Brugada syndrome / J wave syndrome [28 genes]

These two diseases are caused by abnormal functioning of some cardiac ion channels. They are included together in this panel because their pathophysiological mechanism is very similar; some authors even suggest that they are part of the same spectrum of diseases. They manifest themselves by abnormalities in ECG surface with a predisposition to the development of ventricular arrhythmias that may produce syncope, cardiac arrest, or sudden death; these often being the first manifestations of the disease.

• Patients with an electrocardiographic pattern compatible with Brugada syndrome (ST segment elevation ≥2 mm in more than one right precordial lead (V1-V3), followed by a negative T waves) or a diagnosis of early repolarization (J point elevation of ≥1 mm in ≥2 contiguous inferior and/or lateral leads).
• Patients under diagnostic suspicion of the disease presenting some of the following characteristics: Subjects with a personal or familiar history of sudden death. Subjects with a history of syncope of unknown origin. Subjects with ventricular fibrillation of unknown origin.
• Relatives of patients with a genetic diagnosis of Brugada or J wave syndrome (familiar screening).

The probability of detecting a likely causal mutation in a patient under suspicion of Brugada syndrome is approximately 30%. As for J wave syndrome, the probability has not been clearly established.