Familial spastic paraplegia: evidence for a fourth locus

Autosomal dominant familial spastic paraparesis (AD-FSP) is a genetically heterogeneous disorder of the central nervous system characterized by a progressive spasticity of the legs. One gene causing AD-FSP (FSP1) has recently been mapped to chromosome 14q, another gene (FSP2) to chromosome 2p, and a third gene (FSP3) to chromosome 15q. We now report a large Dutch family with AD-FSP without linkage to any of these chromosomes, providing evidence for a fourth locus (FSP4).