chr17-43057075-C-T

Position:

• chr17-43057075-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP3 PP5

The NM_007294.4(BRCA1):​c.5254G>A​(p.Ala1752Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A1752S) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 31)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:3 O:1
• Conservation: PhyloP100: 3.19

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 8 ACMG points.

• PM1: In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 7 benign, 17 uncertain in NM_007294.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-43057075-C-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 55483.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.808
• PP5: Variant 17-43057075-C-T is Pathogenic according to our data. Variant chr17-43057075-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 96944.We mark this variant Likely_pathogenic, oryginal submissions are: {not_provided=1, Likely_pathogenic=2, Uncertain_significance=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA1	NM_007294.4	c.5254G>A	p.Ala1752Thr	missense_variant	19/23	ENST00000357654.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA1	ENST00000357654.9	c.5254G>A	p.Ala1752Thr	missense_variant	19/23	1	NM_007294.4	P4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:3 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:1 Uncertain:1

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Oct 01, 2023	This missense variant replaces alanine with threonine at codon 1752 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 transcription activation, homology-directed DNA repair and a haploid cell proliferation assays (PMID: 24845084, 30209399, 30257991). This variant has been reported in an individual affected with ovarian cancer who underwent testing for the BRCA1 and BRCA2 genes (PMID: 33078592, 34063308). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Although there is a suspicion that this variant may be associated with disease, additional clinical studies are necessary to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Sep 29, 2022	The p.A1752T variant (also known as c.5254G>A), located in coding exon 18 of the BRCA1 gene, results from a G to A substitution at nucleotide position 5254. The alanine at codon 1752 is replaced by threonine, an amino acid with similar properties. Multiple functional studies have show this alteration to be non-functional (Carvalho RS et al. PLoS One, 2014 May;9:e97766; Findlay GM et al. Nature, 2018 10;562:217-222; Fernandes VC et al. J Biol Chem, 2019 04;294:5980-5992; Petitalot A et al. Mol Cancer Res, 2019 01;17:54-69). This alteration has been identified in individuals diagnosed with breast and/or ovarian cancer (Ha HI et al. J Gynecol Oncol, 2020 Nov;31:e83; Park KS et al. Cancers (Basel), 2021 May;13). This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on internal structural analysis, this variant is anticipated to result in a decrease in structural stability (Ambry internal data). This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

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

not provided, no classification provided	in vitro	Brotman Baty Institute, University of Washington	-	- -
Uncertain significance, no assertion criteria provided	clinical testing	Sharing Clinical Reports Project (SCRP)	Feb 07, 2009	- -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

May 24, 2019

Not observed in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: 28781887, 30209399, 30765603, 24845084, 30257991) -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 09, 2024

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 1752 of the BRCA1 protein (p.Ala1752Thr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with ovarian cancer (PMID: 33078592). ClinVar contains an entry for this variant (Variation ID: 96944). 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: 24845084, 28781887, 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	Pathogenic	0.66
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.10
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Benign	0.35	.;T;.;.;T;T;.;.
Eigen	Uncertain	0.31
Eigen_PC	Uncertain	0.33
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Uncertain	0.97	D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.46	D
MetaRNN	Pathogenic	0.81	D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.42	D
MutationAssessor	Benign	1.9	.;L;.;.;.;.;.;.
MutationTaster	Benign	0.77	D;D;D;D;D;D;D;D;D;D;D;N;N;N
PrimateAI	Benign	0.36	T
PROVEAN	Uncertain	-2.5	N;N;.;N;.;.;N;N
REVEL	Pathogenic	0.69
Sift	Uncertain	0.0020	D;D;.;D;.;.;D;D
Sift4G	Uncertain	0.0060	D;D;D;D;D;D;D;D
Polyphen		0.67, 0.98	.;P;.;.;.;D;.;.
Vest4		0.87
MVP		0.90
MPC		0.083
ClinPred		0.89	D
GERP RS		4.1
Varity_R		0.42
gMVP		0.58

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: rs80357074; hg19: chr17-41209092;