For the additive model, the regression coefficients estimate the difference in phenotype associated with each extra copy of the minor allele. Due to low power and potentially misleading results, meta-analyses are not reported for those SNPs for which the MAF or the effective sample size, across CHARGE, is too small (23). The acceptable lower threshold of MAF depends on the total sample size for continuous traits or on the total number of events across all cohorts for dichotomous traits.
