chr2-214809568-A-G

Position:

• chr2-214809568-A-G

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PS1_Moderate PM2

The NM_000465.4(BARD1):​c.2T>C​(p.Met1?) variant causes a start lost change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 34)
• Consequence: BARD1 NM_000465.4 start_lost
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.27

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]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Start lost variant, no new inframe start found.
• PS1: Another start lost variant in NM_000465.4 (BARD1) was described as [Pathogenic] in Lovd
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BARD1	NM_000465.4	c.2T>C	p.Met1?	start_lost	1/11	ENST00000260947.9	NP_000456.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BARD1	ENST00000260947.9	c.2T>C	p.Met1?	start_lost	1/11	1	NM_000465.4	ENSP00000260947.4

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 73

GnomAD4 genome Cov.: 34

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Quest Diagnostics Nichols Institute San Juan Capistrano

Jun 11, 2019

- -

Familial cancer of breast Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 22, 2019

This sequence change affects the initiator methionine of the BARD1 mRNA. However, another in-frame methionine that is highly conserved in mammals is located 25 codons downstream (p.Met26) and could potentially rescue the loss of initiator codon. In summary, this variant is a novel initiatior codon change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. Experimental studies have not been reported for this initiation codon variant and it is currently unknown if translation is rescued by either an in-frame or out-of-frame methionine. While this variant is not present in population databases, the frequency information is unreliable, as metrics indicate poor data quality at this position in the ExAC database. This variant has not been reported in the literature in individuals with a BARD1-related disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.32	D
BayesDel_noAF	Pathogenic	0.22
CADD	Benign	21
DANN	Benign	0.97
DEOGEN2	Benign	0.060	T;.;.;.;T;.;.
Eigen	Benign	0.13
Eigen_PC	Benign	0.13
FATHMM_MKL	Benign	0.55	D
LIST_S2	Uncertain	0.90	D;D;D;D;D;D;.
M_CAP	Pathogenic	1.0	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D;D;D
MetaSVM	Benign	-0.33	T
PROVEAN	Benign	-0.52	N;.;.;.;.;.;N
REVEL	Uncertain	0.50
Sift	Pathogenic	0.0	D;.;.;.;.;.;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D;D
Polyphen		0.90	P;.;.;.;.;.;.
Vest4		0.76
MutPred		0.98		Gain of phosphorylation at M1 (P = 0.002);Gain of phosphorylation at M1 (P = 0.002);Gain of phosphorylation at M1 (P = 0.002);Gain of phosphorylation at M1 (P = 0.002);Gain of phosphorylation at M1 (P = 0.002);Gain of phosphorylation at M1 (P = 0.002);Gain of phosphorylation at M1 (P = 0.002);
MVP		0.94
ClinPred		0.99	D
GERP RS		4.0
RBP_binding_hub_radar		0.97
RBP_regulation_power_radar		2.7
Varity_R		0.95
gMVP		0.47

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: rs1553628504; hg19: chr2-215674292;