rs864622582

chr13-32379892-A-Cchr13-32379892-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 6P and 1B. PM1 PM2 PM5 BP4

The NM_000059.4(BRCA2):c.9096A>C(p.Lys3032Asn) 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 1,613,730 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in same amino acid change has been previously reported as Uncertain significancein ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K3032Q) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • 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:1
• Conservation: PhyloP100: 1.75

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 5 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 7 benign, 15 uncertain in NM_000059.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr13-32379890-AAA-AT is described in Lovd as [Pathogenic].
• BP4: Computational evidence support a benign effect (MetaRNN=0.29146034).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.9096A>C	p.Lys3032Asn	missense_variant	23/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.9096A>C	p.Lys3032Asn	missense_variant	23/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152256 Hom.: 0 Cov.: 32

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: 1461474 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727020

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

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 AF: 0.00000657 AC: 1 AN: 152256 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74386

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

Alfa AF: 0.0000843 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Breast and/or ovarian cancer Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

May 16, 2018

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Nov 25, 2015

This variant is denoted BRCA2 c.9096A>C at the cDNA level, p.Lys3032Asn (K3032N) at the protein level, and results in the change of a Lysine to an Asparagine (AAA>AAC). Using alternate nomenclature, this variant would be defined as BRCA2 9324A>C. This variant has not, to our knowledge, been published in the literature as pathogenic or benign. BRCA2 Lys3032Asn was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, suggesting it is not a common benign variant in these populations. Since Lysine and Asparagine differ in some properties, this is considered a semi-conservative amino acid substitution. BRCA2 Lys3032Asn occurs at a position where amino acids with properties similar to Lysine are tolerated across species and is located in the DNA binding domain (Borg 2010). In silico analyses are inconsistent regarding the effect this variant may have on protein structure and function. Based on currently available evidence, it is unclear whether BRCA2 Lys3032Asn is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 13, 2023

The p.K3032N variant (also known as c.9096A>C), located in coding exon 22 of the BRCA2 gene, results from an A to C substitution at nucleotide position 9096. The lysine at codon 3032 is replaced by asparagine, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Hereditary breast ovarian cancer syndrome Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Aug 17, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.35
BayesDel_addAF	Uncertain	0.047	T
BayesDel_noAF	Benign	-0.17
Cadd	Benign	15
Dann	Uncertain	1.0
Eigen	Benign	-0.10
Eigen_PC	Benign	-0.15
FATHMM_MKL	Uncertain	0.91	D
M_CAP	Benign	0.071	D
MetaRNN	Benign	0.29	T;T
MetaSVM	Benign	-0.84	T
MutationTaster	Benign	0.99	D;D
PrimateAI	Benign	0.44	T
PROVEAN	Benign	-1.1	N;N
REVEL	Uncertain	0.31
Sift	Uncertain	0.0010	D;D
Sift4G	Uncertain	0.0050	D;D
Vest4		0.50
MutPred		0.23		Loss of ubiquitination at K3032 (P = 0.0283);Loss of ubiquitination at K3032 (P = 0.0283);
MVP		0.87
MPC		0.049
ClinPred		0.89	D
GERP RS		-1.5
gMVP		0.41

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: rs864622582; hg19: chr13-32954029;