Fig. 5: Urine-specific mQTLs deliver insights into systemic and kidney-specific processes.

a, The mQTLs highlighted in b,c belongs to the group arising from metabolites only measured in urine. b, The haplotype carrying the derived allele at the galactosylglycerol-associated mQTL at the FUT2 locus shows extended homozygosity as compared to the haplotype carrying the ancestral allele; the x axis represents the genomic coordinates (bp in build 37) around the tested SNP rs516246, the proxy for the index SNP rs679574 (r² = 1); the y axis displays the extended haplotype homozygosity (EHH) statistic (Methods). The EHH around the derived allele is shown by the solid black line, whereas the one of the ancestral allele is shown by the gray dashed line. The dotted light gray line indicates the position of the tested SNP. Black dashes on the x axis represent the positions of SNPs that were used to compute the EHH statistic. c, Phenome-wide association study for rs516246 based on UK Biobank data (https://pheweb.org/UKB-TOPMed/variant/19:48702915-C-T)⁵¹. Excl., excluding. d, The mQTLs highlighted in e–g belongs to the group of urine-specific mQTLs arising from metabolites measured in plasma and urine. e, Regional association plot of the GWAS of urine glycerol levels (linear regression) around the most likely gene, AQP7. The index variant rs62542743 is shown in purple. f, Schematic representation of a presumed loss-of-function effect of AQP-7 p.Gly264Val on tubular reuptake of glycerol. g, Distribution of the log₂-transformed glycerol levels in plasma (red) and urine (blue) by genotype at rs62542743. The black line in the center of each violin represents the median of the data.