A simple spectrophotometric assay for long-chain acyl-CoA dehydrogenase activity measurements in human skin fibroblasts.

Long-chain acyl-CoA dehydrogenase (LCAD) deficiency is an autosomal recessive disorder of fatty acid metabolism characterized by hypoglycemia, muscle weakness and hepato- and cardiomegaly to varying extents. Analysis of organic acids in urine usually reveals dicarboxylic aciduria with elevated levels of adipic, suberic and sebacic acids as well as longer chain dicarboxylic acids. Correct diagnosis of suspected patients requires measurement of LCAD in tissue or preferably, white blood cells and/or cultured skin fibroblasts. In this paper we present a simple spectrophotometric enzyme assay based on the use of ferricenium hexafluorophosphate as electron acceptor. Under optimized conditions the method presented allowed unequivocal identification of LCAD-deficiency in fibroblast homogenates.