Acid Maltase Deficiency (Pompe Disease)

KEY FEATURES

• Glycogen storage disease due to pathogenic variant in the gene encoding acid alfa-1,4-glucosidase

• Age at presentation ranges from infancy to the late fifties and depends on the degree of residual enzyme activity

CLINICAL FINDINGS

• Juvenile and adult-onset forms present with slowly progressive proximal muscle weakness that includes respiratory failure

• Cardiomyopathy less common in the adult form

• Mildly elevated serum creatine kinase

• Muscle biopsy shows glycogen containing lysosomal vacuoles

DIAGNOSIS

• Suggested by detecting reduced acid-1,4-alfa-glucosidase activity on a dried blood spot

• Confirmed by genetic testing

TREATMENT

• Enzyme replacement with recombinant alfa-glucosidase stabilizes disease progression and results in improvement in respiratory function

• Patients who weigh ≥ 40 kg and are not improving on initial enzyme replacement therapy are eligible for treatment with the combination of cipaglucosidase alfa-atga and miglustat, which demonstrated similar efficacy to alglucosidase alfa in a randomized trial