Laboratory Test Information Guide

Details for Breast Cancer (BRCA1 and BRCA2 Screening)

Test Name: Breast Cancer (BRCA1 and BRCA2 Screening)
Alternate Name(s): Hereditary Cancer - Breast/Ovarian
Laboratory: Molecular Diagnostics
Specimen Type: Whole blood-4 mL Lavender EDTA top Vacutainer tube
Collection Information: Sample may be transported at room temperature. Alternative tissues may be accepted after consult with laboratory.
Test Schedule: As Required
Monday - Friday
0800 - 1630 h
Turnaround time from when specimen
is received in testing laboratory:
4-6 weeks
4 weeks
Reference Range: See report
Effective Date:  
Revised Date: 2021-05-14
Critical Value: N/A
Interpretive Comments:  A subset (5-10 %) of breast / ovarian cancers are familial, and a predisposition to develop malignancy in these tissues has been found to segregate with (autosomal dominant) mutations in either the BRCA1 gene (Chr.17) or the BRCA2 gene (Chr.13). Mutations in both BRCA1 and BRCA2 are associated with a markedly elevated lifetime risk of breast cancer (BRCA1: 65% or greater, BRCA2: 45% or greater) as well as an increased lifetime risk of ovarian cancer (BRCA1: 39% or greater, BRCA2: 11% or greater);PMID:12677558.
Special Processing:  
Comments: For more information click on:

Method of Analysis: All coding exons and 20 bp of flanking intronic sequence are enriched using an LHSC customtargeted hybridization protocol (Roche Nimblegen), followed by high throughput sequencing (Illumina). Sequence variants and copy number changes are assessed and interpreted using clinically validated algorithms and commercial software (SoftGenetics: Nextgene, Geneticist Assistant, Mutation Surveyor; and Alamut Visual). All exons have >500x mean read depth coverage, with a minimum 200x coverage at a single nucleotide resolution. This assay meets the sensitivity and specificity of combined Sanger sequencing and MLPA copy number analysis. All variants interpreted as either ACMG category 1, 2, or 3 (pathogenic, likely pathogenic, VUS; PMID: 25741868) are confirmed using Sanger sequencing, MLPA, or other assays. ACMG category 4 and 5 variants (likely benign, benign) are not reported, but are available upon request.
Critical Information Required: Pedigree required.
Storage & Shipment: Must be received in testing laboratory within 48 hours of collection, shipped at room temperature by courier/overnight delivery.
System Codes: 
Referred To:  

Questions? Comments? Contact Laura Gopaul