Figure 4
From: Identification and MS-assisted interpretation of genetically influenced NMR signals in human plasma
Association at the PYROXD2 locus. SNP rs4488133 associates with the ratio between two neighboring chemical shifts (δ = 2.757 ppm and δ = 2.755 ppm; P = 2.9x10-94), displaying an exceptionally strong increase in the strength of association when using ratios of over 82 orders of magnitude. This figure presents the median NMR signal intensities, differentiated by the genotype of SNP rs4488133 (color-coded). A peak at δ = 2.757 ppm is only present in major allele homozygotes (inset). This peak is located on the shoulder of a much larger underlying NMR signal. We argue that in this case the ratio between signals at two neighboring chemical shifts, one of them in a localized peak, is equivalent to applying a local baseline correction, effectively elevating the peak out of the background noise.