Pompe Disease (Type II)
Pompe disease, also called glycogen storage disease type II (GSD-II), is an autosomal recessive metabolic disorder that damages muscle and nerve cells throughout the body. It is caused by a mutation in lysosomal acid alpha-1,4-glucosidase (lysosomal acid maltase), which leads to the accumulation of glycogen in lysosomes. This accumulation of glycogen in various cells and organs leads to the signs and symptoms of Pompe disease. The glycogen accumulation leads to myopathy / progressive muscle weakness, notably limb-girdle muscle weakness. The myopathy may also cause respiratory distress, and Pompe disease often presents as exercise intolerance. Additionally, cardiomegaly / hypertrophic cardiomyopathy (HCM) is perhaps the most common presenting feature of Pompe disease. The diagnosis may be supported by histology, as the excess glycogen in lysosomes can be visualized with the PAS stain.