EARLY MANIFESTATION IN THE NEONATAL-PERIOD AND INCIDENCE OF MEDIUM-CHAIN ACYL-COA DEHYDROGENASE-DEFICIENCY

Most patients with medium-chain acyl-CoA dehydrogenase (MCAD) deficiency fall ill after the neonatal period with sudden severe metabolic crises, characterized by hypoketotic hypoglycemia; this can be fatal and may be misinterpreted as sudden infant death syndrome. For Germany an incidence of 1 in 55 000 affected homozygotes was determined by investigating the frequency of the characteristic mutation A985G from Guthrie cards. The male newborn described here presented at the fourth day of life with severe metabolic acidosis, compensatory tachypnoe and general malaise, which were initially interpreted as signs of neonatal sepsis. Diagnosis of MCAD-deficiency was suspected by the constellation of negative infectious parameters and massive urinary excretion of dicarboxylic acids. The diagnosis was confirmed by a phenylpropioante loading test and homozygosity for the mutation A985G. The clinical situation could be stabilized within 48 hours by parenteral substitution of glucose, bicarbonate and carnitine. Long-term therapy includes the strict avoidance of catabolic situations as well as carnitine substitution. Even in the first days of life the possibility of MCAD-deficiency should be suspected in very ill infants with severe metabolic acidosis and/or hypoglycemia. The prognosis for the children depends on the prompt determination of organic acids in urine, and is excellent, once the diagnosis has been established.