Spastic Paraplegia, HereditaryParaplegiaParaparesis, SpasticPedigreeAdenosine TriphosphatasesGenes, RecessiveGenes, DominantAdaptor Protein Complex 4Agenesis of Corpus CallosumGenetic HeterogeneityMutationLod ScoreMuscle SpasticityMutation, MissenseATP-Dependent ProteasesPhenotypeAge of OnsetGTP PhosphohydrolasesMicrotubulesAxonsMetalloendopeptidasesDNA Mutational AnalysisCorpus CallosumGenetic LinkageMotor NeuronsHeterozygoteSpinal Cord IschemiaSpinal CordChromosome MappingChromosomes, Human, Pair 2EndosomesMembrane Proteins