Rs45438698

This SNP, also known as R578K, affecting an amino acid in exon 1 of the KCNA5 potassium channel gene, may mediate the response to drugs such as quinidine and propafenone.

The risk allele is rs45438698(A), and carriers receiving quinidine or propafenone for the treatment of cardiac arrhythmias may be resistant to the drug (and thus treatment). Note that this allele is rare; it was not observed in African-American or Asian populations, however it is reported to be present at a frequency of 1.1% among Caucasians.