Progress in Enzyme Replacement Therapy in Glycogen Storage Disease Type II

Area of Science:

• Biochemistry
• Genetics
• Lysosomal Storage Disorders

Background:

• Glycogen storage disease type II (GSDII), also known as Pompe disease, is a genetic disorder caused by mutations in the alpha-glucosidase (GAA) gene.
• It presents in infantile, juvenile, and adult-onset forms, with late-onset GSDII often mimicking muscular dystrophies and affecting respiratory function.
• Understanding the natural history and treatment efficacy in late-onset GSDII is vital due to progressive muscle decline.

Purpose of the Study:

• To evaluate the efficacy of enzyme replacement therapy (ERT) in patients with late-onset Glycogen storage disease type II.
• To assess changes in skeletal muscle strength, functional abilities, respiratory function, and quality of life following ERT.
• To determine the importance of diverse clinical parameters in evaluating ERT effectiveness for heterogeneous late-onset GSDII.

Main Methods:

• A cohort of 11 late-onset GSDII patients was studied before and after ERT.
• Muscle strength was assessed using the Medical Research Council (MRC) scale.
• Functional tests, the 6-minute walk test (6MWT), spirometry for respiratory function, and quality of life questionnaires were employed.

Main Results:

• Patients exhibited partial improvements in muscle strength and functional tests after ERT.
• Respiratory function showed some positive changes, and quality of life was also evaluated.
• Improvements were observed over a follow-up period of 3 to 18 months, indicating a trend of benefit.

Conclusions:

• ERT offers partial benefits for late-onset GSDII patients, though individual responses vary significantly.
• A comprehensive assessment protocol using multiple clinical parameters is essential for accurately determining ERT efficacy.
• Further research is needed to optimize ERT strategies for the heterogeneous late-onset GSDII population.