Our verdict is Uncertain significance. Variant got 5 ACMG points: 6P and 1B. PM1PM2PM5BP6
The NM_007294.4(BRCA1):c.5528C>T(p.Ala1843Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000248 in 1,613,946 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A1843E) has been classified as Likely pathogenic.
BRCA1 (HGNC:1100): (BRCA1 DNA repair associated) This gene encodes a 190 kD nuclear phosphoprotein that plays a role in maintaining genomic stability, and it also acts as a tumor suppressor. The BRCA1 gene contains 22 exons spanning about 110 kb of DNA. The encoded protein combines with other tumor suppressors, DNA damage sensors, and signal transducers to form a large multi-subunit protein complex known as the BRCA1-associated genome surveillance complex (BASC). This gene product associates with RNA polymerase II, and through the C-terminal domain, also interacts with histone deacetylase complexes. This protein thus plays a role in transcription, DNA repair of double-stranded breaks, and recombination. Mutations in this gene are responsible for approximately 40% of inherited breast cancers and more than 80% of inherited breast and ovarian cancers. Alternative splicing plays a role in modulating the subcellular localization and physiological function of this gene. Many alternatively spliced transcript variants, some of which are disease-associated mutations, have been described for this gene, but the full-length natures of only some of these variants has been described. A related pseudogene, which is also located on chromosome 17, has been identified. [provided by RefSeq, May 2020]
Verdict is Uncertain_significance. Variant got 5 ACMG points.
PM1
In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 8 benign, 17 uncertain in NM_007294.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr17-43045743-C-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 55614.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BP6
Variant 17-43045742-G-A is Benign according to our data. Variant chr17-43045742-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 496396.We mark this variant Likely_benign, oryginal submissions are: {not_provided=1, Likely_benign=2, Uncertain_significance=2}.
Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:1Other:1
not provided, no classification provided
in vitro
Brotman Baty Institute, University of Washington
-
- -
Uncertain significance, criteria provided, single submitter
clinical testing
Baylor Genetics
Sep 28, 2023
- -
Hereditary breast ovarian cancer syndrome Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Oct 18, 2023
This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 1843 of the BRCA1 protein (p.Ala1843Val). This variant is present in population databases (no rsID available, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with BRCA1-related conditions. ClinVar contains an entry for this variant (Variation ID: 496396). Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (PMID: 30209399) indicates that this missense variant is not expected to disrupt BRCA1 function. Experimental studies have shown that this missense change does not substantially affect BRCA1 function (PMID: 30209399). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
not specified Benign:1
Likely benign, criteria provided, single submitter
clinical testing
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Jul 08, 2024
Variant summary: BRCA1 c.5528C>T (p.Ala1843Val) results in a non-conservative amino acid change located in the BRCT domain (IPR001357) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251346 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.5528C>T in individuals affected with Hereditary Breast And Ovarian Cancer Syndrome has been reported. At least one functional study reports experimental evidence evaluating an impact on protein function and showed no damaging effect of this variant on homology directed repair (HDR) activity (e.g. Findlay_2018). HDR assays qualify as a recognized gold standard on the basis of updated guidance provided by the ClinGen Sequence Variant Interpretation (SVI) working group. The following publication has been ascertained in the context of this evaluation (PMID: 30209399). ClinVar contains an entry for this variant (Variation ID: 496396). Based on the evidence outlined above, the variant was classified as likely benign. -
Hereditary cancer-predisposing syndrome Benign:1
Likely benign, criteria provided, single submitter
clinical testing
Ambry Genetics
Apr 16, 2021
This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -