ABSTRACT
Carious lesions are distributed nonuniformly across tooth surfaces of the complete dentition, suggesting that the effects of risk factors may be surface-specific. Whether genes differentially affect caries risk across tooth surfaces is unknown. We investigated the role of genetics on two classes of tooth surfaces, pit and fissure surfaces (PFS) and smooth surfaces (SMS), in more than 2,600 subjects from 740 families. Participants were examined for surface-level evidence of dental caries, and caries scores for permanent and/or primary teeth were generated separately for PFS and SMS. Heritability estimates (h(2), i.e. the proportion of trait variation due to genes) of PFS and SMS caries scores were obtained using likelihood methods. The genetic correlations between PFS and SMS caries scores were calculated to assess the degree to which traits covary due to common genetic effects. Overall, the heritability of caries scores was similar for PFS (h(2) = 19-53%; p < 0.001) and SMS (h(2) = 17-42%; p < 0.001). Heritability of caries scores for both PFS and SMS in the primary dentition was greater than in the permanent dentition and total dentition. With one exception, the genetic correlation between PFS and SMS caries scores was not significantly different from 100%, indicating that (mostly) common genes are involved in the risk of caries for both surface types. Genetic correlation for the primary dentition dfs (decay + filled surfaces) was significantly less than 100% (p < 0.001), indicating that genetic factors may exert differential effects on caries risk in PFS versus SMS in the primary dentition.
Subject(s)
Dental Caries/genetics , Dental Enamel/pathology , Dental Fissures/genetics , Genetic Predisposition to Disease/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Appalachian Region/epidemiology , Child , Child, Preschool , Cohort Studies , DMF Index , Dental Caries/epidemiology , Dental Caries/pathology , Dental Caries Susceptibility/genetics , Dental Fissures/epidemiology , Dental Restoration, Permanent/statistics & numerical data , Female , Genetic Variation/genetics , Humans , Infant , Male , Middle Aged , Models, Genetic , Phenotype , Population Surveillance , Quantitative Trait, Heritable , Tooth Loss/epidemiology , Tooth, Deciduous/pathology , Young AdultABSTRACT
Dental caries is influenced by a complex interplay of genetic and environmental factors, including dietary habits. Previous reports have characterized the influence of genetic variation on taste preferences and dietary habits. We therefore hypothesized that genetic variation in taste pathway genes (TAS2R38, TAS1R2, GNAT3) may be associated with dental caries risk and/or protection. Families were recruited by the Center for Oral Health Research in Appalachia (COHRA) for collection of biological samples, demographic data, and clinical assessment of oral health, including caries scores. Multiple single-nucleotide polymorphism (SNP) assays for each gene were performed and analyzed by transmission disequilibrium test (TDT) analysis (FBAT software) for three dentition groups: primary, mixed, and permanent. Statistically significant associations were seen in TAS2R38 and TAS1R2 for caries risk and/or protection.
Subject(s)
Dental Caries/genetics , Taste/genetics , Adenine , Adult , Alanine/genetics , Child , Child, Preschool , Cohort Studies , Cytosine , DMF Index , Dental Caries/etiology , Dental Caries Susceptibility/genetics , Female , Gene Frequency/genetics , Genetic Variation/genetics , Genotype , Guanine , Haplotypes/genetics , Humans , Linkage Disequilibrium/genetics , Male , Polymorphism, Single Nucleotide/genetics , Proline/genetics , Receptors, G-Protein-Coupled/genetics , Risk Factors , Thymine , Transducin/genetics , Valine/geneticsABSTRACT
The importance of genetic factors in the genesis of dental caries of both primary and permanent dentitions is well established; however, the degree to which genes contribute to the development of dental caries, and whether these genes differ between primary and permanent dentitions, is largely unknown. Using family-based likelihood methods, we assessed the heritability of caries-related phenotypes for both children and adults in 2,600 participants from 740 families. We found that caries phenotypes in the primary dentition were highly heritable, with genes accounting for 54-70% of variation in caries scores. The heritability of caries scores in the permanent dentition was also substantial (35-55%, all p < 0.01), although this was lower than analogous phenotypes in the primary dentition. Assessment of the genetic correlation between primary and permanent caries scores indicated that 18% of the covariation in these traits was due to common genetic factors (p < 0.01). Therefore, dental caries in primary and permanent teeth may be partly attributable to different suites of genes or genes with differential effects. Sex and age explained much of the phenotypic variation in permanent, but not primary, dentition. Further, including pre-cavitated white-spot lesions in the phenotype definition substantially increased the heritability estimates for dental caries. In conclusion, our results show that dental caries are heritable, and suggest that genes affecting susceptibility to caries in the primary dentition may differ from those in permanent teeth. Moreover, metrics for quantifying caries that incorporate white-spot lesions may serve as better phenotypes in genetic studies of the causes of tooth decay.