LOCALISATION OF ENZYMIC DEFECT IN PROPIONICACIDÆMIA

The clinical and biochemical findings are described in a newborn baby with acidosis and ketosis due to propionicacidæmia, who died at the age of 8 days. The enzymic defect has been localised to a failure of the activity of mitochondrial propionyl CoA carboxylase. The demonstration of a raised plasma-glycine and the presence of long-chain ketones in the urine showed that this child also had ketotic hyperglycinæmia. The coexistence of ketotic hyperglycinæmia with both propionicacidæmia and methylmalonicacidæmia suggests that ketotic hyperglycinæmia is a secondary manifestation of a disturbance of the metabolism of coenzyme A and its esters.