OncoGenetics BRCA1 and BRCA2 Gene Sequence Analysis - Somatic Panel
Definition
In these panels, in addition to BRCA1/BRCA2, the TP53, CDH1, PTEN and PALB2 gene regions are screened together; each leads to a separate syndrome that increases hereditary breast cancer risk through a different mechanism. Pathogenic variants in TP53 cause Li-Fraumeni syndrome, in which breast cancer risk appears at an early age and can even exceed that of BRCA carriers. CDH1 variants lead to hereditary diffuse gastric cancer syndrome; women with this syndrome also have a markedly increased risk of lobular-type breast cancer. PTEN variants cause Cowden syndrome (PTEN hamartoma tumor syndrome), increasing breast, thyroid and endometrial cancer risk. PALB2 encodes a partner protein that positions the BRCA2 protein for DNA repair and is itself considered a significant breast cancer risk gene. The panel aims to evaluate these different risk profiles in a single sample. (A separate glossary entry exists for BRCA1/BRCA2 itself.)
Gene/region examined
BRCA1, BRCA2
Method
Next Generation Sequencing
Accepted sample types
Solid Tumor-FFPE
Description
Covers gene sequence analysis of the BRCA1-2 genes from solid tissue and performs somatic mutation analysis.
Inheritance
All five are inherited in an autosomal dominant manner; a pathogenic variant in one copy of the gene is enough to increase risk. In somatic panel versions, the analysis may also cover changes acquired in tumor tissue.