GALNS and lysosomal storage disease: Mucopolysaccharidosis type IVA (MPS IVA), also known as Morquio syndrome type A (OMIM #253000) is rare autosomal recessive lysosomal storage disorder resulting from mutations in the GALNS gene, leading to a deficiency in the enzyme of N-acetylglucosamine-6-sulphate sulfatase (GALNS).1