Autosomal dominant spastic paraplegia type 36 (SPG36) is a rare, inherited neurological disorder characterized by progressive spasticity (stiffness and difficulty with movement) of the lower limbs. It is caused by mutations in the SPG36 gene, which is located on chromosome 17. Symptoms typically begin in childhood or adolescence and may include difficulty walking, weakness in the legs, and spasticity of the lower limbs. Other symptoms may include bladder and bowel dysfunction, muscle wasting, and cognitive impairment. Treatment is supportive and may include physical therapy, medications, and assistive devices.