13-32333383-T-G

Position:

• chr13-32333383-T-G

Variant summary

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

The NM_000059.4(BRCA2):​c.1905T>G​(p.Asp635Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000686 in 1,457,956 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 nucleotide change resulting in same amino acid change has been previously reported as Pathogenicin Lovd.

• 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: 0.126

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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.19053778).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.1905T>G	p.Asp635Glu	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.1905T>G	p.Asp635Glu	missense_variant	10/27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.1536T>G	p.Asp512Glu	missense_variant	10/27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.1905T>G		non_coding_transcript_exon_variant	9/26	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.86e-7 AC: 1 AN: 1457956 Hom.: 0 Cov.: 35 AF XY: 0.00 AC XY: 0 AN XY: 724880

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: 9.00e-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

Hereditary cancer-predisposing syndrome Uncertain:2 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Apr 30, 2021	This missense variant replaces aspartic acid with glutamic acid at codon 635 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 one individual affected with breast cancer (PMID: 33471991; Leiden Open Variation Database DB-ID BRCA2_007905). 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	Mar 28, 2023	The p.D635E variant (also known as c.1905T>G), located in coding exon 9 of the BRCA2 gene, results from a T to G substitution at nucleotide position 1905. The aspartic acid at codon 635 is replaced by glutamic acid, an amino acid with highly similar properties. This alteration was detected in a cohort of 149 individuals from either families with an accumulation of colorectal cancers or families with only one sporadic case of very early onset colorectal cancer (Djursby M et al. Front Genet, 2020 Sep;11:566266). This amino acid position is poorly 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	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). -

Medulloblastoma;C0346153:Familial cancer of breast;C0376358:Malignant tumor of prostate;C1838457:Fanconi anemia complementation group D1;C2675520:Breast-ovarian cancer, familial, susceptibility to, 2;C2751641:Glioma susceptibility 3;C3150546:Pancreatic cancer, susceptibility to, 2;CN033288:Wilms tumor 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Jan 13, 2022

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 27, 2023

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; Also known as 2133T>G -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 31, 2023

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: 462246). This variant has not been reported in the literature in individuals affected with BRCA2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces aspartic acid, which is acidic and polar, with glutamic acid, which is acidic and polar, at codon 635 of the BRCA2 protein (p.Asp635Glu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.20
BayesDel_addAF	Benign	-0.037	T
BayesDel_noAF	Benign	-0.29
CADD	Benign	18
DANN	Uncertain	0.99
Eigen	Benign	-0.42
Eigen_PC	Benign	-0.54
FATHMM_MKL	Benign	0.27	N
M_CAP	Uncertain	0.13	D
MetaRNN	Benign	0.19	T;T
MetaSVM	Benign	-0.91	T
PrimateAI	Benign	0.25	T
PROVEAN	Benign	-0.77	N;N
REVEL	Benign	0.14
Sift	Uncertain	0.017	D;D
Sift4G	Benign	0.092	T;T
Vest4		0.27
MutPred		0.19		Loss of catalytic residue at D635 (P = 0.035);Loss of catalytic residue at D635 (P = 0.035);
MVP		0.87
MPC		0.020
ClinPred		0.087	T
GERP RS		1.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
gMVP		0.063

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1555282154; hg19: chr13-32907520;