Cause of sudden cardiac death often in young men with no evidence of structural heart disease. The electrocardiogram shows complete or incomplete right bundle branch block, early coved ST segment elevation in the anterior precordial leads. It is caused by abnormality of the genes coding for ion channels and results in increased risk of sudden death from arrhythmia.
- Type 1 (BRS1) due to defects in the SCN5A gene which encodes for a component of the the cardiac sodium channel
- Seen in southeast Asia. Affects males 9 times more frequently than females.
- Type 2 (BRS2) due to defects in the GPD1L gene at 3p22.3 resulting in a 50% reduction in inward current of the sodium channel
- Type 3 (BRS3) due to defects in the CACNA1C gene at 12p13.3
- Type 4 (BRS4) due to defects of the CACNB2 gene
- Type 5 (BRS5) due to defects in the SCN1B gene which encodes for a component of the cardiac sodium channel
- Type 6 (BRS6) due to defects in the KCNE3 gene at 11q13-q14 which encodes for a potassium channel beta subunit
- Type 7 (BRS7) due to defects in the SCN3B gene which encodes for a component of the cardiac sodium channel. It can be more fully unmasked to induce ST changes with procainamide
- Type 8 (BRS8) due to defects in the HCN4 gene which codes for a component of the hyperpolarization-activated potassium channel