rs1308950771

chr13-32339705-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 4P and 3B. PM2 PM5 BP4_Moderate BP6

The NM_000059.4(BRCA2):c.5350A>C(p.Asn1784His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,613,390 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). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N1784?) has been classified as Pathogenic.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:2
• Conservation: PhyloP100: 0.704

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr13-32339705-AA-T is described in ClinVar as [Pathogenic]. Clinvar id is 51844.Status of the report is reviewed_by_expert_panel, 3 stars.
• BP4: Computational evidence support a benign effect (MetaRNN=0.24118456).
• BP6: Variant 13-32339705-A-C is Benign according to our data. Variant chr13-32339705-A-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 462375.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=3, Likely_benign=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.5350A>C	p.Asn1784His	missense_variant	11/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.5350A>C	p.Asn1784His	missense_variant	11/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152218 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461172 Hom.: 0 Cov.: 44 AF XY: 0.00000275 AC XY: 2 AN XY: 726904

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152218 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74372

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Jul 18, 2022	The p.N1784H variant (also known as c.5350A>C), located in coding exon 10 of the BRCA2 gene, results from an A to C substitution at nucleotide position 5350. The asparagine at codon 1784 is replaced by histidine, an amino acid with similar properties. This alteration was identified in 1/527 index patients with either breast, ovarian, or pancreatic cancer (Loizidou MA et al. Clin Genet, 2017 Apr;91:611-615). This amino acid position is not well 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. -
Likely benign, criteria provided, single submitter	clinical testing	Mendelics	Apr 08, 2024	- -
Likely benign, criteria provided, single submitter	curation	University of Washington Department of Laboratory Medicine, University of Washington	Mar 23, 2023	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:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Aug 15, 2023

This missense variant replaces asparagine with histidine at codon 1784 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 breast, ovarian, or pancreatic cancer (PMID:27882536). In a large breast cancer case-control study conducted by the BRIDGES consortium, this variant was reported in 1/60466 cases and 1/53461 controls (PMID: 33471991; Leiden Open Variation Database DB-ID BRCA2_008330). 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. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jun 03, 2022

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. 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: 462375). This missense change has been observed in individual(s) with breast, ovarian, or pancreatic cancer (PMID: 27882536). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces asparagine, which is neutral and polar, with histidine, which is basic and polar, at codon 1784 of the BRCA2 protein (p.Asn1784His). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.14	T
BayesDel_noAF	Benign	-0.43
Cadd	Benign	10
Dann	Uncertain	0.98
Eigen	Benign	-0.82
Eigen_PC	Benign	-0.90
FATHMM_MKL	Benign	0.20	N
M_CAP	Benign	0.045	D
MetaRNN	Benign	0.24	T;T
MetaSVM	Benign	-0.90	T
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.38	T
PROVEAN	Uncertain	-3.7	D;D
REVEL	Benign	0.16
Sift	Uncertain	0.010	D;D
Sift4G	Uncertain	0.032	D;D
Vest4		0.43
MutPred		0.22		Loss of ubiquitination at K1789 (P = 0.0768);Loss of ubiquitination at K1789 (P = 0.0768);
MVP		0.87
MPC		0.023
ClinPred		0.43	T
GERP RS		-0.094
gMVP		0.19

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: rs1308950771; hg19: chr13-32913842;