GLB1 and mucopolysaccharidosis type 4A: MPS IV (Phenotype MIM number, 253000) involves a deficiency in either the N‐acetylgalactosamine‐6‐sulfate sulfatase (GALNS; Gene MIM number, 612222; EC 3.1.6.4) enzyme for MPS IVA, also called Morquio A syndrome or β‐galactosidase for MPS IVB (GLB1; Gene MIM number, 611458) (Phenotype MIM number, 253010) (Khan et al., 2017).