chr17-43057074-G-A

Position:

• chr17-43057074-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PM5 PP3

The NM_007294.4(BRCA1):​c.5255C>T​(p.Ala1752Val) 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 Uncertain significance (★). 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: Uncertain significance criteria provided, single submitter U:2 O:1
• Conservation: PhyloP100: 5.96

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 7 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, 0.79

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA1	NM_007294.4	c.5255C>T	p.Ala1752Val	missense_variant	19/23	ENST00000357654.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA1	ENST00000357654.9	c.5255C>T	p.Ala1752Val	missense_variant	19/23	1	NM_007294.4	P4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

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	Breast Cancer Information Core (BIC) (BRCA1)	Nov 25, 2004	- -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 31, 2020

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. This sequence change replaces alanine with valine at codon 1752 of the BRCA1 protein (p.Ala1752Val). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and valine. This variant is not present in population databases (ExAC no frequency). This variant has been reported in individuals in the Leiden Open-source Variation Database (PMID: 21520333) and Breast Cancer Information Core database (PMID: 10923033). ClinVar contains an entry for this variant (Variation ID: 55484). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. This variant has been reported to affect BRCA1 protein function (PMID: 30209399, 20516115). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.75
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.12
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.35	.;T;.;.;T;T;.;.
Eigen	Uncertain	0.54
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.97	D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.35	D
MetaRNN	Pathogenic	0.79	D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.69	D
MutationAssessor	Benign	1.9	.;L;.;.;.;.;.;.
MutationTaster	Benign	0.90	D;D;D;D;D;D;D;D;D;D;D;D;N;N
PrimateAI	Benign	0.37	T
PROVEAN	Uncertain	-3.2	D;N;.;D;.;.;N;D
REVEL	Pathogenic	0.66
Sift	Uncertain	0.0020	D;D;.;D;.;.;D;D
Sift4G	Uncertain	0.0040	D;D;D;D;D;D;D;D
Polyphen		0.81, 1.0	.;P;.;.;.;D;.;.
Vest4		0.78
MVP		0.94
MPC		0.088
ClinPred		0.93	D
GERP RS		5.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.49
gMVP		0.70

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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: rs80357028; hg19: chr17-41209091;