Critical review of current MPS guidelines and management

Abstract Mucopolysaccharidoses (MPS) are a group of lysosomal storage disordersthat impair degradation of glycosaminoglycans (GAG). The specific GAGs that accumulate depend on the type of MPS, leading to unique characteristic clinical features. Development of guidelinesfor treatment of MPS has traditionally been multifaceted and largely based on palliative care. In the last three decades, hematopoietic stem cell transplantation and enzyme replacement therapyhave been developed based on experimental and clinical studies. Guidelineshave been established with the accumulation of the clinical data from natural history of the disease and therapeutic consequences, mainly sponsored by pharmaceutical companies. In recent years, committees in three countries, Australia (2015), Japan (2017), and Brazil (2018) have adopted guidelinesfor the treatment of MPS II, sponsored and authorized by each government. As novel treatments for MPS including substrate reduction therapy, pharmacological chaperonetherapy, and gene therapy become clinically available, it is increasingly necessary to establish the optimal guidelinefor each type of MPS, considering multiple factors including therapeutic efficacy, adverse effects, age, disease stage, prognosis, feasibility and availability of access to treatment, and cost- performance. In this article, we discuss the historical guidelinesfor specific MPS types and the most recently adopted guidelinesfor MPS II and propose the development of future guidelineswithout conflict of interest and bias leading to mutual benefits to all parties including patients and families, professionals, tax payers, and governments.