Organic aciduria in neonatal multiple carboxylase deficiency.

A Samoan patient and a Saudi-Arabian patient were found to have abnormalities in the pattern of organic acid metabolites characteristic of 3-methylcrotonylglycinuria, propionic acidaemia and lactic acidosis. Both patients died early in life. The metabolic pattern is diagnostic of multiple carboxylase deficiency and an enzymatic diagnosis was made in a subsequent affected sibling of the first patient. Deficiency of the three carboxylases suggests a primary defect in the metabolism of biotin which is required for their activity. The importance of the recognition of the clinical picture is highlighted by the fact that this lethal disease is readily treated with biotin. These patients have prominent skin lesions which can serve as alerting signs for the diagnosis.