chr13-32398420-A-T

Position:

• chr13-32398420-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000059.4(BRCA2):​c.9907A>T​(p.Ser3303Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,874 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6 B:1
• Conservation: PhyloP100: 1.64

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.15281293).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.9907A>T	p.Ser3303Cys	missense_variant	27/27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.9907A>T	p.Ser3303Cys	missense_variant	27/27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.9538A>T	p.Ser3180Cys	missense_variant	27/27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.*1965A>T		non_coding_transcript_exon_variant	26/26	2		ENSP00000506251.1
BRCA2	ENST00000614259.2	n.*1965A>T		3_prime_UTR_variant	26/26	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461874 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727236

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

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:1 Benign:1

Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Mar 06, 2024	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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Oct 05, 2023	This missense variant replaces serine with cysteine at codon 3303 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 in mouse embryonic stem cells has shown this variant does not impact sensitivity to DNA damaging agents (PMID: 33314489). This variant has been reported in at least one individual affected with breast cancer (PMID: 18627636, 33471991; Leiden Open Variation Database DB-ID BRCA2_003783). 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. -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jun 16, 2016

Variant identified in a genome or exome case(s) and assessed due to predicted null impact of the variant or pathogenic assertions in the literature or databases. Disclaimer: This variant has not undergone full assessment. The following are preliminary notes: Reported in 1 paper; ClinVar: 2 VUS -

Breast-ovarian cancer, familial, susceptibility to, 2 Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Breast Cancer Information Core (BIC) (BRCA2)

Sep 18, 2010

- -

BRCA2-related cancer predisposition Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Jul 20, 2024

This missense variant replaces serine with cysteine at codon 3303 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 in mouse embryonic stem cells has shown this variant does not impact sensitivity to DNA damaging agents (PMID: 33314489). This variant has been reported in at least one individual affected with breast cancer (PMID: 18627636, 33471991; Leiden Open Variation Database DB-ID BRCA2_003783). 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. -

BRCA2-related disorder Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Aug 29, 2024

The BRCA2 c.9907A>T variant is predicted to result in the amino acid substitution p.Ser3303Cys. This variant was reported in an individual with early-onset breast cancer and/or a family history of breast or ovarian cancer (referred to as 10135A>T in Table 3, Thirthagiri et al. 2008. PubMed ID: 18627636). Experimental studies suggest this variant does not impact protein function (Sullivan et al. 2020. PubMed ID: 33314489). This variant has not been reported in a large population database, indicating this variant is rare. This variant is interpreted as uncertain in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/52914/). 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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 14, 2023

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. Experimental studies have shown that this missense change does not substantially affect BRCA2 function (PMID: 33314489). 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. ClinVar contains an entry for this variant (Variation ID: 52914). This missense change has been observed in individual(s) with breast cancer (PMID: 18627636, 33314489). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces serine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 3303 of the BRCA2 protein (p.Ser3303Cys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.076
BayesDel_addAF	Benign	-0.14	T
BayesDel_noAF	Benign	-0.44
CADD	Benign	20
DANN	Uncertain	0.98
Eigen	Benign	-0.081
Eigen_PC	Benign	0.0017
FATHMM_MKL	Uncertain	0.85	D
M_CAP	Uncertain	0.095	D
MetaRNN	Benign	0.15	T;T
MetaSVM	Benign	-1.0	T
PrimateAI	Benign	0.35	T
PROVEAN	Benign	-0.94	N;N
REVEL	Benign	0.095
Sift	Benign	0.10	T;T
Sift4G	Benign	0.17	T;T
Vest4		0.17
MutPred		0.14		Gain of catalytic residue at S3303 (P = 0.1039);Gain of catalytic residue at S3303 (P = 0.1039);
MVP		0.84
MPC		0.14
ClinPred		0.69	D
GERP RS		2.9
gMVP		0.25

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

LitVar

Other links and lift over

dbSNP: rs276174930; hg19: chr13-32972557;