| Description |
Hereditary spastic paraplegias (HSPs) are genetically and phenotypically heterogeneous disorders. Spastic paraplegia with thinning of the corpus callosum (ARHSP-TCC) is a relatively frequent form of complicated hereditary spastic paraplegia (cHSP) in which mental retardation and muscle stiffness at onset are followed by slowly progressive paraparesis and cognitive deterioration. Mutations of the SPG11 gene encoding the spatacsin protein have been identified as a major cause of HSP-TCC. Spatacsin is a potential transmembrane protein that is phosphorylated upon DNA damage. It is expressed in all structures of the brain, with a high expression in the cerebellum. SPG11 mutations may occur more frequently in familial than sporadic forms of cHSP without TCC. Kjellin syndrome is found to be associated with mutations in not only the SPG15 gene but also SPG11 gene. Recent studies show Parkinsonism may initiate SPG11-linked HSP TCC and that SPG11 may cause juvenile Parkinsonism.
|