Among patients with PNSs, one patient had polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes syndrome (POEMS); two patients had cerebellar degeneration associated with Hu and Yo antibodies; one patient had seronegative paraneoplastic neuropathy, and one patient had anti-titin-associated myasthenic syndrome. Here, TTN is linked to polyneuropathy.