Generation of a homozygous and heterozygous iPSC line carrying a variant of uncertain significance in CACNA1C, associated with Brugada syndrome.

Up to 40 % of genetic variants identified in inherited arrhythmia syndromes (IAS) are classified as variants of uncertain significance (VUS) due to limited clinical and functional evidence. In Brugada syndrome (BrS), this challenge is further compounded by its polygenic nature, variable expressivity, and incomplete penetrance. Functional characterization in relevant disease models, such as human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), is essential for VUS reclassification. Here, using conventional CRISPR/Cas9, we established two isogenic hiPSC lines harboring the BrS-associated CACNA1C c.989C > T (p.Thr330Met) variant in homozygous and heterozygous configurations to enable future functional assessment.