A new locus for autosomal recessive complicated hereditary spastic paraplegia (SPG26) maps to chromosome 12p11.1-12q14

Abstract
To date nine autosomal recessive HSP loci have been identified and causative mutations found in three genes: SPG7 (paraplegin), SPG20 (spartin), and SPG21 (maspardin). SPG7 encodes paraplegin, a mitochondrial protein, which is a member of the AAA protein superfamily (ATPase associated with diverse cellular activities) and is homologous to a number of yeast mitochondrial metalloproteases.4 SPG7 mutations may result in either pure or complicated HSP phenotypes.4, 5 Muscle biopsy analysis of patients with SPG7 mutations may show histological evidence of mitochondrial dysfunction4, 6 and recently biochemical studies have shown specific defects in mitochondrial respiratory chain function.5, 7