IDUA and mucopolysaccharidosis type 1: Of note, in MPS-I nUCBT-hi mice the level of mono-sulfated KS, which has been associated with severity of skeletal dysplasia in the mouse model of MPS-I, was similar to WT animals (MPS-I nUCBThi vs. WT; p = 0.72) (Fig. 4D).