SPAST and hereditary spastic paraplegia: We performed quantitative RT-PCR experiments on RNA extracted from fibroblasts from (i) a control subject; (ii) an HSP patient with a deletion involving spastin only (exons 2–9; Patient 1); and (iii) a patient with a deletion involving SPAST and DPY30 (SPAST exons 1–17 + DPY30 exons 1–5; Patient 2), using primers amplifying two independent fragments of the DPY30 or SPAST transcripts.