For instance, rs3825942 in LOXL1 is associated with an increased risk of exfoliation syndrome in certain populations, but a reduced risk in others41 (so called risk allele ‘flipping’), and rs6817105 near PITX2 is associated with an ~1.6-fold increased risk of atrial fibrillation overall; however, the level of risk varies widely across populations42. This evidence concerns the gene PITX2 and atrial fibrillation.