The association of Enamelin, Lactoferrin, and Tumour necrosis factor alpha gene polymorphisms with high caries susceptibility in Chinese children under 4 years old

Objective: The aim of this study was to assess the role of ENAM rs3796703, LTF rs1126478, and TNF-alpha rs1800629 in high caries susceptibility. Design: The present case-control study included 1005 unrelated children under 4 years old: 505 with severe caries (dmft index >= 4) and 500 who were caries-free (dmft index = 0 and without white-spot lesions). Questionnaires were obtained from parents and gardians about the children's diet and oral behavioural habits. All the children received dental examinations and oral swabbing for human genomic DNA collection. ENAM rs3796703, LTF rs1126478, and TNF-alpha rs1800629 were genotyped by Sanger sequencing. Results: The frequency of the ENAM rs3796703 T allele (6.7% in the caries group and 4.2% in the caries-free group), CT genotype (12.7% in the caries group and 8.4% in the caries-free group), TNF-alpha rs1800629 A allele (4.8% in the caries group and 6.8% in the caries-free group), and AG genotype (8.7% in the caries group and 13.2% in the caries-free group) were significantly different between the caries and caries-free groups (p < 0.05). No significant difference was found in the LTFrs1126478 allele frequency and genotype distribution between the two groups. The ENAM rs3796703 CT genotype increased caries susceptibility by 60.9% compared to the CC genotype (beta = 0.746, OR = 1.609), and the TNF-alpha rs1800629 AG genotype reduced caries susceptibility by 47.4% compared to the GG genotype (beta = -0.642, OR = 0.526). In terms of habits covariates, prolongation of night feeding time by 1 month increased caries susceptibility by 3.3% (beta = 0.033, OR = 1.033); additionally, sweets and acidic drinks consumption 1-2 times per day increased caries susceptibility by 218.2% (beta =1.158, OR = 3.182), and consumption 3 or more times pe/r day increased susceptibility by 883.5% (13 = 2.286, OR = 9.835) compared to non-consumption. Topical fluoride application decreased caries susceptibility by 43.0% (beta = -0.562, OR = 0.570). Conclusions: The ENAM and TNF-alpha genes are likely associated with caries experience in Chinese children. The ENAM rs3796703 CT genotype might be involved in caries susceptibility, while TNF-alpha rs1800629 AG genotype might be involved in caries protection. (C) 2017 Published by Elsevier Ltd.Capital Foundation for Clinical Characteristics and Application Research [Z141107002514058]; Construction Project of the National Key Discipline of Paediatric Dentistry - Ministry of Health, PR ChinaSCI(E)ARTICLE75-818