September 1, 2000Journal of Cardiovascular Electrophysiology
Hypokalemia‐Induced Long QT Syndrome with an Underlying Novel Missense Mutation in S4‐S5 Linker of KCNQ1
Population
A 47-year-old woman with marked QT prolongation (QTc = 620 msec) and repeated episodes of torsades de…
Comparison
Mutational analysis and whole cell patch clamp… vs Wild-type KCNQ1 channels (in functional analysis)
Design
Case_report
Authors
Discussion
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Member takes
Implication
May flag genetic susceptibility in hypokalemia-triggered torsades; hypothesis-generating and should not yet change practice.
Structured PICO
P
Population
A 47-year-old woman with marked QT prolongation (QTc = 620 msec(1/2)) and repeated episodes of torsades de pointes associated with hypokalemia (2.6 mEq/L), and COS7 cells for functional analysis.
I
Intervention
Mutational analysis (PCR/SSCP) and whole cell patch clamp experiments
C
Comparator
Wild-type KCNQ1 channels (in functional analysis)
O
Outcome
Identification of genetic mutation and functional characterization of the mutant channelsurrogate
A novel KCNQ1 mutation (R259C) can cause 'silent' congenital long QT syndrome that becomes clinically manifest as torsades de pointes during severe hypokalemia.
Cite This Study
Kubota et al. (2000) studied this question.