Contribution of BARD1 gene to male breast cancer- report of a family with different types of cancer.

BACKGROUND

Breast cancer (BC) arises from a combination of genetic and environmental factors, continues to be the leading cause of cancer-related mortality among women. Although male BC accounts for <1 % of all BC cases, its incidence seems to be increasing. Germline pathogenic variants in cancer susceptibility genes underlie about 30 % of male BC patients. This study aimed to identify the genetic cause of BC in a man to facilitate his clinical management and enable genetic counseling and preventive screening for his at-risk relatives.

METHODS

We conducted a clinical examination and molecular genetic testing on a man with BC having a family history of several malignancies. BRCA sequencing panel followed by exome sequencing (ES) were performed and bioinformatics tools were used to evaluate the variants' pathogenicity. ACMG guidelines was used for the variant interpretation and Sanger sequencing and co-segregation analysis were performed for its confirmation.

RESULTS

According to ES findings, a novel heterozygous variant (c.1802T>C) was detected in the BARD1 gene, fulfilling the pathogenic criteria. The proband's brother, suffering from colorectal cancer, was also found to harbor this variant, suggesting its role in the familial clustering of both breast and colorectal cancer.

CONCLUSION

We successfully identified a novel BARD1 pathogenic variant in an Iranian man suffering from BC. Identification of disease-causing variant in some cancer, especially male BC can be useful in genetic counseling, early diagnosis and implementing preventive measures. We also recommend cancer genetic counseling for the healthy at-risk family members, with a focus on different hereditary cancer syndromes.