Glycogen Storage Disease

Glycogen storage disease (GSD) is a rare condition that changes the way the body uses and stores glycogen, a form of sugar or glucose. Glycogen is a main source of energy for the body. Glycogen is stored in the liver. When the body needs more energy, certain proteins called enzymes break down glycogen into glucose. They send the glucose out into the body. When someone has GSD, they are missing one of the enzymes that breaks down glycogen. When an enzyme is missing, glycogen can build up in the liver. Or glycogen may not form properly. This can cause problems in the liver or muscles, or other parts of the body. GSD is passed down from parents to children (is hereditary). It is most often seen in babies or young children. But some forms of GSD may appear in adults. Types of GSD are grouped by the enzyme that is missing in each one. Each GSD has its own symptoms and needs different treatment. There are several types of GSD, but the most common types are types I, III, and IV. Glycogen storage disease is passed down from parents to children (hereditary). It happens because both parents have an abnormal gene (gene mutation) that affects a specific way that glycogen is stored or used. Most GSDs occur because both parents pass on the same abnormal gene to their children. In most cases parents don’t show any symptoms of the disease. Glycogen storage disease is passed down from parents to children (inherited). Someone is more at risk for GSD if they have a family member with the disease.