ABSTRACT
Polymorphisms in genes encoding the enzymes involved in the metabolism of homocysteine, such as methionine synthase (MTR) and methionine synthase reductase (MTRR), play an important function in the metabolism of folic acid and vitamin B12. The present study aimed to evaluate the association of polymorphisms in genes MTR (rs1805087) and MTRR (rs1801394) with susceptibility of early childhood caries (ECC) and with body mass index alterations. A cross-sectional study was performed in 488 children aged from 2 to 6 years from 25 public day care centers in Rio de Janeiro, Brazil. Demographic data and oral health habits were obtained through a questionnaire. Anthropometric measurements and caries experience data were collected by 2 examiners (κ = 0.80). Genotyping of the selected polymorphisms was carried out by TaqMan real-time PCR using genomic DNA extracted from buccal cells. Allele and genotype frequencies were compared between groups with and without disease. The t test, χ2 test, odds ratio, Pearson correlation tests, and logistic regression analysis were used (p ≤ 0.05). The mean white spot lesion score was 1.18 (±2.57) in normal weight children and 2.50 (±3.87) in underweight children (p = 0.05). For MTRR polymorphisms, significant differences were observed for allele and genotype frequency distributions between caries-free and caries-affected children (p = 0.03 and 0.04 for allele and genotype frequencies, respectively) and in the genotype frequencies between normal weight and underweight children (p = 0.04). Our results suggest an association between underweight and ECC; in addition it is suggested that MTRR is a common genetic risk factor for ECC and underweight.
Subject(s)
Dental Caries/genetics , Ferredoxin-NADP Reductase/genetics , Polymorphism, Single Nucleotide , Thinness/genetics , Child, Preschool , Cross-Sectional Studies , Female , Humans , MaleABSTRACT
BACKGROUND: Matrix metalloproteinases and their inhibitors might be involved in enamel formation. AIM: This study aimed to evaluate the association between polymorphisms in MMP2, MMP3, MMP9, MMP20, TIMP1, and TIMP2 with white spot lesions (WSL) and early childhood caries (ECC). DESIGN: A cross-sectional study was performed on 786 children aged from 2 to 6 years in Brazil. After clinical evaluation, they were classified into groups with disease (the presence of WSL and/or ECC) and without disease (the absence of WSL or ECC). Genotyping of the selected polymorphisms was carried out with TaqMan real-time PCR, using genomic DNA extracted from buccal cells. Allele and genotype frequencies were compared between groups. Chi-square test, odds ratio (OR), and logistic regression were used (P ≤ 0.05). RESULTS: The dmft score was 1.3 (SD: 2.4), and 41.34% of the children have at least one caries lesion. In MMP9, the GG genotype was more frequent in the group without disease (P = 0.006). In a recessive model, WSL was associated with the marker rs1711437 in MMP20 (P = 0.019; OR = 1.20, 95% CI 1.02-1.42). The marker rs1784418 in MMP20 showed an association between the allele G distribution for the WSL group (P = 0.020; OR = 0.73, 95% CI 0.55-0.96). CONCLUSION: MMP9 and MMP20 are involved in WSL and ECC development.
Subject(s)
Dental Caries/genetics , Matrix Metalloproteinases/genetics , Tissue Inhibitor of Metalloproteinase-1/genetics , Tissue Inhibitor of Metalloproteinase-2/genetics , Alleles , Child , Child, Preschool , Cross-Sectional Studies , DNA/genetics , Dental Caries/enzymology , Female , Gene Frequency , Genetic Predisposition to Disease , Genotype , Humans , Isoenzymes , Male , Mouth Mucosa , Polymorphism, Genetic , Real-Time Polymerase Chain Reaction , Risk FactorsABSTRACT
Bone morphogenetic proteins (BMPs) play an important role during the initial process of enamel development and therefore may play a role in caries susceptibility. The purpose of this study was to evaluate the association between the polymorphisms in the BMP2, BMP4 and BMP7 genes and their association with caries experience and primary enamel microhardness characteristics. DNA from buccal cells as well as clinical and demographic information from 1,731 subjects from three different data sets from Brazil were included. Polymorphisms in BMP2, BMP4 and BMP7 were analyzed by real-time polymerase chain reaction from genomic DNA. Association between caries experience, genotype, and allele distribution in both cohorts was evaluated using χ(2) and logistic regression analyses. In the family-based set, the association between caries experience and alleles was tested using the transmission disequilibrium test. In the Rio de Janeiro cohort, microhardness data on 108 exfoliated primary teeth before and after demineralization and remineralization challenges was included. Associations between microhardness values and genotype and allele distribution were evaluated using χ(2) and logistic regression analyses. Differences between caries experience and some risk factors were statistically significant. In the cohort from Nova Friburgo, BMP2 was associated with caries experience in primary dentition during logistic regression analysis (p = 0.023; OR = 2.58; 95% CI 1.13-5.86). There was no association between genotype and allele distribution for BMP polymorphisms and primary enamel microhardness alterations. Our result suggests that BMP2 may be involved in caries experience in primary dentition from a Nova Friburgo cohort.
