No abstract

Background: Breast cancer (BC) is the most common malignant tumor in women around the world. Genetic factors do play a vital role in the development and progression of BC. Genetic alterations in the ESR1 (estrogen receptor 1) gene can lead to estrogen dysfunction and increased risk for BC. Nevertheless, due to genetic diversity, the information from different studies is contradictory and controversial. Objectives: This study aimed to investigate the potential relationship between the rs1801132 and rs2234693 single nucleotide polymorphism (SNPs) of the ESR1 gene with susceptibility to BC in the Iranian population. Methods: The genotyping of the rs2234693 and rs1801132 SNPs was assessed in 63 BC patients referred to Imam Hasan Mojtaba Center, which is a charity-based foundation for cancer care in Dezful, Iran, from March 2018 to November 2019. Also, 65 healthy women were selected as a control group. The genotyping of the SNPs was performed using the high-resolution melting (HRM) technique and confirmed by DNA sequencing. Results: The genotype distribution and allele frequency of the rs2234693 SNP were significantly different in BC patients compared to the control group (genotype frequency with P = 0.018 and allele frequency with P = 0.004, OR = 2.085, 95% CI = 1.253 -3.468). In genetic models, rs2234693 increased BC risk in recessive model (P = 0.005, OR = 2.813, 95% CI = 1.363 - 5.802). However, there was no significant difference regarding genotype distribution of the rs1801132 SNP between the BC patients and controls. Conclusions: Our results showed that the CC genotype of the rs2234693 SNP is significantly associated with BC. Accordingly, it can be suggested that the rs2234693 SNP be considered for susceptibility to BC.

Background: Gastric cancer (GC) is the fourth common cancer in the world and the second cause of cancer-related mortality. Germline mutations in the E-cadherin gene (CDH1) are the most common cause of hereditary diffuse GC (HDGC) and explain 25%–30% of cases. In HDGC families without the pathogenic CDH1 variant, there is poor management and therapeutic strategies, and detect other genetic defects in HDGC, except CDH1 gene will be useful for further clarification of the disease mechanisms and risk-reducing strategies. Here, we reported an Iranian pedigree with familial HDGC to assess the fundamental genetic causes by whole-exome sequencing (WES). Materials and Methods: WES performed in an Iranian with a history of familial GC in whom no pathogenic variants or indels has been found in CDH1 and CTNNA1 genes with Sanger sequencing and multiplex ligation-dependent probe amplification methods. Results: Prioritizing genes associate with HDGC recognized several variants include c.2572T>C, and c.3161C>G in ataxia-telangiectasia mutated (ATM), c.1114A>C in BRCA2, and finally c.1173A>G in PIK3CA. Protein function prediction software tools reveal that c.3161C>G in ATM is likely pathogen. Conclusion: The results of this study suggested a role for the known cancer predisposition gene ATM in families with HDGC with no pathogenic variant in CDH1. Our results suggested that mutations in ATM and other genes, particularly the mutations found in this study, should be considered even in one case of positive familial status of HDGC disease. The presence of these mutations in patients with familial history raises important issues regarding genetic counseling.