Abstract
In this study, the molecular profile of different BRCA-associated tumor types was assessed with regard to the classification and annotation of detected BRCA1/2 variants. The aim was to establish guidelines in order to facilitate the interpretation of BRCA1/2 alterations in routine diagnostics. Annotation of detected variants was evaluated compared to background mutations found in normal tissue samples and manually reviewed according to distinct online databases. This retrospective study included 48 samples (45 tumors, three non-tumors), which were sequenced with the GeneReader (QIAGEN). Thereof ten samples were additionally analyzed with the Ion S5™ (Thermo Fisher) and 20 samples with the MiSeq™ (Illumina®) to compare the different NGS devices, as well as the sequencing results and their quality. The analysis showed that the individual NGS platforms detected different numbers of BRCA1/2 alterations in the respective tumor sample. In addition, the GeneReader revealed variability in the detection and classification of pathogenic alterations within the platform itself as well as in comparison with the other platforms or online databases. The study concluded that the Ion S5™ in combination with the Oncomine™ Comprehensive Assay v3 is most recommendable for current and prospective requirements of molecular analysis in routine diagnostics. In addition to the two BRCA1/2 genes, a broad number of other genes (BRCAness genes and genes involved in the repair pathway) is covered by the panel, which may open up new treatment options for patients depending on the respective eligibility criteria.
Highlights
Germline mutations in BRCA1/2 cause the hereditary breast and ovarian cancer (HBOC) syndrome, an autosomal dominant disease [1–3], that lead to an increased lifetime risk of developing these cancers, and a risk for the development of a broad range of other cancer types [4]
Since BRCA1 and BRCA2 interact in such a large protein complex, next-generation sequencing (NGS) approaches are recommended for a mutational analysis that include BRCA associated genes or other tumor suppressor genes such as TP53 and PTEN
The aim of this study was to establish a uniform procedure for the detection and interpretation of BRCA1 and BRCA2 alterations in different BRCA associated tumor diseases and to facilitate routine diagnostics. 48 patient samples were sequenced with different NGSbased technology platforms
Summary
Germline mutations in BRCA1/2 cause the hereditary breast and ovarian cancer (HBOC) syndrome, an autosomal dominant disease [1–3], that lead to an increased lifetime risk of developing these cancers, and a risk for the development of a broad range of other cancer types (i.e., prostate or pancreatic cancers) [4]. Mutations in BRCA1/2 are predicted to disrupt proteinprotein interactions, necessary for DNA repair [5–8]. In BRCA1 the RING finger is a protein-protein interaction domain which may have ubiquitin ligase activity Another proteinprotein interaction motif is the BRCT domain that is found predominantly in proteins involved in DNA repair [9]. BRCA2 contains nine separate potential RAD51 binding domains: eight BRC repeats and a structurally independent carboxy-terminal domain. Both BRCA1 and BRCA2 contain nuclear localization sequences (NLS) [9]. Since BRCA1 and BRCA2 interact in such a large protein complex, next-generation sequencing (NGS) approaches are recommended for a mutational analysis that include BRCA associated genes (so-called BRCAness genes: ATM, CHEK2, CDK12, FANCA, NBN, PALB2, RAD51, etc.,) or other tumor suppressor genes such as TP53 and PTEN
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call