17-43104928-G-C

Position:

• chr17-43104928-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_007294.4(BRCA1):​c.241C>G​(p.Gln81Glu) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3 O:1
• Conservation: PhyloP100: 4.24

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]

BRCA1 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.241C>G	p.Gln81Glu	missense_variant	5/23	ENST00000357654.9	NP_009225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9	c.241C>G	p.Gln81Glu	missense_variant	5/23	1	NM_007294.4	ENSP00000350283.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Aug 05, 2021	The p.Q81E variant (also known as c.241C>G), located in coding exon 4 of the BRCA1 gene, results from a C to G substitution at nucleotide position 241. The glutamine at codon 81 is replaced by glutamic acid, an amino acid with highly similar properties. This alteration was partially functional in a high-throughput, genome editing, haploid cell survival assay but showed wild-type like function in other assays (Findlay GM et al. Nature, 2018 10;562:217-222; Starita LM et al. Am J Hum Genet, 2018 10;103:498-508). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Dec 11, 2019	This missense variant replaces glutamine with glutamic acid at codon 81 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). Splice site prediction tools suggest that this variant may not impact RNA splicing. Functional assays showed that this variant is functional in a homology-directed DNA repair HDR assay (PMID: 30219179). Additionally, this variant has been reported to be intermediate functional in a haploid cell proliferation assay (PMID: 30209399). This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has not been identified 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

Jan 22, 2017

This sequence change replaces glutamine with glutamic acid at codon 81 of the BRCA1 protein (p.Gln81Glu). The glutamine residue is moderately conserved and there is a small physicochemical difference between glutamine and glutamic acid. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a BRCA1-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. -

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

not provided, no classification provided

in vitro

Brotman Baty Institute, University of Washington

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Pathogenic	0.31	D
BayesDel_noAF	Pathogenic	0.21
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Benign	0.32	.;T;.;.;.;.;T;.;.;T;T;.;T;T;.;.
Eigen	Uncertain	0.48
Eigen_PC	Uncertain	0.47
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.95	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.54	D
MetaRNN	Uncertain	0.54	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Uncertain	2.5	M;M;M;M;.;M;.;.;.;.;.;.;.;.;.;.
PrimateAI	Uncertain	0.50	T
PROVEAN	Benign	-0.84	N;N;N;N;N;N;N;N;N;.;N;N;N;N;N;.
REVEL	Uncertain	0.63
Sift	Benign	0.37	T;D;D;T;D;T;T;D;D;.;D;D;D;T;D;.
Sift4G	Uncertain	0.024	D;D;D;T;D;T;.;T;D;.;D;.;D;.;.;.
Polyphen		0.80, 0.92, 0.95	.;P;.;.;.;P;.;.;P;.;.;.;.;.;.;.
Vest4		0.64
MutPred		0.36		Gain of helix (P = 0.0425);Gain of helix (P = 0.0425);Gain of helix (P = 0.0425);Gain of helix (P = 0.0425);.;Gain of helix (P = 0.0425);Gain of helix (P = 0.0425);.;Gain of helix (P = 0.0425);Gain of helix (P = 0.0425);Gain of helix (P = 0.0425);.;Gain of helix (P = 0.0425);Gain of helix (P = 0.0425);.;.;
MVP		0.93
MPC		0.28
ClinPred		0.95	D
GERP RS		4.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.47
gMVP		0.32

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs80357350; hg19: chr17-41256945; COSMIC: COSV58785539; COSMIC: COSV58785539;