Accumulation of GAG in MPS IH iPS cells. GAGs, normalized to genomic DNA, were significantly higher in both MPS IH cell types: MPS IH iPS cells vs wild-type iPS cells (mean ± SEM, 16.9 ± 0.4 vs 9.6 ± 1.0; P < .02); and MPS IH heme iPS vs wild-type heme iPS (13.8 ± 0.5 vs 8.2 ± 0.2; P < 0.01). GAG levels in gene-correlated cells were significantly lower in both cell types: MPS IH iPS cells vs MPS IH IDUA iPS cells (mean ± SEM, 12.3 ±0.1; P < .01); and MPS IH heme iPS cells vs MPS IH IDUA heme iPS cells (8.7 ± 0.3; P < .01). When GAG levels of gene-corrected cells were compared to that of wild-type cells, no significant difference was found. These data are the results of 3 independent measurements for each cell type and genotype. GAG indicates glycosaminoglycan; iPS, induced pluripotent stem cells; Heme iPS, iPS cell-derived hematopoietic cells; WT, wild type; and MPS, mucopolysaccharidosis type I, Hurler syndrome.