[Hereditary spastic paraplegia: up to date]

Hereditary spastic paraplegia (HSP) is a clinically and genetically heterogeneous group of neurodegenerative disorders that are clinically characterized by progressive spasticity and weakness of the lower limbs. HSP genetic loci are designated SPG1-72 in order of their discovery. In 206 Japanese families with autosomal dominant HSP, SPG4 was the most common form, accounting for 38%, followed by SPG3A (5%), SPG31 (5%), SPG10 (2%), and SPG8 (1%). We have identified novel mutations in the C12orf65 gene and the LYST gene in several Japanese families with autosomal recessive HSP. JASPAC will facilitate gene discovery and mechanistic understanding of HSP. The future challenge will be the establishment of treatment of HSP.