**3. Genome wide association analysis**

Rhodin et al. in their systematic analysis listed top genes NIN, ABHD12B, WHAMM, AP3B2, CPEB1, HGD, ZNF675, EMK1, TNFRSF10B, HTR4, WDR59, JDP2, OTOF, ANGEL2, etc. that showed evidence of association with severity of periodontitis and colonization of microorganisms [22]. GWAS is a recent development in the field of research. It highlights suggestive loci that could play an important role in periodontitis. However, the method is expensive and technique sensitive. Many GWAS in periodontitis has been carried out and has shown differential expression of varied genes [23–26].
