Genetic Racial Differences and Atrial Fibrillation

Study Questions:

Is the higher prevalence of atrial fibrillation (AF) among whites than blacks explained by genetic factors?


Genetic testing for nine single nucleotide polymorphisms (SNPs) associated with AF was performed in 17,325 individuals (4,938 blacks) without a prior history of AF. Incident AF during follow-up was detected using clinic electrocardiograms, hospital discharge summaries, death certificates, and Medicare claims data.


One SNP (rs10824026) was found to account for 11-32% of the increased incidence of AF in white individuals. No other SNPs that could explain the higher incidence of AF in whites were identified.


A small portion of the higher risk of AF in whites than blacks is explained by a difference in the prevalence of a SNP. Most of the increased risk of AF in whites is mediated by environmental or other genetic factors.


Prior studies have indicated that black individuals have roughly a 40% lower risk of developing AF compared to white individuals, despite a higher prevalence of risk factors such as hypertension. The reasons for this ‘black paradox’ have been unclear. The present study demonstrates that only a small part of the difference is attributable to one particular SNP (rs10824026), which is protective against AF and which is more prevalent in blacks. The results imply that a genetic and/or environmental factor that is largely responsible for the lower risk of AF in blacks remains unidentified.

Clinical Topics: Arrhythmias and Clinical EP, Prevention, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Arrhythmias, Cardiac, Atrial Fibrillation, African Americans, Electrocardiography, Genetic Testing, Incidence, Medicare, Polymorphism, Single Nucleotide, Prevalence, Risk Factors, Secondary Prevention

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