17-43099877-C-T

Variant names:

• chr17-43099877-C-T
• rs876658381
• NM_007294.4:c.445G>A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM2 PM5 BP4

The NM_007294.4(BRCA1):​c.445G>A​(p.Glu149Lys) 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 benign 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. E149A) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 31)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 1.95

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
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-43099876-TC-TTT is described in Lovd as [Pathogenic].
• BP4: Computational evidence support a benign effect (MetaRNN=0.30956647).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.445G>A	p.Glu149Lys	missense_variant	Exon 7 of 23	ENST00000357654.9	NP_009225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9	c.445G>A	p.Glu149Lys	missense_variant	Exon 7 of 23	1	NM_007294.4	ENSP00000350283.3

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Mar 19, 2020

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome Uncertain:1

Oct 23, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.E149K variant (also known as c.445G>A), located in coding exon 6 of the BRCA1 gene, results from a G to A substitution at nucleotide position 445. The glutamic acid at codon 149 is replaced by lysine, an amino acid with similar properties. This amino acid position is well 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. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Mar 08, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt BRCA1 protein function. This sequence change replaces glutamic acid with lysine at codon 149 of the BRCA1 protein (p.Glu149Lys). The glutamic acid residue is moderately conserved and there is a small physicochemical difference between glutamic acid 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 conditions. ClinVar contains an entry for this variant (Variation ID: 230088). 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	Benign	0.14
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.20
CADD	Benign	23
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.25	.;T;.;.;.;.;.;T;.;T;.;T;T;.;T;T
Eigen	Benign	0.084
Eigen_PC	Benign	0.12
FATHMM_MKL	Benign	0.63	D
LIST_S2	Uncertain	0.89	D;D;D;D;D;D;T;T;D;D;D;D;D;D;D;T
M_CAP	Uncertain	0.22	D
MetaRNN	Benign	0.28	T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.88	T
MutationAssessor	Uncertain	2.4	M;M;M;M;.;M;.;.;.;.;.;.;.;.;.;.
PrimateAI	Benign	0.39	T
PROVEAN	Benign	-1.8	N;N;N;N;N;N;N;N;N;N;N;.;N;N;N;N
REVEL	Uncertain	0.60
Sift	Uncertain	0.0080	D;D;D;D;D;D;T;T;D;D;D;.;D;D;D;T
Sift4G	Uncertain	0.034	D;D;D;T;D;T;.;.;T;.;D;.;D;.;D;.
Polyphen		0.92, 0.99, 1.0, 0.40	.;P;.;.;.;D;.;D;.;.;B;.;.;.;.;.
Vest4		0.35
MutPred		0.27		Gain of ubiquitination at E149 (P = 4e-04);Gain of ubiquitination at E149 (P = 4e-04);Gain of ubiquitination at E149 (P = 4e-04);Gain of ubiquitination at E149 (P = 4e-04);.;Gain of ubiquitination at E149 (P = 4e-04);.;.;.;.;Gain of ubiquitination at E149 (P = 4e-04);Gain of ubiquitination at E149 (P = 4e-04);Gain of ubiquitination at E149 (P = 4e-04);.;Gain of ubiquitination at E149 (P = 4e-04);.;
MVP		0.91
MPC		0.29
ClinPred		0.79	D
GERP RS		3.9
Varity_R		0.068
gMVP		0.47

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: rs876658381; hg19: chr17-41251894;