Aquaporin (AQP) Locus 12q13 is associated with caries experience

Objectives: To determine if genetic variation in the aquaporin locus in humans is associated with caries in the primary or permanent dentition.
Methods: Saliva samples from 876 human subjects at ages 16, 17 and 18 and dmft/DMFT scores from the same subjects ages 5, 12, 14, 16, 17 and 18 from western Norway were obtained. Eight calibrated clinicians performed the sample collection in dental clinics as part of a regular examination. DNA extractions from whole saliva were performed. Genotyping of five SNPs in the aquaporin locus (rs1996315, rs296763, rs3759129, rs3736309, and rs2878771) was obtained by PCR using Taqman chemistry and end-point analysis. The genotypes were compared against the dmft/DMFT scores, taking trends in caries experience into consideration as ages increased. This study was approved by the local IRB, and written informed consent was obtained from all participants. Association was tested using the software PLINK.
Results: Patients were broken down into subgroups for comparison based on DMFT/dmft scores such as no caries, high caries (dmft/DMFT ≥ 4), low caries (dmft/DMFT ≤ 3), those who showed a decrease in dmft score, and those who exhibited a “spike” or increase of 4 or more caries between age points. Confidence intervals were set at 95%. The table shows significant associations based on these comparisons.
Conclusions: We found association between the aquaporin locus and caries experience. Variations in aquaporin expression during adolescence and dental development may affect water channel proteins contributing to salivary output, leading to an elevated caries risk.