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Objectives: To evaluate the association of allelic and genotypic frequencies of PSCA (rs2976392), TNF-α (rs1800629), PARP1 (rs1136410) and TP53 (rs368771578) SNPs with GC susceptibility in a Brazilian population. Materials and Methods: This is a retrospective study, which included 102 paraffin-embedded adenocarcinoma tissue samples > 5 years of obtention, with 204 alleles for each studied SNP. Other 102 healthy tissue samples were included as controls. For analysis, the genotyping method Dideoxy Single Allele-Specific -PCR was used. Statistical analysis was performed with the Bioestat software 5.3, determining Hardy-Weinberg's equilibrium for the genotypic frequencies p-values < 0.05 were considered significant. Results: PSCA (rs2976392) and TNF-α (rs1800629) SNPs were associated with GC in the analyzed samples (X 2 =10.3/102 and p<0.001/0.00001, respectively). TNF-α (rs1800629) SNP presented also a statistically significant relationship between its genotypes and the morphological pattern (intestinal/diffuse) (p<0.032). However, PARP1 (rs1136410) and TP53 (rs368771578) SNPs were in Hardy-Weinberg's equilibrium and, therefore, were not significantly associated with GC in these samples (X 2 =0.73/2.89 and p<0.39/0.08). Conclusions: PSCA (rs2976392) and TNF-α (rs1800629) SNPs are potential molecular markers of susceptibility to GC development. PARP1 (rs1136410) and TP53 (rs368771578) SNPs were not associated with the risk of GC development.

Objective: Perform genotyping of SNPs in the promoter region of the SMO gene in BCC samples from patients from northeastern Brazil, and to determine if there is an association of these SNPs of the gene in question with the susceptibility to the development of the BCC. Methods: 100 samples of paraffined tissue from patients with histopathological diagnosis of BCC and 100 control samples were analyzed for each polymorphism by a newly developed genotyping method, the Dideoxy Single Allele Specific -PCR. The software Bioestat -version 5.3 and Haploview 4.2 were used for the statistical analysis. For all tests a P-value <0.05 was considered significant. Results: The SNP rs538312246 is the Hardy-Weinberg equilibrium, therefore, it did not present significant association with the BCC (X² =2.343 and P<0.158). However, the CpG-SNPs rs375350898 and rs75827493 were significantly associated to the BCC in the analyzed samples (X 2 = 27,740/21,500 and P <0001), the SNP rs75827493 showed a significant association with the BCC of the nodular subtype (P <0.0069). Therefore, our results suggest that SNPs rs375350898 and rs75827493 are potential molecular markers for susceptibility to BCC. Conclusion: The ability to detect SNP in a population, especially in promoter regions, has profoundly changed human genetic studies. This study allowed the understanding of the relationship between the presence of SNPs in CpG islands of the promoter region of the SMO gene can modify the methylation pattern and provide susceptibility to BCC in the population.

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