Left-right asymmetry in palatal rugae is associated with genetic variants in WNT signaling pathway

Abstract

ObjectiveThe present study evaluated the association between genetic variants in WNT3A and WNT11, and palatal rugae phenotypes. DesignEighty-five biological unrelated orthodontic patients were included. Dental casts were assessed and data regarding the length, shape, direction and unification of rugae were recorded. The individuals were subsequently classified for each of the following rugae traits: total amount of rugae; bilateral symmetry in the amount, length and shape of the rugae; presence of secondary or fragmentary rugae; presence of unifications; predominant shape; and, direction of the rugae. Genetic variants in WNT3A (rs708111) and WNT11 (rs1533767) were genotyped by real-time PCR. Genotype and allele distributions were compared with an established alpha of 5 %. ResultsThe wavy and curve rugae were the most common. Genotype/phenotype analyses identified that the presence of the rs708111 A allele (OR = 2.2, 95 % CI: 1.1–4.4, p = 0.01) and the rs1533767 G allele (OR = 2.3, 95 % CI: 1.0–5.3, p = 0.05) increased in more than two times the chance of having bilateral asymmetry in the amount of the rugae. In the recessive model, individuals carrying two risk alleles (AA) of WNT3A rs708111 had a higher risk of presenting this phenotype. SNP-SNP interaction analysis revealed that individuals carrying one rs708111 A allele and rs1533767 G allele showed even a higher chance of having bilateral asymmetry in the amount of rugae (OR = 5.6, 95 % CI: 1.1–28.8, p = 0.03). No associations were identified for other rugae phenotype (p > 0.05). ConclusionGenetic variants in WNT3A and WNT11 were associated with the left-right asymmetry in the amount of palatal rugae.