For people living with long QT syndrome, a genetic heart rhythm disorder that can trigger sudden cardiac death, treatment options are limited and often imperfect. Current therapies help manage risk, but they do not fix the underlying molecular problem.
Researchers are now pointing toward a different strategy: correcting the defect at its source. In a study published in JCI Insight, a Vanderbilt University team reports the discovery of a small molecule that improves trafficking of the cardiac potassium channel KCNQ1, offering proof of principle that this common cause of disease may be druggable.
The study was led by Charles Sanders, the Aileen M. Lange and Annie Mary Lyle Professor of Cardiovascular Research and professor of biochemistry, with graduate student Katherine Clowes Moster serving as first author. The work represents a collaboration among the Vanderbilt labs of Sanders and Jens Meiler, multiple Vanderbilt core facilities, and the lab of Alfred George at Northwestern University.
Targeting the root cause of LQT1
KCNQ1 is a potassium channel that plays a central role in regulating the electrical current needed for the heartbeat. Variants in the gene encoding KCNQ1 are responsible for LQT1, a form of long QT syndrome.
“We know there are over 300 disease variant forms, and roughly half act by reducing the surface trafficking of this channel, most often by destabilizing the channel so that it misfolds and is either trapped in the cell or targeted for degradation,” Sanders said.
While current therapies for LQT1 focus on managing symptoms or reducing arrhythmia risk, they do not address the underlying molecular defect in many patients: the improper folding and trafficking of the KCNQ1 protein.
In the new study, the team looked for small molecules that could improve the trafficking of KCNQ1 to the cell surface, effectively correcting one of the most common disease mechanisms.
A high-throughput search for a corrector molecule
The project built on more than a decade of collaborative work among the Sanders, George, and Meiler labs to define the mechanisms underlying arrhythmia in over 100 KCNQ1 variants seen in LQT1. That foundational work made it possible to pursue a rational, early-stage drug discovery strategy.
With support from Vanderbilt’s chemical biology and screening infrastructure, “We developed a method that allowed us to quickly search for small molecules that altered the levels of KCNQ1 in the cell and/or the efficiency of its trafficking to the plasma membrane,” Moster said.
Using this approach, the researchers identified a compound, VU0494372, that enhances KCNQ1 trafficking. VU0494372 increased surface expression of wild-type KCNQ1 and showed an even greater effect on some disease-associated variants.
The team also determined that the trafficking corrector appears to bind at a site overlapping with that of ML277, a well-characterized KCNQ1 channel activator.
A proof of principle and a path forward
The researchers emphasized that, although the study provides crucial proof of concept, VU0494372 itself is unlikely to become a therapeutic drug. “The proof of principle that can find trafficking correctors that rescue the mistrafficking of KCNQ1 will hopefully inspire others to pursue new molecules of this genre for development as LQT1 drugs,” Sanders said.
Looking ahead, the team is continuing to characterize VU0494372 and other compounds identified in the screen. They are also developing a multiplexed trafficking assay that will enable testing of the compounds’ effect on many KCNQ1 variants in parallel.
“The new assay will help provide insight into the effect of these small molecules on a large number of disease-associated variants, as well as provide more information about their mechanisms of action,” Moster said.
Current treatments for LQT1 can carry significant side effects and risks, like beta-blocker medications that can be accompanied by fatigue, dizziness, slow heart rate, and other side effects. The ultimate goal, Sanders said, is far more transformative.
“The dream is to develop a pill to prevent or treat LQT1 that would be lifesaving but that isn’t accompanied by the sometimes life-changing problems current therapies can lead to,” Sanders said.
If realized, that vision would mark a fundamental shift: treating long QT syndrome not just by managing arrhythmias, but by correcting the molecular defects at their source.
Go deeper
The paper “High throughput screening identifies a trafficking corrector for long-QT syndrome associated KCNQ1 variants” was published in JCI Insight in January 2026.
Funding
The research was supported by the National Institutes of Health.
School of Medicine Basic Sciences shared resources
The researchers made extensive use of Vanderbilt core facilities, including the High-Throughput Screening Core and the Molecular Design and Synthesis Center, and resources within the Center for Structural Biology.