Spastic Paraplegia, HereditaryParaplegiaReflex, BabinskiSpasmMuscle SpasticityPedigreeParaparesis, SpasticAdaptor Protein Complex 4Genes, RecessiveGenes, DominantAdenosine TriphosphatasesParaparesis, Tropical SpasticCerebellar AtaxiaAgenesis of Corpus CallosumLod ScoreSpinal Cord IschemiaPelizaeus-Merzbacher DiseaseMutation, MissenseChromosomes, Human, Pair 2Cerebral PalsyMutationHuman CharacteristicsHereditary Sensory and Motor NeuropathyQuadriplegiaOptic AtrophyAge of OnsetGenetic LinkageGenetic HeterogeneityPhenotypeSyndromeExomeSpinal CordLeukocyte L1 Antigen ComplexSpinocerebellar DegenerationsIntellectual DisabilityConsanguinitySpinal Cord InjuriesATP-Dependent ProteasesMyelin Proteolipid ProteinCorpus CallosumChromosome MappingDNA Mutational AnalysisHeterozygoteMotor Neurons