ACOX1 and Zellweger spectrum disorders: Moser et al. [82] reported elevated plasma levels of VLCFA in patients with X-ALD, ZS, neonatal adrenoleukodystrophy (NALD), infantile Refsum’s disease (IRD), and in patients with deficiencies of peroxisomal acyl-coenzyme A oxidase (ACOX1), D-bifunctional protein (DBP), and 3-oxoacyl-coenzyme A thiolase.