ABCC9 gene
In our study, the clinical diagnosis of patient R44 with mutation c.3589C>T in ABCC9 gene is Brugada (BrS) syndrome and short QT syndrome (SQTS). The variation, c.3589C>T, has been reported in Hu et al. (Hu et al., 2014 ), which is the first to identify ABCC9 as a susceptibility gene for early repolarization syndrome (ERS) and BrS. BrS is an inherited cardiac disease leading to ventricular fibrillation and an increased risk of sudden cardiac death (SCD) in structurally normal hearts (Sarquella-Brugada et al., 2016 ; Sieira et al., 2016 ). Genetic characterization of the Brs syndrome might not only be able to better establish the diagnostic ECG pattern (ST elevation, sinus node dysfunction, or conduction abnormalities) but also to clarify the overlap syndromes (Sieira et al., 2017 ). SQTS is a rare, life-threatening, inherited heart disease characterized by ventricular tachyarrhythmias leading to syncope and sudden cardiac death (Bjerregaard et al., 2018 ; El-Battrawy et al., 2018 ;Campuzano et al., 2018 ). Genetic testing is essential in diagnosing the disease (Bjerregaard et al., 2018 ). Clinical manifestations associated with SQTS may range from asymptomatic, palpitations, syncope, dizziness, atrial fibrillation, ventricular arrhythmias, and SCD (El-Battrawy et al., 2018 ; Campuzano et al., 2018 ). In a published study (Bienengraeber et al., 2004 ), researchers identified two mutations in ABCC9 , encoding the regulatory SUR2A subunit of the cardiac KATPchannel, by scanning of genomic DNA from individuals with heart failure and rhythm disturbances due to idiopathic dilated cardiomyopathy.