Glycogen Storage Disease Type IV (GSD IV), also known as Andersen disease, is a rare genetic disorder that affects the body's ability to break down glycogen, a stored form of glucose. This condition is caused by mutations in the GBE1 gene, which is responsible for producing an enzyme called branching enzyme. Without this enzyme, glycogen accumulates in an abnormal structure, leading to various health issues. Symptoms of GSD IV can vary but often include liver dysfunction, muscle weakness, and growth delays in children. The severity of the disease can differ among individuals, and it may lead to complications such as liver cirrhosis or heart problems. Early diagnosis and management are crucial for improving quality of life.