17-43063349-C-G

Position:

• chr17-43063349-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_007294.4(BRCA1):​c.5177G>C​(p.Arg1726Thr) 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 (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1 O:1
• Conservation: PhyloP100: 1.21

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 2 ACMG points.

• PM1: In a domain BRCT 1 (size 94) in uniprot entity BRCA1_HUMAN there are 74 pathogenic changes around while only 17 benign (81%) in NM_007294.4
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.21039203).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.5177G>C	p.Arg1726Thr	missense_variant	18/23	ENST00000357654.9	NP_009225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9	c.5177G>C	p.Arg1726Thr	missense_variant	18/23	1	NM_007294.4	ENSP00000350283	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 13, 2022

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. Experimental studies have shown that this missense change does not substantially affect BRCA1 function (PMID: 30209399). This sequence change replaces arginine, which is basic and polar, with threonine, which is neutral and polar, at codon 1726 of the BRCA1 protein (p.Arg1726Thr). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with BRCA1-related conditions. ClinVar contains an entry for this variant (Variation ID: 531408). 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. -

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	Benign	0.26
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.030
CADD	Benign	18
DANN	Benign	0.93
DEOGEN2	Benign	0.14	.;T;.;.;T;T;.;.;.;T
Eigen	Benign	-0.27
Eigen_PC	Benign	-0.25
FATHMM_MKL	Benign	0.74	D
LIST_S2	Uncertain	0.93	D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.28	D
MetaRNN	Benign	0.21	T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.49	T
MutationAssessor	Benign	1.8	.;L;.;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	N;N;N;N;N;N;N;N;N;N;N;N;N;N
PrimateAI	Benign	0.38	T
PROVEAN	Uncertain	-3.0	D;N;.;D;.;.;N;D;D;N
REVEL	Uncertain	0.53
Sift	Benign	0.19	T;D;.;T;.;.;D;T;T;D
Sift4G	Benign	0.14	T;T;T;T;T;T;T;T;.;.
Polyphen		0.092, 0.42, 0.42	.;B;.;.;.;B;.;.;.;B
Vest4		0.56
MVP		0.83
MPC		0.15
ClinPred		0.20	T
GERP RS		3.5
Varity_R		0.27
gMVP		0.60

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: rs786203547; hg19: chr17-41215366; COSMIC: COSV58792001; COSMIC: COSV58792001;