Elosulfase alfa (Vimizim®; BioMarin Pharmaceutical Inc., Novato, CA, USA) is a recombinant human GALNS associated with increased endurance, reduced urine keratan sulfate and acceptable safety profile, and it has been approved as enzyme replacement therapy (ERT) for MPS IVA [22, 23]. This evidence concerns the gene GALNS and mucopolysaccharidosis type 4A.