AN ATYPICAL FORM OF PYRUVATE-CARBOXYLASE DEFICIENCY

A further-case of pyruvate carboxylase (PC) deficiency with all atypic al clinical and biochemical presentation and evolution is described Th e initial neonatal symptoms started with metabolic acidosis, tendency, to hypoglycalemia as described in type B, or French phenotype, brit b iochemical data showed no hyperammonaemia and normal amino acids. The study of cellular redox potential status revealed high lactate/low pyr uvate values that strongly suggested a PC deficiency which was confirm ed by enzymatic activity in cultured fibroblasts. However the clinical course was not rapidly deteriorating and the patient responded to mod erately high-carbohydrate diet and supplementations of bicarbonate and aspartate. This case leads us to underline: 1) the importance of eval uating the cellular redox potential status for a rapid diagnosis of ne onatal lactic acidosis; 2) the usefulness of an aggressive treatment d uring episodes of metabolic acidosis in modifying the devastating natu re of the disease; 3) the lack of cor relation between clinical and bi ochemical data in this atypical case.