13-32331009-CAA-C

Variant names:

• chr13-32331009-CAA-C
• rs75096777
• NM_000059.4:c.774_775delAA

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1 PP5_Very_Strong

The NM_000059.4(BRCA2):​c.774_775delAA​(p.Glu260SerfsTer15) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000411 in 1,459,014 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★★). Synonymous variant affecting the same amino acid position (i.e. Q258Q) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: BRCA2 NM_000059.4 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:8 U:1
• Conservation: PhyloP100: 1.20
• Publications: 6 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 16 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PP5: Variant 13-32331009-CAA-C is Pathogenic according to our data. Variant chr13-32331009-CAA-C is described in ClinVar as Pathogenic. ClinVar VariationId is 188425.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.774_775delAA	p.Glu260SerfsTer15	frameshift	Exon 9 of 27	NP_000050.3
	BRCA2	NM_001432077.1		c.774_775delAA	p.Glu260SerfsTer15	frameshift	Exon 9 of 27	NP_001419006.1
	BRCA2	NM_001406720.1		c.774_775delAA	p.Glu260SerfsTer15	frameshift	Exon 9 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.774_775delAA	p.Glu260SerfsTer15	frameshift	Exon 9 of 27	ENSP00000369497.3
	BRCA2	ENST00000544455.6	TSL:1	c.774_775delAA	p.Glu260SerfsTer15	frameshift	Exon 9 of 27	ENSP00000439902.1
	BRCA2	ENST00000530893.7	TSL:1	c.405_406delAA	p.Glu137SerfsTer15	frameshift	Exon 9 of 27	ENSP00000499438.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000411 AC: 6 AN: 1459014 Hom.: 0 AF XY: 0.00000551 AC XY: 4 AN XY: 725980

⚠️ 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: 33412

American (AMR) AF: 0.00 AC: 0 AN: 44678

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26102

East Asian (EAS) AF: 0.00 AC: 0 AN: 39660

South Asian (SAS) AF: 0.00 AC: 0 AN: 86122

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53390

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

European-Non Finnish (NFE) AF: 0.00000541 AC: 6 AN: 1109578

Other (OTH) AF: 0.00 AC: 0 AN: 60310

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.0153586), 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
2	1	-	not provided (3)
2	-	-	Breast-ovarian cancer, familial, susceptibility to, 2 (2)
2	-	-	Hereditary breast ovarian cancer syndrome (2)
1	-	-	Familial cancer of breast (1)
1	-	-	Hereditary cancer-predisposing syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.2
Mutation Taster		=0/200	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs75096777; hg19: chr13-32905146;