For this reason, in this study, we evaluated a large cohort of patients with diagnoses of PSP, CBS, and indeterminate APS for intermediate expansions in C9orf72 to investigate if they are associated with disease risk and if they influence clinical phenotypes, such as age of disease onset, progression to disability, or survival time after symptom onset. Here, C9orf72 is linked to autoimmune polyendocrinopathy.