Paraplegin gene analysis in hereditary spastic paraparesis (HSP) pedigrees in northeast England

OBJECTIVE: To identify the frequency and characterize the phenotype of paraplegin mutations in the hereditary spastic paraparesis (HSP) population in the northeast of England. BACKGROUND: HSP is a disorder that shows both clinical and genetic heterogeneity. To date, 13 loci have been associated with an HSP phenotype, with the causative gene having been identified in four of these. Two autosomal genes have been identified, paraplegin and spastin, and two X-linked genes have been identified, L1CAM (cell adhesion molecule) and proteolipid protein. METHODS: Thirty HSP pedigrees from the northeast of England were analyzed for mutation in each of the 17 exons of the paraplegin gene. RESULTS: A single family with a paraplegin mutation was identified in which the paraplegin mutation co-segregates with an HSP phenotype in an apparent dominant manner. The authors also describe frequent polymorphism in the paraplegin gene in both the HSP and control populations. CONCLUSION: Mutations in the paraplegin gene are not a common cause of HSP in the northeast of England. The phenotype of the paraplegin-related HSP family described had several striking features including amyotrophy, raised creatine kinase, sensorimotor peripheral neuropathy, and oxidative phosphorylation defect on muscle biopsy.