NM_000059.4:c.8990A>G

Variant names:

• chr13-32379786-A-G
• rs770449225
• NM_000059.4:c.8990A>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_000059.4(BRCA2):​c.8990A>G​(p.Tyr2997Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 13/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y2997F) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 0.519
• Publications: 5 publications found

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 Gene-Disease associations (from GenCC):

• breast-ovarian cancer, familial, susceptibility to, 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), ClinGen
• Fanconi anemia complementation group D1

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, ClinGen, G2P
• pancreatic cancer, susceptibility to, 2

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• sarcoma

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• hereditary breast ovarian cancer syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Fanconi anemia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• medulloblastoma

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 6 benign, 14 uncertain in NM_000059.4
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.098309755).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.8990A>G	p.Tyr2997Cys	missense_variant	Exon 23 of 27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.8990A>G	p.Tyr2997Cys	missense_variant	Exon 23 of 27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.8621A>G	p.Tyr2874Cys	missense_variant	Exon 23 of 27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.*1048A>G		non_coding_transcript_exon_variant	Exon 22 of 26	2		ENSP00000506251.1
BRCA2	ENST00000614259.2	n.*1048A>G		3_prime_UTR_variant	Exon 22 of 26	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000399 AC: 1 AN: 250792 AF XY: 0.00

Gnomad AFR exome AF: 0.0000616

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

Jan 20, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In silico analysis supports that this missense variant does not alter protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); Also known as 9218A>G; This variant is associated with the following publications: (PMID: 32377563, 31911673, 29884841, 29684080, 25980754, 12228710) -

Feb 09, 2018

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome Uncertain:1

Nov 19, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Y2997C variant (also known as c.8990A>G), located in coding exon 22 of the BRCA2 gene, results from an A to G substitution at nucleotide position 8990. The tyrosine at codon 2997 is replaced by cysteine, an amino acid with highly dissimilar 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 Uncertain:1

May 25, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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: 409567). This missense change has been observed in individual(s) with Lynch syndrome (PMID: 25980754). This variant is present in population databases (rs770449225, gnomAD 0.007%). This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 2997 of the BRCA2 protein (p.Tyr2997Cys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.062
BayesDel_addAF	Benign	-0.059	T
BayesDel_noAF	Benign	-0.14
CADD	Benign	13
DANN	Uncertain	0.98
Eigen	Benign	-0.88
Eigen_PC	Benign	-0.86
FATHMM_MKL	Benign	0.11	N
M_CAP	Benign	0.026	D
MetaRNN	Benign	0.098	T;T
MetaSVM	Benign	-1.0	T
PhyloP100		0.52
PrimateAI	Benign	0.24	T
PROVEAN	Benign	-1.8	N;N
REVEL	Uncertain	0.34
Sift	Benign	0.28	T;T
Sift4G	Benign	0.21	T;T
Vest4		0.30
MutPred		0.33		Loss of phosphorylation at Y2997 (P = 0.0287);Loss of phosphorylation at Y2997 (P = 0.0287);
MVP		0.76
MPC		0.032
ClinPred		0.077	T
GERP RS		-1.5
gMVP		0.28
Mutation Taster		=79/21	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs770449225; hg19: chr13-32953923;