BRCA1 and BRCA2 mutations in a sample of breast and ovarian cancer families from the Colombian pacific

Frequency of actionable Exomic secondary findings in 160 Colombian patients: Impact in the healthcare system

INTRODUCTION

By 2021, the American College of Medical Genetics and Genomics (ACMG) published the last version of their secondary findings (SF) reporting recommendations for cases in which a person receives a genetic test.

OBJECTIVE

To determine in a sample of the Colombian population the prevalence of SF for the 59 genes on the ACMG SF v2.0 list associated with 27 genetic diseases.

MATERIALS AND METHODS

An analytical cross-sectional study was developed by examining the sequences of 160 exomes. Based on the ACMG guidelines, a variant classification algorithm was designed to filter and select reportable SF.

RESULTS

Eleven pathogenic variants were identified in 13/160 (8.13%) patients in genes APOB, BRCA2, CACNA1S, COL3A1, LDLR, MYBPC3, PCSK9, PKP2, PMS2 and RYR2. No association was found between the sociodemographic variables and the SF to report (P > 0,05).

CONCLUSION

We reported the first approach of actionable pathogenic variants spectrum in the Colombian population. Given the frequency found in this study and the clinical impact of genomic variants on health, it is essential to actively search for SF having the opportunity to receive genetic counselling, prevention and clinical management.

Identification of Variants (rs11571707, rs144848, and rs11571769) in the BRCA2 Gene Associated with Hereditary Breast Cancer in Indigenous Populations of the Brazilian Amazon

Estimates show that 5–10% of breast cancer cases are hereditary, caused by genetic variants in autosomal dominant genes; of these, 16% are due to germline mutations in the BRCA1 and BRCA2 genes. The comprehension of the mutation profile of these genes in the Brazilian population, particularly in Amazonian Amerindian groups, is scarce. We investigated fifteen polymorphisms in the BRCA1 and BRCA2 genes in Amazonian Amerindians and compared the results with the findings of global populations publicly available in the 1000 Genomes Project database. Our study shows that three variants (rs11571769, rs144848, and rs11571707) of the BRCA2 gene, commonly associated with hereditary breast cancer, had a significantly higher allele frequency in the Amazonian Amerindian individuals in comparison with the African, American, European, and Asian groups analyzed. These data outline the singular genetic profiles of the indigenous population from the Brazilian Amazon region. The knowledge about BRCA1 and BRCA2 variants is critical to establish public policies for hereditary breast cancer screening in Amerindian groups and populations admixed with them, such as the Brazilian population.