2-214780868-A-C

Position:

• chr2-214780868-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000465.4(BARD1):​c.1006T>G​(p.Cys336Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,814 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BARD1 NM_000465.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.134

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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.088409305).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BARD1	NM_000465.4	c.1006T>G	p.Cys336Gly	missense_variant	4/11	ENST00000260947.9	NP_000456.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BARD1	ENST00000260947.9	c.1006T>G	p.Cys336Gly	missense_variant	4/11	1	NM_000465.4	ENSP00000260947	P2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251146 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135772

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461814 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 727198

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial cancer of breast Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 24, 2016

This sequence change replaces cysteine with glycine at codon 336 of the BARD1 protein (p.Cys336Gly). The cysteine residue is highly conserved and there is a large physicochemical difference between cysteine and glycine. This variant is present in population databases (rs752869298, ExAC 0.01%) but has not been reported in the literature in individuals with a BARD1-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies. Algorithms developed to predict the effect of sequence changes on mRNA splicing suggest that this variant may alter mRNA splicing, but this prediction has not been confirmed by published transcriptional studies. In summary, this is a rare missense change with uncertain impact on protein function and mRNA splicing. There is no indication that this variant causes disease, but the evidence is insufficient at this time to prove that conclusively. Therefore, it has been classified as a Variant of Uncertain Significance. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Dec 05, 2023

This missense variant replaces cysteine with glycine at codon 336 of the BARD1 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with BARD1-related disorders in the literature. This variant has been identified in 1/251146 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.059
BayesDel_addAF	Benign	-0.16	T
BayesDel_noAF	Benign	-0.30
CADD	Benign	4.4
DANN	Benign	0.48
DEOGEN2	Benign	0.27	T;.
Eigen	Benign	-1.4
Eigen_PC	Benign	-1.5
FATHMM_MKL	Benign	0.086	N
LIST_S2	Benign	0.63	T;T
M_CAP	Benign	0.028	D
MetaRNN	Benign	0.088	T;T
MetaSVM	Benign	-0.96	T
MutationAssessor	Benign	1.7	L;.
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.24	T
PROVEAN	Benign	-1.8	N;.
REVEL	Benign	0.21
Sift	Benign	0.41	T;.
Sift4G	Benign	0.52	T;T
Polyphen		0.097	B;.
Vest4		0.52
MutPred		0.43		Loss of stability (P = 8e-04);.;
MVP		0.44
MPC		0.11
ClinPred		0.032	T
GERP RS		-6.8
Varity_R		0.079
gMVP		0.22

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: rs752869298; hg19: chr2-215645592;