BRCAssure: BRCA1 Targeted Analysis

This test code is intended for those individuals who have a family member with a known BRCA1 variant and wished to be tested only for that variant. A copy of the positive family member's laboratory report or genetic counseling letter documenting the variant is required for this testing. Only the specific region of the BRCA1 gene containing the familial variant will be tested. If the familial variant is a large deletion or duplication of BRCA1, BRCAssure®: BRCA1 and BRCA2 Deletion/Duplication Analysis [485050] should be ordered. If there is no family member with a known BRCA1 variant or if there is no documentation of the familial variant, BRCAssure®: BRCA1 and BRCA2 Comprehensive Analysis [485030] should be ordered. Please call 800-345-GENE (4343) for more information regarding documentation requirements or other questions.

A BRCAssure® clinical questionnaire and documentation of the familial BRCA1 variant should be submitted with specimen specimens. Contact CMBP genetics services at 800-345-4363 to coordinate testing. To order Oragene Dx 500 saliva collection kits using PeopleSoft No. 87917, contact your local Labcorp branch supply department.

Technologies used do not detect germline mosaicism and do not rule out the presence of large chromosomal aberrations, including rearrangements, gene fusions, or variants in regions or genes not included in this test, or possible inter/intragenic interactions between variants. Variant classification and/or interpretation may change with time if more information becomes available. False-positive or false-negative results may occur for reasons that include: genetic variants, pseudogene interference, technical handling, blood transfusions, bone marrow transplantation, mislabeling of samples, or erroneous representation of family relationships. For heterozygous variants in the same gene, the assay cannot determine whether they are on the same or a different chromosome; to determine phase and clinical significance, rarely, parental testing may be required. Exact breakpoints of exon-level deletions/duplications are not determined. The presence of an inherited cancer syndrome due to a different genetic cause cannot be ruled out. Any interpretation should be clinically correlated with information about the patient's presentation and relevant family history.

This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.

Next-generation sequencing: Genomic regions of interest are selected using a custom capture reagent for target enrichment and sequenced via the Illumina® next generation sequencing platform. Regions of interest include all exons and intron/exon junctions (+/-20 nucleotides) of the BRCA1 (NM_007294.3) and BRCA2 (NM_000059.3) genes. Sequencing reads are aligned with the human genome reference GRCh37/hg19 build. Minimum mean coverage is 40X. Any segment failing minimum read depth coverage is rescued by bi-directional Sanger sequencing to complete sequence analysis. Variants, including SNVs and CNVs, are identified using a custom bioinformatics pipeline.

Reported variants: Pathogenic and likely pathogenic variants and variants of uncertain significance (VUS) are reported. Non-deletion variants are specified using the numbering and nomenclature recommended by the Human Genome Variation Society (HGVS). Benign variants are not reported. Variant classification and confirmation are consistent with ACMG standards and guidelines.^1,2 Detailed variant classification information is available upon request. A variant of uncertain significance (VUS) should not be used in clinical decision making; a VUS is classified based on inadequate or conflicting evidence regarding its pathogenicity or clinical relevance.