chr13-32338464-G-C

Variant names:

• chr13-32338464-G-C
• rs587781406
• NM_000059.4:c.4109G>C

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000059.4(BRCA2):​c.4109G>C​(p.Gly1370Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 15/20 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. G1370V) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6 B:1
• Conservation: PhyloP100: 0.0250
• Publications: 8 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.10564488).

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.4109G>C	p.Gly1370Ala	missense	Exon 11 of 27	NP_000050.3
	BRCA2	NM_001432077.1		c.4109G>C	p.Gly1370Ala	missense	Exon 11 of 27	NP_001419006.1
	BRCA2	NM_001406720.1		c.4109G>C	p.Gly1370Ala	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.4109G>C	p.Gly1370Ala	missense	Exon 11 of 27	ENSP00000369497.3
	BRCA2	ENST00000544455.6	TSL:1	c.4109G>C	p.Gly1370Ala	missense	Exon 11 of 27	ENSP00000439902.1
	BRCA2	ENST00000530893.7	TSL:1	c.3740G>C	p.Gly1247Ala	missense	Exon 11 of 27	ENSP00000499438.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2 Benign:1

Aug 03, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces glycine with alanine at codon 1370 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 an individual affected with kidney cancer (PMID: 26689913). This variant has been identified in 1/243242 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.

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).

Nov 27, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.G1370A variant (also known as c.4109G>C), located in coding exon 10 of the BRCA2 gene, results from a G to C substitution at nucleotide position 4109. The glycine at codon 1370 is replaced by alanine, an amino acid with similar properties. This amino acid position is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.

not specified Uncertain:1

Oct 09, 2023

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.4109G>C (p.Gly1370Ala) 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 was absent in 248174 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.4109G>C has been reported in the literature in individual(s) affected with breast- or ovarian cancer (Tran_2022), however it was also reported in women, older than age 70 years who have never had cancer (in the FLOSSIES database). These reports 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 publication has been ascertained in the context of this evaluation (PMID: 35070997). Five submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as uncertain significance.

BRCA2-related cancer predisposition Uncertain:1

Aug 06, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces glycine with alanine at codon 1370 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 an individual affected with kidney cancer (PMID: 26689913). This variant has been identified in 1/243242 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.

not provided Uncertain:1

Feb 26, 2021

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Hereditary breast ovarian cancer syndrome Uncertain:1

Feb 17, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 1370 of the BRCA2 protein (p.Gly1370Ala). This variant is present in population databases (rs587781406, gnomAD 0.0009%). This missense change has been observed in individual(s) with breast or ovarian cancer (PMID: 35070997). ClinVar contains an entry for this variant (Variation ID: 186065). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae 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	0.098
BayesDel_addAF	Benign	-0.25	T
BayesDel_noAF	Benign	-0.59
CADD	Benign	1.2
DANN	Benign	0.90
Eigen	Benign	-0.96
Eigen_PC	Benign	-0.93
FATHMM_MKL	Benign	0.090	N
M_CAP	Benign	0.032	D
MetaRNN	Benign	0.11	T
MetaSVM	Benign	-0.90	T
PhyloP100		0.025
PrimateAI	Benign	0.21	T
PROVEAN	Benign	-0.12	N
REVEL	Benign	0.089
Sift	Benign	0.30	T
Sift4G	Benign	0.74	T
Vest4		0.21
MutPred		0.20		Gain of helix (P = 0.0425)
MVP		0.79
MPC		0.021
ClinPred		0.024	T
GERP RS		-1.3
gMVP		0.055
Mutation Taster		=78/22	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

Other links and lift over

dbSNP: rs587781406; hg19: chr13-32912601;