Pompe disease, aka acid maltase deficiency, is a type of glycogen storage disease. This metabolic disorder is rare, inherited and caused by gene mutations that result in the inability or severely limit the ability to produce an enzyme known as acid maltase. Enzymes are vital because they speed up chemical reactions that put together or break apart molecules.
The role of acid maltase is to prevent your cells from accumulating too much glycogen stores. As glycogen begins to gather in cells beyond capacity, acid maltase is released to catalyze the breakdown of the excess for use elsewhere or removal out of you body. However, a deficiency of this enzyme causes cells to become overwhelmed with glycogen, resulting in progressive tissue damage. Typically, glycogen build up has the greatest impact on your heart, respiratory and skeletal muscles.
The primary symptom of Pompe disease is myopathy, or muscle weakness, due to tissue damage. A couple other general symptoms are hypotonia, cardiomyopathy, cardiomegaly and respiratory insufficiency. Acid maltase deficiency eventually leads to heart or respiratory failure.
Because there’s a variety of gene mutations that occur in Pompe disease, the degree of enzyme deficiency varies. Therefore, the onset and severity of symptoms differs amongst individuals.
Generally, with a total or near total deficiency of acid maltase, symptoms arise soon after birth and health affects progress rapidly. This manifestation of the disease is referred to as early onset or infantile Pompe disease. In contrast, late onset Pompe disease occurs with a partial deficiency, which causes symptoms to be noticed anytime from early childhood on and the course of the disease is slower.
There is no cure for Pompe disease at this time. Treatment involves enzyme replacement therapy for deficient acid maltase, which reduces glycogen accumulation. And depending on your level of disease progression, a variety of symptomatic and supportive treatment may be necessary as well.