Association of GLUT2 and TAS1R2 genotypes with risk for dental caries

Abstract

To determine whether common polymorphisms in the sweet taste receptor (TAS1R2) and glucose transporter (GLUT2) genes are associated with dental caries, 80 healthy Caucasian individuals aged 21-32 years were genotyped and grouped based on the TAS1R2 (Ile191Val) and GLUT2 (Thr110Ile) polymorphisms. Clinical and radiographic examinations were conducted by a single examiner who was blinded to the genotypes. To assess caries prevalence, three different caries scores were determined: DMFT (decayed, missing, and filled teeth), DMFT + X-ray and ICDAS (International Caries Detection and Assessment System). Associations between genotypes and caries prevalence were analyzed using Student's t test. Based on the genotypes for each of the GLUT2 and TAS1R2 genes, individuals were stratified into four groups for comparison of caries scores. A higher DMFT score (mean ± SE; 4.3 ± 0.4 vs. 6.1 ± 1.2, p = 0.04) was observed among carriers of the Ile allele for GLUT2 (risk group). Carriers of the Val allele for TAS1R2 (resistant group) demonstrated lower caries scores: DMFT (4.1 ± 0.5 vs. 5.8 ± 0.9, p = 0.05), DMFT + X-ray (4.9 ± 0.6 vs. 7.5 ± 0.9, p = 0.01), and ICDAS (19.5 ± 2.2 vs. 26.14 ± 2.82, p = 0.03). Based on genotype stratification, caries scores were significantly lower in the double resistant group as compared to the double risk groups: DMFT (9.1 ± 0.08 vs. 4.2 ± 0.01, p < 0.01), DMFT + X-ray (10.5 ± 0.07 vs. 5.2 ± 0.01, p < 0.01) and ICDAS (32.9 ± 0.2 vs. 19.9 ± 0.01, p = 0.01). In conclusion, GLUT2 and TAS1R2 genotypes individually and in combination are associated with caries risk. Considering the combination of risk/resistance genotypes might further our understanding of genetic predispositions to dental caries and improve the accuracy of caries prediction models.