with a distal glycolytic block shows a significant accumulation of sugar phosphates. The reason of the reduction of alanine levels was uncertain. A compensatory mechanism for energy supply to the muscle tissue was considered.