SPG11 mutations are common in familial cases of complicated hereditary spastic paraplegia

BACKGROUND: Autosomal recessive hereditary spastic paraplegia (ARHSP) with thin corpus callosum (TCC) is a common form of complex hereditary spastic paraplegia. The genetic lesion underlying ARHSP-TCC was localized to chromosome 15q13-q15 and given the designation SPG11. Recently, the gene encoding spatacsin (KIAA1840) has been shown to contain mutations that underlie the majority of ARHSP-TCC cases. METHODS: We present a complete analysis of the 40 coding exons of this gene in patients with sporadic (n = 25) or familial (20 probands) complex hereditary spastic paraplegia with and without thinning of the corpus callosum. RESULTS: We identified seven mutations, including deletions, insertions, and nonsense mutations, which were all predicted to lead to premature truncation of the protein. CONCLUSION: We conclude that mutations on KIAA1840 are frequent in complex autosomal recessive hereditary spastic paraplegia but an infrequent cause of sporadic complex hereditary spastic paraplegia.