ACADVL and very long chain acyl-CoA dehydrogenase deficiency: Numerous studies have examined the clinical course of patients with FAODs identified by NBS.38–41 In the earliest of these, eight asymptomatic patients from Germany and the United States with possible VLCAD deficiency identified by NBS (n = 7; 2–3 days at analysis) or family screening (n = 1; 3 years at analysis) underwent enzyme and/or genetic analysis to confirm and characterize their diagnosis.38 Molecular analysis identified missense variants in seven of eight patients, and biochemical assays found that VLCAD activity was reduced to 6–11% of normal in four of eight patients.