Hereditary breast and ovary cancer in Uruguay

screening results for mutations in susceptibility genes by new generation sequencing

Abstract

Introduction: breast cancer is women’s first cause of death in Uruguay. According to estimations, around 7% of cases result from germinal mutations by deoxyribonucleic acid. The cost of genetic sequencing has dramatically dropped thanks to the arrival of next-generation sequencing (NGS). This technological change opened a new era in the study of hereditary cancer in our country.
Objective: to communicate the results of using NGS technology and multigenic panels in Uruguayan families with high risk of hereditary breast cancer.
Method: 135 high risk families referred by the genetic counselling consultation that is provided at the Uruguayan Collaborative Group (Hereditary Oncological Conditions Research) were sequenced. When the family history clearly suggested hereditary breast and ovary cancer was a possibility, exclusive NGS sequencing was done for BRCA1 and BRCA2 genes; when the family pattern was not clear to this respect, multigenic panels were used.
Results: exclusive NGS sequencing for BRCA1 and BRCA2 genes was done in 62 families, and multigenic panels were used in 73 families. 29 pathogenic mutations were identified (21 in BRCA genes and 8 in other genes). Two of them were new to the disease and three could be considered recurrent in the Uruguayan population.
Conclusions: this study is the first one in Uruguay to report the results of this new technology in hereditary breast cancer. The finding of 29 pathogenic mutations contributes to outlining the mutational profile of our country.