2-214809527-G-A

Position:

• chr2-214809527-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM1 PM2 BP4

The NM_000465.4(BARD1):​c.43C>T​(p.Arg15Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000209 in 1,435,926 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R15H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: BARD1 NM_000465.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.42

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 Uncertain_significance. Variant got 3 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 17 uncertain in NM_000465.4
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.26476687).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BARD1	NM_000465.4	c.43C>T	p.Arg15Cys	missense_variant	1/11	ENST00000260947.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BARD1	ENST00000260947.9	c.43C>T	p.Arg15Cys	missense_variant	1/11	1	NM_000465.4	P2

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome AF: 0.00000209 AC: 3 AN: 1435926 Hom.: 0 Cov.: 74 AF XY: 0.00000140 AC XY: 1 AN XY: 712814

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: 0.00000272

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 34

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 07, 2022

The p.R15C variant (also known as c.43C>T), located in coding exon 1 of the BARD1 gene, results from a C to T substitution at nucleotide position 43. The arginine at codon 15 is replaced by cysteine, an amino acid with highly dissimilar properties. This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Familial cancer of breast Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Apr 20, 2022

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 15 of the BARD1 protein (p.Arg15Cys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with BARD1-related conditions. ClinVar contains an entry for this variant (Variation ID: 530053). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.23
BayesDel_addAF	Benign	-0.028	T
BayesDel_noAF	Benign	-0.28
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.096	T;.;.;.;T;.;.
Eigen	Benign	-0.45
Eigen_PC	Benign	-0.34
FATHMM_MKL	Benign	0.31	N
LIST_S2	Uncertain	0.90	D;D;D;D;D;D;.
M_CAP	Pathogenic	0.80	D
MetaRNN	Benign	0.26	T;T;T;T;T;T;T
MetaSVM	Benign	-0.66	T
MutationAssessor	Benign	0.90	L;.;L;.;.;L;.
MutationTaster	Benign	0.90	D;D
PrimateAI	Uncertain	0.75	T
PROVEAN	Benign	-1.8	N;.;.;.;.;.;N
REVEL	Benign	0.15
Sift	Benign	0.16	T;.;.;.;.;.;T
Sift4G	Benign	0.23	T;D;T;D;D;T;D
Polyphen		0.029	B;.;.;.;.;.;.
Vest4		0.28
MutPred		0.32		Loss of MoRF binding (P = 0.0116);Loss of MoRF binding (P = 0.0116);Loss of MoRF binding (P = 0.0116);Loss of MoRF binding (P = 0.0116);Loss of MoRF binding (P = 0.0116);Loss of MoRF binding (P = 0.0116);Loss of MoRF binding (P = 0.0116);
MVP		0.92
MPC		0.46
ClinPred		0.86	D
GERP RS		2.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.10
gMVP		0.57

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: rs1553628470; hg19: chr2-215674251;