This is a second tier test and REQUIRES PERMISSION from ARUP's Genetic Counselor (800-242-2787, x2141) before ordering. Preferred initial test is the sequencing and deletion/duplication test.
- Patient Preparation
- Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
- Specimen Preparation
- Transport 3 mL whole blood. (Min: 1 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Characteristics: Female carriers of BRCA1 mutations have a breast cancer risk of 57 percent and ovarian cancer risk of 40 percent by age 70. Female carriers of BRCA2 mutations have a breast cancer risk of 49 percent and ovarian cancer risk of 18 percent by age 70. BRCA1 mutation carriers may also be at increased risk for fallopian, peritoneal, cervical, uterine, and pancreatic cancer. BRCA2 mutation carriers may be at increased risk for pancreatic, stomach, gallbladder, bile duct, and melanoma cancers. Men with BRCA1 mutations are at increased risk for breast cancer and possibly pancreatic, prostate, and testicular cancers while male carriers of BRCA2 mutations are at increased risk for breast, pancreatic and prostate cancers.
Prevalence: 1 in 500 individuals has a BRCA1 or BRCA2 mutation; 5-10 percent of breast cancer and 10-15 percent of ovarian cancer are caused by germline BRCA1 or BRCA2 mutations.
Inheritance: Autosomal dominant.
Cause: Pathogenic germline mutations in several genes cause hereditary breast and ovarian cancer (HBOC) syndrome. Mutations in tumor suppressor genes, BRCA1 and BRCA2, are causative for the majority of HBOC.
Genes Tested: BRCA1 and BRCA2.
Clinical Sensitivity: Approximately 10 percent of BRCA1 and BRCA2 mutations.
Methodology: Multiplex ligation-dependent probe amplification (MLPA) to detect large BRCA1 and BRCA2 locus and intragenic deletions/duplications. Analytical Sensitivity and Specificity: 99 percent.
Limitations: Rare diagnostic errors can occur due to probe site mutations. Breakpoints for large deletions/duplications will not be determined. BRCA1 and BRCA2 base pair substitutions, small deletions/duplications, deep intronic, and regulatory region mutations will not be detected. Other genes causing HBOC syndrome are not tested.
|Component Test Code*||Component Chart Name||LOINC|
|2011916||BRCA DelDup Specimen||31208-2|
|2011917||BRCA DelDup Interpretation||59041-4|