Glycogen is the form of sugar your body stores in your liver and muscles for future energy needs. Glycogen storage diseases are complex genetic conditions in which certain enzymes -- ones involved in creating glycogen or breaking it down into sugar for your body to use -- are missing or don't work correctly. This can result in liver, heart, muscle, and respiratory problems. While there is no cure, our team of internationally recognized experts uses special diets and medical treatments to manage these diseases and their symptoms. We work you or your child to improve growth, development, and health.