Integrative analysis of 61 KCNQ1 variants revealed that impaired trafficking to the plasma membrane was the most common cause of loss of function, highlighting diverse pathogenic mechanisms in LQT1.
Integrative analysis of 61 KCNQ1 variants reveals that while impaired trafficking is the most common cause of loss-of-function in LQT1, diverse mechanisms exist, which impacts the accuracy of current pathogenicity prediction tools.
encoding a cardiac potassium channel predispose to sudden cardiac death in type 1 congenital long QT syndrome (LQT1). To determine the spectrum of molecular mechanisms responsible for this life-threatening condition, we used an integrative approach to determine the biophysical, functional, and trafficking properties of 61 KCNQ1 variants distributed throughout all domains of the channel. Impaired trafficking to the plasma membrane was the most common cause of LOF across all channel domains, often but not always coinciding with protein instability. However, many LOF variants, particularly in transmembrane domains, trafficked normally, but when coexpressed with KCNE1 exhibited impaired conductance, altered voltage dependence, or abnormal gating kinetics, highlighting diverse pathogenic mechanisms. This indicates a need for personalized treatment approaches for LQT1. Use of our data to benchmark variant pathogenicity prediction methods demonstrated that prediction accuracy depends on the exact mechanism of pathogenicity associated with a given variant.
Brewer et al. (Wed,) conducted a other in type 1 congenital long QT syndrome (LQT1). Integrative analysis of KCNQ1 variants was evaluated on biophysical, functional, and trafficking properties. Integrative analysis of 61 KCNQ1 variants revealed that impaired trafficking to the plasma membrane was the most common cause of loss of function, highlighting diverse pathogenic mechanisms in LQT1.