13-32338434-A-T

Position:

• chr13-32338434-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP6_Moderate

The NM_000059.4(BRCA2):​c.4079A>T​(p.Asp1360Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,458,650 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely benign (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D1360G) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Likely benign criteria provided, single submitter U:1 B:1
• Conservation: PhyloP100: 1.98

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
• BP6: Variant 13-32338434-A-T is Benign according to our data. Variant chr13-32338434-A-T is described in ClinVar as [Likely_benign]. Clinvar id is 433782.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.4079A>T	p.Asp1360Val	missense_variant	11/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.4079A>T	p.Asp1360Val	missense_variant	11/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1458650 Hom.: 0 Cov.: 35 AF XY: 0.00000138 AC XY: 1 AN XY: 725250

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 Cov.: 33

ClinVar

Significance: Likely benign

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

-

The BRCA2, p.Asp1360Val variant was not identified in the literature, nor was it identified in the dbSNP, NHLBI Exome Sequencing Project (Exome Variant Server), Exome Aggregation Consortium (ExAC), LOVD, COSMIC, ClinVar, Clinvitae, BRCA Share (UMD), GeneInsight COGR, ARUP, or BIC databases. The variant was identified by our laboratory in 2 individuals with breast cancer. The variant was not observed by Myriad (personal communication). The p.Asp1360 residue is not conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein; this information is not very predictive of pathogenicity. The c.4079A>T variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) do not predict a difference in splicing. In summary, based on the above information, the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of unknown significance. -

Hereditary cancer-predisposing syndrome 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). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
BayesDel_addAF	Uncertain	0.013	T
BayesDel_noAF	Benign	-0.22
CADD	Benign	18
DANN	Uncertain	0.99
Eigen	Benign	-0.17
Eigen_PC	Benign	-0.28
FATHMM_MKL	Benign	0.70	D
M_CAP	Uncertain	0.11	D
MetaRNN	Uncertain	0.57	D;D
MetaSVM	Benign	-0.92	T
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.25	T
PROVEAN	Pathogenic	-6.3	D;D
REVEL	Benign	0.17
Sift	Uncertain	0.0010	D;D
Sift4G	Uncertain	0.031	D;D
Vest4		0.52
MutPred		0.48		Gain of sheet (P = 0.0149);Gain of sheet (P = 0.0149);
MVP		0.89
MPC		0.16
ClinPred		0.91	D
GERP RS		1.9
gMVP		0.35

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: rs730881529; hg19: chr13-32912571;