SPG3A is the most frequent cause of hereditary spastic paraplegia with onset before age 10 years

This is the authors' abstract. We don't add key points for this paper.

Seven families with six different SPG3A mutations were identified among 106 with autosomal dominant hereditary spastic paraplegia (HSP). Two mutations were novel (T162P, C375R). SPG3A was twice as frequent as SPG4 in patients with onset before age 10 years (31.8%). Later onset was not observed. The phenotype was pure HSP, but disease duration was longer than in non-SPG3A/SPG4 patients, leading ultimately to greater handicap.