rs397508885

Positions:

• chr17-43093963-A-C
• chr17-43093963-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM2 PP3_Moderate BP6

The NM_007294.4(BRCA1):​c.1568T>G​(p.Leu523Trp) 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 1,461,494 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L523V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:2
• Conservation: PhyloP100: 0.346

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.851
• BP6: Variant 17-43093963-A-C is Benign according to our data. Variant chr17-43093963-A-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 54295.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=5, Likely_benign=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA1	NM_007294.4	c.1568T>G	p.Leu523Trp	missense_variant	10/23	ENST00000357654.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA1	ENST00000357654.9	c.1568T>G	p.Leu523Trp	missense_variant	10/23	1	NM_007294.4	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461494 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 726996

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Oct 31, 2023	The p.L523W variant (also known as c.1568T>G), located in coding exon 9 of the BRCA1 gene, results from a T to G substitution at nucleotide position 1568. The leucine at codon 523 is replaced by tryptophan, an amino acid with similar properties. This alteration has been described as a novel alteration of unknown significance in a familial breast cancer cohort (Frost et al. Dis Markers. 2005;21(1):29-36). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jun 22, 2023	This missense variant replaces leucine with tryptophan at codon 523 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 an individual affected with breast cancer in the literature (PMID: 15735322). 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. -
Likely benign, criteria provided, single submitter	curation	University of Washington Department of Laboratory Medicine, University of Washington	Mar 23, 2023	Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673). -

Hereditary breast ovarian cancer syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Sep 22, 2023	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. 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: 54295). This variant is also known as 1687T>G. This missense change has been observed in individual(s) with breast cancer (PMID: 15735322). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces leucine, which is neutral and non-polar, with tryptophan, which is neutral and slightly polar, at codon 523 of the BRCA1 protein (p.Leu523Trp). -
Uncertain significance, criteria provided, single submitter	clinical testing	Institute for Biomarker Research, Medical Diagnostic Laboratories, L.L.C.	Oct 03, 2023	- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Aug 09, 2019

Observed in one or more individuals with a personal history of breast cancer (Frost 2005); Not observed in large population cohorts (Lek 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Also known as BRCA1 1687T>G; This variant is associated with the following publications: (PMID: 15735322) -

Breast-ovarian cancer, familial, susceptibility to, 1 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Myriad Genetics, Inc.

Aug 17, 2023

This variant is considered likely benign. This variant is strongly associated with less severe personal and family histories of cancer, typical for individuals without pathogenic variants in this gene [PMID: 25085752]. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.19
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
CADD	Benign	22
DANN	Benign	0.96
DEOGEN2	Uncertain	0.46	T;.;.;.;T;T;.
Eigen	Uncertain	0.31
Eigen_PC	Benign	0.12
FATHMM_MKL	Benign	0.095	N
LIST_S2	Benign	0.59	T;T;T;T;T;T;T
M_CAP	Pathogenic	0.57	D
MetaRNN	Pathogenic	0.85	D;D;D;D;D;D;D
MetaSVM	Uncertain	0.20	D
MutationAssessor	Pathogenic	3.9	H;H;.;.;.;.;.
MutationTaster	Benign	1.0	N;N;N;N;N;N;N;N;N;N;N;N;N;N
PrimateAI	Benign	0.32	T
PROVEAN	Pathogenic	-5.5	D;D;D;D;.;D;D
REVEL	Uncertain	0.61
Sift	Pathogenic	0.0	D;D;D;D;.;D;D
Sift4G	Uncertain	0.0050	D;D;D;D;.;D;.
Polyphen		1.0	D;.;.;P;.;.;.
Vest4		0.60
MutPred		0.77		Loss of helix (P = 3e-04);Loss of helix (P = 3e-04);.;Loss of helix (P = 3e-04);.;Loss of helix (P = 3e-04);.;
MVP		0.97
MPC		0.57
ClinPred		0.90	D
GERP RS		2.4
Varity_R		0.42
gMVP		0.19

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: rs397508885; hg19: chr17-41245980;