Although these two diseases may overlap clinically they differ pathologically, with PD α-synuclein aggregates forming Lewy bodies in neurons, in MSA the pathological hallmark is the presence of oligodendroglial glial cytoplasmic inclusions (GCIs) containing aggregated α-synuclein, with additional α-synuclein accumulation forming less frequent neuronal cytoplasmic inclusions (NCIs) [26, 35, 46]. This evidence concerns the gene SNCA and Parkinson disease.