17-43092968-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM2 PP3_Moderate BP6

The NM_007294.4(BRCA1):c.2563C>A(p.Gln855Lys) 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q855L) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:1
• Conservation: PhyloP100: 4.53

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 Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.849
• BP6: Variant 17-43092968-G-T is Benign according to our data. Variant chr17-43092968-G-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 569114.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA1	NM_007294.4	c.2563C>A	p.Gln855Lys	missense_variant	10/23	ENST00000357654.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA1	ENST00000357654.9	c.2563C>A	p.Gln855Lys	missense_variant	10/23	1	NM_007294.4	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 42

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Jun 10, 2019

The BRCA1 c.2563C>A; p.Gln855Lys variant, to our knowledge, is not reported in the medical literature or gene-specific databases. However, another variant in the same codon, p.Gln855Pro, is reported in the literature in an individual with breast cancer (Momozawa 2018). The p.Gln855Lys variant is reported in the ClinVar database (Variation ID: 569114), but is absent from general population databases (Exome Variant Server, Genome Aggregation Database), indicating it is not a common polymorphism. The amino acid at this position is highly conserved and computational analyses (SIFT, PolyPhen-2) predict that this variant is deleterious. Due to limited information, the clinical significance of the variant is uncertain at this time. References: Momozawa Y et al. Germline pathogenic variants of 11 breast cancer genes in 7,051 Japanese patients and 11,241 controls. Nat Commun. 2018 Oct 4;9(1):4083. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Feb 28, 2018

This sequence change replaces glutamine with lysine at codon 855 of the BRCA1 protein (p.Gln855Lys). The glutamine residue is highly conserved and there is a small physicochemical difference between glutamine and lysine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with 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: "Probably Damaging"; Align-GVGD: "Class C0"). 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. -

Hereditary cancer-predisposing syndrome Benign:1

Likely benign, criteria provided, single submitter

curation

University of Washington Department of Laboratory Medicine, University of Washington

Mar 23, 2023

Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Pathogenic	0.31	D
BayesDel_noAF	Pathogenic	0.20
Cadd	Uncertain	25
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.68	D;.;.;.
Eigen	Pathogenic	0.83
Eigen_PC	Pathogenic	0.75
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.95	D;D;D;D
M_CAP	Uncertain	0.21	D
MetaRNN	Pathogenic	0.85	D;D;D;D
MetaSVM	Pathogenic	0.92	D
MutationAssessor	Pathogenic	3.4	M;M;.;.
MutationTaster	Benign	0.87	D;D;D;D;D;D;D;D;D;D;D;D;D;D
PrimateAI	Benign	0.43	T
PROVEAN	Uncertain	-3.6	D;D;D;D
REVEL	Pathogenic	0.80
Sift	Pathogenic	0.0	D;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D
Polyphen		1.0	D;.;.;D
Vest4		0.77
MutPred		0.66		Gain of ubiquitination at Q855 (P = 0.0104);Gain of ubiquitination at Q855 (P = 0.0104);.;Gain of ubiquitination at Q855 (P = 0.0104);
MVP		0.96
MPC		0.51
ClinPred		1.0	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Varity_R		0.83
gMVP		0.36

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: rs80357131; hg19: chr17-41244985;