Department of Specific Formation, Dental School, Fluminense Federal University, Nova Friburgo, Brazil.
Caries Res. 2017;51(2):102-108. doi: 10.1159/000451037. Epub 2017 Jan 25.
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.
基因多态性在涉及同型半胱氨酸代谢的酶的基因中，如蛋氨酸合成酶（MTR）和蛋氨酸合成酶还原酶（MTRR），在叶酸和维生素 B12 的代谢中发挥重要作用。本研究旨在评估 MTR（rs1805087）和 MTRR（rs1801394）基因多态性与儿童早期龋（ECC）易感性和体重指数改变的关系。在巴西里约热内卢的 25 家公立日托中心进行了一项横断面研究，共纳入 488 名年龄在 2 至 6 岁的儿童。通过问卷获得人口统计学数据和口腔健康习惯。通过 2 名检查者（κ = 0.80）收集体格测量和龋齿经验数据。使用 TaqMan 实时 PCR 从颊细胞提取的基因组 DNA 对选定的多态性进行基因分型。在有和没有疾病的组之间比较等位基因和基因型频率。使用 t 检验、卡方检验、比值比、皮尔逊相关检验和逻辑回归分析（p≤0.05）。正常体重儿童的平均白色斑点病变评分为 1.18（±2.57），体重不足儿童为 2.50（±3.87）（p=0.05）。对于 MTRR 多态性，无龋和龋病儿童之间观察到等位基因和基因型频率分布存在显著差异（等位基因和基因型频率分别为 p=0.03 和 0.04），正常体重和体重不足儿童之间的基因型频率也存在显著差异（p=0.04）。我们的结果表明体重不足与 ECC 之间存在关联；此外，还表明 MTRR 是 ECC 和体重不足的常见遗传危险因素。
