chr13-32370955-G-A

Variant names:

• chr13-32370955-G-A
• rs397507404
• NM_000059.4:c.8488-1G>A

Variant summary

Our verdict is Pathogenic. The variant received 22 ACMG points: 22P and 0B. PVS1 PS3 PM2 PP5_Very_Strong

The NM_000059.4(BRCA2):​c.8488-1G>A variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,766 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★★). ClinVar reports functional evidence for this variant: "SCV000278235: Results from various functional splicing assays performed on this alteration demonstrated that this mutation results in three to five different abnormally spliced transcripts, which includes production of an abnormal transcript that loses 12 nucleotides of exon 20, a transcript that retains intron 19, and another transcript with exon 20 skipping (Acedo et al. Breast Cancer Res. 2012 May; 25:14(3):R87; Santos C et al. J. Mol. Diagn. 2014 May;16(3):324-34; Acedo et al Hum. Mutat. 2015 Feb;36(2):210-21; Ambry internal data).; SCV000683971: Functional studies have shown that the mutant protein results in a decreased number of cells with RAD51 foci and reduced focus size, confers a moderate defect in homologous recombination, and disrupts replication fork protection function (PMID:32354836).; SCV000283345: Studies have shown that this variant is associated with altered splicing resulting in multiple RNA products ( PMID:22632462, 24607278, 25382762; internal data).; SCV000916934: Several publications report experimental evidence evaluating an impact on protein function, indicating that the variant impairs protein function (e.g. Howlett_2002, Godthelp_2006).; SCV005045709: Experimental RNA analysis in patient lymphocytes and minigene assay have shown that this variant may cause aberrant transcripts (PMID:22632462, 12065746, 24607278).; SCV004822645: Functional studies have shown that the mutant protein results in a decreased number of cells with RAD51 foci and reduced focus size, confers a moderate defect in homologous recombination, and disrupts replication fork protection function (PMID:32354836).".

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: BRCA2 NM_000059.4 splice_acceptor, intron
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Pathogenic reviewed by expert panel P:28 U:1
• Conservation: PhyloP100: 9.32
• Publications: 32 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):

• BRCA2-related cancer predisposition

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• breast-ovarian cancer, familial, susceptibility to, 2

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

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
• 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 22 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PS3: PS3 evidence extracted from ClinVar submissions: SCV000278235: Results from various functional splicing assays performed on this alteration demonstrated that this mutation results in three to five different abnormally spliced transcripts, which includes production of an abnormal transcript that loses 12 nucleotides of exon 20, a transcript that retains intron 19, and another transcript with exon 20 skipping (Acedo et al. Breast Cancer Res. 2012 May; 25:14(3):R87; Santos C et al. J. Mol. Diagn. 2014 May;16(3):324-34; Acedo et al Hum. Mutat. 2015 Feb;36(2):210-21; Ambry internal data).; SCV000683971: Functional studies have shown that the mutant protein results in a decreased number of cells with RAD51 foci and reduced focus size, confers a moderate defect in homologous recombination, and disrupts replication fork protection function (PMID: 32354836).; SCV000283345: Studies have shown that this variant is associated with altered splicing resulting in multiple RNA products ( PMID: 22632462, 24607278, 25382762; internal data).; SCV000916934: Several publications report experimental evidence evaluating an impact on protein function, indicating that the variant impairs protein function (e.g. Howlett_2002, Godthelp_2006).; SCV005045709: Experimental RNA analysis in patient lymphocytes and minigene assay have shown that this variant may cause aberrant transcripts (PMID: 22632462, 12065746, 24607278).; SCV004822645: Functional studies have shown that the mutant protein results in a decreased number of cells with RAD51 foci and reduced focus size, confers a moderate defect in homologous recombination, and disrupts replication fork protection function (PMID: 32354836).
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 13-32370955-G-A is Pathogenic according to our data. Variant chr13-32370955-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 38164.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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BRCA2	NM_000059.4	MANE Select	c.8488-1G>A		splice_acceptor intron	N/A	NP_000050.3	A0A7P0T9D7
	BRCA2	NM_001432077.1		c.8488-1G>A		splice_acceptor intron	N/A	NP_001419006.1	A0A7P0T9D7
	BRCA2	NM_001406720.1		c.8488-1G>A		splice_acceptor intron	N/A	NP_001393649.1	A0A8V8TPZ2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BRCA2	ENST00000380152.8	TSL:5 MANE Select	c.8488-1G>A		splice_acceptor intron	N/A	ENSP00000369497.3	P51587
	BRCA2	ENST00000544455.6	TSL:1	c.8488-1G>A		splice_acceptor intron	N/A	ENSP00000439902.1	P51587
	BRCA2	ENST00000530893.7	TSL:1	c.8119-1G>A		splice_acceptor intron	N/A	ENSP00000499438.2	A0A590UJI7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461766 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727186

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.0000447 AC: 2 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39680

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53394

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111946

Other (OTH) AF: 0.00 AC: 0 AN: 60390

GnomAD4 genome Cov.: 32

Alfa AF: 0.00000563 Hom.: 0

Bravo AF: 0.00000756

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
10	-	-	Breast-ovarian cancer, familial, susceptibility to, 2 (10)
5	-	-	Hereditary breast ovarian cancer syndrome (5)
5	-	-	not provided (5)
2	-	-	Hereditary cancer-predisposing syndrome (2)
1	-	-	BRCA2-related cancer predisposition (1)
1	-	-	BRCA2-related disorder (1)
1	-	-	Familial cancer of breast (1)
1	-	-	Fanconi anemia complementation group D1 (1)
1	-	-	Gastric cancer (1)
-	1	-	Inherited breast cancer and ovarian cancer (1)
1	-	-	Medulloblastoma;C0346153:Familial cancer of breast;C0376358:Prostate cancer;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 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
CADD	Pathogenic	34
DANN	Uncertain	0.99
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		9.3
GERP RS		5.1
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.89
Splicevardb		3.0
SpliceAI score (max)		0.92		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.37		Position offset: 13
DS_AL_spliceai		0.92		Position offset: 1

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

Other links and lift over

dbSNP: rs397507404; hg19: chr13-32945092; COSMIC: COSV104430719;