17-43124077-C-T
Variant summary
Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM1BP4_ModerateBP6
The NM_007294.4(BRCA1):c.20G>A(p.Arg7His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,613,318 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign 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. R7G) has been classified as Uncertain significance.
Frequency
Consequence
NM_007294.4 missense
Scores
Clinical Significance
Conservation
Publications
- breast-ovarian cancer, familial, susceptibility to, 1Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, ClinGen, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
- Fanconi anemia, complementation group SInheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
- pancreatic cancer, susceptibility to, 4Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
- hereditary breast ovarian cancer syndromeInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- Fanconi anemiaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Likely_benign. The variant received -1 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| BRCA1 | NM_007294.4 | c.20G>A | p.Arg7His | missense_variant | Exon 2 of 23 | ENST00000357654.9 | NP_009225.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| BRCA1 | ENST00000357654.9 | c.20G>A | p.Arg7His | missense_variant | Exon 2 of 23 | 1 | NM_007294.4 | ENSP00000350283.3 |
Frequencies
GnomAD3 genomes AF: 0.00000658 AC: 1AN: 152056Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000279 AC: 7AN: 251074 AF XY: 0.0000221 show subpopulations
GnomAD4 exome AF: 0.00000547 AC: 8AN: 1461262Hom.: 0 Cov.: 30 AF XY: 0.00000550 AC XY: 4AN XY: 726996 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000658 AC: 1AN: 152056Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74272 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:1Benign:2
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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. -
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not provided Uncertain:1Benign:1
This variant is denoted BRCA1 c.20G>A at the cDNA level, p.Arg7His (R7H) at the protein level, and results in the change of an Arginine to a Histidine (CGC>CAC). Using alternate nomenclature, this variant would be defined as BRCA1 139G>A. This variant has been observed in at least one individual referred for BRCA1 testing (Judkins 2005). It was demonstrated to have E3 ligase activity and BARD1 interaction similar to wildtype and was able to rescue homology-directed repair in a cell line lacking endogenous BRCA1 (Starita 2015). BRCA1 Arg7His was not observed in large population cohorts (Lek 2016). This variant is located in the RING domain and a region known to interact with BRD7 (Harte 2010, Borg 2010, Paul 2014). In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function. Based on currently available evidence, it is unclear whether BRCA1 Arg7His is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -
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Breast-ovarian cancer, familial, susceptibility to, 1 Benign:2
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BS1(Supporting)+BS3(Strong)+BP4(Supporting) according to ACMG/AMP classification guidelines specified for BRCA1 & BRCA2 (Classification Criteria V1.0.0 2023-09-08 - https://cspec.genome.network/cspec/ui/svi/affiliation/50087) (PMID: 38160042) -
not specified Uncertain:1
Variant summary: BRCA1 c.20G>A (p.Arg7His) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 2.8e-05 in 251074 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.20G>A has been reported in the literature in individuals affected with breast and/or ovarian cancer without evidence of causality (e.g. Judkins_2005, Innella_2024). These reports do not provide unequivocal conclusions about association of the variant with Hereditary Breast And Ovarian Cancer Syndrome. 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 publications have been ascertained in the context of this evaluation (PMID: 16267036, 25823446, 30209399, 38160042). ClinVar contains an entry for this variant (Variation ID: 184875). Based on the evidence outlined above, the variant was classified as VUS-possibly benign. -
Breast-ovarian cancer, familial, susceptibility to, 1;C3280442:Pancreatic cancer, susceptibility to, 4;C4554406:Fanconi anemia, complementation group S Uncertain:1
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Familial cancer of breast;C2676676:Breast-ovarian cancer, familial, susceptibility to, 1;C3280442:Pancreatic cancer, susceptibility to, 4;C4554406:Fanconi anemia, complementation group S Uncertain:1
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Hereditary breast ovarian cancer syndrome Uncertain:1
This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 7 of the BRCA1 protein (p.Arg7His). This variant is present in population databases (rs144792613, gnomAD 0.02%). 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: 184875). Invitae Evidence Modeling incorporating data from in vitro experimental studies (PMID: 30209399) indicates that this missense variant is not expected to disrupt BRCA1 function with a negative predictive value of 95%. Experimental studies have shown that this missense change does not substantially affect BRCA1 function (PMID: 25823446, 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at