The variant received 21 classification points (ACMG Germline Pathogenicity v2019). PS3PM1_SupportingPM2PM5PP3_StrongPP5_Very_Strong
The NM_007294.4(BRCA1):c.191G>A (p.Cys64Tyr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a cumulative frequency of 0.00000138 (AC=2) in the gnomAD database across 1,449,660 control chromosomes (no homozygotes observed). The grpmax filtering allele frequency (95% CI) is 0.000000907. In-silico predictor (REVEL) classifies this variant as likely damaging/oncogenic. Splicing prediction tools (SpliceAI) predict no significant impact on normal splicing. Variant has been reported in ClinVar as Pathogenic/Likely Pathogenic (★★★). ClinVar reports functional evidence for this variant: "SCV000075654: Experimental studies have shown that this missense change affects BRCA1 function (PMID:7894491, 8944023, 11326114, 19287957, 24516540)." and additional evidence is available in ClinVar. A different missense at the same amino acid position has been reported as Pathogenic/Likely Pathogenic in ClinVar: p.C64G: Pathogenic (ClinVar VariationId 17660, 2 stars) Other variants at the same amino acid position have been reported in ClinVar (not pathogenic): p.C64= (synonymous): unknown significance (ClinVar VariationId 867931); p.C64F: unknown significance (ClinVar VariationId 867930) This exact variant is curated in the UniProt human variants database 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):
BRCA1-related cancer predisposition
Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
breast-ovarian cancer, familial, susceptibility to, 1
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics
new If you want to explore the variant's impact on the transcript NM_007294.4, check out the Mutation Effect Viewer. This is especially useful for frameshift variants or if you want to visualize the effect of exon loss / intron retention.
Classification according to ACMG Germline Pathogenicity v2019
Our verdict: Pathogenic. The variant received 21 points.
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Criterion Code & Title / Strength
Strength
Rationale / Clinical Context
PS3Functional studies show damaging effect
Well-established functional study supports damaging effect (PS3); SCV000075654: Experimental studies have shown that this missense change affects BRCA1 function (PMID: 7894491, 8944023, 11326114, 19287957, 24516540).; SCV000918679: Several publications report experimental evidence evaluating an impact on protein function (example, Findlay_2018). The most pronounced variant effect results in a loss of homology directed repair (HDR) activity.; SCV005374666: "Reported by one calibrated study to exhibit protein function similar to pathogenic control variants." PMID: 30209399; SCV003927164: Experimental studies have shown that this missense change abolishes E3 ubiquitin ligase activity (PMID: 11320250).; SCV000186951: "This alteration is located in the highly conserved 5' RING domain and has been shown to result in abolished ubiquitin protein ligase activity (Ruffner H et al.Proc Natl Acad Sci USA. 2001 Apr 24;98(9):5134-9)."; SCV000911053: Functional studies have reported that this variant impacts BRCA1 function in ubiquitin ligase, BARD1 binding, haploid cell proliferation and yeast colony size assays (PMID: 11320250, 12732733, 25823446, 27272900, 30209399).; SCV000292502: Published functional studies demonstrate a damaging effect: reduced or absent ubiquitin ligase activity, decreased BARD1 binding, decreased cell survival, and abnormal yeast colony size and spot formation (Ruffner 2001, Starita 2015, Thouvenot 2016, Findlay 2018); SCV000600273: Multiple functional studies have demonstrated that this variant has a damaging effect on BRCA1 protein function (PMID: 30209399 (2018), 27272900 (2016), 25823446 (2015), 23397983 (2014), 22034289 (2012), 15131401 (2004), 8944023 (1996)).; SCV004101417: Reported by one calibrated study to exhibit protein function similar to pathogenic control variants (PMID: 30209399) (PS3 met).
PM1Mutational hot spot or critical domain
Missense neighbourhood moderate hotspot (≥2 P/LP within ±8 AA, OR ≥ 2 vs. background) — PM1 supporting; In-domain: 0 pathogenic, 0 benign rare missense variants.; ±8 AA neighbourhood: 12 pathogenic, 19 benign (OR vs. background: 3.2).
PM2Absent/extremely low in population databases
Very rare in gnomAD for AD/XL gene (popmax AF < threshold/10) — PM2; GnomAD popmax AF = 0.000000907 — very rare for AD+AR gene (base 0.0001, raised to 0.000118 by highest known P/LP ClinVar AF 0.000118) — PM2 moderate.
PM5Novel missense at known pathogenic residue
Different pathogenic missense at same AA residue in ClinVar (PM5); ClinVar contains a germline Pathogenic/Likely Pathogenic entry at the same amino acid position with a different amino acid change: p.C64G: Pathogenic (ClinVar VariationId 17660, 2 stars); Other variants at the same amino acid residue (not pathogenic): p.C64= (synonymous): unknown significance (ClinVar VariationId 867931); p.C64F: unknown significance (ClinVar VariationId 867930)
Automated classification analysis was done for transcript: NM_007294.4. You can select a different transcript below to see updated classification assignments.
MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.
MaveDB functional evidence
MaveDB is a public repository of laboratory assays that test the effect of thousands of variants at once — treat this as supporting research data and interpret it with great caution; it is not a clinical classification.
1 abnormal
3 no calibration
4 assays found for this variant.
Clinical calibration: 1 functionally abnormal (PS3), 0 functionally normal (BS3).
Meta-analysis of urn:mavedb:00000097-a-1, urn:mavedb:00000097-b-1, urn:mavedb:00000097-c-1, urn:mavedb:00000097-d-1, urn:mavedb:00000097-e-1 and 21 others