Neonatal screening for medium-chain acyl-CoA dehydrogenase deficiency

Neonatal screening for medium-chain acyl-CoA dehydrogenase (MCAD) deficienc y has not yet been Introduced in the UK, primarily because of uncertainty a bout the natural history of the disorder and concerns about the specificity of the screening test. To obtain data on these Issues, we did a retrospect ive study in which we analysed the concentrations of acylcarnitines in stor ed neonatal blood spots, and reviewed patients with high octanoylcarnitine concentrations at age 7-9 years. The high morbidity and mortality associate d with the disorder, and the specificity of acylcarnitine analysis seen In our study support the introduction of screening for MCAD deficiency.