A NEW LOCUS FOR AUTOSOMAL RECESSIVE HEREDITARY SPASTIC PARAPLEGIA MAPS TO CHROMOSOME 16Q24.3

Hereditary spastic paraplegia is a genetically and phenotypically hete rogeneous disorder. Both pure and complicated forms have been describe d, with autosomal dominant, autosomal recessive, and X-linked inherita nce. Various loci (SPG1-SPG6) associated with this disorder have been mapped. Here, we report linkage analysis of a large consanguineous fam ily affected with autosomal recessive spastic paraplegia with age at o nset of 25-42 years. Linkage analysis of this family excluded all prev iously described spastic paraplegia loci. A genomewide linkage analysi s showed evidence of linkage to chromosome 16q24.3, with markers D16S4 13 (maximum LOD score 3.37 at recombination fraction [theta] of .00) a nd D16S303 (maximum LOD score 3.74 at theta = .00). Multipoint analysi s localized the disease gene in the most telomeric region, with a LOD score of 4.2. These data indicate the presence of a new locus linked t o pure recessive spastic paraplegia, on chromosome 16q24.3, within a c andidate region of 6 cM.