rs1434821822

Positions:

• chr13-32370412-A-G
• chr13-32370412-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_000059.4(BRCA2):​c.8342A>G​(p.Asn2781Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,320 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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: 0.0000014 (0 hom.)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:3
• Conservation: PhyloP100: 9.26

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 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.807

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.8342A>G	p.Asn2781Ser	missense_variant	19/27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.8342A>G	p.Asn2781Ser	missense_variant	19/27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.7973A>G	p.Asn2658Ser	missense_variant	19/27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.*400A>G		non_coding_transcript_exon_variant	18/26	2		ENSP00000506251.1
BRCA2	ENST00000614259	n.*400A>G		3_prime_UTR_variant	18/25	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461320 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727002

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000504

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary breast ovarian cancer syndrome Pathogenic:1 Uncertain:1

Likely pathogenic, criteria provided, single submitter	clinical testing	Breast Care Center, Daerim St. Mary`s Hospital	Dec 12, 2024	The c.8342A>G variant in coding exon 19 of the BRCA2 gene results in a p.Asn2781Ser substitution. This position is highly conserved across most species (PMID: 19656164). This non-truncating nonsynonymous variant is located in an exonic hotspot and/or a critical functional domain of the gene. A different amino acid change at the same position (p.Asn2781Ile) has been reported as likely pathogenic in an ovarian cancer case (PMID: 18559594) and esophageal squamous cell cancer (PMID: 31396961). The c.8342A>G variant is not found in the gnomAD genomes and has an allele frequency of 0.004458% in the East Asian population of the gnomAD exomes database. Multiple computational prediction tools suggest a deleterious effect of this nonsynonymous missense variant on BRCA2 function. This variant was identified in three breast cancer patients: Patient 1 was diagnosed at the age of 50 and had a family history of breast cancer in her mother and sister, both diagnosed in their early 50s; Patient 2 was diagnosed with synchronous bilateral breast cancer at the age of 44; and Patient 3 was diagnosed with breast cancer at the age of 45. Additionally, this variant has been reported in other Korean breast cancer patients and families (PMID: 19656164, 28111427). Based on the available evidence, this variant is classified as likely pathogenic. -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 14, 2023	This sequence change replaces asparagine, which is neutral and polar, with serine, which is neutral and polar, at codon 2781 of the BRCA2 protein (p.Asn2781Ser). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with breast cancer (PMID: 19656164, 28111427). ClinVar contains an entry for this variant (Variation ID: 1331803). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on BRCA2 protein function. 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. -

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jul 16, 2021	This missense variant replaces asparagine with serine at codon 2781 of the BRCA2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with breast cancer (PMID: 19656164) and in another individual affected with familial breast cancer with a pathogenic BRCA1 covariant (PMID: 28111427). 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Feb 01, 2024	The p.N2781S variant (also known as c.8342A>G), located in coding exon 18 of the BRCA2 gene, results from an A to G substitution at nucleotide position 8342. The asparagine at codon 2781 is replaced by serine, an amino acid with highly similar properties. This alteration has been reported in cohorts of Korean breast cancer cases; however, at least one individual was also positive for a pathogenic mutation in the BRCA1 gene (Seong MW et al. Clin Genet, 2009 Aug;76:152-60; Park JS et al. Cancer Res Treat, 2017 Oct;49:1012-1021). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.42
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.040
CADD	Uncertain	25
DANN	Uncertain	1.0
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Pathogenic	1.0	D
M_CAP	Uncertain	0.13	D
MetaRNN	Pathogenic	0.81	D;D
MetaSVM	Pathogenic	0.84	D
PrimateAI	Uncertain	0.54	T
PROVEAN	Benign	-1.5	N;N
REVEL	Pathogenic	0.71
Sift	Pathogenic	0.0	D;D
Sift4G	Uncertain	0.0080	D;D
Vest4		0.66
MutPred		0.79		Gain of glycosylation at N2781 (P = 0.0142);Gain of glycosylation at N2781 (P = 0.0142);
MVP		0.97
MPC		0.16
ClinPred		1.0	D
GERP RS		5.3
gMVP		0.89

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: rs1434821822; hg19: chr13-32944549;