Aquaporin Genes Interact with Fluoride in Caries

ANTOMSHOAA I; POLETTA FA; MEREB J; LOPEZ CAMELO JS; CASTILLA EE; ORIOLI I; VIEIRA AR

Encuentro; 89th General Session & exhibition of the IADR; 2011

Objective: Caries is a multifactorial disease influenced by environmental factors and factors related to individual susceptibility. Twin studies suggest that genes modulate susceptibility and have a significant impact on the development of caries. An increasing number of studies have investigated the possible association between gene variants and caries experience. Genes involved in enamel formation and immune response have been suggested as factors that increase susceptibility to caries. Other possible candidate genes are genes involved in saliva production. The aim of this work was to investigate if variation in aquaporin (AQP) genes possibly involved in saliva function, contributes to caries susceptibility. Methods: DNA samples of 274 subjects were obtained from 76 families from the Patagonian region of Argentina. Eight markers in or flanking the genes AQP2, AQP5, and AQP6 were selected based on gene structure and linkage disequilibrium relationships inferred from data from the International HapMap Project. Families were divided in two groups: from sites with highly prevalent fluorosis and sites without fluorosis. Individuals with high caries experience (based on DMFT/dmft scores corrected by age) were considered affected for this analysis. The Family-Based Association Test (FBAT) software was used to test overtransmission of alleles and p-values lower than 0.05 were considered statistically significant. Results: A haplotype composed of alleles of the markers rs3759129 (5´ flanking AQP5) and rs1996315 (in AQP6) was associated with high caries experience in families from sites without fluorosis (p=0.01) under a dominant model. Conclusion: Genetic variation in aquaporin genes is associated with high caries experience and its contribution may be influenced by fluoride exposure. This work is supported by the NIH grant R01-DE18914 and CNPq (National Research council of Brazil), process # 573993/2008-4; INAGEMP.