Table 4.

Advantages and disadvantages of ERT or HSCT for MPS patients.

	ERT	HSCT	References
Advantage	•Low risk of mortality •No need of a donor and can immediately be conducted. •No age limit •Not limited by health condition •Not limited by medical facility	•One time permanent treatment •Secretion of active enzyme to various tissues •Continuous expression: more physiological •Improvement of cognitive function with early treatment •Cost-effective (less than one year the expense of ERT)	•Current study •[17] •[23], [24], [25]
Disadvantage	•Continuous life-time treatment •Weekly-based treatment for 4–5 h •Little effect on brain, bone, and heart valves •Short half-life of injected enzyme •High-cost	•A chance of mortality although the risk has been reduced •Rigorous treatment regime for 2–3 months •Age limitationa •Limited by health condition •Limited by medical facility	Personal communications •Dr. Chinen for MPS III •Dr. Orii for MPS VII •Dr. Tanaka and Dr. Yabe for MPS II

^aImpact on CNS involvement for patients with a severe type is limited by age and HSCT is preferred before the signs and symptoms of CNS disease appear. In this context, the age limitation could be applied to patients with a severe form.