chr13-32333300-G-A

Position:

• chr13-32333300-G-A

Variant summary

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

The NM_000059.4(BRCA2):​c.1822G>A​(p.Asp608Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000688 in 1,453,414 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: 6.9e-7 (0 hom.)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:1
• Conservation: PhyloP100: 0.566

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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.1280975).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.1822G>A	p.Asp608Asn	missense_variant	10/27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.1822G>A	p.Asp608Asn	missense_variant	10/27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.1453G>A	p.Asp485Asn	missense_variant	10/27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.1822G>A		non_coding_transcript_exon_variant	9/26	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.88e-7 AC: 1 AN: 1453414 Hom.: 0 Cov.: 35 AF XY: 0.00 AC XY: 0 AN XY: 722742

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: 9.01e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Dec 22, 2022	Identified in individuals with breast cancer, but also in unaffected controls (Dorling et al., 2021); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Also known as 2050G>A; This variant is associated with the following publications: (PMID: 33471991) -
Uncertain significance, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Oct 18, 2017	- -

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

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). -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Dec 16, 2023	The c.1822G>A (p.D608N) alteration is located in exon 10 (coding exon 9) of the BRCA2 gene. This alteration results from a G to A substitution at nucleotide position 1822, causing the aspartic acid (D) at amino acid position 608 to be replaced by an asparagine (N). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

BRCA2-related cancer predisposition Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Aug 13, 2024

This missense variant replaces aspartic acid with asparagine at codon 608 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 1/60466 cases and 1/53461 unaffected individuals (PMID: 33471991; Leiden Open Variation Database DB-ID BRCA2_007896). 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

Labcorp Genetics (formerly Invitae), Labcorp

Sep 01, 2021

This sequence change replaces aspartic acid with asparagine at codon 608 of the BRCA2 protein (p.Asp608Asn). The aspartic acid residue is weakly conserved and there is a small physicochemical difference between aspartic acid and asparagine. This variant is not present in population databases (ExAC no frequency). 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: 419884). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The asparagine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.093
BayesDel_addAF	Benign	-0.17	T
BayesDel_noAF	Benign	-0.49
CADD	Benign	13
DANN	Uncertain	0.99
Eigen	Benign	-0.60
Eigen_PC	Benign	-0.66
FATHMM_MKL	Benign	0.11	N
M_CAP	Uncertain	0.13	D
MetaRNN	Benign	0.13	T;T
MetaSVM	Benign	-0.92	T
PrimateAI	Benign	0.26	T
PROVEAN	Benign	-0.62	N;N
REVEL	Benign	0.16
Sift	Benign	0.16	T;T
Sift4G	Benign	0.083	T;T
Vest4		0.27
MutPred		0.15		Loss of ubiquitination at K604 (P = 0.059);Loss of ubiquitination at K604 (P = 0.059);
MVP		0.85
MPC		0.022
ClinPred		0.080	T
GERP RS		-2.1
gMVP		0.12

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: rs1064794170; hg19: chr13-32907437;