Peroxisomal single enzyme deficiencies include among others, acyl-CoA oxidase deficiency (Ferdinandusse et al., 2007), ACBD5 deficiency (Ferdinandusse et al., 2017), and the most common peroxisomal disorder, adrenoleukodystrophy (ALD) (Moser et al., 2001). Here, ACBD5 is linked to adrenoleukodystrophy.