This file contains IHGC2021 migraine meta-analysis (102,084 cases and 771,257 controls) results for 8,117 genome-wide significant variants (p < 5e-8) from GWAMA program (https://genomics.ut.ee/en/tools/gwama-tutorial). 

Meta-analysis combined 5 studies in following order:
UKBB
Gormley et al. 2016 (no23andMe)
23andMe
GeneRISK
HUNT

rs_number - Marker ID 
chromosome - Marker chromosome
position - Marker position (bp, build37)
reference_allele - Effect allele
other_allele - Non effect allele
beta - Overall beta value for reference allele for meta-analysis
beta_95L - Lower 95% CI for BETA
beta_95U - Upper 95% CI for BETA
z - Z-score
p.value - Meta-analysis p-value
-log10_p-value - Absolute value of logarithm of meta-analysis p-value to the base of 10.
q_statistic - Cochran's heterogeneity statistic
q_p-value - Cochran's heterogeneity statistic's p-value
i2 - Heterogeneity index I2 by Higgins et al 2003
n_studies - Number of studies with marker present
n_samples - Number of samples with marker present (will be NA if marker is present in any input file where N column is not present)
effects - Summary of effect directions ('+' - positive effect of reference allele, '-' - negative effect of reference allele, '0' - no effect (or non-significant) effect of reference allele, '?' - missing data)
Neff  - effective sample size from 1/(f_i *(1-f_i )* se_i^2), where se_i is the standard error of variant i and f_i is its MAF.