Brugada Syndrome and AKAP9: Reconciling Clinical Findings With Diagnostic Uncertainty
INTRODUCTION: Brugada Syndrome typically presents with sudden nocturnal arrhythmias. Diagnosis may be challenging due to variable and transient electrocardiogram patterns and nondiagnostic provocation studies. Genetic testing can establish the etiology, but results may be inconclusive with variants of uncertain significance. CASE: A 24-year-old male with family history of sudden cardiac death was found unresponsive due to seizure. He was hemodynamically stable. ECG showed saddle-back ST elevations in V1 and V2. Procainamide challenge was negative. We subsequently performed genetic testing, which demonstrated AKAP9 variant. DISCUSSION: AKAP9 is a scaffolding protein that facilitates phosphorylation of delayed-rectifier potassium channels. The AKAP9 variant alters potassium current causing disordered repolarization and ventricular reentry. It has been previously linked to other channelopathies, but its pathogenicity is fully undetermined. CONCLUSION: Genetic testing is a useful tool to determine the origin of channelopathy, but inconclusive results with variants of uncertain significance should be clinically correlated.
Garris, R., Vasudev, R., Gupta, P., Tiyyagura, S., Shamoon, F., & Bikkina, M. (2019). Brugada Syndrome and AKAP9: Reconciling Clinical Findings With Diagnostic Uncertainty. Journal of Electrocardiology, 57, 119-121. https://doi.org/10.1016/j.jelectrocard.2019.09.013