Furthermore, we found significant positive correlations with estimated zinc deficiency prevalence (p-value < 0.05) for five of the eleven GWAS SNPs, including variants in SLC39A4, SLC30A8, SLC30A2, DPEP1 , and RB1/RCBTB2 ( Fig 5A and Table F in S1 File), supporting an overall trend that zinc-increasing alleles correlate with estimated zinc deficiency (one-sided binomial test p-value = 1.12E-04).
By comparing genetic associations in regions that contained genome-wide significant variants in either the urinary or blood zinc GWAS, we found that only rs13135092 ( SLC39A8 ; p-value of 2.84e-09 in the urinary zinc excretion GWAS) and rs2434860 ( DPEP1/CHMP1A/SPATA2L ; p-value of 3.50E-11 in the urinary zinc excretion GWAS) were nominally significant in the blood zinc GWAS with effects in opposite directions (p-values of 8.05E-03 and 0.042, respectively), whereas the remaining SNPs did not show any overlap even at the nominal significance level (Table A in S1 File).