Pompe Disease

Combined incidence (infantile vs. late-onset): 1:40,000.

Infantile form has higher incidence in African-American and Chinese populations.

Late-onset disease has a higher incidence in the Netherlands.

Respiratory insufficiency

Aspiration pneumonia

Pulm edema

Myocardial ischemia

Respiratory insufficiency, which may require prolonged mechanical ventilation

Myocardial ischemia

Arrhythmias, sudden death

GE reflux, aspiration pneumonia

Difficult extubation and ventilator dependence

Only glycogen storage disease that is also a lysosomal storage disease.

Deficiency of lysosomal enzyme acid-α glucosidase.

Lysosomal glycogen accumulates in several organ systems, most importantly cardiac, skeletal, and smooth muscle.

Clinical features are mostly neuromuscular.

Two major forms: Infantile versus late-onset.

Infantile presents with cardiomyopathy, hypotonia, and muscle weakness ultimately leading to death secondary to cardiorespiratory failure within the first year of life.

Cardiomyopathy usually not seen in late-onset variants, which can present at any age. Usually characterized by muscle weakness followed by muscles of respiration and diaphragm. Respiratory failure is usually cause of death or severe morbidity.

Pts with late-onset Pompe disease usually present with slowly progressive myopathy, which can be mistaken for limb girdle muscular dystrophy.

Measurement of GAA activity in skin fibroblasts is the current gold standard test to confirm diagnosis.

Disorder of acid α-glucosidase.

Disease severity correlates inversely with residual acid α-glucosidase activity.

Autosomal recessive inheritance pattern.