[K(+)](o)-dependent change in conformation of the HERG1 long QT mutation N629D channel results in partial reversal of the in vitro disease phenotype.

Objectives: We hypothesized that exposure of N629D/wildtype channels to transient increases in [K(+)](o) could alter the conformation of the outer vestibule and thus reverse the disease phenotype. N629D is a recently described mutation of the HERG1 gene that causes familial long QT syndrome. This mutation alters the pore signature sequence resulting in loss of K(+) selectivity.