Pelizaeus-Merzbacher disease is a rare genetic disorder that affects the nervous system, primarily impacting the myelin sheath, which insulates nerve fibers. This condition is caused by mutations in the PLP1 gene, leading to improper formation of myelin. Symptoms often include motor difficulties, coordination problems, and cognitive challenges, typically appearing in early childhood. The disease is classified as a type of leukodystrophy, which refers to disorders that affect the white matter of the brain. Diagnosis is usually made through clinical evaluation and genetic testing. While there is currently no cure, supportive therapies can help manage symptoms and improve quality of life.