Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP3
The NM_007294.4(BRCA1):c.3401A>T(p.Glu1134Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,666 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 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. E1134K) has been classified as Uncertain significance.
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]
BRCA1 Gene-Disease associations (from GenCC):
breast-ovarian cancer, familial, susceptibility to, 1
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, ClinGen, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41452
American (AMR)
AF:
0.0000654
AC:
1
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68038
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Age Distribution
Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.00000824
AC:
1
ClinVar
Significance: Conflicting classifications of pathogenicity
Breast-ovarian cancer, familial, susceptibility to, 1Uncertain:2
Aug 15, 2023
All of Us Research Program, National Institutes of Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing
This missense variant replaces glutamic acid with valine at codon 1134 of the BRCA1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 3/250826 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Apr 06, 2018
Counsyl
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing
This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
not providedUncertain:2
Feb 01, 2024
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing
The BRCA1 c.3401A>T (p.Glu1134Val) variant has been reported in the published literature in an individual undergoing genetic testing for hereditary cancer (PMID: 31853058 (2020)), and described to be located in a region of the BRCA1 gene that is tolerant to missense sequence changes (PMID: 31911673 (2020)). The frequency of this variant in the general population, 0.000087 (3/34578 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded conflicting predictions that this variant is benign or damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -
Dec 17, 2024
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing
Identified in individuals referred for multi-gene panel testing with personal or family history of cancer (PMID: 30630528, 31853058); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Also known as 3520A>T; This variant is associated with the following publications: (PMID: 16616110, 30630528, 29884841, 31911673, 31853058, 32377563) -
The p.E1134V variant (also known as c.3401A>T), located in coding exon 9 of the BRCA1 gene, results from an A to T substitution at nucleotide position 3401. The glutamic acid at codon 1134 is replaced by valine, an amino acid with dissimilar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Mar 23, 2023
University of Washington Department of Laboratory Medicine, University of Washington
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:curation
Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673). -
Hereditary breast ovarian cancer syndromeUncertain:1
Sep 29, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing
This sequence change replaces glutamic acid, which is acidic and polar, with valine, which is neutral and non-polar, at codon 1134 of the BRCA1 protein (p.Glu1134Val). This variant is present in population databases (rs762744684, gnomAD 0.009%). 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: 233080). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt BRCA1 protein function with a negative predictive value of 95%. 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. -