Identification of Novel SCN5A Single Nucleotide Variants in Brugada Syndrome: A Territory-Wide Study From Hong Kong

BACKGROUND: The aim of this study is to report on the genetic composition of Brugada syndrome (BrS) patients undergoing genetic testing in Hong Kong. METHODS: Patients with suspected BrS who presented to the Hospital Authority of Hong Kong between 1997 and 2019, and underwent genetic testing, were analyzed retrospectively. RESULTS: A total of 65 subjects were included (n = 65, 88% male, median presenting age 42 [30–54] years old, 58% type 1 pattern). Twenty-two subjects (34%) showed abnormal genetic test results, identifying the following six novel, pathogenic or likely pathogenic mutations in SCN5A: c.674G > A, c.2024-11T > A, c.2042A > C, c.4279G > T, c.5689C > T, c.429del. Twenty subjects (31%) in the cohort suffered from spontaneous ventricular tachycardia/ventricular fibrillation (VT/VF) and 18 (28%) had incident VT/VF over a median follow-up of 83 [Q1–Q3: 52–112] months. Univariate Cox regression demonstrated that syncope (hazard ratio [HR]: 4.27 [0.95–19.30]; P = 0.059), prior VT/VF (HR: 21.34 [5.74–79.31; P < 0.0001) and T-wave axis (HR: 0.970 [0.944–0.998]; P = 0.036) achieved P < 0.10 for predicting incident VT/VF. After multivariate adjustment, only prior VT/VF remained a significant predictor (HR: 12.39 [2.97–51.67], P = 0.001). CONCLUSION: This study identified novel mutations in SCN5A in a Chinese cohort of BrS patients.