Glycogen storage disease due to acid maltase deficiency, juvenile onset (Orphanet rare-disease nomenclature entry Orphanet_308573) is glycogen storage disease due to acid maltase deficiency, non-classical infantile onset (AMDNCI), is form of glycogen storage disease due to acid maltase deficiency (AMD, see this term), a metabolic myopathy affecting respiratory and skeletal muscles that may fatally impede respiratory function during childhood. Also known as: Alpha-1,4-glucosidase acid deficiency, juvenile onset, GSD due to acid maltase deficiency, juvenile onset, GSD type 2, juvenile onset, Glycogen storage disease type 2, juvenile onset, Glycogenosis due to acid maltase deficiency, juvenile onset, Glycogenosis type 2, juvenile onset, Pompe disease, juvenile onset.