Diagnostic algorithms

Diagnostic algorithms have been developed based on the key presenting features of infantile- and late-onset Pompe disease.

The first steps in diagnosis are obtaining an accurate clinical history, reviewing pertinent patient findings and reviewing the results of initial laboratory and clinical investigations. Confirmatory diagnosis is made based on absence (infantile-onset) or marked reduction (late-onset) of acid α-glucosidase (GAA) enzyme activity.1

Clinical evaluations

The following clinical examinations aid in assessing the extent and severity of suspected Pompe disease.1, 2

Examination Typical findings
Infantile-onset disease
Chest radiography Massive cardiomegaly
Electrocardiography Short PR interval, tall QRS complexes
Echocardiography Hypertrophic cardiomyopathy (+/- left ventricular outflow tract obstruction)
Late-onset disease
Pulmonary assessment
 
≥10% reduction in forced vital capacity from seated to supine
Neurologic
Manual or quantitative muscle testing
Pattern of weakness, proximal more than distal
Electromyography Increase in muscle membrane irritability
Myotonic discharges
Brief motor unit action potentials
Nerve conduction studies Normal
Muscle biopsy Glycogen accumulation
Infantile- and late-onset disease
Serum creatine kinase Usually elevated
Serum enzymes (aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase) Elevation
Urine glucose tetrasaccharide (Glc4) Elevation

 

References

  1. 1.Kishnani PS, Steiner RD, Bali D, Berger K, Byrne BJ, Case LE. Pompe disease diagnosis and management guideline. Genet Med. 2006;8.
  1. 2.Diagnostic criteria for late-onset (childhood and adult) Pompe disease. Muscle Nerve. 2009;40.