The most common of these haplotypes included: *9+rs145308399~5576G>A(E97K) in CYP2A6 and *1+rs138264188~17731C>T (T67M) in CYP2B6, especially among Orcadians (AF=0.4% and 0.7%, respectively). Here, CYP2A6 is linked to atrial fibrillation.