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

Most patients with medium-chain acyl-CoA dehydrogenase (MCAD) deficien cy fall ill after the neonatal period with sudden severe metabolic cri ses, 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 invest igating the frequency of the characteristic mutation A985G from Guthri e cards. The male newborn described here presented at the fourth day o f life with severe metabolic acidosis, compensatory tachypnoe and gene ral malaise, which were initially interpreted as signs of neonatal sep sis. Diagnosis of MCAD-deficiency was suspected by the constellation o f negative infectious parameters and massive urinary excretion of dica rboxylic acids. The diagnosis was confirmed by a phenylpropioante load ing test and homozygosity for the mutation A985G. The clinical situati on could be stabilized within 48 hours by parenteral substitution of g lucose, bicarbonate and carnitine. Long-term therapy includes the stri ct avoidance of catabolic situations as well as carnitine substitution . Even in the first days of life the possibility of MCAD-deficiency sh ould be suspected in very ill infants with severe metabolic acidosis a nd/or hypoglycemia. The prognosis for the children depends on the prom pt determination of organic acids in urine, and is excellent, once the diagnosis has been established.