rs1057518640

Positions:

• chr17-43067676-G-A
• chr17-43067676-G-C
• chr17-43067676-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_007294.4(BRCA1):​c.5006C>T​(p.Ala1669Val) 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. A1669S) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 30)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 2.58

Genes affected

BRCA1 (HGNC:1100): (BRCA1 DNA repair associated) This gene encodes a 190 kD nuclear phosphoprotein that plays a role in maintaining genomic stability, and it also acts as a tumor suppressor. The BRCA1 gene contains 22 exons spanning about 110 kb of DNA. The encoded protein combines with other tumor suppressors, DNA damage sensors, and signal transducers to form a large multi-subunit protein complex known as the BRCA1-associated genome surveillance complex (BASC). This gene product associates with RNA polymerase II, and through the C-terminal domain, also interacts with histone deacetylase complexes. This protein thus plays a role in transcription, DNA repair of double-stranded breaks, and recombination. Mutations in this gene are responsible for approximately 40% of inherited breast cancers and more than 80% of inherited breast and ovarian cancers. Alternative splicing plays a role in modulating the subcellular localization and physiological function of this gene. Many alternatively spliced transcript variants, some of which are disease-associated mutations, have been described for this gene, but the full-length natures of only some of these variants has been described. A related pseudogene, which is also located on chromosome 17, has been identified. [provided by RefSeq, May 2020]

BRCA1 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM1: In a domain BRCT 1 (size 94) in uniprot entity BRCA1_HUMAN there are 74 pathogenic changes around while only 17 benign (81%) in NM_007294.4
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.5006C>T	p.Ala1669Val	missense_variant	16/23	ENST00000357654.9	NP_009225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9	c.5006C>T	p.Ala1669Val	missense_variant	16/23	1	NM_007294.4	ENSP00000350283.3

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 30

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Sep 16, 2021	This missense variant replaces alanine with valine at codon 1669 of the BRCA1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in at least one individual affected with breast cancer (PMID: 23469205, 29868112). This variant has not been identified 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Apr 28, 2023	The p.A1669V variant (also known as c.5006C>T), located in coding exon 15 of the BRCA1 gene, results from a C to T substitution at nucleotide position 5006. The alanine at codon 1669 is replaced by valine, an amino acid with similar properties. This alteration was identified in an individual diagnosed with a triple negative breast cancer (Torrezan GT et al. Front Genet, 2018 May;9:161). This amino acid position is highly 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. -

Breast neoplasm Uncertain:1

Uncertain significance, criteria provided, single submitter

research

A.C.Camargo Cancer Center / LGBM, A.C.Camargo Cancer Center

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Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 02, 2021

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. Experimental studies have shown that this missense change does not substantially affect BRCA1 function (PMID: 30209399, 30765603). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt BRCA1 protein function. ClinVar contains an entry for this variant (Variation ID: 373827). This variant is also known as c.5125C>T. This missense change has been observed in individual(s) with breast cancer (PMID: 23469205, 29868112). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 1669 of the BRCA1 protein (p.Ala1669Val). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.41
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.11
CADD	Benign	18
DANN	Uncertain	1.0
DEOGEN2	Benign	0.14	.;T;.;.;T;.;.;.;T;.
Eigen	Uncertain	0.55
Eigen_PC	Uncertain	0.50
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Uncertain	0.90	D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.49	D
MetaRNN	Uncertain	0.64	D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.23	D
MutationAssessor	Benign	1.5	.;L;.;.;.;.;.;.;.;.
PrimateAI	Uncertain	0.50	T
PROVEAN	Uncertain	-2.7	D;N;.;D;.;N;D;D;N;D
REVEL	Uncertain	0.60
Sift	Uncertain	0.022	D;D;.;D;.;D;D;D;D;D
Sift4G	Benign	0.066	T;T;T;D;T;T;T;.;.;D
Polyphen		0.95, 1.0	.;P;.;.;.;.;.;.;D;.
Vest4		0.52
MVP		0.85
MPC		0.089
ClinPred		0.90	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.78
gMVP		0.52

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.11		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: rs1057518640; hg19: chr17-41219693;