To further explore the pathogenesis of SCA19/22, we obtained SCA19/22-iPSC-derived neurons as a patient-derived neuron model might explain the initial characteristics of SCA19/22 better than the mouse model and other disease models of non-human origin and might provide a more detailed understanding of the pathogenesis of SCA19/22 caused by the KCND3 c.1130 C>T (p.T377M) mutation. The gene discussed is KCND3; the disease is spinocerebellar ataxia type 19/22.