A plausible interplay between the top-SNP rs56113850 and rs113288603 was detected. When analysed within the largest of our cohorts (YFS) the minor allelic effect size of rs113288603 increased from non-significant (beta = 0.05, p = 0.522) to highly significant (beta = -0.47, p = 1.32E-09) when rs56113850 was added to the model; when an interaction term (rs56113850*rs113288603) was also added to the model the effect size further increased (beta = -0.62, p = 1.32E-03). Similarly, the effect size of rs56113850 increased from -0.67 (p<2E-16) to -0.83 (p<2E-16) when rs113288603 was added to the model; addition of an interaction term (rs56113850*rs113288603) to the model did not further affect the results (beta = -0.82, p<2E-16).
