13-32336595-A-G
Variant summary
Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate
The NM_000059.4(BRCA2):c.2240A>G(p.Glu747Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000031 in 1,613,998 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/20 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. E747A) has been classified as Likely benign.
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 -2 ACMG points.
Variant Effect in Transcripts
ACMG analysis was done for transcript: NM_000059.4. You can select a different transcript below to see updated ACMG assignments.
RefSeq Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| BRCA2 | NM_000059.4 | MANE Select | c.2240A>G | p.Glu747Gly | missense | Exon 11 of 27 | NP_000050.3 | ||
| BRCA2 | NM_001432077.1 | c.2240A>G | p.Glu747Gly | missense | Exon 11 of 27 | NP_001419006.1 | |||
| BRCA2 | NM_001406720.1 | c.2240A>G | p.Glu747Gly | missense | Exon 11 of 27 | NP_001393649.1 |
Ensembl Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| BRCA2 | ENST00000380152.8 | TSL:5 MANE Select | c.2240A>G | p.Glu747Gly | missense | Exon 11 of 27 | ENSP00000369497.3 | ||
| BRCA2 | ENST00000544455.6 | TSL:1 | c.2240A>G | p.Glu747Gly | missense | Exon 11 of 27 | ENSP00000439902.1 | ||
| BRCA2 | ENST00000530893.7 | TSL:1 | c.1871A>G | p.Glu624Gly | missense | Exon 11 of 27 | ENSP00000499438.2 |
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152236Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000358 AC: 9AN: 251276 AF XY: 0.0000515 show subpopulations
GnomAD4 exome AF: 0.0000322 AC: 47AN: 1461762Hom.: 0 Cov.: 33 AF XY: 0.0000440 AC XY: 32AN XY: 727178 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152236Hom.: 0 Cov.: 32 AF XY: 0.0000403 AC XY: 3AN XY: 74376 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:2Benign:2
This alteration is classified as 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 glutamic acid with glycine at codon 747 of the BRCA2 protein. Computational prediction suggests that this variant may not impact protein structure and function. A functional study has reported that this variant does not impact BRCA2 function in the rescue of sensitivity to poly(ADP)-ribose polymerase inhibitors in BRCA2-deficient cells (PMID: 32444794). This variant has been reported in individuals affected with breast cancer (PMID: 32846166, 33552952, 37725154). This variant has been identified in 9/251276 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.
Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673).
Breast-ovarian cancer, familial, susceptibility to, 2 Uncertain:3
This missense variant replaces glutamic acid with glycine at codon 747 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). A functional study has shown that the variant has neutral impact on sensitivity to PARP inhibitors (PMID: 32444794). This variant has been reported in 2 individuals affected with breast cancer (PMID: 32846166, 33552952). This variant has been identified in 9/251276 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.
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease.
not provided Uncertain:3
Observed in individuals with a personal history of breast and/or ovarian cancer (PMID: 33552952); Published functional studies demonstrated cell viability similar to wild-type when exposed to various PARP inhibitors (PMID: 32444794); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Also known as 2468A>G; This variant is associated with the following publications: (PMID: 25722345, 32846166, 29884841, 31853058, 33552952, 32444794)
In the published literature, this variant has been reported in individuals affected with breast and/or ovarian cancer (PMIDs: 33552952 (2020), 32846166 (2020)). Functional studies have shown that the variant results in normal sensitivity to PARP inhibitors (PMID: 32444794 (2020)), however further research is needed to understand the global impact of the variant on protein function. The frequency of this variant in the general population, 0.00029 (9/30612 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 benign. Based on the available information, we are unable to determine the clinical significance of this variant.
The BRCA2 p.Glu747Gly variant was not identified in the literature nor was it identified in the UMD-LSDB database. The variant was also identified in dbSNP (ID: rs397507283) as "With Uncertain significance allele", ClinVar (classified as uncertain significance by Invitae, Ambry Genetics, GeneDx and three other submitters), and LOVD 3.0 (2x). The variant was identified in control databases in 9 of 246080 chromosomes at a frequency of 0.00004 (Genome Aggregation Database Feb 27, 2017). The variant was observed in the following populations: Other in 1 of 5480 chromosomes (freq: 0.0002) and South Asian in 8 of 30782 chromosomes (freq: 0.0003), while the variant was not observed in the African, Latino, European, Ashkenazi Jewish, East Asian, or Finnish populations. The p.Glu747 residue is not conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein; this information is not very predictive of pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. 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.
Hereditary breast ovarian cancer syndrome Uncertain:2
This sequence change replaces glutamic acid, which is acidic and polar, with glycine, which is neutral and non-polar, at codon 747 of the BRCA2 protein (p.Glu747Gly). This variant is present in population databases (rs397507283, gnomAD 0.03%). This missense change has been observed in individual(s) with breast and/or ovarian cancer (PMID: 32846166, 33552952). ClinVar contains an entry for this variant (Variation ID: 37778). 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%. Experimental studies have shown that this missense change does not substantially affect BRCA2 function (PMID: 32444794). 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.2240A>G (p.Glu747Gly) results in a non-conservative amino acid change in the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change. The variant allele was found at a frequency of 3.6e-05 in 251276 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.2240A>G has been observed in individual(s) affected with Hereditary Breast And Ovarian Cancer Syndrome, without strong evidence for causality (Yildiz_2020, Akcay_2020, Kadri_2021). These report(s) do not 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. The following publications have been ascertained in the context of this evaluation (PMID: 32846166, 33552952, 32658311). ClinVar contains an entry for this variant (Variation ID: 37778). Based on the evidence outlined above, the variant was classified as uncertain significance.
Fanconi anemia complementation group D1 Uncertain:1
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease.
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at