Danon disease (MONDO_0010281) is a lysosomal glycogen storage disease characterized by severe cardiomyopathy and variable degrees of muscle weakness, frequently associated with intellectual deficit. Also known as: ANTOPOL disease, Danon disease, X-linked dominant, GSD due to LAMP-2 deficiency, LAMP2 lysosomal glycogen storage disease, glycogen storage disease type IIb, glycogenosis due to LAMP-2 deficiency, lysosomal glycogen storage disease caused by mutation in LAMP2, lysosomal glycogen storage disease with normal acid maltase activity.