BRCA1 and BRCA2 are tumor suppressor genes that have an essential role in both DNA repair and cell cycle control systems. Germline BRCA1 and BRCA2 mutations are implicated in 25-50% of hereditary breast cancer cases.


BRCA1 and BRCA2 are tumor suppressor genes that have an essential role in both DNA repair and cell cycle control systems. Germline BRCA1 and BRCA2 mutations are implicated in 25-50% of hereditary breast cancer cases.

Hereditary breast-ovarian cancer (HBOC) syndrome is an autosomal dominant cancer predisposition syndrome caused by germline BRCA1/2 mutations. Mutations in these two highly penetrant genes increase the chance for cancer of the breast, ovaries and fallopian tubes, pancreas and prostate.3,4 Studies suggest female BRCA1 mutation carriers have between a 57-87% risk to develop breast cancer and between a 39-40% risk to develop ovarian cancer by age 70.4-9 Similarly male BRCA1 mutation carriers have a cumulative breast cancer risk of 1.2% by age 70.10,11

Similar studies suggest female BRCA2 mutation carriers have between a 45-84% risk to develop breast cancer and between an 11-18% risk to develop ovarian cancer (including primary peritoneal and fallopian tube) by age 70.7-9,14 Male BRCA2 mutation carriers have up a 15% prostate cancer risk and a cumulative breast cancer risk of 6.8% by ages 65 and 70 respectively.10-14 Furthermore, BRCA1/2 mutation carriers are at an increased risk for melanoma and cancer of the pancreas, gall bladder, bile duct and the stomach.15 Cancer risks are further modified by family history, reproductive choices, lifestyle and environmental factors and other genetic factors.

BRCA1/2 mutations are more common in individuals of Ashkenazi Jewish (AJ) descent, with a carrier frequency of 1/40 or 2.6%4,5 compared to a frequency of 0.2% or 1/500 in the non-AJ general population. Three founder mutations: BRCA1 gene c.68_69delAG (BIC: 185delAG) and c.5266dupC (BIC: 5382insC) and one in BRCA2 c.5946delT (BIC: 6174delT), account for up to 99% of identified AJ mutations.4,5 BRCA1 185delAG has a frequency of 1% and attributes to 16-20% of breast cancer cases diagnosed before 50 years-of-age; BRCA1 5382insC with a frequency of 0.13%; and BRCA2 6174delT with frequency of 1.52% in the AJ population and attributes to 15% of breast cancer cases diagnosed before 50 years-of-age.4,5

Disease Name 
Hereditary breast-ovarian cancer
Testing Benefits & Indication 

BRCA1/2 testing may be considered for individuals with a personal or family history of any of the following: 
- Early-onset breast cancer (<45 years-of-age) or bilateral breast cancer
- Two primary breast cancers or clustering of breast and ovarian cancer
- Presence of male breast cancer
- Ovarian cancer at any age
- At-risk populations (e.g. Ashkenazi Jewish descent)

The American Society of Clinical Oncology (ASCO) recommends that genetic testing be offered to individuals with suspected inherited (genetic) cancer risk in situations where test results can be interpreted and when they can affect medical management of the patient.If increased risk of a hereditary cancer syndrome is suspected, the American Congress (formerly College) of Obstetricians and Gynecologists (ACOG) recommends referral to a specialist in cancer genetics or a healthcare provider with expertise in genetics for complete hereditary cancer risk assessment, which may lead to genetic testing.16 Establishing a molecular diagnosis can help guide preventive measures, direct surgical options and estimate personal and familial cancer risk. 

Test Description 

BRCA1 coding exons 1-22, BRCA2 coding exons 1-26, plus the flanking regions of the 5’ and 3’ ends of all the introns (ranging from between 31-338bp from an exon) are analyzed. Clinically significant intronic findings beyond 5 base pairs are always reported.  Intronic variants of unknown or unlikely clinical significance are not reported beyond 5 basepairs from the splice junction. Genomic deoxyribonucleic acid (gDNA) is isolated from the patient’s specimen using standardized methodology and quantified using a spectrophotometer.  Sequence enrichment is carried out by incorporating the gDNA into microdroplets along with primer pairs designed to the target BRCA1 and BRCA2 coding exons, and adjacent intronic nucleotides followed by polymerase chain reaction (PCR) and next generation sequencing.  Follow-up sequencing is performed for any regions missing or with insufficient read depth coverage for reliable heterozygous variant detection.  Suspect variant calls other than benign alterations are verified by a second sequencing methodology. Comprehensive (full-gene) gross deletion/duplication analysis using the multiplex ligation-dependent probe amplification (MLPA) kits P002-C2 (BRCA1) and P045-B3 (BRCA2), developed by MRC Holland, is also performed. Sequence analysis is based on the following NCBI reference sequences: BRCA1  - NM_007294 and BRCA2  - NM_000059. 

Mutation Detection Rate 

Ambry's BRCA1/2 analysis can detect >99.9% of described mutations in both genes, when present (analytic sensitivity).

Specimen Requirements 

Blood: Collect 3-5cc blood in purple top EDTA tube (preferred) or yellow top citric acetate tube
Storage: 2-8°C and do not freeze
Shipment: Room temperature for two-day delivery
For transfusion patients: Wait at least two weeks after a packed cell or platelet transfusion and at least four weeks after a whole blood transfusion prior to blood draw

DNA: Collect 20μg of of DNA in TE (10mM Tris-Cl pH 8.0, 1mM EDTA); preferred at 200 ng/μl
Quality:Please provide DNA OD 260:280 ratio (preferred 1.7-1.9) and send agarose picture with high molecular weight genomic DNA, if available
Storage: -20°C
Shipment: Frozen on dry ice is preferred, or ship on ice

Fill 1 tube with saliva up to black line (1cc of saliva) in Oragene Self Collection container. After tube is closed 1cc of buffer will mix with saliva for a total volume of 2cc.
Storage: At room temperature in sterile bag.
Shipment: Ship room temperature for two-day delivery

Turnaround Time 
8838 BRCA1/2 Gene Sequence and
Deletion/Duplication Analyses (Concurrent)                                           
(Blood)  7 - 14
(Saliva)  9 - 16
8862 BRCA1/2 Analysis with reflex to 
BRCAplus if negative
14 - 21
5892 BRCA Ashkenazi Jewish 3-site Mutation panel 7 - 10
5894 BRCA Ashkenazi Jewish 3-site Mutation panel
with reflex to BRCA1/2 Analysis if negative 
14 - 21
5890 BRCA1/2 Deletion/Duplication Analysis only 14
5864 BRCA1 Specific Site Analysis 7 - 14
5884 BRCA2 Specific Site Analysis 7 - 14


  1. National Comprehensive Cancer Network. Clinical practice guidelines in oncology, genetic/familial high-risk assessment: breast and ovarian. Available at: 2010. Accessed 5.29.13.
  2. American Society of Clinical Oncology Policy Statement Update: Genetic testing for cancer susceptibility. J Clin Oncol. 2003 Jun 15; 21(12):2397-406.
  3. Rohini, R., Chun, J., Powell, S. (2012). BRCA1 and BRAC2: different roles in a common pathway of genome protection. Nature.12:68-78.
  4. Ferla R, et al. (2007). Founder mutations in BRCA1 and BRCA2 genes. Annals of Oncology. 18;(Supplement 6):vi93-vi98.
  5. Janavivius R. (2010). Founder BRCA1/2 mutations in Europe: implications for hereditary breast-ovarian cancer prevention and control. EPMA Journal.,1:397-412.
  6. Tulinius H, et al. (2002). The effect of a single BRCA2 mutation on cancer in Iceland. J Med Genet. 39:457-462
  7. Ford D, et al. (1998). Genetic heterogeneity and penetrance analysis of the BRCA1 and BRCA2 genes in breast cancer families. The Breast Cancer Linkage Consortium. Am J Hum Genet62(3):676-689. 
  8. Antonious A, et al. (2003). Average risks of breast and ovarian cancer associated with BRCA1 or BRCA2 mutations detected in case series unselected for family history: a combined analysis of 22 studies. Am J Hum Genet. 72(5):1117-1130. 
  9. Chen S, et al. (2007). Meta-analysis of BRCA1 and BRCA2 penetrance. J Clin Oncol. 25(11):1329-1333. 
  10. Tai Y, et al. (2007). Breast cancer risk among male BRCA1 and BRCA2 mutation carriers. J Natl Canc Inst99(23):1811-1814. 
  11. Thompson  D, et al. (2002). Cancer incidence in BRCA1 mutation carriers. J Natl Canc Inst. 94(18):1358-1365. 
  12. Kote-Jerai Z, et al. (2011). BRCA2 is a moderate penetrance gene contributing to young-onset prostate cancer: implications for genetic testing in prostate cancer patients. British J Cancer105(8):1230-1234. 
  13. Folkins A and Longacre T. (2013). Hereditary gynecological malignancies: advances in screening and treatment. Histopathology62:2-30.
  14. Mahoney-Shannon K. and Chittenden A. (2012). Genetic testing by cancer site: breast. The Can Journal18(4):310-319.
  15. Van Asperen C, et al. (2005). Cancer risks in BRCA2 families: estimates for sites other than breast and ovary. J Med Genet. 42(9):711-719.
  16. American Congress of Obstetricians and Gynecologists Committee on Genetics. Committee Opinion No. 634: Hereditary cancer syndromes and risk assessment. Obstet Gynecol. June 2015. 125(6):1538-1543.