17-43051069-G-T

Variant names:

• chr17-43051069-G-T
• rs1800757
• NM_007294.4:c.5326C>A

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_007294.4(BRCA1):​c.5326C>A​(p.Pro1776Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1 O:1
• Conservation: PhyloP100: 1.19

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 4 ACMG points.

• PM1: In a domain BRCT 2 (size 99) in uniprot entity BRCA1_HUMAN there are 69 pathogenic changes around while only 15 benign (82%) in NM_007294.4
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.5326C>A	p.Pro1776Thr	missense_variant	Exon 20 of 23	ENST00000357654.9	NP_009225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9	c.5326C>A	p.Pro1776Thr	missense_variant	Exon 20 of 23	1	NM_007294.4	ENSP00000350283.3

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

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

Apr 28, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Advanced modeling of experimental studies (such as gene expression, population dynamics, functional pathways, and cell-cycle effects in cell culture) performed at Invitae indicates that this missense variant is not expected to disrupt BRCA1 protein function. ClinVar contains an entry for this variant (Variation ID: 865307). This variant has not been reported in the literature in individuals affected with BRCA1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces proline, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 1776 of the BRCA1 protein (p.Pro1776Thr). Experimental studies have shown that this missense change does not substantially affect BRCA1 function (PMID: 30209399). 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. -

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

-

Brotman Baty Institute, University of Washington

Significance: not provided

Review Status: no classification provided

Collection Method: in vitro

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Pathogenic	0.33	D
BayesDel_noAF	Pathogenic	0.23
CADD	Benign	17
DANN	Benign	0.28
DEOGEN2	Benign	0.14	.;T;.;.;T;T;.;.
Eigen	Benign	0.14
Eigen_PC	Benign	0.19
FATHMM_MKL	Benign	0.75	D
LIST_S2	Uncertain	0.87	D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.49	D
MetaRNN	Uncertain	0.43	T;T;T;T;T;T;T;T
MetaSVM	Uncertain	0.051	D
MutationAssessor	Benign	1.7	.;L;.;.;.;.;.;.
PrimateAI	Benign	0.46	T
PROVEAN	Benign	-1.7	N;N;.;N;.;.;N;N
REVEL	Uncertain	0.48
Sift	Benign	0.55	T;D;.;T;.;.;D;T
Sift4G	Benign	0.96	T;T;T;T;T;T;T;T
Polyphen		0.67, 0.0050	.;P;.;.;.;B;.;.
Vest4		0.43
MVP		0.81
MPC		0.39
ClinPred		0.67	D
GERP RS		3.2
RBP_binding_hub_radar		0.92
RBP_regulation_power_radar		2.7
Varity_R		0.35
gMVP		0.33

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: rs1800757; hg19: chr17-41203086;