A basic understanding of mucopolysaccharidosis: Incidence, clinical features, diagnosis, and management

Intractable Rare Dis Res. 2020 Feb;9(1):1-9. doi: 10.5582/irdr.2020.01011.

PMID: 32201668

Jing Zhou, Jing Lin, Wing Ting Leung, Ling Wang

Summary: Early and accurate diagnosis in the asymptomatic stage is critical for mucopolysaccharidosis (MPS) patients. This study updates details on the clinical manifestations, diagnosis, and treatment of the various types of MPS with the hopes of generating further interest in the disease.

Abstract

Background: Mucopolysaccharidoses (MPS) is a category of rare lysosomal storage diseases (LSD) with multi-organic and serious symptoms. MPS occur worldwide in various types though it has relative a low incidence. The prevalent form of MPS differs across continents, suggesting that it may be associated to geography and ethnicity. The primary cause of MPS is undegraded glycosaminoglycans (GAGs) caused by enzyme deficiencies. Coarse facial features, cognitive retardation, hepatosplenomegaly, hernias, kyphoscoliosis, corneal clouding, and other clinical features vary depending on the underlying enzyme deficiency. Different types of MPS may have similar symptoms, particularly MPS I and II, but there are some differences, such as serious neurological problems in MPS III and hydrops fetalis in MPS VII. These clinical features help with diagnosis, but for better outcomes, early and accurate diagnosis in the asymptomatic stage is critical.

Objective: Novel methods such as urinary and blood GAG tests, enzyme assays, and gene tests help to diagnose MPS and to determine its subtype. Traditional MPS treatments such as hematopoietic stem cell transplantation (HSCT) and enzyme replacement therapy (ERT) are successful in some types of MPS, but not effective at treating all MPS. Newer therapies, such as advanced ERT, gene therapy, and substrate reduction therapy (SRT), increase the effectiveness of the treatment. This study updates details on the clinical manifestations, diagnosis, and treatment of the various types of MPS with the hopes of generating further interest in the disease.