KCNMA1 and epilepsy: Nonetheless, like all potassium channels, maxi-K+ is expressed in many other organs, such as the brain, and variants in KCNMA1 are known to cause epilepsy.49 However, sudden unexpected death in epilepsy (SUDEP) is more frequently seen in older children (10.2 ± 5.7 years) and only 2% of all SUDEP appeared in infants under one year of age.50