chr2-214728894-T-A

Variant names:

• chr2-214728894-T-A
• rs149262370
• NM_000465.4:c.2116A>T

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000465.4(BARD1):​c.2116A>T​(p.Lys706*) variant causes a stop gained change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. K706K) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: BARD1 NM_000465.4 stop_gained
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 5.46
• Publications: 0 publications found

Genes affected

BARD1 (HGNC:952): (BRCA1 associated RING domain 1) This gene encodes a protein which interacts with the N-terminal region of BRCA1. In addition to its ability to bind BRCA1 in vivo and in vitro, it shares homology with the 2 most conserved regions of BRCA1: the N-terminal RING motif and the C-terminal BRCT domain. The RING motif is a cysteine-rich sequence found in a variety of proteins that regulate cell growth, including the products of tumor suppressor genes and dominant protooncogenes. This protein also contains 3 tandem ankyrin repeats. The BARD1/BRCA1 interaction is disrupted by tumorigenic amino acid substitutions in BRCA1, implying that the formation of a stable complex between these proteins may be an essential aspect of BRCA1 tumor suppression. This protein may be the target of oncogenic mutations in breast or ovarian cancer. Multiple alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2013]

BARD1 Gene-Disease associations (from GenCC):

• breast cancer

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• hereditary breast carcinoma

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen
• familial ovarian cancer

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• hereditary nonpolyposis colon cancer

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 44 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-214728894-T-A is Pathogenic according to our data. Variant chr2-214728894-T-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 1786177.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BARD1	NM_000465.4	c.2116A>T	p.Lys706*	stop_gained	Exon 11 of 11	ENST00000260947.9	NP_000456.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BARD1	ENST00000260947.9	c.2116A>T	p.Lys706*	stop_gained	Exon 11 of 11	1	NM_000465.4	ENSP00000260947.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:1

Oct 29, 2020

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.K706* variant (also known as c.2116A>T), located in coding exon 11 of the BARD1 gene, results from an A to T substitution at nucleotide position 2116. This changes the amino acid from a lysine to a stop codon within coding exon 11. Premature stop codons are typically deleterious in nature; however, this stop codon occurs at the 3' terminus of BARD1, is not expected to trigger nonsense-mediated mRNA decay, and removes only the last ~7% of the protein. The exact functional impact of these removed amino acids is unknown at this time; however, structural analysis suggests this alteration results in loss of a large part of a well-ordered C-terminal BRCT domain with destabilization of the structure, which could disrupt protein-protein interactions (Birrane G et al. Biochemistry. 2007 Jul; 46(26):7706-12; Feki A et al. Oncogene. 2005 May; 24(23):3726-36; Edwards RA et al. Biochemistry. 2008 Nov; 47(44):11446-56; Rodriguez M et al. J. Biol. Chem. 2003 Dec; 278(52):52914-8; Ambry internal data). In addition, this alteration impacts the BRCT domain of BARD1, which has been shown to be necessary for homology-directed DNA repair (Laufer M et al. J Biol Chem, 2007 Nov;282:34325-33, Adamovich AI et al. PLoS Genet, 2019 03;15:e1008049). This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.61	D
BayesDel_noAF	Pathogenic	0.63
CADD	Pathogenic	43
DANN	Uncertain	1.0
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.72
FATHMM_MKL	Uncertain	0.94	D
PhyloP100		5.5
Vest4		0.70
ClinPred		1.0	D
GERP RS		4.6
Mutation Taster		=1/199	disease causing

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: rs149262370; hg19: chr2-215593618;