chr2-214728857-T-A

Position:

• chr2-214728857-T-A

Variant summary

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

The NM_000465.4(BARD1):​c.2153A>T​(p.Asn718Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. N718S) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: BARD1 NM_000465.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.54

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 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BARD1	NM_000465.4	c.2153A>T	p.Asn718Ile	missense_variant	11/11	ENST00000260947.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BARD1	ENST00000260947.9	c.2153A>T	p.Asn718Ile	missense_variant	11/11	1	NM_000465.4	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 16, 2016

The p.N718I variant (also known as c.2153A>T), located in coding exon 11 of the BARD1 gene, results from an A to T substitution at nucleotide position 2153. The asparagine at codon 718 is replaced by isoleucine, an amino acid with dissimilar properties. This variant was not reported in population based cohorts in the following databases: Database of Single Nucleotide Polymorphisms (dbSNP), NHLBI Exome Sequencing Project (ESP), and 1000 Genomes Project. In the ESP, this variant was not observed in 6503 samples (13006 alleles) with coverage at this position. To date, this alteration has been detected with an allele frequency of approximately 0.001% (greater than 120000 alleles tested) in our clinical cohort. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.61
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.050
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Benign	0.38	T;.;.;.;T;.
Eigen	Uncertain	0.40
Eigen_PC	Uncertain	0.37
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.97	D;D;D;D;D;.
M_CAP	Uncertain	0.19	D
MetaRNN	Uncertain	0.65	D;D;D;D;D;D
MetaSVM	Uncertain	-0.076	T
MutationAssessor	Uncertain	2.2	M;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Benign	0.42	T
PROVEAN	Pathogenic	-5.2	D;.;.;.;.;.
REVEL	Uncertain	0.32
Sift	Uncertain	0.0020	D;.;.;.;.;.
Sift4G	Pathogenic	0.0010	D;D;D;D;D;D
Polyphen		1.0	D;.;.;.;.;.
Vest4		0.74
MutPred		0.44		Gain of helix (P = 0.0022);.;.;.;.;.;
MVP		0.92
MPC		0.48
ClinPred		0.99	D
GERP RS		4.7
Varity_R		0.87
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: rs773166130; hg19: chr2-215593581;