Pyruvate carboxylase deficiency is an autosomal recessive disease in which there is lactic acidosis, convulsions, retarded development and hypotonia.
The disorder has been sub-divided into two groups. In one there is a neonatal presentation with hepatomegaly, ketosis, hyperammonaemia and citrullinaemia with death by age 3 months. In the other there is an infantile presentation with survival for several years but with gross retardation.
ENZYME TESTS: The disease is tested for in the SAS laboratory by assaying pyruvate carboxylase in fibroblasts as a preliminary step in the investigation of patients with unexplained lactic acidosis.