Sensitivity to carbohydrate in a patient with familial intermittent lactic acidosis and pyruvate dehydrogenase deficiency.

A 9-year old boy with severe mental and growth retardation and diffuse neurologic damage had minimal elevation of blood pyruvate (0.21 mM) and lactate (2.1 mM) on a normal diet but developed life-threatening lactic acidosis (pH 7.14; lactate 21.0 MM) on a diet containing 65% carbohydrate and 15% fat. Subsequently, blood pyruvate levels rose significantly higher than in 16 control subjects during a glucose tolerance test whereas the glucose levels were normal. Two sisters died with spontaneous lactic acidosis and an otherwise similar clinical course...