Low-threshold T-type calcium channels (approximately at -60 mV) show unique electrophysiological features with the fast inactivation and slow deactivation kinetics. T-type calcium channels are expressed in the mammalian brain and involved in the pathophysiology of epilepsy, pain and sleep. Recently, a novel de novo mutant Cav3.1 T-type calcium channel at V1330E have been reported by meta-analyses of the exome sequences of patients with schizophrenia (Iyegbe CO et al., 2022. Nature), however, its electrophysiological properties are still unknown. In this study, we aimed to compare the electrophysiological properties of mutant Cav3.1 at between the A961T associated with cerebellar ataxia (gain-of-function) and the V1330E. Each mutant Cav3.1 at A961T and V1330E was generated and transiently transfected in Neuro2A cells. Using the whole-cell patch-clamp technique, we successfully demonstrated that mutant Cav3.1 (A961T) displays very slow inactivation kinetics and unique changes in the steady state kinetics compared with wild-type Cav3.1 channel as well as previously observation. We currently analyze the property of mutant Cav3.1 (V1330E) and would like to present the data and discuss the significance of the mutation at V1330E on site.