The second most significant DMP mapped to the gene ROBO2 (Roundabout Guidance Receptor 2; cg17282085; q = 4.9 × 10–12, ∆β = − 0.14), which is a suggestive risk gene for periodontitis (age 20–60 years; rs264537-C, p = 3 × 10–6, odds ratio = 1.35 [95% confidence interval 1.19–1.54]) [17]. Here, ROBO2 is linked to periodontitis.