The activities in patients with different MPS types were as follows: IDUA in MPS I (mean: 0.428 μM/h; value: 0.414–0.442, n = 2), I2S in MPS II (mean: 0.085 μM/h; range: 0.051–0.203, n = 14), NAGLU in MPS IIIB (0.046 μM/h, n = 1), GALNS in MPS IVA (mean: 0.031 μM/h; range: 0–0.125, n = 4), and ARSB in MPS VI (mean: 0.232 μM/h; value: 0.230–0.234, n = 2), respectively. This evidence concerns the gene GALNS and mucopolysaccharidosis type 6.