Overview

Rare genetic autosomal recessive disorder caused by a deficiency of the lysosomal enzyme acid α-glucosidase thereby inhibiting breakdown of glycogen. Glycogen toxicity ensues due to accumulation (typically in skeletal and cardiac muscles) causing progressive muscle weakness and myopathies.

Clinical manifestations

Classic infantile-onset: Severest form presenting with failure to thrive, hypotonia, cardiomyopathy and respiratory insufficiency. Poor prognosis

Non classic ( infantile- or late onset): Broad clinical spectrum presenting with motor developmental delay, respiratory muscle weakness including, with minimal to no cardiac involvement. Though clinical progression is slower, most patients eventually become wheelchair bound or affected with respiratory complications.

Diagnosis and Treatment

Whole blood assay measures alpha-glucosidase enzyme activity. Muscle Biopsies may also be considered.

Enzyme Replacement Therapy (ERT) with recombinant human acid α-glucosidase has significantly improved morbidity and mortality with early treatment.

Anaesthetic implications

Patients typically present for facilitation of long term ERT, muscle biopsy or non specific surgery.

Consider regional anaesthesia to avoid systemic effects of general anaesthesia and opiates. All general anaesthetics at lower doses have been used safely in affected patients.

Succinylcholine

Expert opinion Suxamethonium should be avoided due to the risk of hyperkalemia and rhabdomyolysis.