Genetic Variant BRCA2:p.Lys1323* (chr13-32338322-A-T) – ACMG Classification: Pathogenic (18 pts)

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000059.4(BRCA2):c.3967A>T(p.Lys1323*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,232 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★★). Synonymous variant affecting the same amino acid position (i.e. K1323K) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Consequence

BRCA2
NM_000059.4 stop_gained

Scores

Clinical Significance

Pathogenic reviewed by expert panel P:11

Conservation

PhyloP100: 0.705

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

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 13-32338322-A-T is Pathogenic according to our data. Variant chr13-32338322-A-T is described in ClinVar as [Pathogenic]. Clinvar id is 51577.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr13-32338322-A-T is described in Lovd as [Pathogenic]. Variant chr13-32338322-A-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA2	NM_000059.4 link	c.3967A>T	p.Lys1323*	stop_gained	Exon 11 of 27	ENST00000380152.8	NP_000050.3	P51587

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
BRCA2	ENST00000380152.8 link	c.3967A>T	p.Lys1323*	stop_gained	Exon 11 of 27	5	NM_000059.4	ENSP00000369497.3	P51587
BRCA2	ENST00000530893.7 link	c.3598A>T	p.Lys1200*	stop_gained	Exon 11 of 27	1		ENSP00000499438.2	A0A590UJI7
BRCA2	ENST00000614259.2 link	n.3967A>T		non_coding_transcript_exon_variant	Exon 10 of 26	2		ENSP00000506251.1	A0A7P0TAP7

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152232

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

Cov.:

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152232

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74370

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:11

Revision: reviewed by expert panel

LINK: link

Submissions by phenotype

Breast-ovarian cancer, familial, susceptibility to, 2

Pathogenic:4

Oct 02, 2015

Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), c/o University of Cambridge

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Sep 08, 2016

Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA)

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

Variant allele predicted to encode a truncated non-functional protein. -

Apr 12, 1999

Breast Cancer Information Core (BIC) (BRCA2)

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Nov 29, 2016

Counsyl

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided

Pathogenic:2

Jan 04, 2018

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This nonsense variant causes the premature termination of BRCA2 protein synthesis. The frequency of this variant in the general population, 0.0000066 (1/152232 chromosomes, http://gnomad.broadinstitute.org), is consistent with pathogenicity. In the published literature, the variant has been reported in individuals (PMID: 16912212 (2006)) and families (PMID: 31409081 (2019)) affected with breast/ovarian cancer, as well as in a family affected with pancreatic cancer (PMID: 25356972 (2015)). Based on the available information, this variant is classified as pathogenic. -

Dec 06, 2022

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Observed in individuals with breast cancer or familial pancreatic cancer (Malone 2006, Zhen 2014); Truncating variants in this gene are considered pathogenic by a well-established clinical consortium and/or database; Not observed in large population cohorts (gnomAD); Also known as 4195A>T; This variant is associated with the following publications: (PMID: 25356972, 16912212, 28152038, 29446198, 31409081, 30702160, 30322717) -

Hereditary breast ovarian cancer syndrome

Pathogenic:2

Jun 04, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Lys1323*) 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). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with pancreatic cancer (PMID: 25356972). This variant is also known as 4195A>T. ClinVar contains an entry for this variant (Variation ID: 51577). For these reasons, this variant has been classified as Pathogenic. -

Oct 04, 2023

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: BRCA2 c.3967A>T (p.Lys1323X) results in a premature termination codon, predicted to cause absence of the protein due to nonsense mediated decay, which is a commonly known mechanism for disease. The variant was absent in 229776 control chromosomes (gnomAD). c.3967A>T has been reported in the literature in individuals with personal and/or family history of Hereditary Breast and Ovarian Cancer, as well as pancreatic cancer (Rebbeck_2018, Zhen_2014, Malone_2006). These data indicate that the variant is likely to be associated with disease. Seven submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

BRCA2-related cancer predisposition

Pathogenic:1

Sep 12, 2024

All of Us Research Program, National Institutes of Health

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.3967A>T variant in the BRCA2 gene is located on the exon 11 and introduces a premature translation termination codon (p.Lys1323*), resulting in an absent or disrupted protein product. The variant has been reported in individuals with hereditary breast and ovarian cancer or pancreatic cancer (PMID: 31409081, 25356972). The other protein termination codon variants located in the same exon (p.Ser1404*, p.Gln2160*, p.Cys2256*) have been interpreted as pathogenic (ClinVar ID: 91815, 266950, 52180). Loss-of-function variants in the BRCA2 gene are known to cause hereditary breast and ovarian cancer (PMID: 8988179, 11897832, 29446198). This variant has been reported in ClinVar as pathogenic by the expert panel (ID: 51577). The variant is rare in general population according to gnomAD (1/1587958 chromosomes (v4.1)). Therefore, the c.3967A>T (p.Lys1323*) variant in the BRCA2 gene has been classified as pathogenic. -

Familial cancer of breast

Pathogenic:1

Jan 22, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome

Pathogenic:1

Mar 07, 2023

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.K1323* pathogenic mutation (also known as c.3967A>T), located in coding exon 10 of the BRCA2 gene, results from an A to T substitution at nucleotide position 3967. This changes the amino acid from a lysine to a stop codon within coding exon 10. This pathogenic mutation [designated as K1323X (4195A>T)] has been detected in at least one family diagnosed with familial pancreatic cancer (Zhen DB et al. Genet. Med. 2015 Jul;17:569-77). 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.36

BayesDel_noAF

Pathogenic

0.27

CADD

Pathogenic

DANN

Uncertain

0.98

Eigen

Benign

-0.078

Eigen_PC

Benign

-0.42

FATHMM_MKL

Benign

0.38

Vest4

0.80

GERP RS

-1.8

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over