[Lactic acid acidosis with mitochondrial myopathy due to a pyruvate dehydrogenase deficiency].

We report on a patient, now 17 year old, in whom lactic acidosis was detected at the age of 7 while attempting to diagnose the causes of increasing weakness. The laboratory examinations revealed elevated pyruvate, alanine and oxaloacetate levels in serum and also a lowered citrate level. This led us to suspect a disturbance of the pyruvate dehydrogenase complex. Reduced pyruvate dehydrogenase activation in leucocytes and muscle tissue was indeed found. This article reports on the 10 year history of this case and attempts to establish a connection between the various symptoms observed and the underlying metabolic defect.