In this cohort, no pathogenic or likely pathogenic variants were found in PEX2. Mutations in PEX2 are implicated in metabolic disease, which extends from Zellweger syndrome (most severe) to neonatal adrenoleukodystrophy (intermediate) and infantile Refsum disease (currently considered the mildest) [35]. This evidence concerns the gene PEX2 and Refsum disease.