Screening for medium chain acyl-CoA dehydrogenase deficiency has still not been evaluated

EDITOR—Every baby born in the United Kingdom is screened for phenylketonuria and congenital hypothyroidism at 6-14 days of age. Several screening laboratories now use tandem mass spectrometry for estimating blood phenylalanine concentration. Tandem mass spectrometry can assay simultaneously, in the same sample, many other metabolites and can thus potentially detect other metabolic disorders, including medium chain acyl-CoA dehydrogenase deficiency. Medium chain acyl-CoA dehydrogenase deficiency is almost as common as phenylketonuria, affecting roughly 1:15 000 births in the United Kingdom. Infants with …