Age of Onset, Animals, Disease Models, Animal, Genetic Predisposition to Disease, Humans, Huntington Disease, Ligases, Mice, Mice, Knockout, Mice, Transgenic, Nerve Tissue Proteins, Parkinson Disease, Proteins, Synucleins, Thiolester Hydrolases, Ubiquitin Thiolesterase, Ubiquitin-Protein Ligases, alpha-Synuclein