In this work, we describe, for the first time, PITX2-related changes in mitochondrial activity in human iPSC atrial cardiomyocytes (aCMs) derived from a young patient with paroxysmal AF carrying a gain-of-function mutation in PITX2 (rs138163892) (Mora et al., 2017; Mechakra et al., 2019) when compared to its isogenic control. This evidence concerns the gene PITX2 and Paroxysmal atrial fibrillation.