rs80359436

Positions:

• chr13-32338612-AG-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000059.4(BRCA2):​c.4258delG​(p.Asp1420fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000138 in 1,444,516 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: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: BRCA2 NM_000059.4 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:15
• Conservation: PhyloP100: 0.305

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 Pathogenic. Variant got 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 13-32338612-AG-A is Pathogenic according to our data. Variant chr13-32338612-AG-A is described in ClinVar as [Pathogenic]. Clinvar id is 51617.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr13-32338612-AG-A is described in Lovd as [Pathogenic]. Variant chr13-32338612-AG-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.4258delG	p.Asp1420fs	frameshift_variant	11/27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.4258delG	p.Asp1420fs	frameshift_variant	11/27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.3889delG	p.Asp1297fs	frameshift_variant	11/27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.4258delG		non_coding_transcript_exon_variant	10/26	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000819 AC: 2 AN: 244196 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 132480

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000179

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000138 AC: 2 AN: 1444516 Hom.: 0 Cov.: 35 AF XY: 0.00 AC XY: 0 AN XY: 715414

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: 0.00000182

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:15

Revision: reviewed by expert panel

Submissions by phenotype

Breast-ovarian cancer, familial, susceptibility to, 2 Pathogenic:7

Pathogenic, criteria provided, single submitter	clinical testing	Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), c/o University of Cambridge	Oct 02, 2015	- -
Pathogenic, no assertion criteria provided	clinical testing	BRCAlab, Lund University	Aug 26, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Department of Medical Genetics, Oslo University Hospital	Jul 01, 2015	- -
Pathogenic, no assertion criteria provided	clinical testing	Sharing Clinical Reports Project (SCRP)	Apr 17, 2012	- -
Likely pathogenic, criteria provided, single submitter	literature only	Counsyl	Oct 20, 2014	- -
Pathogenic, reviewed by expert panel	curation	Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA)	Sep 08, 2016	Variant allele predicted to encode a truncated non-functional protein. -
Pathogenic, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA2)	May 29, 2002	- -

not provided Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jul 05, 2017	This deletion of one nucleotide in BRCA2 is denoted c.4258delG at the cDNA level and p.Asp1420IlefsX28 (D1420IfsX28) at the protein level. The normal sequence, with the base that is deleted in brackets, is TAAAA[delG]ATTT. The deletion causes a frameshift which changes an Aspartic Acid to an Isoleucine at codon 1420, and creates a premature stop codon at position 28 of the new reading frame. This variant is predicted to cause loss of normal protein function through either protein truncation or nonsense-mediated mRNA decay. BRCA2 c.4258delG has been observed in association with breast cancer and is known to be a pathogenic founder variant in the Swedish population (Hakansson 1997, Haraldsson 1998, Loman 2001, Janavicius 2010). We consider this variant to be pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Clinical Genetics Laboratory, Skane University Hospital Lund	Sep 18, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital	Aug 15, 2023	- -

Hereditary cancer-predisposing syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Sep 13, 2023	The c.4258delG pathogenic mutation is located in coding exon 10 of the BRCA2 gene. This results from a deletion of one nucleotide at nucleotide position 4258, causing a translational frameshift with a predicted alternate stop codon (p.D1420Ifs*28). This mutation has been reported in two unrelated Scandinavian families with histories of breast, cervical, and pancreatic cancers, as well as in tumor tissue from three unrelated males diagnosed with breast cancer (Håkansson S et al. Am J Hum Genet. 1997 May;60(5):1068-78). The c.4258delG pathogenic mutation is commonly found in the Swedish population and has been reported as a Swedish founder mutation (Janaviius R. EPMA J. 2010 Sep;1(3):397-412). Of note, this mutation is also designated as 4486delG. In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -
Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Mar 09, 2022	This variant deletes 1 nucleotide in exon 11 of the BRCA2 gene, creating a frameshift and premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. This variant is a known Swedish founder mutation and has been reported in 5 individuals affected with breast cancer, including 3 male individuals, and has also been observed in unaffected individuals (PMID: 10615237, 11504767, 33471991). This variant has been identified in 19 families among the CIMBA participants (PMID: 29446198). This variant has been identified in 2/244196 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Loss of BRCA2 function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -

Hereditary breast ovarian cancer syndrome Pathogenic:2

Pathogenic, no assertion criteria provided	research	Research Molecular Genetics Laboratory, Women's College Hospital, University of Toronto	Jan 31, 2014	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jun 26, 2022	For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 51617). This variant is also known as c.4486delG. This premature translational stop signal has been observed in individual(s) with breast cancer (PMID: 9150154). This variant is present in population databases (rs80359436, gnomAD 0.002%). This sequence change creates a premature translational stop signal (p.Asp1420Ilefs*28) in the BRCA2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in BRCA2 are known to be pathogenic (PMID: 20104584). -

not specified Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Aug 06, 2018

The BRCA2 c.4258delG; p.Asp1420fs variant (rs80359436), also known as 4486delG, is reported in the literature in families with breast cancer (Hakansson 1997, Winter 2016), and is commonly found in the Swedish population (Janavicius 2010). This variant is reported as pathogenic by multiple laboratories in ClinVar (Variation ID: 51617), and is observed in the general population with a low overall allele frequency of 0.0008% (2/240284 alleles) in the Genome Aggregation Database. This variant deletes a single nucleotide causing a frameshift, and is predicted to result in a truncated protein or absent transcript. Based on the above information, this variant is considered pathogenic. REFERENCES Hakansson S et al. Moderate frequency of BRCA1 and BRCA2 germ-line mutations in Scandinavian familial breast cancer. Am J Hum Genet. 1997 May;60(5):1068-78. Janavicius R. Founder BRCA1/2 mutations in the Europe: implications for hereditary breast-ovarian cancer prevention and control. EPMA J. 2010 Sep;1(3):397-412. Winter C et al. Targeted sequencing of BRCA1 and BRCA2 across a large unselected breast cancer cohort suggests that one-third of mutations are somatic. Ann Oncol. 2016 Aug;27(8):1532-8. -

Computational scores

Source: dbNSFP v4.3

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: rs80359436; hg19: chr13-32912749;