Succinyl-CoA: 3-ketoacid CoA-transferase deficiency. A cause for ketoacidosis in infancy

To explain the cause of a unique form of severe and intermittent ketoacidosis in an infant who expired after 6 months of life, tissue culture fibroblasts and post mortem tissue were examined for enzyme activities that catalyze glucose and ketoacid oxidation. No measurable succinyl-CoA: 3-ketoacid CoA-transferase (CoA-transferase) activity could be detected in homogenates of the post mortem brain, muscle and kidney tissue, or in the cultured skin fibroblasts. Since seven other enzyme activities involving both glycolysis and ketone body oxidation were present in these same tissues, it was reasonable to conclude that the observed absence of CoA-transferase activity was not an artifact of homogenate preparation. It was concluded that the absence of CoA-transferase activity resulted in a loss of intracellular homeostasis leading to ketoacidosis. In addition, the absence of this enzyme appears to be a reasonable explanation for the alteration in glucose metabolism that was previously reported in fibroblasts from this patient.