Approximately one quarter of genes identified in epilepsy encode ion channel proteins, including voltage-gated channels (Na+, K+, Ca2+ channels and hyperpolarization-activated cyclic nucleotide-gated channels) and ligand-gated ion channels (N-Methyl-D-Aspartate receptors, Gamma-aminobutyric acid receptors and Nicotinic Acetylcholine receptors) [77]. The gene discussed is GLRA3; the disease is epilepsy.