chr17-43049178-C-T

Variant names:

• chr17-43049178-C-T
• rs587782019
• NM_007294.4:c.5349G>A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 4P and 1B. PM1 PM2 BP6

The NM_007294.4(BRCA1):​c.5349G>A​(p.Met1783Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,984 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M1783R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4 B:2
• Conservation: PhyloP100: 1.40
• Publications: 12 publications found

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]

BRCA1 Gene-Disease associations (from GenCC):

• breast-ovarian cancer, familial, susceptibility to, 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, ClinGen, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• Fanconi anemia, complementation group S

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
• pancreatic cancer, susceptibility to, 4

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• hereditary breast ovarian cancer syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Fanconi anemia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM1: In a hotspot region, there are 22 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 8 benign, 77 uncertain in NM_007294.4
• PM2: Very rare variant in population databases, with high coverage
• BP6: Variant 17-43049178-C-T is Benign according to our data. Variant chr17-43049178-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 141796.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.5349G>A	p.Met1783Ile	missense_variant	Exon 21 of 23	ENST00000357654.9	NP_009225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9	c.5349G>A	p.Met1783Ile	missense_variant	Exon 21 of 23	1	NM_007294.4	ENSP00000350283.3

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152148 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461836 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727214

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111966

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152148 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 74326

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000241 AC: 1 AN: 41430

American (AMR) AF: 0.00 AC: 0 AN: 15272

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5194

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10614

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68022

Other (OTH) AF: 0.00 AC: 0 AN: 2088

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:2

Feb 27, 2017

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: The BRCA1 c.5349G>A (p.Met1783Ile) causes a missense change involving the alteration of a non-conserved nucleotide. 2/4 in silico tools predict a benign outcome for this variant (SNPs&GO not captured due to low reliability index). This variant is absent in 121,174 control chromosomes. The variant has been reported in one affected proband in the literature, along with a likely pathogenic variant that co-segregated with disease in the family, while the variant of interest was absent in two affected individuals (Ricevuto_2001). In functional studies, the variant showed comparable activity to wild-type BRCA1 (Lee_2010). One reputable clinical lab has classified the variant as a variant of uncertain significance. Taken together, this variant has been classified as a VUS-possibly benign. -

Jan 17, 2023

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The frequency of this variant in the general population, 0.0000066 (1/152148 chromosomes, http://gnomad.broadinstitute.org), is uninformative in assessment of its pathogenicity. In the published literature, the variant was reported in a family affected with breast and ovarian cancer (PMID: 11410501 (2001)). Functional studies have shown the variant to have no protein folding defect, normal peptide binding activity and specificity, and normal transcriptional activity (PMID: 20516115 (2010), 24845084 (2014), 28781887 (2016), 29884841 (2019), 30209399 (2018)). Based on the available information, we are unable to determine the clinical significance of this variant. -

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

Sep 07, 2023

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Apr 12, 2024

Lupski Lab, Baylor-Hopkins CMG, Baylor College of Medicine

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: curation

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 GRCh38:17:43049178:C>T was assigned evidence codes ['BS3', 'BP4'] and an overall classification of Likely benign -

Hereditary breast ovarian cancer syndrome Uncertain:1

Nov 09, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 1783 of the BRCA1 protein (p.Met1783Ile). 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: 141796). 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 with a negative predictive value of 95%. Experimental studies have shown that this missense change does not substantially affect BRCA1 function (PMID: 20516115, 30209399, 30765603). 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

May 18, 2021

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.78
BayesDel_addAF	Pathogenic	0.17	D
BayesDel_noAF	Uncertain	0.010
CADD	Benign	18
DANN	Benign	0.97
DEOGEN2	Benign	0.12	.;T;.;T;T;T;.;.
Eigen	Benign	-0.31
Eigen_PC	Benign	-0.27
FATHMM_MKL	Uncertain	0.83	D
LIST_S2	Benign	0.79	T;T;T;T;T;T;T;T
M_CAP	Pathogenic	0.41	D
MetaRNN	Uncertain	0.58	D;D;D;D;D;D;D;D
MetaSVM	Uncertain	-0.20	T
MutationAssessor	Benign	1.9	.;M;.;.;.;.;.;.
PhyloP100		1.4
PrimateAI	Benign	0.48	T
PROVEAN	Uncertain	-2.7	D;N;.;.;.;.;N;D
REVEL	Uncertain	0.47
Sift	Benign	0.094	T;D;.;.;.;.;D;T
Sift4G	Uncertain	0.055	T;T;T;T;T;T;T;T
Polyphen		0.41, 0.76	.;B;.;.;.;P;.;.
Vest4		0.54
MVP		0.77
MPC		0.14
ClinPred		0.62	D
GERP RS		2.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.17
gMVP		0.77
Mutation Taster		=74/26	polymorphism

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

Other links and lift over

dbSNP: rs587782019; hg19: chr17-41201195;