Muscle beta-enolase deficiency is a glycolysis disorder reported in one patient to date and characterized clinically by exercise intolerance and myalgia due to severe enolase deficiency in muscle. The disease is glycogen storage disease due to muscle beta-enolase deficiency (Monarch Disease Ontology entry MONDO_0013046). Also known as: GSD due to muscle beta-enolase deficiency, GSDXIII, glycogen storage disease type 13, glycogenosis due to muscle beta-enolase deficiency, glycogenosis type 13, muscle enolase deficiency, muscular enolase deficiency.