Novel mutations in spastin gene and absence of correlation with age at onset of symptoms

Autosomal dominant hereditary spastic paraplegia is genetically heterogeneo us, with at least five loci identified by linkage analysis. Recently, mutat ions in spastin were identified in SPG4, the most common locus for dominant hereditary spastic paraplegia that was previously mapped to chromosome 2p2 2. We identified five novel mutations in the spastin gene in five families with SPG4 mutations from North America and Tunisia and showed the absence o f correlation between the predicted mutant spastin protein and age at onset of symptoms.