Pompe Disease

Question 1

Pompe

Answer 1

Lysosomal acid alpha-glucosidase (GAA, also called acid maltase) deficiency.

Deficiency of lysosomal GAA leads to accumulation of glycogen in lysosomes and cytoplasm, which results in tissue destruction.

Question 2

Late-onset disease (juvenile and adult presentations)

Answer 2

Skeletal myopathy (usually in a limb-girdle distribution) and a protracted course leading to respiratory failure without cardiomyopathy

Question 3

Infantile-onset GAA deficiency

Answer 3

• Profound hypotonia and cardiac insufficiency

Question 4

Investigations

Answer 4

• ECG: demonstrating short PR interval and giant QRS complexes in all leads, suggesting biventricular hypertrophy.
• EMG: demonstrating myopathic discharges, sometimes associated with abundant myotonic and complex repetitive discharges, most prominent in the paraspinal muscles (late-onset form).
• Elevated CK

Question 5

Treatment

Answer 5

• Enzyme replacement therapy
• Physical and occupational therapy
• Supportive care (eg, mechanical ventilation for respiratory failure)