SNCA and amyotrophic lateral sclerosis: Immunohistochemical analysis of α-synuclein and p62 expression in the SN of 17 cases of brains with C9ORF72 expansion and 51 cases of ALS without C9ORF72 expansion, showed that only one case had α-synuclein-positive neuron cell pulp content (with C9ORF72 expansion) 54.