Abstract
Two new cases of malonyl coenzyme A (CoA) decarboxylase deficiency are described. Hitherto, the worldwide experience of the disorder has been confined to reports on two affected Australian children. The new cases are Scots born and are the offspring of consanguinous parents of Scots/Irish origin. They were investigated during episodes of vomiting and febrile convulsions associated with concomitant developmental delay. Malonic aciduria and grossly reduced malonyl CoA decarboxylase activity were demonstrated and the total ion current chromatograms of urinary organic acid profiles obtained by gas chromatography-mass spectrometry are presented. The clinical and biochemical features of the Scots and Australian patients are compared.