Association of Candidate Genes with Dental Caries in Young Children

Objective:  Dental caries is one of the most common oral diseases and is influenced by a complex interplay of genetic and environmental factors.  Identification of risk factors in young children would enable more targeted and proactive approaches to improve oral health at the earliest stages.  We investigated the association of caries in young children with genes from multiple relevant oral processes.

Methods:  From the studies of the Center for Oral Health Research in Appalachia 217 young children (1≤age<6) and their parents were included in this study Biological samples, demographic data and clinical assessment of caries scored for dft and dfs were collected.  Genetic association was investigated using Pearson chi-squared case-control analysis, FBAT software TDT analysis, and regression analysis.  The phenotypic scores included “no caries” (dft/s=0,n=139), “low” (dft/s ≤1,n=177), “any caries” (dft/s ³1,n=78), and “severe” (dft/s ratio to extant teeth³20%,n=47).  Genotyping using Taqman chemistry was conducted with 28 SNPs in 21 candidate genes involved in saliva, taste preference and various proteinases.

Results:  The cysteine proteinase, CTSB has genotypic and allelic association with “severe versus low” (genotypic p=0.007, allelic p=0.003) and “severe versus no caries” (p=0.02, p=0.005) while TDT indicated borderline association with “severe” caries (p=0.08).  The salivary gland water channel, AQP5 shows genotypic and allelic association with “not low versus low” (p=0.002, p=0.003) and “any-caries versus low” (p=0.006, p=0.01).  Regression modeling revealed AQP5 accounts for 14% of the variation in dft/dfs but there were insufficient informative trios for TDT analysis of AQP5.  Two SNPs in the taste receptor TASR2R38 were associated with “low” caries (p=0.004, p=0.03) and thus protective. .

Conclusions:. We have identified genes of various functional classifications that are associated with either protection from caries or susceptibility to caries in young children.  Regression modeling has further revealed AQP5 accounting for 14% of the dft/dfs variation. 

NIH Grant #R01-DE014889.