SCN5A and atrial fibrillation: SCN5A gene mutations are associated with a clinical spectrum, including Brugada syndrome, long-QT syndrome, progressive cardiac conduction disease, sinus node dysfunction, atrial fibrillation, DCM, multifocal ectopic Purkinje-related premature contractions, irritable bowel syndrome (IBS) and other gastrointestinal disorders, such as chronic idiopathic intestinal pseudo-obstruction (32, 34, 41, 42).