MMP-9 -1562 C>T (rs3918242) Promoter Polymorphism as a Susceptibility Factor for Multiple Gingival Recessions

The objective of this pilot study was to investigate the potential role of -1562 C>T single nucleotide polymorphism (SNP) in the promoter region of the matrix metalloproteinase-9 (MMP-9) gene as a risk modulator in the development of multiple gingival recessions (MGRs) in young adults in the Serbian population. The study sample comprised 161 systemically healthy people: 60 with MGRs and 101 controls with healthy periodontal tissues. Genotyping was done using polymerase chain reaction/restriction fragment length polymorphism approach on DNA obtained from buccal swabs. Clinical measurements included vertical recession depth (VRD), clinical attachment level (CAL), keratinized gingival width (KGW), visible plaque index (PI), and bleeding on probing (BOP). Heterozygotes (CT) were significantly more frequent in the MGRs group than in the control group (P = .005) and carriers of the T allele had an approximately threefold increase of MGRs risk. Patients with the CT genotype exhibited significantly higher values of VRD and CAL and significantly lower values of KGW than patients with the wildtype genotype. Associations among different genotypes and periodontal biotypes in the MGRs group remained insignificant because all participants exhibited thin biotype. The -1562 C>T SNP in the promoter region of MMP-9 appears to be a risk factor for MGR development and a potential predictor of more severe clinical phenotype.