IDS and mucopolysaccharidosis type 2: By comparison, in the case of Mucopolysaccharidosis II (MPS II), while also an X-linked lysosomal storage disorder whose deficit of lysosomal enzyme iduronate 2-sulphatase results in accumulation of glycosaminoglycans in multiple organ systems [34], female carriers of pathogenic variants in iduronate 2-sulfatase (IDS) are rarely affected unless there is a simultaneous presence of two mutant alleles or another coincidental genetic impact [35].