Glycogen storage disease

Glycogen storage disorders are a group of inborn errors of metabolism characterized by accumulation of glycogen in various tissues. This accumulation is the histological hallmark of these disorders although the phenotype shows variable overlap. Hepatomegaly, hypoglycaemia, elevated lactate and urate with or without neutrophil dysfunction are the classical presentations for the commonest disorders namely GSD types I a, 1b and III. Elevated creatine kinase, weakness, hypertrophic cardiomyopathy with or without rhabdomyolysis represent the commonest muscle subtypes with the best known ones being GSD II, III and V. Control of glucose deficiency by added calories, tube feeding or modified cornstarch is frequently the main basis of treatment. Supportive therapies are needed to establish near normality. Potential curative therapies are enzyme replacement therapies by mode of liver transplantation, bone marrow transplantation or use of recombinant enzyme.