Relevance of expanded neonatal screening of medium-chain Acyl Co-A dehydrogenase deficiency: Outcome of a decade in Galicia (Spain)

Abstract

Neonatal screening of medium-chain acyl-CoAdehydrogenase deficiency (MCADD) is of major importancedue to the significant morbidity and mortality in undiagnosedpatients. MCADD screening has been performed routinelyin Galicia since July 2000, and until now 199,943newborns have been screened. We identified 11 cases ofMCADD, which gives an incidence of 1/18,134. Duringthis period, no false negative screens have been detected.At diagnosis, all identified newborns were asymptomatic.Our data showed that octanoylcarnitine (C8) and C8/C10ratio are the best markers for screening of MCADD. C8 wasincreased in all patients and C8/C10 was increased in all butone patient.The common mutation, c.985A>G, was found in homozygosity in seven newborns and in compound heterozygosity in three, while one patient did not carry the common mutationat all. In addition, two novel mutations c.245G>C(p.W82S) and c.542A>G (p.D181G) were identified. Tenof the 11 identified newborns did not experience any episodes of decompensation. The patient with the highest level of medium chain acylcarnitines at diagnosis, who was homozygousfor the c.985A>G mutation, died at the age of2 years due to a severe infection.This is the first report of the results from neonatal screeningfor MCADD in Spain. Our data provide further evidenceof the benefits of MCADD screening and contribute to betterunderstanding of this disease.