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Metabolic & Lysosomal

Pompe Disease

Affects approximately
1 in 40,000 people (infantile form: 1 in 138,500; late-onset: 1 in 60,000)

Also known as: Pompe's disease, glycogen storage disease type II, acid maltase deficiency

Pompe Disease

About Pompe Disease

Pompe disease is an autosomal recessive lysosomal storage disorder caused by deficiency of acid alpha-glucosidase (GAA), an enzyme essential for breaking down glycogen. Without adequate enzyme activity, glycogen accumulates excessively in lysosomes throughout the body, with most severe impact on skeletal muscle, cardiac muscle, and the diaphragm. The infantile-onset form (before age 12 months) is the most severe, characterized by hypotonia, feeding difficulties, and progressive cardiomyopathy that can be fatal by age 2 without treatment. Late-onset Pompe disease, presenting after age 1 year, has slower progression but still causes progressive proximal muscle weakness with eventual respiratory complications. Since the introduction of enzyme replacement therapy (alglucosidase alfa), outcomes have improved dramatically, particularly when treatment is initiated early. Even patients diagnosed later can benefit from enzyme replacement, which can slow or stabilize disease progression.

Common Symptoms

  • Progressive muscle weakness and loss of tone
  • Heart enlargement (cardiomegaly) in infants
  • Breathing difficulties, especially when lying flat
  • Hypotonia and feeding difficulties in infants
  • Exercise intolerance and fatigue in older children
  • Respiratory muscle weakness in late-onset disease

Who It Affects

Infantile-onset form (before age 1) is most severe and rapidly progressive. Late-onset form typically presents in childhood to adulthood with limb-girdle muscle weakness. Affects males and females equally across all ethnicities.

Getting Involved in Clinical Trials

Clinical trials are exploring improved enzyme replacement formulations, gene therapy approaches, and small-molecule therapies that may cross the blood-brain barrier more effectively. The Pompe Disease Rare Optimizer (PRO) registry and the Acid Maltase Deficiency Association are excellent resources for finding current trials and connecting with specialists experienced in Pompe disease management. Early diagnosis through newborn screening (where available) dramatically improves outcomes. If you or your child has been recently diagnosed, ask your metabolic specialist about trial eligibility and discuss enzyme replacement therapy initiation, as timing of treatment is critical for preventing irreversible muscle damage.

Trusted Sources

Active Clinical Trials for Pompe Disease

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