Value of next-generation sequencing in inherited arrhythmia syndromes

Background Genetic studies are clinically recommended in some cases of inherited arrhythmia syndromes. Next-generation sequencing (NGS) would be helpful because of its high analytical throughput and relative speed. This study aimed to assess the mutation-detection yield obtained by NGS compared with conventional Sanger sequencing method. Methods Patients with aborted sudden cardiac death and their families who underwent gene sequencing tests for inherited arrhythmia syndromes were retrospectively and enrolled in this study from 2017 to 2022 at Chonnam National University Hospital. We evaluated NGS study results of 17 patients (NGS group) and Sanger study results of 19 patients (Sanger group). Results 64.7% of NGS and 94.7% of Sanger group were probands. Type 1 Brugada pattern ECG was more frequent in NGS group (64.7% vs. 21.1%; p = 0.007). BrS was the most common disorder in NGS group (76.5%), and idiopathic ventricular fibrillation was the most common one in Sanger group (63.2%). Mutations with uncertain significance were the most common ones in NGS group (89.5%), and pathogenic or likely pathogenic mutations were the most common ones in Sanger group (45.7%). When positive yield was defined as the ratio of pathogenic or likely pathogenic mutations that were detected by sequencing, the yields were 10.5% and 45.7% in NGS and Sanger groups, respectively. The NGS arrhythmia panel did not cover two inherited arrhythmia-related mutations (RYR1, APOA5) that were detected by the Sanger method. The extended NGS arrhythmia panel was able to detect 84.8% of inherited arrhythmia-related mutations that were detected in Sanger group. Conclusions NGS study has some limitations in obtaining the full genetic data of probands. Well-designed NGS panels are needed to increase the efficiency of the NGS study. With the well-designed panels, large-scale gene sequencing can efficiently and rapidly be applied in real clinical practices, especially in inherited fatal arrhythmia syndromes that have a high detection yield in genetic analyses.