Novel and previously reported genomic loci that associate with serum folate levels at <i>P</i><2.2×10⁻⁹.

Association results for serum folate in Icelandic and Danish study samples separately and combined. The effect allele is the allele associated with increased serum folate levels. The effect is on a quantile normalized scale. Data were combined in fixed effect meta-analyses based on P-value and direction of effect adjusted for the number of individuals in each sample. Values of I2 are percentages. Association between serum folate levels and MTHFR rs1801133 in the Inter99 cohort has been published previously [14]. Chr., chromosome; EAF, effect allele frequency; HET, heterogeneity; SNV, single nucleotide variant. 1The annotation is based on the RefSeq hg18. 2The reference allele based on Build 36 hg18 is shown in bold. 3In the Icelandic data a 2 bp INDEL in exon 3 of FOLR3 associated more strongly with serum folate levels. As only SNVs were analyzed in the Danish data this data was not available for the Danish samples. 4The rs652197 variant was initially discovered in the Icelandic samples but subsequently genotyped in Danish samples to confirm the association.