Glycogen storage diseases (GSDs) are inherited metabolic disorders caused by defects in glycogen synthesis, degradation, or regulation, resulting in abnormal glycogen accumulation or impaired glucose homeostasis. Clinical manifestations vary by subtype and may include fasting hypoglycemia, hepatomegaly, myopathy, cardiomyopathy, exercise intolerance, or multisystem disease.

This panel includes genes associated with the major hepatic, muscle, and multisystem glycogen storage disorders, including glycogen storage disease types I–XV, Pompe disease, Danon disease, and related glycogen metabolism disorders. Representative genes include G6PC1, GAA, PYGL, PYGM, PHKA2, GBE1, GYS2, and LAMP2.

This panel is recommended for patients with clinical features suggestive of a glycogen storage disorder, particularly those with hypoglycemia, hepatomegaly, elevated liver enzymes, exercise intolerance, recurrent rhabdomyolysis, cardiomyopathy, or unexplained hyperCKemia.