ACADVL and very long chain acyl-CoA dehydrogenase deficiency: It is an autosomal recessive disorder caused by ACADVL variants, leading to impairment of the first intramitochondrial step of the catabolism of long-chain fatty acids.1 The incidence of VLCAD deficiency based on NBS reports varies among countries and regions, though much less than MCAD deficiency (Table 1).