Anterior Horn CellsCase-Control StudiesSpinal Muscular Atrophies of ChildhoodHornsMuscular Atrophy, SpinalSpinal CordPosterior Horn CellsNeuronal Apoptosis-Inhibitory ProteinMenisci, TibialSMN Complex ProteinsArthrogryposisSurvival of Motor Neuron 1 ProteinSpinal Cord DiseasesParalysisNeuromuscular DiseasesMotor Neuron DiseaseMotor NeuronsAmyotrophic Lateral SclerosisMuscular AtrophyNerve DegenerationElectromyographyMagnetic Resonance ImagingCyclic AMP Response Element-Binding ProteinBrainNerve Tissue Proteins