NM_000059.4:c.1773_1776delTTAT

Variant names:

• chr13-32333245-GTTTA-G
• rs80359304
• NM_000059.4:c.1773_1776delTTAT

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000059.4(BRCA2):​c.1773_1776delTTAT​(p.Ile591MetfsTer22) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000137 in 1,459,756 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: BRCA2 NM_000059.4 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:18 U:1
• Conservation: PhyloP100: 4.59
• Publications: 18 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: Pathogenic. The variant received 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 13-32333245-GTTTA-G is Pathogenic according to our data. Variant chr13-32333245-GTTTA-G is described in ClinVar as Pathogenic. ClinVar VariationId is 51190.Status of the report is reviewed_by_expert_panel, 3 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000059.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BRCA2	NM_000059.4	MANE Select	c.1773_1776delTTAT	p.Ile591MetfsTer22	frameshift	Exon 10 of 27	NP_000050.3
	BRCA2	NM_001432077.1		c.1773_1776delTTAT	p.Ile591MetfsTer22	frameshift	Exon 10 of 27	NP_001419006.1
	BRCA2	NM_001406720.1		c.1773_1776delTTAT	p.Ile591MetfsTer22	frameshift	Exon 10 of 27	NP_001393649.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BRCA2	ENST00000380152.8	TSL:5 MANE Select	c.1773_1776delTTAT	p.Ile591MetfsTer22	frameshift	Exon 10 of 27	ENSP00000369497.3
	BRCA2	ENST00000544455.6	TSL:1	c.1773_1776delTTAT	p.Ile591MetfsTer22	frameshift	Exon 10 of 27	ENSP00000439902.1
	BRCA2	ENST00000530893.7	TSL:1	c.1404_1407delTTAT	p.Ile468MetfsTer22	frameshift	Exon 10 of 27	ENSP00000499438.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1459756 Hom.: 0 AF XY: 0.00000275 AC XY: 2 AN XY: 726206

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33376

American (AMR) AF: 0.00 AC: 0 AN: 44500

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26106

East Asian (EAS) AF: 0.00 AC: 0 AN: 39674

South Asian (SAS) AF: 0.0000233 AC: 2 AN: 85862

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53392

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1110776

Other (OTH) AF: 0.00 AC: 0 AN: 60308

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.0296732), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
7	-	-	Breast-ovarian cancer, familial, susceptibility to, 2 (7)
4	-	-	Hereditary breast ovarian cancer syndrome (4)
3	1	-	not provided (4)
2	-	-	Hereditary cancer-predisposing syndrome (2)
1	-	-	Breast-ovarian cancer, familial, susceptibility to, 1 (1)
1	-	-	Familial cancer of breast (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		4.6
Mutation Taster		=0/200	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs80359304; hg19: chr13-32907382;