Overview
Definition
An autosomal recessive lysosomal storage disease caused by acid alpha-glucosidase deficiency, leading to glycogen accumulation in cardiac and skeletal muscles.
Epidemiology
Prevalence ~1 in 40,000 live births.
Etiology & Risk Factors
- GAA gene mutations
- Glycogen deposition in lysosome and cytoplasm of myocytes
Clinical Symptoms
- Floppy baby syndrome (hypotonia)
- Macroglossia (enlarged tongue)
- Cardiomegaly / Hypertrophic cardiomyopathy
- Progressive proximal muscle weakness
Clinical Approach
Diagnosis
- Deficiency of acid alpha-glucosidase (GAA) activity
- Muscle biopsy showing vacuolar myopathy with glycogen staining
Management
- Enzyme Replacement Therapy (Alglucosidase alfa)
- Respiratory support and physical therapy
Complications
- Cardiorespiratory failure
- Progressive diaphragmatic weakness
- Severe motor delay