Intended purpose
The SALSA MLPA Probemix P077 BRCA2 Confirmation is an in vitro diagnostic (IVD)
1 or a research use only (RUO) semi-quantitative assay
2 for the detection of deletions or duplications in the
BRCA2 gene in genomic DNA isolated from human peripheral whole blood specimens. P077 BRCA2 Confirmation is intended to confirm a potential cause for and clinical diagnosis of hereditary breast and ovarian cancer (HBOC) syndrome, or, in rare cases, Fanconi Anemia type D1, as initially determined using SALSA MLPA Probemix P045 BRCA2/CHEK2 or SALSA MLPA Probemix P090 BRCA2. As they provide a more extensive coverage of the
BRCA2 gene, P045 BRCA2/CHEK2 or P090 BRCA2 should be used as a first tier probemix. This P077 BRCA2 Confirmation probemix cannot be used to verify
CHEK2 mutations found with P045 BRCA2/CHEK2. However, the P190 CHEK2 probemix is available for deletion or duplication analysis of other
CHEK2 exons.
Discordant results between the P077 BRCA2 Confirmation probemix and the P045 BRCA2/CHEK2 or P090 BRCA2 probemix should be investigated with a different technique.
Assay results are intended to be used in conjunction with other clinical and diagnostic findings, consistent with professional standards of practice, including clinical genetic evaluation, and counselling, as appropriate. The results of this test should be interpreted by a clinical molecular geneticist or equivalent.
This device is not intended to be used for standalone diagnostic purposes, pre-implantation or prenatal testing, population screening, or for the detection of, or screening for, acquired or somatic genetic aberrations, e.g from DNA extracted from formalin-fixed paraffin embedded (FFPE) or fresh tumour materials.
There are three probemixes available for BRCA2 testing at MRC Holland. Content and use is described below:
SALSA MLPA Probemix |
Target gene(s) |
Coverage |
Use for |
Remarks |
P045 BRCA2/CHEK2 |
BRCA2, CHECK |
BRCA2: Each exon CHEK2: Exon 1, 9, 1100delC mutation (exon 11) |
Initial testing by MLPA |
All BRCA2 probes are identical to those present in P090 BRCA2 |
P090 BRCA2 |
BRCA2 |
BRCA2: Each exon |
Initial testing by MLPA |
All BRCA2 probes are identical to those present in P045 BRCA2/CHEK2 |
P077 BRCA2 Confirmation |
BRCA2 |
BRCA2: Each exon |
Confirmation of MLPA results |
The ligation sites of all P077 BRCA2 probes differ from those targeted by P045/P090 BRCA2 |
1 Please note that this probemix is for in vitro diagnostic (IVD) use in the countries specified at the end of this product description. In all other countries, the product is for research use only (RUO).
2 To be used in combination with a SALSA MLPA Reagent Kit and Coffalyser.Net analysis software.
Clinical background
Breast and ovarian carcinomas are among the most common malignancies in developed countries. The majority of cases are considered sporadic, but in a substantial portion, a clear history of cases within a family is present. The BRCA1 and BRCA2 proteins are associated with the activation of double-strand break repair and homologous recombination and are important in maintaining genomic stability. Germline mutations in the
BRCA1 and
BRCA2 genes are linked to a high risk of young-onset hereditary breast and ovarian cancer. Features characteristic of hereditary, versus sporadic, breast cancer are: younger age at diagnosis, frequent bilateral disease, and more frequent occurrence of diseases such as prostate and breast canceramong male relatives. Mutations in the
BRCA1 and
BRCA2 genes account for about 20-25% of hereditary breast cancers (Easton 1999) and about 5-10% of all breast cancers (Campeau et al. 2008). In addition, mutations in the
BRCA1 and
BRCA2 genes cause around 15% of ovarian cancers (Pal et al. 2005). Women with a germline
BRCA2 mutation
have a 45-62% lifetime risk of developing breast cancer, while the risk of women in the general population is 12%. The lifetime risk of developing ovarian cancer in women with a germline
BRCA2 mutation is 11-17%, compared to 1-2% in the general population. Deletions and duplications are more frequent for
BRCA1 than for
BRCA2 in most populations
. CNVs in
BRCA2 account for 2-3% of all pathogenic
BRCA2 mutations, dependent on the population. More information is available at
http://www.ncbi.nlm.nih.gov/books/NBK1247/.
Biallelic pathogenic variants of
BRCA2 can result in Fanconi Anemia (FA) type D1. FA is characterized by physical abnormalities (such as short stature or abnormal skin pigmentation), bone marrow failure and increased risk for malignancies. The incidence of FA in general is 1:160,000, of which type D1 comprises around 3% of the cases. FA type D1 is associated with early-onset acute leukaemia and solid tumours. More information on FA is available at
https://www.ncbi.nlm.nih.gov/books/NBK1401/.
Probemix content
The SALSA MLPA Probemix P077-B1 BRCA2 Confirmation contains 50 MLPA probes with amplification products between 124 and 503 nucleotides (nt). This includes 38 probes for the
BRCA2 region. At least one MLPA probe is present for each exon in the
BRCA2 transcript. In addition, one probe is included for introns 3, 7, 12 and 13; two probes are included for exons 8, 16, 18 and 27, and three probes are included for the large exon 11. One probe is included detecting a sequence upstream of
BRCA2 exon 1 to determine the extent of a deletion or duplication. In addition, 12 reference probes are included that detect autosomal chromosomal locations. Complete probe sequences and the identity of the genes detected by the reference probes are available online (
www.mrcholland.com).
This probemix contains nine quality control fragments generating amplification products between 64 and 105 nt: four DNA Quantity fragments (Q-fragments), two DNA Denaturation fragments (D-fragments), one Benchmark fragment, and one chromosome X and one chromosome Y-specific fragment. More information on how to interpret observations on these control fragments can be found in the MLPA General Protocol and online at
www.mrcholland.com.
SALSA Artificial Duplication DNA SD024
In case no positive DNA sample is available in your laboratory, an artificial duplication DNA sample for this probemix (catalogue number SD024) can be ordered from MRC Holland. This SD024 Artificial Duplication DNA will show a duplication of two or more probes when using the following probemixes: P077, P045 and P090 BRCA2; P002 and P087 BRCA1. The SD024 Artificial Duplication DNA is a mixture of human female genomic DNA and a titrated amount of plasmid containing selected probe target sequences. For further details, please consult the SD024 Artificial Duplication DNA product description, available online:
www.mrcholland.com.
This product is for research use only (RUO).
Sample DNA
Sample DNA developed for this product: