Glycogen Storage Disease Type I

Excerpt

Glycogen storage disease type I (GSD I), also known as Von Gierke disease, is an inherited disorder caused by deficiencies of specific enzymes in the glycogen metabolism pathway. It was first described by Von Gierke in 1929 who reported excessive hepatic and renal glycogen in the autopsy reports of 2 children. It comprises 2 major subtypes, GSD Ia and GSD Ib. In GSD Ia, there is a deficiency of enzyme glucose-6-phosphatase (G6Pase) which cleaves glycogen to glucose thus leading to hypoglycemia and lactic acidosis. Patients with GSD 1b have normal G6Pase enzyme activity but have a deficiency of the transporter enzyme, glucose-6-phosphate translocase (G6PT). Patients present with manifestations of hypoglycemia and metabolic acidosis typically around 3 to 4 months of age. In patients suspected of having the disease, genetic testing is the investigation of choice to confirm the diagnosis. Dietary treatment prevents hypoglycemia and improves the life expectancy of patients. However, to prevent long-term complications such as hepatic adenomas and renal failure, animal models of GSD I are being developed to study the disease more closely and develop new treatment strategies such as gene therapy.