MPS III, also known as Sanfilippo syndrome, is a rare genetic disorder that affects the body's ability to break down certain sugars called glycosaminoglycans. This leads to a buildup of these substances in cells, causing progressive damage, particularly in the brain. Symptoms typically appear in early childhood and may include developmental delays, behavioral issues, and sleep disturbances. There are four subtypes of MPS III, labeled A through D, each caused by a deficiency in different enzymes. As the condition progresses, individuals may experience worsening cognitive decline and physical challenges. While there is currently no cure, supportive therapies can help manage symptoms and improve quality of life.