This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Glycogen, Subject name: Biochemistry
Pompe's disease is due to deficiency of: 
Select and explain. 
A. Acid maltase, B. Muscle phosphorylase, C. Branching enzyme, D. Debranching enzyme
A: Acid maltase
Answer: A: Acid maltase 
Explanation: Pompe's disease is: Type II glycogen storage disease It is the only GSD which is a Lysosomal Storage Disease. Due to deficiency of acid maltase enzyme (also known as Acid a (1 - 4)Glucosidase). This enzyme is present in lysosomes, catalyzes the minor pathway of glycogen breakdown. Patient has: hyperophic cardiomyopathy progressive skeletal myopathy Death occurs within 2 years due to cardiac failure The muscle biopsy show vacuoles. The treatment for Pompe disease is recombinant enzyme alglucosidase alfa (Myozyme).