The lead variant for SCN10A has been previously significantly associated with atrial fibrillation and flutter and cardiac conduction.22CAV1 has been previously associated with QRS duration, PR interval, and QT interval, while SCN5A and SCN10A have previously well-described roles in cardiac rhythm and conduction phenotypes.22–25ARHGAP24 has been previously associated with ECG parameters including PR interval, QRS duration, and QT interval26,27; however, our analysis has identified for the first time ARHGAP24 as a gene associated with a prognostically significant phenogroup. Here, ARHGAP24 is linked to atrial fibrillation.