Glycogen storage disease type 6 (Hers disease) is an autosomal recessive disease predominantly affecting liver function. Mutations on the liver isoform of the glycogen phosphorylase gene, PYGL, create defects that cause a buildup of glycogen in the liver. Most cases will present by early childhood. Common findings include hepatomegaly and growth retardation. Abnormal laboratory findings include hypoglycemia, lactic acidosis, and hyperlipidemia. A special diet can be prescribed to maintain regular glucose levels.