Centro de Investigación Aplicada en Ambiente y Salud, CIACYT-Medicina, Universidad Autónoma de San Luis Potosí, Sierra Leona No. 550, Lomas 2da. sección, CP 78210 San Luis Potosí, SLP, Mexico.
Departamento de Farmacia, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Noria Alta s/n, CP 36050 Guanajuato, Gto., Mexico.
Arch Oral Biol. 2018 Dec;96:21-25. doi: 10.1016/j.archoralbio.2018.08.010. Epub 2018 Aug 23.
To determine the allelic and genotypic frequencies of rs 412777 polymorphism in the Collagen type I alpha 2 chain (COL1A2) gene and the association with the severity of dental fluorosis in children between 6 and 12 years old in the State of San Luis Potosi, Mexico.
A cross-sectional study was designed; participants were 230 children from two rural communities of San Luis Potosí. Fluoride in drinking water and urine samples was quantified using a potentiometric method with a selective ion electrode. Dental fluorosis was diagnosed using the Thylstrup-Fejerskov index while the identification of the polymorphism was made by allelic discrimination, using allele-specific probes by real-time Polymerase chain reaction (PCR). Statistical analysis was carried out with Student's t-test and Chi-square and Odds Ratio (OR). A confidence interval of 95% and a value of p < 0.05 were considered.
The concentration of fluoride in drinking water was 2.36 ± 0.02 mg/L in Ojo Caliente and 4.56 ± 0.07 mg/L in La Reforma, the concentration of fluoride in urine was 2.05 ± 0.62 mg/L and 2.99 ± 0.99 mg/L respectively. The prevalence of dental fluorosis was 100% and the frequency of alleles was 67% wild-type and 33% mutant allelic, alleles were found in Hardy-Weinberg equilibrium (X = 0.33, p = 0.89). The association between the degree of dental fluorosis and the evaluated polymorphism was statistically significant (OR = 7.10, 95% CI = 3.96-12.70, p < 0.05).
An association of rs 412777 polymorphism in the COL1A2 gene with dental fluorosis was found. Therefore, genetic variants represent a relevant risk factor to develop dental fluorosis, as it was proven in this study conducted in Mexican children.
确定 COL1A2 基因 rs412777 多态性的等位基因和基因型频率，并探讨其与墨西哥圣路易斯波托西州 6 至 12 岁儿童氟斑牙严重程度的关系。
采用横断面研究设计，选取来自圣路易斯波托西州两个农村社区的 230 名儿童为研究对象。采用离子选择性电极的电位法对饮用水和尿样中的氟含量进行定量检测。采用 Thylstrup-Fejerskov 指数对氟斑牙进行诊断，通过实时聚合酶链反应（PCR）的等位基因特异性探针进行等位基因鉴别，从而确定多态性。采用学生 t 检验、卡方检验和比值比（OR）进行统计分析。置信区间为 95%，p 值<0.05 时认为差异具有统计学意义。
Ojo Caliente 的饮用水氟浓度为 2.36±0.02mg/L，La Reforma 的饮用水氟浓度为 4.56±0.07mg/L，尿氟浓度分别为 2.05±0.62mg/L 和 2.99±0.99mg/L。氟斑牙的患病率为 100%，野生型等位基因频率为 67%，突变型等位基因频率为 33%，等位基因处于 Hardy-Weinberg 平衡状态（X=0.33，p=0.89）。氟斑牙严重程度与评估的多态性之间存在统计学关联（OR=7.10，95%CI=3.96-12.70，p<0.05）。
COL1A2 基因 rs412777 多态性与氟斑牙存在关联。因此，遗传变异是导致氟斑牙发生的一个重要危险因素，这在本研究中得到了证实。
