chr17-43063349-C-A

Position:

• chr17-43063349-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM1 BP4 BP6

The NM_007294.4(BRCA1):​c.5177G>T​(p.Arg1726Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000754 in 1,458,812 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000075 (0 hom.)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:2 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 0 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
• BP4: Computational evidence support a benign effect (MetaRNN=0.26771137).
• BP6: Variant 17-43063349-C-A is Benign according to our data. Variant chr17-43063349-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 187201.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=3, Likely_benign=2, not_provided=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.5177G>T	p.Arg1726Ile	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>T	p.Arg1726Ile	missense_variant	18/23	1	NM_007294.4	ENSP00000350283.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000754 AC: 11 AN: 1458812 Hom.: 0 Cov.: 30 AF XY: 0.0000110 AC XY: 8 AN XY: 726024

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000992

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:2 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Sep 25, 2023	This missense variant replaces arginine with isoleucine at codon 1726 of the BRCA1 protein. Computational prediction tools and conservation analyses are inconclusive regarding the impact of this variant on the protein function. Functional studies have reported that this variant does not impact BRCA1 function in a haploid cell proliferation assay (PMID: 30209399) and in a homology-directed DNA repair assay (PMID: 30257991). This variant has been reported in one individual affected with breast cancer and the analysis of the tumor sample showed normal allelic balance indicating the absence of loss of heterozygosity (PMID: 35039532). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). 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. -
Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	May 10, 2021	This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

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

not provided, no classification provided	in vitro	Brotman Baty Institute, University of Washington	-	- -
Likely benign, criteria provided, single submitter	curation	Lupski Lab, Baylor-Hopkins CMG, Baylor College of Medicine	Apr 12, 2024	Each variant was annotated with functional scores from MAVE data which was translated into functional evidence codes. All other evidence codes and combining criteria were adhered to as closely as possible based on the ClinGen VCEP (Variant Curation Expert Panel) gene-specific recommendations. See Supplemental Figure 34 of final paper (Supp Fig. 28 in preprint: doi:10.1101/2024.04.11.24305690) for a table to see which lines of evidence we did not have data for. The ClinGen VCEPs are highly regarded as the gold-standard for gene-specific variant curation and are developed after extensive evaluation of the evidence by clinical and scientific experts for the particular gene to classify genomic variants on a spectrum from pathogenic to benign using the 2015 ACMG/AMP Variant Interpretation Guidelines as a backbone (PMID: 25741868). Reclassification of these VUS variants from gnomAD or All of Us focused only on variants originally prescribed as VUS in ClinVar. To ensure reproducibility, transparency, and increased throughput, all the procedures for annotating variants and assigning evidence codes were codified using Python. All code has been made freely available and is linked in the Code Availability section and all reclassified variants with evidence codes used can be found in Tables S18-19 (preprint: doi:10.1101/2024.04.11.24305690). For the MAVE data, the clinical curation and clinical strength assignment as per the ClinGen recommendations in Brnich et al. (2020) (PMID: 31892348) for or against pathogenicity or benignity of each of these MAVE datasets utilized in this study were previously published in Fayer et al. (2021) (PMID: 34793697).In brief, for BRCA1 variants, if a variant was categorized as FUNC (functional), it was assigned BS3 evidence and no PS3 evidence, whereas if it was categorized as LOF (loss of function), the variant was assigned PS3 evidence and no BS3 evidence. Variants categorized as INT (intermediate) were left unannotated. For the BRCA1 combining criteria, greater than or equal to 1 criteria of strong benign evidence was enough to reclassify the VUS as Likely Benign. This variant GRCh38:17:43063349:C>A was assigned evidence codes ['BS3', 'BP4'] and an overall classification of Likely benign -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Quest Diagnostics Nichols Institute San Juan Capistrano

Nov 26, 2024

The BRCA1 c.5177G>T (p.Arg1726Ile) variant has been reported in the published literature in at least one individual with personal or family history of breast and/or ovarian cancer (PMID: 21120943 (2011)). Functional studies have indicated that this variant does not affect the homology-directed DNA repair ability of the BRCA1 protein however it may result in defective localization (PMID: 30257991 (2018), 37731132 (2023)). This variant has not been reported in large, multi-ethnic general populations (Genome Aggregation Database, http://gnomad.broadinstitute.org). Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 06, 2023

This sequence change replaces arginine, which is basic and polar, with isoleucine, which is neutral and non-polar, at codon 1726 of the BRCA1 protein (p.Arg1726Ile). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with personal and/or family history of breast and/or ovarian cancer (PMID: 21120943). ClinVar contains an entry for this variant (Variation ID: 187201). Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (PMID: 30209399) indicates that this missense variant is not expected to disrupt BRCA1 function. Experimental studies have shown that this missense change does not substantially affect BRCA1 function (PMID: 30209399, 30257991). 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	Uncertain	0.49
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.040
CADD	Benign	23
DANN	Uncertain	0.98
DEOGEN2	Benign	0.28	.;T;.;.;T;T;.;.;.;T
Eigen	Benign	-0.20
Eigen_PC	Benign	-0.19
FATHMM_MKL	Benign	0.71	D
LIST_S2	Uncertain	0.96	D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.37	D
MetaRNN	Benign	0.27	T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.34	T
MutationAssessor	Uncertain	2.0	.;M;.;.;.;.;.;.;.;.
PrimateAI	Benign	0.37	T
PROVEAN	Pathogenic	-4.5	D;N;.;D;.;.;N;D;D;D
REVEL	Uncertain	0.52
Sift	Benign	0.062	T;D;.;T;.;.;D;T;D;D
Sift4G	Uncertain	0.053	T;T;T;D;T;T;T;T;.;.
Polyphen		0.093, 0.20, 0.72	.;B;.;.;.;B;.;.;.;P
Vest4		0.56
MVP		0.82
MPC		0.19
ClinPred		0.45	T
GERP RS		3.5
Varity_R		0.36
gMVP		0.64

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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;