rs80357007
Variant summary
Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1PM2PP3_Moderate
The NM_007294.4(BRCA1):c.5288G>T(p.Gly1763Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,740 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. G1763E) 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_pathogenic. The variant received 6 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 31
GnomAD4 exome AF: 0.00000137 AC: 2AN: 1461740Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0AN XY: 727180 show subpopulations ⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
GnomAD4 genome Cov.: 31
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Pathogenic:1Uncertain:1
This missense variant replaces glycine with valine at codon 1763 of the BRCA1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function. Functional studies have reported contradictory findings for this variant protein with impact on BRCA1 function in a haploid cell proliferation assay and assays on protein stability, phosphopeptide binding and specificity and transcription activation assays (PMID: 20516115, 30209399, 30765603), and no impact in a homology-directed repair assay and in cellular assays for responses to DNA damaging agent and PARP inhibitor (PMID: 29113215, 35196514). This variant has been reported in one individual each affected with breast cancer (PMID: 29113215) and ovarian cancer (PMID: 37121054). A multifactorial analysis has reported a likelihood ratio based on personal and family history of 1.148 from log(LR)=0.059960604 (PMID: 31853058). This variant has not been identified 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. -
The p.G1763V variant (also known as c.5288G>T), located in coding exon 19 of the BRCA1 gene, results from a G to T substitution at nucleotide position 5288. The glycine at codon 1763 is replaced by valine, an amino acid with dissimilar properties. One functional study found that this nucleotide substitution is non-functional in a high-throughput, genome editing, haploid cell survival assay (Findlay GM. et al. Nature 2018 10;562(7726):217-222). In addition, multiple functional assays assessing protein folding stability, phosphopeptide binding, and transcriptional activity showed compromised function (Lee MS et al. Cancer Res. 2010 Jun 15;70(12):4880-90). This variant was reported as indeterminant in a homology directed repair assay, but functional in an assay of cisplatin resistance (Adamovich AI et al. Am J Hum Genet. 2022 Apr;109(4):618-630). Another study that utilized bioinformatics analysis and a series of experiments investigating cell proliferation, cell cycle regulation, and chemotherapy response determined that this alteration did not affect the tumor suppressor function of BRCA1; however, the physiological relevance of these findings are unclear (Zhang H et al. Oncol Lett, 2017 Nov;14:5839-5844). Based on internal structural analysis, G1763V is deleterious (Ambry internal data; Wu, Q et al. Mol Cell 2016 Feb;61(3):434-448). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:2
PS3(Strong)+PM2(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) -
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not specified Uncertain:1
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BRCA1-related cancer predisposition Uncertain:1
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not provided Uncertain:1
This variant is denoted BRCA1 c.5288G>T at the cDNA level, p.Gly1763Val (G1763V) at the protein level, and results in the change of a Glycine to a Valine (GGG>GTG). This variant has been identified in at least one individual with breast cancer (Judkins 2005). Functional studies have shown that this variant exhibits compromised phosphopeptide binding activity and specificity, mild protein folding defects, and reduced transcriptional activity compared to wild type (Lee 2010). BRCA1 Gly1763Val was not observed in large population cohorts (NHLBI Exome Sequencing Project, The 1000 Genomes Consortium 2015, Lek 2016). Since Glycine and Valine share similar properties, this is considered a conservative amino acid substitution. BRCA1 Gly1763Val occurs at a position that is conserved across species and is located in the BRCT 2 domain and a region known to interact with multiple other proteins (Paul 2014, UniProt). In silico analyses predict that this variant is probably damaging to protein structure and function. Based on currently available evidence, it is unclear whether BRCA1 Gly1763Val is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -
Hereditary breast ovarian cancer syndrome Uncertain:1
This sequence change replaces glycine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 1763 of the BRCA1 protein (p.Gly1763Val). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with familial breast cancer (PMID: 29113215). ClinVar contains an entry for this variant (Variation ID: 55507). Invitae Evidence Modeling incorporating data from in vitro experimental studies (PMID: 30209399) indicates that this missense variant is expected to disrupt BRCA1 function with a positive predictive value of 95%. Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on BRCA1 function (PMID: 20516115, 29113215, 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