chr13-32338833-A-G

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2BP4_ModerateBP6

The NM_000059.4(BRCA2):​c.4478A>G​(p.Glu1493Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,788 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. E1493A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

BRCA2
NM_000059.4 missense

Scores

1
3
11

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:9B:3

Conservation

PhyloP100: 1.66

Publications

9 publications found
Variant links:
Genes affected
BRCA2 (HGNC:1101): (BRCA2 DNA repair associated) Inherited mutations in BRCA1 and this gene, BRCA2, confer increased lifetime risk of developing breast or ovarian cancer. Both BRCA1 and BRCA2 are involved in maintenance of genome stability, specifically the homologous recombination pathway for double-strand DNA repair. The largest exon in both genes is exon 11, which harbors the most important and frequent mutations in breast cancer patients. The BRCA2 gene was found on chromosome 13q12.3 in human. The BRCA2 protein contains several copies of a 70 aa motif called the BRC motif, and these motifs mediate binding to the RAD51 recombinase which functions in DNA repair. BRCA2 is considered a tumor suppressor gene, as tumors with BRCA2 mutations generally exhibit loss of heterozygosity (LOH) of the wild-type allele. [provided by RefSeq, May 2020]
BRCA2 Gene-Disease associations (from GenCC):
  • breast-ovarian cancer, familial, susceptibility to, 2
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), ClinGen
  • Fanconi anemia complementation group D1
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, ClinGen, G2P
  • pancreatic cancer, susceptibility to, 2
    Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
  • sarcoma
    Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
  • hereditary breast ovarian cancer syndrome
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Fanconi anemia
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • medulloblastoma
    Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -1 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.20477825).
BP6
Variant 13-32338833-A-G is Benign according to our data. Variant chr13-32338833-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 126045.

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
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
BRCA2
NM_000059.4
MANE Select
c.4478A>Gp.Glu1493Gly
missense
Exon 11 of 27NP_000050.3
BRCA2
NM_001432077.1
c.4478A>Gp.Glu1493Gly
missense
Exon 11 of 27NP_001419006.1
BRCA2
NM_001406720.1
c.4478A>Gp.Glu1493Gly
missense
Exon 11 of 27NP_001393649.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
BRCA2
ENST00000380152.8
TSL:5 MANE Select
c.4478A>Gp.Glu1493Gly
missense
Exon 11 of 27ENSP00000369497.3
BRCA2
ENST00000544455.6
TSL:1
c.4478A>Gp.Glu1493Gly
missense
Exon 11 of 27ENSP00000439902.1
BRCA2
ENST00000530893.7
TSL:1
c.4109A>Gp.Glu1370Gly
missense
Exon 11 of 27ENSP00000499438.2

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152240
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000399
AC:
1
AN:
250396
AF XY:
0.00000738
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461548
Hom.:
0
Cov.:
35
AF XY:
0.00000138
AC XY:
1
AN XY:
727076
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44716
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39688
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86234
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53334
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111818
Other (OTH)
AF:
0.00
AC:
0
AN:
60386
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152240
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74384
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41464
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5204
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4838
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10630
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.625
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000378
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:9Benign:3
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1Benign:2
Jan 07, 2025
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces glutamic acid with glycine at codon 1493 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 detected in a breast cancer case-control meta-analysis in 0/60466 cases and 1/53461 unaffected individuals (PMID: 33471991; Leiden Open Variation Database DB-ID BRCA2_008219). This variant has been identified in 2/281792 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.

Oct 25, 2024
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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.

Mar 23, 2023
University of Washington Department of Laboratory Medicine, University of Washington
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:curation

Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673).

not provided Uncertain:2
Sep 08, 2017
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is denoted BRCA2 c.4478A>G at the cDNA level, p.Glu1493Gly (E1493G) at the protein level, and results in the change of a Glutamic Acid to a Glycine (GAA>GGA). Using alternate nomenclature, this variant would be defined as BRCA2 4706A>G. This variant has not, to our knowledge, been published in the literature as pathogenic or benign. BRCA2 Glu1493Gly was not observed at a significant allele frequency in large population cohorts (NHLBI Exome Sequencing Project, The 1000 Genomes Consortium 2015, Lek 2016). Since Glutamic Acid and Glycine differ in polarity, charge, size or other properties, this is considered a non-conservative amino acid substitution. BRCA2 Glu1493Gly occurs at a position that is not conserved and is located in the RAD51 and POLH binding domains (Roy 2012, Buisson 2014). In silico analyses are inconsistent regarding the effect this variant may have on protein structure and function. Based on currently available evidence, it is unclear whether BRCA2 Glu1493Gly is a pathogenic or benign variant. We consider it to be a variant of uncertain significance.

Jul 28, 2019
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Breast-ovarian cancer, familial, susceptibility to, 2 Uncertain:1Benign:1
May 29, 2002
Breast Cancer Information Core (BIC) (BRCA2)
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

Jul 13, 2023
Myriad Genetics, Inc.
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered 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 variant has been observed in trans with a known pathogenic variant in one or more individuals lacking clinical features consistent with gene-specific recessive disease.

not specified Uncertain:1
Aug 02, 2021
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: BRCA2 c.4478A>G (p.Glu1493Gly) 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 5.6e-06 in 357318 control chromosomes (gnomAD and publication). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.4478A>G in individuals affected with Hereditary Breast And Ovarian Cancer Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Six ClinVar submitters (evaluation after 2014) cite the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance.

Medulloblastoma;C0346153:Familial cancer of breast;C0376358:Prostate cancer;C1838457:Fanconi anemia complementation group D1;C2675520:Breast-ovarian cancer, familial, susceptibility to, 2;C2751641:Glioma susceptibility 3;C3150546:Pancreatic cancer, susceptibility to, 2;CN033288:Wilms tumor 1 Uncertain:1
Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

BRCA2-related cancer predisposition Uncertain:1
Sep 12, 2024
All of Us Research Program, National Institutes of Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

BRCA2-related disorder Uncertain:1
May 23, 2024
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

The BRCA2 c.4478A>G variant is predicted to result in the amino acid substitution p.Glu1493Gly. This variant was reported in a control and not in affected individuals in a breast cancer case-control study (Breast Cancer Association Consortium. 2021. PubMed ID: 33471991). This variant is reported in 0.0040% of alleles in individuals of African descent in gnomAD and has conflicting interpretations of pathogenicity in ClinVar ranging from uncertain to benign (http://www.ncbi.nlm.nih.gov/clinvar/variation/126045). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence.

Hereditary breast ovarian cancer syndrome Uncertain:1
Sep 30, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glutamic acid, which is acidic and polar, with glycine, which is neutral and non-polar, at codon 1493 of the BRCA2 protein (p.Glu1493Gly). This variant is present in population databases (rs80358679, gnomAD 0.004%). This variant has not been reported in the literature in individuals affected with BRCA2-related conditions. ClinVar contains an entry for this variant (Variation ID: 126045). 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.

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.077
BayesDel_addAF
Benign
-0.21
T
BayesDel_noAF
Benign
-0.43
CADD
Benign
12
DANN
Uncertain
1.0
Eigen
Benign
-0.54
Eigen_PC
Benign
-0.51
FATHMM_MKL
Uncertain
0.88
D
M_CAP
Benign
0.041
D
MetaRNN
Benign
0.20
T
MetaSVM
Benign
-0.96
T
PhyloP100
1.7
PrimateAI
Benign
0.26
T
PROVEAN
Pathogenic
-4.9
D
REVEL
Benign
0.17
Sift
Benign
0.091
T
Sift4G
Uncertain
0.0030
D
Vest4
0.29
MutPred
0.36
Loss of ubiquitination at K1489 (P = 0.0607)
MVP
0.86
MPC
0.023
ClinPred
0.41
T
GERP RS
0.0098
gMVP
0.32
Mutation Taster
=96/4
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs80358679; hg19: chr13-32912970; API