Mutations in a newly identified GTPase gene cause autosomal dominant hereditary spastic paraplegia

The hereditary spastic paraplegias (HSPs; Strumpell-Lorrain syndrome, MIM number 18260) are a diverse class of disorders characterized by insidiously progressive lower-extremity spastic weakness (reviewed in refs. 1-3). Eight autosomal dominant HSP (ADHSP) loci have been identified, the most frequent of which is that linked to the SPG4 locus on chromosome 2p22 (found in -42%)(1), followed by that linked to the SPG3A locus on chromosome 14q11-q21 (in similar to9%)(1). Only SPG4 has been identified(4) as a causative gene in ADHSP. Its protein (spastin) is predicted to participate in the assembly or function of nuclear protein complexes(4). Here we report the identification of mutations in a newly identified GTPase gene, SPG3A, in ADHSP affected individuals.