Despite the large size of our meta-analysis and the substantial increase in the number of menarche loci, these together explained between 3.6–6.1% of the variance in age at menarche, equivalent to 7.2–12.2% of its heritability. The majority of menarche loci had estimated effect sizes of between 2 to 3 weeks per allele. Assuming the presence of many true menarche SNPs with an effect size of 2 weeks per allele, even our large meta-analysis would only have had sufficient power to detect half of those SNPs with a MAF of 50%, and only 1 in 10 of those SNPs with MAF of 10% (Supplementary Fig. 8).
