Isovaleric acidaemia in two South African children

Two siblings who were repeatedly admitted to hospital with acute episodes of vomiting, dehydration and coma were found to be suffering from isovaleric acidaemia. This condition is a rare inherited abnormality of leucine metabolism, which is frequently fatal in the early weeks of life and leads to mental retardation in a high proportion of those who survive early attacts. However, both our patients were of normal intelligence. The clinical presentation, biochemical defect, diagnosis and suggested therapies are reviewed.