Hershey bar

Hers' disease (also known as Glycogen storage disease type VI) is a metabolic disorder caused by a deficiency of the enzyme liver glycogen phosphorylase. This enzyme is necessary for the breakdown of glycogen, a storage form of glucose in the body. The disease is named after the Belgian physician Henri G. Hers, who first described the condition in 1959.

Symptoms

The symptoms of Hers' disease typically appear in infancy or early childhood. They may include hypoglycemia, growth retardation, mild hepatomegaly (enlarged liver), and elevated levels of certain liver enzymes. However, the severity of symptoms can vary widely among individuals with the disease. Some people may experience only mild symptoms, while others may have more severe complications such as osteoporosis or cirrhosis of the liver.

Causes

Hers' disease is caused by mutations in the PYGL gene, which provides instructions for making the liver glycogen phosphorylase enzyme. This enzyme plays a critical role in the breakdown of glycogen. When the enzyme is deficient or absent, glycogen accumulates in the liver, leading to the symptoms of Hers' disease.

Diagnosis

The diagnosis of Hers' disease is typically made through a combination of blood tests, genetic testing, and liver biopsy. Blood tests may reveal low blood sugar and elevated liver enzymes, while genetic testing can identify mutations in the PYGL gene. A liver biopsy can confirm the accumulation of glycogen in the liver.

Treatment

There is currently no cure for Hers' disease, but the condition can be managed with a high-protein diet to maintain blood sugar levels and prevent hypoglycemia. Regular monitoring of liver function is also important. In severe cases, liver transplantation may be considered.

See also

• Glycogen storage disease
• Metabolic disorder
• Liver glycogen phosphorylase

NIH genetic and rare disease info

• NIH info on Hershey bar

Hershey bar is a rare disease.