| A pure form of hereditary spastic paraplegia with a childhood or adolescent onset of slowly progressive, pure crural muscle spastic paraparesis which manifests with mild lower limb weakness, gait difficulties, extensor plantar responses, and hyperreflexia of lower extremities. Less common manifestations reported include cerebellar oculomotor disturbance with saccadic eye pursuit, pes cavus and scoliosis. Some patients also present pin and vibration sensory loss in distal legs. The disease is caused by homozygous or compound heterozygous mutation in the DDHD1 gene on chromosome 14q22. |