glycogen storage disease I (MONDO_0002413) is glycogenosis due to glucose-6-phosphatase (G6P) deficiency or glycogen storage disease, (GSD), type 1, is a group of inherited metabolic diseases, including types a and b, and characterized by poor tolerance to fasting, growth retardation and hepatomegaly resulting from accumulation of glycogen and fat in the liver. Also known as: G6P deficiency, GSD due to G6P deficiency, GSD type 1, GSD type I, GSD1, Glycogen Storage Disease Type I, deficiency of glucose-6-phosphatase, glycogen storage disease due to G6P deficiency.