KCNN3 (Potassium Calcium-Activated Channel Subfamily N Member 3) is a Protein Coding gene. Diseases associated with KCNN3 include Spinocerebellar Ataxia 2 and Bipolar Disorder. Among its related pathways are Insulin secretion and Transmission across Chemical Synapses. GO annotations related to this gene include protein heterodimerization activity and calcium-activated potassium channel activity. An important paralog of this gene is KCNN2.Action potentials in vertebrate neurons are followed by an afterhyperpolarization (AHP) that may persist for several seconds and may have profound consequences for the firing pattern of the neuron. Each component of the AHP is kinetically distinct and is mediated by different calcium-activated potassium channels. This gene belongs to the KCNN family of potassium channels. It encodes an integral membrane protein that forms a voltage-independent calcium-activated channel, which is thought to regulate neuronal excitability by contributing to the slow component of synaptic AHP. This gene contains two CAG repeat regions in the coding sequence. It was thought that expansion of one or both of these repeats could lead to an increased susceptibility to schizophrenia or bipolar disorder, but studies indicate that this is probably not the case. Alternatively spliced transcript variants encoding different isoforms have been found for this gene.