Our results revealed a similar cell proliferation between MPS1-H iPSCs and rMPS1-H iPSCs during neuronal differentiation, the accumulation of GAGs, resulting for IDUAα deficiency, remains the most evident hypothesis that could explain these defects as it was highlighted in MPS3 also known as Sanfilippo syndrome [18,19,20]. This evidence concerns the gene IDUA and mucopolysaccharidosis type 3.