Figure 1.

Human KCNMA1 mutations. Schematic of the KCNMA1 gene product, the α-subunit of the BK channel (GenBank accession no. NM_002247.3). The voltage-sensitive pore-forming region of the BK channel is comprised of transmembrane domains S0–S6, while the intracellular gating ring contains the two Ca²⁺ binding sites in the RCK1 and RCK2 domains. Red indicates GOF mutations (n = 2), blue indicates LOF or putative LOF mutations (n = 11), and black indicates putative benign mutations (n = 3) or VUS (n = 1). *C413Y/N499fs is a double mutation harbored by a single patient. Numbers to the right or left of each mutation indicate the total number of patients carrying each mutation reported in published studies. N995S, N999S, and N1053S are the same amino acid substitution, but are reported in the literature using three different reference sequencing number schemes.