Prevalence of environmental and genetic risk factors for gastric cancer in a popu

胃癌（GC）可以被认为是健康差距的一个指标，因为它是更普遍的， 发展中国家，死亡率更高。在墨西哥，GC是第三大死亡原因， CVD和肺癌，在美国，西班牙裔的GC发病率也高于白色美国人。的 胃癌的病因包括幽门螺杆菌感染、饮食因素和遗传易感性。由于 居住在德克萨斯州的MA儿童数量众多， 我们正在进行的研究“环境暴露移民/季节性移民遗传易感性的生物标志物” 农场工人儿童（无国界医生研究），我们建议使用分子和环境流行病学 评估上述GC风险因素在该少数人群中的患病率。在 此外，我们将开发并验证一个FFQ，以评估MA儿童的叶酸和维生素B-12摄入量 住在德克萨斯州。我们的短期目标是估计社会， 与MA儿童GC风险相关的环境和遗传因素， 降低风险的长期目标，可以通过预防性干预措施加以改变。的 研究的具体目标是：1。从500 MA中生成流行病学和饮食GC风险数据 5至18岁的儿童。我们将获得社会经济和饮食信息，GC家族史， 胃部疾病（GD）、儿童病史和GD症状，通过结构化双语 问卷调查采用间接访谈技术与母亲和儿童参与者。2：基因型a 参与叶酸-DNA甲基化的关键基因作为GC风险的中间生物标志物。我们将 对儿童进行亚甲基四氢叶酸还原酶（MTHFR）基因多态性的基因分型， 位置677 C>T，因为该基因的变异性可以严重影响叶酸的分布和可用性， 这反过来又会增加GC的风险。3：测定叶酸、维生素B-12和同型半胱氨酸 孩子们的水平。我们将分析红细胞中叶酸的水平和 儿童参与者的血浆作为GC风险的中间生物标志物，因为叶酸缺乏可导致 同型半胱氨酸的积累，这反过来又减少了DNA所需的甲基的可用性 甲基化4.确定抗HP抗体的血清阳性率。我们将分析 儿童参与者是否存在抗HP IgG抗体，这是HP暴露的指标， GC的危险因素。由于遗传易感性或 环境因素对癌症预防有重要意义。我们的研究结果可能 还有助于减少全球和美国现有的GC健康差距。

Gastric cancer (GC) can be considered an indicator of health disparity since it is more prevalent in developing countries, where the mortality is higher. In Mexico GC is the 3rd leading cause of mortality after CVD and lung cancer, and in the US, GC incidence is also higher in Hispanics than in white Americans. The etiologic factors for GC include Helicobacter Pylori infection, dietary factors and genetic susceptibility. Due to the large number of MA children residing in Texas, and the high prevalence of gastric disorders observed in our on-going study "Biomarkers of Genetic Susceptibility in Environmentally Exposed Migrant/Seasonal Farmworker Children (MSF Study), we propose to use a molecular and environmental epidemiologic approach to assess the prevalence of the aforementioned GC risk factors among this minority population. In addition, we will develop and validate a FFQ to assess the folate and vitamin B-12 intake of MA children residing in Texas. Our short-term goal is to estimate the magnitude of the prevalence of the social, environmental and genetic factors that have been associated with GC risk among MA children, with the long-term goal of reducing the risk that can be modified through preventive interventions. The specific aims of the study are to: 1. Generate epidemiological and dietary GC risk data from 500 MA children ages 5 to 18. We will obtain socioeconomic and dietary information, family history of GC and gastric disorders (GD), children's medical history and symptoms of GD via a structured bilingual questionnaire using indirect interviewing techniques with the mother and child participants. 2: Genotype a key gene involved in folate-DNA methylation as an intermediate biomarker for GC risk. We will genotype the children for polymorphisms in the methylenetetrahydrofolate reductase (MTHFR gene at position 677C>T since variability in this gene can critically influence the distribution and availability of folate, which in turn can increase the risk for GC. 3: Determine the folate, vitamin B-12 and homocysteine levels of the children. We will analyze the levels of folate in the erythrocytes and the homocysteine in the plasma of the children participants as intermediate biomarkers for GC risk since folate deficiency can lead to an accumulation of homocysteine, which in turn reduces the availability of methyl groups needed for DNA methylation 4. Determine the seroprevalence of antibodies against HP. We will analyze the serum of the children participants for the presence of IgG antibody against HP, which is an indicator of HP exposure, and a risk factor for GC. The ability to identify children are risk for GC, due to either genetic predisposition or environmental factors has substantial implication for cancer prevention. Findings from our study may also serve to reduce existent GC health disparities worldwide and in the U.S.