MCAD-deficiency with severe neonatal onset, fatal outcome and normal acylcarnitine profile

Abstract

Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is an autosomal recessively inherited disorder of fatty acid oxidation with a potentially fatal outcome in undiagnosed patients. The introduction of tandem mass spectrometry into newborn screening (NBS) has led to the inclusion of MCADD in NBS in many countries, which has resulted in a significant reduction of morbidity and mortality. We report a child with MCADD presenting neonatally with apnoea and heart arrest. Despite intensive efforts to rescue the child, including reanimation for 90 min, the child died at the second day of life. Autopsy revealed fatty liver and also fat storage in heart muscle, which was suggestive of a fatty acid oxidation defect. However, acylcarnitines determined from stored EDTA blood were not suggestive of MCADD. Nevertheless, a subsequent whole exome sequencing analysis revealed homozygosity for the ACADM gene c.1084A>G/p.Lys362Glu mutation.