[Clinical aspects of hereditary spastic paraplegias]

Hereditary spastic paraplegias (HSPs) were characterized by progressive leg spasticity with various additional symptoms as follows: peripheral neuropathy, cerebellar ataxia, extrapyramidal symptoms, mental impairment, optic atrophy, pigmental retinopathy, and so on. Many genetic loci (SPG1-72) and more than 50 genes were identified so far. Recently, we identified the causative gene, C12orf65, that was reported the gene for Leigh syndrome, for autosomal recessive spastic paraplegia with optic atrophy and neuropathy (SPG55). We also identified the mutation of the LYST gene, that is causative gene for Chediak-Higashi syndrome, for the autosomal recessive complicated spastic paraplegia with cerebellar ataxia and neuropathy. In this review, we introduced clinical symptoms about our cases suffered from SPG4, SPG11, SPG55 and complicated spastic paraplegia due to adult Chediak-Higashi syndrome. SPG4, that is usually exhibits pure spastic paraplegia, but our case shows mental impairment and variable age of onset. HSPs are clinically and genetically heterogeneous syndromes, i. e., same gene mutations with different clinical manifestations or same clinical presentations with different gene mutations. We should perform board range differential diagnosis and analysis of numerous causative genes to the patients with spastic paraplegia, especially autosomal recessive trait.