17-43051104-A-G

Position:

• chr17-43051104-A-G

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM1 PM2 PP3_Moderate PP5_Very_Strong

The NM_007294.4(BRCA1):​c.5291T>C​(p.Leu1764Pro) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L1764Q) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 31)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:10 U:1 O:1
• Conservation: PhyloP100: 5.03

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 Pathogenic. Variant got 14 ACMG points.

• PM1: In a hotspot region, there are 4 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, 0.917
• PP5: Variant 17-43051104-A-G is Pathogenic according to our data. Variant chr17-43051104-A-G is described in ClinVar as [Pathogenic]. Clinvar id is 55510.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr17-43051104-A-G is described in Lovd as [Pathogenic]. Variant chr17-43051104-A-G is described in Lovd as [Pathogenic]. Variant chr17-43051104-A-G is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA1	NM_007294.4	c.5291T>C	p.Leu1764Pro	missense_variant	20/23	ENST00000357654.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA1	ENST00000357654.9	c.5291T>C	p.Leu1764Pro	missense_variant	20/23	1	NM_007294.4	P4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:10 Uncertain:1 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

Breast-ovarian cancer, familial, susceptibility to, 1 Pathogenic:5 Uncertain:1 Other:1

Pathogenic, criteria provided, single submitter	clinical testing	Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), c/o University of Cambridge	Oct 02, 2015	- -
Pathogenic, reviewed by expert panel	curation	Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA)	Aug 10, 2015	IARC class based on posterior probability from multifactorial likelihood analysis, thresholds for class as per Plon et al. 2008 (PMID: 18951446). Class 5 based on posterior probability = 0.99 -
Pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Feb 14, 2018	- -
Uncertain significance, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA1)	Feb 20, 2004	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Mar 28, 2024	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Aug 08, 2023	This missense variant replaces leucine with proline at codon 1764 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). Functional studies have reported that this variant impacts BRCA1 function in homology-directed DNA repair, transcription activation, haploid cell proliferation and additional assays (PMID: 30257991, 30209399, 29884841, 27272900, 23867111, 20516115, 20378548, 17308087). This variant has been reported in at least three individuals affected with breast and/or ovarian cancer and in several suspected hereditary breast and ovarian cancer families (PMID: 18824701, 29446198, 30257646, 31076742). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Based on the available evidence, this variant is classified as Likely Pathogenic. -
not provided, no classification provided	in vitro	Brotman Baty Institute, University of Washington	-	- -

not provided Pathogenic:2

Pathogenic, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Pathogenic, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -

Hereditary breast ovarian cancer syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Nov 02, 2023	This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 1764 of the BRCA1 protein (p.Leu1764Pro). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with a personal and/or family history of breast and/or ovarian cancer (PMID: 18824701, 26022348, 29446198, 30257646; Invitae). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 55510). Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (PMID: 30209399) indicates that this missense variant is expected to disrupt BRCA1 function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects BRCA1 function (PMID: 17305420, 17308087, 20378548, 20516115, 23867111, 27272900, 30209399). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jan 31, 2017	Variant summary: The BRCA1 c.5291T>C (p.Leu1764Pro) variant located in the BRCT domain (via InterPro) involves the alteration of a conserved nucleotide, which 5/5 in silico tools predict a damaging outcome. Multiple functional studies have been performed that support these predictions. The variant of interest has not been observed in controls (ExAC, 1000 Gs, or ESP) and has been reported in multiple affected individuals via publications and databases. The variant of interest has been indicated to cause fold destabilization. In addition, multiple clinical diagnostic laboratories/reputable databases classified this variant as pathogenic. Taken together, this variant is classified as pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 17, 2024

The p.L1764P variant (also known as c.5291T>C), located in coding exon 19 of the BRCA1 gene, results from a T to C substitution at nucleotide position 5291. The leucine at codon 1764 is replaced by proline, an amino acid with similar properties. The Leu1764 residue is deeply buried in the hydrophobic core of the highly conserved BRCT domain and as such, thermodynamic stability assays indicate that p.L1764P has a destabilizing effect (Rowling PJ et al. J Biol Chem. 2010 Jun; 285(26):20080-7). Functional studies including c-DNA complementation, homologous recombination, yeast-based assays, nuclear localization and solubility assays, and transcription activation assays have all demonstrated deficient function (Carvalho MA et al. Cancer Res. 2007 Feb; 67(4):1494-501; Bouwman P et al. Cancer Discov. 2013 Oct; 3(10):1142-55; Lee MS et al. Cancer Res. 2010 Jun 15;70(12):4880-90; Woods NT et al. NPJ Genom Med 2016 Mar;1; Petitalot A et al. Mol. Cancer Res. 2019 01;17(1):54-69). One functional study found that this nucleotide substitution is deleterious in a high throughput genome editing haploid cell survival assay (Findlay GM et al. Nature. 2018 10;562(7726):217-222). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.92
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Benign	0.39	.;T;.;.;T;T;.;.
Eigen	Uncertain	0.59
Eigen_PC	Uncertain	0.57
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Uncertain	0.90	D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.85	D
MetaRNN	Pathogenic	0.92	D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.63	D
MutationAssessor	Uncertain	2.3	.;M;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.55	T
PROVEAN	Pathogenic	-4.4	D;N;.;D;.;.;N;D
REVEL	Pathogenic	0.68
Sift	Uncertain	0.0010	D;D;.;D;.;.;D;D
Sift4G	Uncertain	0.0040	D;D;D;D;D;D;D;D
Polyphen		1.0, 1.0	.;D;.;.;.;D;.;.
Vest4		0.91
MVP		0.99
MPC		0.57
ClinPred		0.99	D
GERP RS		5.1
Varity_R		0.89
gMVP		0.83

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: rs80357281; hg19: chr17-41203121;