1. Generate epidemiological and dietary gastric cancer (GC) risk data from 500 Mexican-American (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 children's mothers.
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-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. |