PITX2 and atrial fibrillation: Numerous AF loci were found to be in relation to genes that encode for transcription factors that include PITX2, ZFHX3, PRRX1, SOX5, and TBX5. Of the genetic loci (novel and known) found to be associated with AF in this study, seven were related to several AF phenotypes that include electrocardiographic traits, stroke, and left ventricle internal diastolic diameter.