Pompe Disease, a Storage Cardiomyopathy

Pompe disease also known as glycogen storage disease type II, is a rare and progressive lysosomal storage disorder caused by the deficiency of the enzyme acid α-glucosidase. This results in the accumulation of glycogen in various tissues particularly involving the heart, skeletal muscle and liver. It is inherited in an autosomal recessive manner due to mutations in the GAA gene. There are several known pathogenic variants, some of which are particularly common in certain geographical regions. Pompe disease is a single disease exhibiting a heterogeneous clinical spectrum depending on the extent of enzyme deficiency, the age of onset, the progression of the disease and the degree of organ involvement. It may lead to muscle weakness, hypotonia, respiratory compromise and premature death. Pompe disease is classically divided into two forms, infantile and late-onset disease. The infantile form is further subdivided into classical and non-classical subtypes. Cardiac involvement is particularly seen in the infantile phenotype of the condition, presenting as severe cardiomyopathy associated with conduction abnormalities. Enzyme replacement therapy with recombinant human acid α-glucosidase is the approved treatment option for patients with this metabolic condition. Further research is currently being done to explore more treatment options. One must keep in mind other metabolic and mitochondrial conditions, which may give a similar cardiac and neurological clinical picture.