SPAST and hereditary spastic paraplegia: Mutations in >70 distinct loci (SPG 1–72) and >50 genes have been identified in patients with HSPs.4 5 Mutations in the spastin gene (SPAST) are the most common cause of HSP, accounting for 45% of all autosomal-dominant forms.6 7SPAST is an ATPase, belonging to the AAA family, involved in microtubule dynamics.8 9 All types of mutations have been described in SPAST with missense mutations clustered mainly in the AAA domain, while nonsense, splice-site mutations and insertions/deletions can be found in different locations throughout the gene.10