chr17-43049156-C-A

Position:

• chr17-43049156-C-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_007294.4(BRCA1):​c.5371G>T​(p.Val1791Leu) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,888 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 nucleotide change resulting in same amino acid change has been previously reported as Uncertain significancein ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V1791A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:1 O:1
• Conservation: PhyloP100: 4.31

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 Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 8 benign, 17 uncertain in NM_007294.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.842

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA1	NM_007294.4	c.5371G>T	p.Val1791Leu	missense_variant	21/23	ENST00000357654.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA1	ENST00000357654.9	c.5371G>T	p.Val1791Leu	missense_variant	21/23	1	NM_007294.4	P4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251456 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135894

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461888 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727246

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5 Benign:1 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:3 Other:1

not provided, no classification provided	in vitro	Brotman Baty Institute, University of Washington	-	- -
Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Dec 13, 2023	This missense variant replaces valine with leucine at codon 1791 of the BRCA1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function. A functional study reported that this variant does not impact BRCA1 function in a haploid human cell proliferation assay (PMID: 30209399). This variant has been described in at least one individual each affected with breast or ovarian cancer (PMID: 25948282, 26845104) and it also has been detected in a breast cancer case-control meta-analysis in 1/60466 cases and 1/53461 unaffected individuals (PMID: 33471991; Leiden Open Variation Database DB-ID BRCA1_006151). This variant has been identified in 1/251456 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	University of Washington Department of Laboratory Medicine, University of Washington	Nov 20, 2015	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Institute of Human Genetics, University of Leipzig Medical Center	Jan 01, 2019	- -

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Dec 07, 2021	This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Nov 16, 2023	This missense variant replaces valine with leucine at codon 1791 of the BRCA1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function. A functional study reported that this variant does not impact BRCA1 function in a haploid human cell proliferation assay (PMID: 30209399). This variant has been described in at least one individual each affected with breast or ovarian cancer (PMID: 25948282, 26845104) and it also has been detected in a breast cancer case-control meta-analysis in 1/60466 cases and 1/53461 unaffected individuals (PMID: 33471991; Leiden Open Variation Database DB-ID BRCA1_006151). This variant has been identified in 1/251456 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. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 05, 2023

This sequence change replaces valine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 1791 of the BRCA1 protein (p.Val1791Leu). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with hereditary breast and/or ovarian cancer (PMID: 25948282, 26845104). ClinVar contains an entry for this variant (Variation ID: 142002). Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (PMID: 30209399) indicates that this missense variant is not expected to disrupt BRCA1 function with a negative predictive value of 95%. Experimental studies have shown that this missense change does not substantially affect BRCA1 function (PMID: 30209399, 30257991). 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	Uncertain	0.41
BayesDel_addAF	Pathogenic	0.29	D
BayesDel_noAF	Pathogenic	0.18
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Benign	0.13	.;T;.;T;T;T;.;.
Eigen	Uncertain	0.58
Eigen_PC	Uncertain	0.60
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.91	D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.58	D
MetaRNN	Pathogenic	0.84	D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.70	D
MutationAssessor	Benign	1.9	.;L;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D;D;D;N;N
PrimateAI	Uncertain	0.59	T
PROVEAN	Uncertain	-2.4	N;N;.;.;.;.;N;N
REVEL	Uncertain	0.64
Sift	Uncertain	0.0050	D;D;.;.;.;.;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D;D;D
Polyphen		0.055, 0.36	.;B;.;.;.;B;.;.
Vest4		0.77
MVP		0.98
MPC		0.11
ClinPred		0.94	D
GERP RS		5.4
Varity_R		0.70
gMVP		0.59

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: rs145758886; hg19: chr17-41201173; COSMIC: COSV105177659;