Interactions with the aquaporin 5 gene increase the susceptibility to molar-incisor hypomineralization.

• The rs13115627-GG genotype may be protective against MIH in our population. • The rs1784418-TT genotype and rs1800972-CC genotype related to an increased MIH risk. • The carriers with rs1996315‐AG and rs923911-AC genotypes have a higher MIH risk. The aim of this study was to evaluate whether individual genetic factors involved in amelogenesis, the immune response and water channel proteins may increase the susceptibility to Molar-Incisor Hypomineralization (MIH) in Chinese children. DNA samples were collected from 86 cases with MIH cases and 344 controls. Sixteen single-nucleotide polymorphisms (SNPs) were investigated. Logistic regression analysis was performed to assess association between SNPs and the risk of MIH. Our results showed that the risk of MIH in the rs13115627-AA genotype carriers and the rs1784418-TT genotype carriers were significantly higher than that among those with the rs13115627-GG genotype (OR (95 % CI)) = 4.942 (0.658-37.131) and the rs1784418-CT genotype (OR (95 % CI)) = 2.023 (1.63–3.521). The population with the rs1800972‐CC genotype and the rs1800972‐C allele had a higher risk to develop MIH, OR (95 % CI) = 2.284 (1.267–4.115), OR (95 % CI) = 2.427 (1.493–3.953) respectively. In the Aquaporin 5(AQP5) gene, we individually analyzed two SNPs, rs1996315 and rs923911. We found no significant associations between them and MIH. However, in the analysis of the gene-gene interactions, we discovered a significant two‐locus model (P = 0.023) involving rs1996315 and rs923911. Participants with the rs1996315‐AG and rs923911-AC genotypes had the highest MIH risk, compared to participants with the rs1996315‐GG and rs923911-CC genotypes, OR (95 % CI) = 3.603 (1.147–11.318). This study showed that genetic variants in the AMBN, MMP20 and DEFB1 genes may contribute to MIH in the permanent dentition of children. Moreover, interactions among AQP5 gene may also increase the MIH susceptibility. [ABSTRACT FROM AUTHOR]