A method for diagnosing a disease can include detecting, in a sample from a patient, an autoantibody binding to Septin-7. A polypeptide comprising Septin-7 or a variant thereof can be used for the diagnosis of a disease. Preferably, the polypeptide is used to detect an autoantibody binding to Septin-7 in a sample. A kit is useful for the diagnosis of a disease. The kit may include a polypeptide that includes Septin-7 or a variant thereof or a medical device that includes a polypeptide that includes Septin-7 or a variant thereof and an autoantibody to Septin-7.