Facioscapulohumeral Muscular Dystrophy (FSHD) is a genetic disorder that primarily affects the muscles of the face, shoulders, and upper arms. It is characterized by progressive muscle weakness and wasting, which can lead to difficulties in facial expressions, lifting the arms, and performing daily activities. Symptoms typically begin in adolescence or early adulthood, but they can also appear later in life. FSHD is caused by changes in the DUX4 gene, which leads to the abnormal expression of certain proteins that damage muscle cells. The condition is inherited in an autosomal dominant pattern, meaning that only one copy of the mutated gene from an affected parent can cause the disorder in their children. There is currently no cure, but physical therapy and supportive care can help manage symptoms.