17-43057078-G-C

Position:

• chr17-43057078-G-C

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Moderate PP5_Moderate

The ENST00000357654.9(BRCA1):​c.5251C>G​(p.Arg1751Gly) 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 Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1751Q) has been classified as Benign.

• Frequency: Genomes: not found (cov: 31)
• Consequence: BRCA1 ENST00000357654.9 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1 U:1 O:1
• Conservation: PhyloP100: 2.15

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 10 ACMG points.

• PM1: In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 9 benign, 17 uncertain in ENST00000357654.9
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-43057077-C-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 55482.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.889
• PP5: Variant 17-43057078-G-C is Pathogenic according to our data. Variant chr17-43057078-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 433728.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.5251C>G	p.Arg1751Gly	missense_variant	19/23	ENST00000357654.9	NP_009225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9	c.5251C>G	p.Arg1751Gly	missense_variant	19/23	1	NM_007294.4	ENSP00000350283	P4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Likely pathogenic

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

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary breast ovarian cancer syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 06, 2020

This variant is not present in population databases (ExAC no frequency). This sequence change replaces arginine with glycine at codon 1751 of the BRCA1 protein (p.Arg1751Gly). The arginine residue is highly conserved and there is a moderate physicochemical difference between arginine and glycine. This variant has not been reported in the literature in individuals with BRCA1-related conditions. ClinVar contains an entry for this variant (Variation ID: 433728). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. This variant disrupts the p.Arg1751 amino acid residue in BRCA1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 15172985, 15235020, 17305420, 20516115, 30765603). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. This variant has been reported to affect BRCA1 protein function (PMID: 30209399, 30765603). -

Malignant tumor of breast Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

-

The BRCA1 p.Arg1751Gly variant was not identified in the literature, nor was it identified in the dbSNP, NHLBI Exome Sequencing Project (Exome Variant Server), Exome Aggregation Consortium (ExAC), HGMD, LOVD, COSMIC, ClinVar, GeneInsight VariantWire, BIC or UMD. The p.Arg1751 residue is conserved across mammals and most other organisms, and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) suggest that the p.Arg1751Gly variant may impact the protein. However, this information is not predictive enough to assume pathogenicity. The variant occurs outside of the splicing consensus sequence and 1 of 5 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) predict a greater than 10% difference in splicing; this is not very predictive of pathogenicity. In summary, based on the above information, the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of unknown significance. -

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

not provided, no classification provided

in vitro

Brotman Baty Institute, University of Washington

-

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.55
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.36
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Benign	0.38	.;T;.;.;T;T;.;.
Eigen	Uncertain	0.22
Eigen_PC	Benign	0.20
FATHMM_MKL	Uncertain	0.79	D
LIST_S2	Uncertain	0.96	D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.60	D
MetaRNN	Pathogenic	0.89	D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.44	D
MutationAssessor	Benign	2.0	.;M;.;.;.;.;.;.
MutationTaster	Benign	0.97	D;D;D;D;D;D;D;D;D;D;D;D;N;N
PrimateAI	Benign	0.44	T
PROVEAN	Pathogenic	-5.8	D;N;.;D;.;.;N;D
REVEL	Pathogenic	0.71
Sift	Uncertain	0.0020	D;D;.;D;.;.;D;D
Sift4G	Uncertain	0.0030	D;D;D;D;D;D;D;D
Polyphen		0.32, 1.0	.;B;.;.;.;D;.;.
Vest4		0.94
MVP		0.82
MPC		0.10
ClinPred		0.89	D
GERP RS		1.6
Varity_R		0.57
gMVP		0.81

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: rs80357123; hg19: chr17-41209095;