Functional characterization of splice variants in hereditary breast and ovarian cancer susceptibility genes.

Hereditary breast and ovarian cancer (HBOC) is an autosomal dominant cancer predisposition syndrome primarily associated with germline mutations in BRCA1 and BRCA2. Nevertheless, the implementation of multigene panels using Next Generation Sequencing (NGS) has expanded the mutational spectrum for this hereditary syndrome. As a result, the number of variants of uncertain clinical significance (VUS) has increased, and their functional and clinical interpretations remains a challenge for genetic counseling. This article reports three splice variants in susceptibility genes detected in women diagnosed with invasive ductal breast cancer. According to in silico predictions, these splicing-disrupting mutations in cancer susceptibility genes are likely to be pathogenic. Splicing functional assays were performed by reverse transcription polymerase chain reaction (RT-PCR) followed by capillary electrophoresis and Sanger sequencing. The characterization of these splicing events has enabled the identification of variants susceptible to alternative or abnormal splicing and their clinical classification according to the consensus criteria of the American College of Medical Genetics and Genomics-Association for Molecular Pathology (ACMG-AMP). This research increases our current knowledge about splice variants, thereby improving diagnostic performance and their clinical classification to support appropriate genetic counseling.