Hyperalaninemia hyperpyruvicemia and lactic acidosis due to pyruvate carboxylase deficiency of the liver; treatment with thiamine and lipoic acid.

A 16-month-old female infant with severe mental and motor retardation, clinically diagnosed as Leigh's encephalomyelopathy, forms the basis of this study. This infant was found to have lactic acidosis, low cerebrospinal fluid glucose, hyperalaninemia, and increased levels of urine lactate, pyruvate and alanine. These laboratory studies suggested an inborn error in gluconeogenesis. Further investigation revealed a low level of hepatic pyruvate carboxylase activity. The patient's elder sister who also had mental and motor deterioration was then also found to have an elevated blood lactate. These two siblings clinically and biochemically showed improvement with treatment consisting of thiamine and lipoic acid.