13-32346877-A-G
Variant summary
Our verdict is Likely benign. The variant received -1 ACMG points: 4P and 5B. PM1PM2BP4_StrongBP6
The NM_000059.4(BRCA2):c.6988A>G(p.Ile2330Val) 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 1,457,896 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/20 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. I2330N) has been classified as Uncertain significance.
Frequency
Consequence
NM_000059.4 missense
Scores
Clinical Significance
Conservation
Publications
- breast-ovarian cancer, familial, susceptibility to, 2Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), ClinGen
- Fanconi anemia complementation group D1Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, ClinGen, G2P
- pancreatic cancer, susceptibility to, 2Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
- sarcomaInheritance: 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
- medulloblastomaInheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
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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 |
|---|---|---|---|---|---|---|---|---|
| BRCA2 | NM_000059.4 | c.6988A>G | p.Ile2330Val | missense_variant | Exon 13 of 27 | ENST00000380152.8 | NP_000050.3 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| BRCA2 | ENST00000380152.8 | c.6988A>G | p.Ile2330Val | missense_variant | Exon 13 of 27 | 5 | NM_000059.4 | ENSP00000369497.3 | ||
| BRCA2 | ENST00000530893.7 | c.6619A>G | p.Ile2207Val | missense_variant | Exon 13 of 27 | 1 | ENSP00000499438.2 | |||
| BRCA2 | ENST00000614259.2 | n.6988A>G | non_coding_transcript_exon_variant | Exon 12 of 26 | 2 | ENSP00000506251.1 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome AF: 0.00000137 AC: 2AN: 1457896Hom.: 0 Cov.: 29 AF XY: 0.00000276 AC XY: 2AN XY: 725284 show subpopulations ⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
Age Distribution
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Breast-ovarian cancer, familial, susceptibility to, 2 Uncertain:2Benign:1
This variant is considered likely benign. This variant is strongly associated with less severe personal and family histories of cancer, typical for individuals without pathogenic variants in this gene [PMID: 25085752].
This missense variant replaces isoleucine with valine at codon 2330 of the BRCA2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in individuals with a personal or family history of breast and/or ovarian cancer or prostate cancer (PMID: 27741520, 29161300, 29659569, 33471991; Leiden Open Variation Database DB-ID BRCA2_001102, 35264596, 35980532, 36329109, 36977404). 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.
Hereditary cancer-predisposing syndrome Uncertain:1Benign:2
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.
This missense variant replaces isoleucine with valine at codon 2330 of the BRCA2 protein. Computational prediction suggests that this variant may not impact protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in individuals and family affected with breast and/or ovarian cancer (PMID: 27741520, 29161300, 33471991; Leiden Open Variation Database DB-ID BRCA2_001102, 35264596, 35980532, 36329109, 36977404) or prostate cancer (PMID: 29659569). 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.
BP1_Strong, PM2_Supporting c.6988A>G, located in exon 13 of the BRCA2 gene, is predicted to result in the substitution of isoleucine by valine at codon 2330, p.(Ile2330Val). This position is outside a (potentially) clinically important functional domain and, moreover, the SpliceAI algorithm predicts no significant impact on splicing (BP1_strong). It is not present in the population database gnomAD v2.1.1, non cancer dataset (PM2_Supporting). To our knowledge, neither relevant clinical data nor well-stablished functional studies have been reported for this variant. In addition, it was also identified in the following databases: BRCA Exchange (Not Yet Reviewed), ClinVar (1x likely benign, 9x uncertain significance) and LOVD (1x likely benign, 2x uncertain significance). Based on the currently available information, c.6988A>G is classified as a likely benign variant according to ClinGen-BRCA2 Guidelines version v1.0.0.
not provided Uncertain:2
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Observed in individuals with breast or prostate cancer (Fernandes et al., 2016; Paulo et al., 2018; Ren et al., 2021; Guindalini et al., 2022; Matta et al., 2022); Also known as 7216A>G; This variant is associated with the following publications: (PMID: 29161300, 28651617, 27741520, 29659569, 33007869, 29884841, 32377563, 36977404, 36329109, 34196900, 35264596)
The BRCA2 c.6988A>G (p.Ile2330Val) variant has been reported in the published literature in in individuals with breast and/or ovarian cancer (PMIDs: 35264596 (2022), 36329109 (2022), 34196900 (2021), 33471991 (2021), 28651617 (2017), 27741520 (2016), see also LOVD (http://databases.lovd.nl/shared/genes/BRCA2)) and prostate cancer (PMID: 29659569 (2018)). This variant has also been identified in reportedly healthy individuals (PMID: 34196900 (2021), see also LOVD (http://databases.lovd.nl/shared/genes/BRCA2)). This variant has not been reported in large, multi-ethnic general populations (Genome Aggregation Database, http://gnomad.broadinstitute.org). 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 benign. Based on the available information, we are unable to determine the clinical significance of this variant.
Hereditary breast ovarian cancer syndrome Uncertain:2
This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 2330 of the BRCA2 protein (p.Ile2330Val). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with a personal and/or family history of breast cancer and/or ovarian cancer (PMID: 27741520, 28651617, 29161300, 36329109). ClinVar contains an entry for this variant (Variation ID: 234463). 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 BRCA2 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.
not specified Uncertain:1
Variant summary: BRCA2 c.6988A>G (p.Ile2330Val) results in a conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a benign effect of the variant on protein function. The variant was absent in 249986 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.6988A>G has been reported in the literature in an HBOC proband with a personal history of breast cancer at age 24 and a family history of breast cancer with no reported co-segregation (Fernandes_2016), as a VUS in another study reporting HBOC probands from Southern Brazil (Alemar_2017), as a VUS specimen previously analyzed at another clinical laboratory (Buzolin_2017), in a study of cancer predisposition panel sequencing in patients with prostate cancer (Paulo_2018). None of these report(s) provide unequivocal conclusions about association of the variant with Hereditary Breast And Ovarian Cancer Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Six clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance.
Malignant tumor of breast Uncertain:1
The BRCA2 p.Ile2330Val variant was identified in 2 of 1534 proband chromosomes (frequency: 0.001) from individuals or families with breast or ovarian cancer (Alemar 2017, Fernandes 2016). The variant was also identified in dbSNP (ID: rs876661032) as "With Uncertain significance allele", ClinVar (classified as uncertain significance by GeneDx, Invitae, and Integrated Genetics/Laboratory Corporation of America), and LOVD 3.0 (2x). The variant was not identified in the COGR, Cosmic, MutDB, UMD-LSDB, BIC Database, ARUP Laboratories, or Zhejiang University databases. It was not identified in the 1000 Genomes Project, the NHLBI GO Exome Sequencing Project, the Exome Aggregation Consortium (August 8th 2016), or the Genome Aggregation Database (Feb 27, 2017). The p.Ile2330 residue is not conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) do not suggest a high likelihood of impact to the protein; however, this information is not predictive enough to rule out pathogenicity. The variant occurs outside of the splicing consensus sequence and 1 of 5 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) predict a greater than 10% difference in splicing; this is not very predictive of pathogenicity. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance.
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at