Meta-analysis of promoter B and A SNPs for association with early onset lone AF. Meta-analyses of the results (additive genetic model) from the three cohorts were performed using a fixed effect model. Promoter SNP B (top), but not promoter SNP A (bottom), was significantly associated with early onset lone AF. Grey boxes reflect the weighting (W), based on sample size, of each cohort in the meta-analysis. MAF, minor allele frequency for cases/controls; OR, odds ratio for lone AF with each additional copy of minor allele; CI, confidence interval. *denotes P<0.05.