Association of taste receptor gene polymorphisms with dental caries

Abstract This study was performed to evaluate the interplay between dental caries, nutritional status, and genetic polymorphisms in TAS1R1 and TAS1R2 (taste receptor, type 1, member 1 and 2) in preschool children and pre-adolescents. We included 525 subjects (306 preschool children and 219 pre-adolescents). Parents/caregivers answered a self-administered questionnaire about their children's systemic health, characteristics, oral hygiene habits, and diet. Clinical examination was performed to evaluate dental caries and nutritional status. Saliva samples were collected for DNA extraction. The genotyping of rs17492553 ( TAS1R1 ), rs3935570, and rs4920566 ( TAS1R2 ) polymorphisms was performed using real-time PCR with Taqman Genotyping Master Mix and SNP assay. Both univariate and multivariate Poisson regression analyses with robust variance were used for the data analysis. In preschool children, consumption of sweets between meals increased the prevalence of dental caries by 85% (PR c = 1.85; 95%CI 1.39-2.46; p < 0.001), whereas in pre-adolescents, this prevalence increased by 34% (PR a = 1.34; 95%CI 1.11-1.62; p = 0.002), regardless of genetic polymorphisms . Moreover, individuals carrying at least one allele C in rs17492553 presented 23% more prevalence of dental caries (PR a = 1.23; 95%CI 1.02-1.49 p = 0.030). Nutritional status was not associated with dental caries, neither with genetic polymorphisms . Consumption of sweets between meals increased the prevalence of dental caries. In pre-adolescents, rs17492553 genetic polymorphism in TAS1R1 was associated with dental caries.

Genetic sensitivity to bitter taste of 6-n Propylthiouracil: A useful diagnostic aid to detect early childhood caries in pre-school children.

PURPOSE: Genetic factor to bitter taste perception appears to be largely mediated by the TAS2R38 gene. The insensitivity to bitter compounds like 6-n-propylthiouracil (PROP) is mediated by this gene. PROP, a pharmacological drug used in treatment of Graves’ disease, proved to be useful tool in determining the genetic sensitivity levels to bitter and sweet taste. The purpose of this study is to show much simpler PROP sensitivity technique for the clinical examiner and its application as a diagnostic aid in Early Childhood Caries (ECC) detection among preschool children. MATERIALS AND METHODS: A total of 119 children belonging to the age group of 36 to 71 months of both sexes, were recruited from A. J. Institute of Dental Sciences, Mangalore (Karnataka). PROP sensitivity test was carried out to determine the inherent genetic ability to taste a bitter or sweet substance. This study used simpler scaling method to find out genetic sensitivity to bitter taste; one who tasted bitter as taster and one who was not able to differentiate/tasted like paper as non-taster. A questionnaire was provided to evaluate their dietary habits and caries experience was recorded. Collected data were tabulated and subjected to statistical analysis. RESULTS: In the total of 119 children the mean dmfs was definitely higher in non-taster children compared to tasters. The tasters had a mean dmfs value of 9.5120 (S.D. 7.0543) and non-tasters had a value of 7.7250 (S.D. 8.33147), which was statistically significant. The results suggested that there was increase in caries experience among the group of non-tasters as compared to tasters. Tasters tended to be sweet dislikers and non-tasters tended to be sweet likers. On the whole, tasters had a bad dentition as compared to non tasters. CONCLUSION: The PROP sensitivity test (filter paper test) proved to be a useful diagnostic tool in determining the genetic sensitivity levels of bitter taste. The knowledge of a child's taste perception can help us in identifying the children who are at higher risk for ECC.

Possible relation between phenylthiocarbamide taste sensitivity and goitre

The ability or inability to taste the bitterness of phenylthiocarbamide [PTC] is a classic inherited trait that has been studied in relation to various diseases. This study was carried out to find out any possible association between PTC-taste sensitivity and goitre. A total number of 471 subjects were studied. Among them 224 subjects were normal, healthy adults, taken as control and 247 were patients of goitre coming to Nishtar Hospital Multan for treatment. A 0.5% solution of PTC was freshly prepared. A drop of PTC Wution was placed on the dorsum of the tongue and the person was asked to state the taste perceived. Person was asked to spit out the chemical and rinse the mouth with water afterwards. Patients of goitre were clinically diagnosed by inspection and palpation method out of 224 normal healthy adults, 18.3% were non-tasters to PTC. Among 247 patients of goitre 36.84% were non-tasters to PTC. Number of non-tasters was highly significantly [P0 < 001] increased in the goitre patients as compared with the normal subjects. Percentage of non-tasters was non-significantly increased among male patients of goitre as compared with the normal subjects. Among female population, 10.88% of normal healthy females were non-taster to PTC and 37.37% of females having goitres were found to be non-tasters to PTC. Difference was highly significant [P0 < .001]. Female non-tasters to PTC are more prone to develop goitre as compared with the normal healthy females. PTC non-taster status is a vulnerability marker for females

Genetic sensitivity to the bitter taste of 6-n propylthiouracil: a new risk determinant for dental caries in children.

The aims of the present study were to contrast the prevalence of dental caries in children with different genetic sensitivity levels to the bitter taste of 6-n-propylthiouracil (PROP) and to determine the taste quality and taste intensity preferences of food products among the taster and nontaster groups. Overall caries experience (dmfs/DMFS) was significantly higher for nontasters than tasters. Caries experience on the available surfaces (dfs/DFS) was found to be significantly higher in nontasters than in medium tasters and in medium tasters than in supertasters (r=-0.41, P < 0.001). Majority of the nontasters were sweet likers and preferred strong tasting food products, while majority of the supertasters were sweet dislikers and preferred weak tastes. There was a significant increase in the overall caries experience in the population, as the genetic ability to detect PROP taste decreased ( P < 0.001). After all associated factors (age, gender, race, number of teeth and OHI-S) were controlled; multiple linear regression analyses revealed that taste was the only variable significantly related to overall caries experience.

Taste sensitivity in pregnancy.

Taste sensitivity to Phenyl-thio-Carbamide (PTC) and glucose were studied in 150 females during the 3 trimesters of their pregnancy periods. The taste sensitivity to PTC was determined by Harris and Kalmus method. For taste intensity and hedonic evaluation, 7 concentrations of glucose solutions were used. Taste sensitivity to both PTC and glucose increases during the 1st trimester of pregnancy. In comparison to non-pregnant females (from previous study) taste thresholds and hedonics decreases in pregnancy.