Also notable among the 288 NDD risk genes are ion channels with roles in excitability including calcium channel subunits CACNA1A/1E (C6); the auxiliary calcium channel subunit CACNA2D3 (C8); three pore-forming sodium channel subunits, SCN8A (C6), SCN1A (C5), and the well-known strong NDD risk gene SCN2A (C8); and potassium channel subunits KCNQ2/3 (C8) [98]. Here, SCN2A is linked to Neurodevelopmental delay.