A pure form of hereditary spastic paraplegia with characteristics of adult onset of crural spastic paraparesis, hyperreflexia, extensor plantar responses, proximal muscle weakness, mild muscle atrophy, decreased vibration sensation at ankles and mild urinary dysfunction. Foot deformities have been reported to eventually occur in some patients. No abnormalities are noted on brain magnetic resonance imaging and peripheral nerve conduction velocity studies. [from
SNOMEDCT_US]