Long-term efficacy of hematopoietic stem cell transplantation on brain involvement in patients with mucopolysaccharidosis type II: A nationwide survey in Japan

► HSCT showed effectiveness on brain or heart involvements in MPS II patients, when performed before a sign of brain atrophy appear in MRI for brain and before valvular regurgitation appear for heart. ► HSCT showed efficacy on cribriform lesion and ventricular dilatation in MRI of MPS II. ► Cardiac valvular regurgitation was diminished in 32% valves of HSCT-treated patients. ► Urinary GAG in HSCT-treated patients was lower than in ERT-treating patients.