Figure 1.

Pedigree of the investigated family and topological models of the mutant KCNQ3 subunit. A, Pedigree of the family investigated. ʻ + ʼ indicates the wild‐type KCNQ3 allele; ʻ−ʼ indicates the mutant KCNQ3 p.(Phe534Ilefs*15) allele. The arrow indicates the proband. B, Schematic topology of a KCNQ3 subunit: S₁‐S₆ refer to the six transmembrane segments, while boxes labeled from A to D depict the four α‐helical regions in the intracellular C‐terminus. The p.(Phe534Ilefs*15) variant located in the helix B is indicated by the arrow. The aa sequence deleted in the mutant KCNQ3 protein is indicated by a dashed line. The red line indicates the amino acid sequence altered by the frameshift variant. C, Partial alignments of the primary sequences of KCNQ3 and KCNQ3 p.(Phe534Ilefs*15, indicated as KCNQ3^MUT) subunits. The B and C helices are highlighted with darker blue boxes.