Our verdict is Uncertain significance. Variant got 1 ACMG points: 1P and 0B. PP3
The NM_007294.4(BRCA1):āc.1922T>Cā(p.Ile641Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000867 in 1,613,838 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).
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]
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The p.I641T variant (also known as c.1922T>C), located in coding exon 9 of the BRCA1 gene, results from a T to C substitution at nucleotide position 1922. The isoleucine at codon 641 is replaced by threonine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Mar 29, 2023
Color Diagnostics, LLC DBA Color Health
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This missense variant replaces isoleucine with threonine at codon 641 of the BRCA1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been detected in a breast cancer case-control meta-analysis in 3/60466 cases and 0/53461 unaffected individuals (PMID: 33471991; Leiden Open Variation Database DB-ID BRCA1_004716), and this variant also has been reported in 1 individual age 70 years or older without cancer in the FLOSSIES database (https://whi.color.com/variant/17-41245626-A-G). This variant has been identified in 2/282404 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. -
Jun 24, 2021
Sema4, Sema4
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: curation
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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). -
not provided Uncertain:3Other:1
Dec 06, 2024
GeneDx
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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; Observed in individuals with breast cancer (PMID: 33471991); Also known as 2041T>C; This variant is associated with the following publications: (PMID: 32377563, 10426999, 10792030, 15343273, 33471991, 31853058) -
Jun 30, 2023
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
In the published literature, this variant has been reported to be located in a region of the BRCA1 gene that is tolerant to missense sequence changes (PMID: 31911673 (2020)). In a large-scale breast cancer association study, the variant was observed in an individual with breast cancer (PMID: 33471991 (2021), see also LOVD (http://databases.lovd.nl/shared/genes/BRCA1)). The frequency of this variant in the general population, 0.0000071 (2/282404 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 predictions that this variant is damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -
Nov 06, 2020
Mayo Clinic Laboratories, Mayo Clinic
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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GenomeConnect, ClinGen
Significance: not provided
Review Status: no classification provided
Collection Method: phenotyping only
GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -
Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:3
Oct 11, 2016
Counsyl
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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Nov 30, 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 isoleucine with threonine at codon 641 of the BRCA1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in individuals with personal or family history of breast and ovarian cancer (Leiden Open Variant Database individual #00272017; Color internal data) and an individual age 70 years or older without cancer by FLOSSIES. This variant has been identified in 2/282404 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 21, 2016
Michigan Medical Genetics Laboratories, University of Michigan
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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not specified Uncertain:1
Jan 02, 2019
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
Variant summary: BRCA1 c.1922T>C (p.Ile641Thr) results in a non-conservative amino acid change in 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 4.1e-06 in 245800 control chromosomes (gnomAD). 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.1922T>C in individuals affected with Hereditary Breast and Ovarian Cancer and no experimental evidence demonstrating its impact on protein function have been reported. Six ClinVar submissions from clinical diagnostic laboratories (evaluation after 2014) cite the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Inherited ovarian cancer (without breast cancer) Uncertain:1
Sep 06, 2024
Genomics and Molecular Medicine Service, East Genomic Laboratory Hub, NHS Genomic Medicine Service
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
PP3,BP1 -
Hereditary breast ovarian cancer syndrome Uncertain:1
Jan 29, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This sequence change replaces isoleucine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 641 of the BRCA1 protein (p.Ile641Thr). This variant is present in population databases (rs730881474, gnomAD 0.0009%). 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: 182138). 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 expected to disrupt BRCA1 protein function with a positive predictive value of 80%. 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. -