Initial replication of the top hit rs314276 and adjacent rs314277 was done in mothers from the Avon Longitudinal Study of Parents and Children (ALSPAC). This population-based study recruited pregnant women with expected delivery dates between April 1991 and December 1992 from Bristol, UK13. Genotypes for rs314276 and rs314277 and recalled menarche data were available for 6,456 mothers. Replication samples were also available from a further 10,824 women in the EPIC-Norfolk Study, excluding women who had been analyzed in the GWA study. rs314276 was directly genotyped in 10,453 women, of whom 8,411 had valid data on age at menarche. SNP rs314276 was genotyped in a further 948 women with a valid age at menarche from the MRC National Survey of Health and Development (NSHD), a prospective birth cohort study comprising a stratified sample of all births in England, Scotland and Wales in one week in March 1947 (ref. 14). A further 558 women from the 1958 British Birth Cohort (B58C), a prospective birth cohort originally consisting of all births in England, Wales and Scotland during one week in 1958, had rs314276 genotypes and age at menarche data available.
