OnkoGenetiks® Breast-Ovarian plus
Definition
In addition to BRCA1/BRCA2, these panels screen the TP53, CDH1, PTEN and PALB2 gene regions 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 cause 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), with increased risk of breast, thyroid and endometrial cancer. PALB2 encodes a partner protein that positions the BRCA2 protein at the site needed for DNA repair, and is itself considered an important breast cancer risk gene. The panel aims to evaluate these different risk profiles in a single sample. (A separate glossary term exists for BRCA1/BRCA2 itself.)
Gene/region examined
BRCA1, BRCA2, TP53, CDH1, PTEN, PALB2
Method
Next Generation Sequencing
Accepted sample types
Blood (EDTA)
Description
Covers sequence analysis of the BRCA1, BRCA2, TP53, CDH1, PTEN and PALB2 genes. Approximately 100X coverage, CNV analysis of the BRCA1/2 genes is included.
Inheritance
All five are inherited in an autosomal dominant manner; a pathogenic variant in one copy of the gene is sufficient to increase risk. Somatic panel versions may also cover acquired changes in tumor tissue.