Breast cancer (BC) is the most common cancer in women, accounting for 25% of all new cases of cancer. Most BC cases are sporadic, while 5-10% are estimated to be due to an inherited predisposition. Autosomal dominant alterations in two genes, BRCA1 and BRCA2, are likely to account for most familial cases of early-onset BC and/or ovarian cancer (OC), and for 3-4% of all BC. Prevalence of germline BRCA mutations has been estimated to be about 1:1,600 women in the general population. The lifetime risk of developing hereditary BC (HBC) and/or OC can reach 80%. For a given mutation in the susceptibility gene, disease severity and age at onset show great variability within and between BC families, suggesting the involvement of other genetic as well as non-genetic factors. HBC is not associated with specific phenotypic features and diagnosis relies upon the following main characteristics:
- increasing numbers of affected family members through the same bloodline (either maternal or paternal),
- early onset of disease (<40 y.o.),
- an excess of bilateral disease,
- an association with ovarian cancer (at any age), and
- occurrence of BC in males.
Genetic testing confirms the diagnosis and allows better management of people at high risk of developing BC and/or OC. The management strategies include surveillance, surgical options and chemoprevention, and accurate treatment of BC and OC in mutation carriers, but the treatment guidelines are still under debate.
Genetic counselling of BC and OC patients and their families is offered at CMG.
Presymptomatic testing of healthy family members for a given gene region requires the most precise molecular diagnosis possible in the index case and is performed at CMG if BRCA1/2 mutation is detected and confirmed.
Detection: We offer DNA test for the whole-gene screening of BRCA1 and BRCA2 using the high-resolution melting curve analysis with following confirmation by direct sequencing analysis.
! Attention: Due to the absence of population specific BRCA1/2 mutations among Armenians, the BRCA1&2 genetic testing can’t be restricted only on the screening of mutations common for other ethnic groups.
Specimen Requirements: genomic DNA is isolated from the peripheral blood, collected in 2 ml EDTA Vacutainer tube (lavender top). In case if DNA is already extracted, the minimum concentration should be 100 ng/µl.
Transportation: The blood specimen can be stored in the refrigerator (for 1 or 2 days) and shipped to CMG at room temperature. In case of the DNA, it can be shipped to CMG at room temperature within 1-2 days.
Turnaround time: 1,5-2 months
For further information please contact:
Tel.: (+374 10) 544367
Fax: (+374 10) 544366