Extensive genetic heterogeneity in the "pure" form of autosomal dominant familial spastic paraplegia (Strümpell's disease).

Three dominantly inherited "pure" form of familial spastic paraplegia (FSP) genes have been genetically mapped to regions of chromosomes, yet no specific genes or mutations have been identified (FSP1; chromosome 14q, FSP2; chromosome 2p and FSP3; chromosome 15q). We studied a "pure" form of autosomal dominant FSP family from North American of Italian descent for linkage to three dominant FSP loci. We excluded all three known loci with markers (D14S288, D14S269, D14S281, D2S352, D2S367, D15S210, D15S122, and D15S156) in our "pure" dominant FSP family. Our result suggests that dominant FSP is very genetically heterogeneous, and the existence of at least a fourth locus (FSP4) for the pure form of autosomal dominant FSP (Strümpell's disease).