NM_007294.4:c.67G>C

Variant names:

• chr17-43124030-C-G
• rs372047427
• NM_007294.4:c.67G>C

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.67G>C​(p.Glu23Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,784 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E23V) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:2
• Conservation: PhyloP100: 3.52
• Publications: 16 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 20 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 14 benign, 74 uncertain in NM_007294.4
• PM2: Very rare variant in population databases, with high coverage
• BP6: Variant 17-43124030-C-G is Benign according to our data. Variant chr17-43124030-C-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 441390.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_007294.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BRCA1	NM_007294.4	MANE Select	c.67G>C	p.Glu23Gln	missense	Exon 2 of 23	NP_009225.1
	BRCA1	NM_001407581.1		c.67G>C	p.Glu23Gln	missense	Exon 2 of 24	NP_001394510.1
	BRCA1	NM_001407582.1		c.67G>C	p.Glu23Gln	missense	Exon 2 of 24	NP_001394511.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BRCA1	ENST00000357654.9	TSL:1 MANE Select	c.67G>C	p.Glu23Gln	missense	Exon 2 of 23	ENSP00000350283.3
	BRCA1	ENST00000471181.7	TSL:1	c.67G>C	p.Glu23Gln	missense	Exon 2 of 24	ENSP00000418960.2
	BRCA1	ENST00000470026.6	TSL:1	c.67G>C	p.Glu23Gln	missense	Exon 2 of 23	ENSP00000419274.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000399 AC: 1 AN: 250924 AF XY: 0.00000737

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000882

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460784 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726790

African (AFR) AF: 0.00 AC: 0 AN: 33460

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26114

East Asian (EAS) AF: 0.00 AC: 0 AN: 39646

South Asian (SAS) AF: 0.00 AC: 0 AN: 86234

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53412

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111104

Other (OTH) AF: 0.00 AC: 0 AN: 60334

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:2 Benign:1

May 04, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces glutamic acid with glutamine at codon 23 of the BRCA1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). This variant has been reported to be functional in a haploid cell proliferation assay (PMID: 30209399). This variant has been reported in individuals and families affected with breast and/or ovarian cancer (PMID: 21918854, 32380732, 32856854). This variant has been identified in 1/250924 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The 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.

Mar 02, 2020

BRCAlab, Lund University

Significance: Uncertain significance

Review Status: no assertion criteria provided

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 GRCh38:17:43124030:C>G was assigned evidence codes ['BS3', 'BP4'] and an overall classification of Likely benign

not specified Uncertain:1

Nov 25, 2020

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: BRCA1 c.67G>C (p.Glu23Gln) results in a conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 250924 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.67G>C has been reported in the literature in individuals with a personal or family history of breast and/or ovarian cancer (Keshavarzi_2012, Chowdhury_2020, Incorvaia_2020). These reports do not provide unequivocal conclusions about association of the variant with Hereditary Breast and Ovarian Cancer Syndrome. An in vitro study that assessed the effect of the variant in a haploid human cell line whose survival is dependent on intact BRCA1 function, demonstrated no damaging effect of this variant (Findlay 2018). Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation, and both of them classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance.

not provided Uncertain:1

Nov 20, 2024

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The BRCA1 c.67G>C (p.Glu23Gln) variant has been reported in the published literature in individuals with breast and/or ovarian cancer (PMIDs: 21918854 (2012), 26109977 (2015), 32380732 (2020), and 32856854 (2020)). A functional study demonstrated that this variant retained functional activity in a large-scale study using a haploid cell line (PMID: 30209399 (2018)). The frequency of this variant in the general population, 0.000004 (1/250924 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. 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

Jul 24, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamic acid, which is acidic and polar, with glutamine, which is neutral and polar, at codon 23 of the BRCA1 protein (p.Glu23Gln). This variant is present in population databases (rs372047427, gnomAD 0.0009%). This missense change has been observed in individual(s) with breast cancer and/or ovarian cancer (PMID: 21918854, 32380732, 32856854). ClinVar contains an entry for this variant (Variation ID: 441390). 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 are conflicting or provide insufficient evidence to determine the effect of this variant on BRCA1 function (PMID: 25823446, 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.

Hereditary cancer-predisposing syndrome Benign:1

Dec 31, 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 v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.61
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Uncertain	0.060
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.32	T
Eigen	Uncertain	0.30
Eigen_PC	Uncertain	0.31
FATHMM_MKL	Uncertain	0.84	D
LIST_S2	Benign	0.82	T
M_CAP	Pathogenic	0.41	D
MetaRNN	Uncertain	0.67	D
MetaSVM	Uncertain	0.17	D
MutationAssessor	Benign	0.30	N
PhyloP100		3.5
PrimateAI	Uncertain	0.63	T
PROVEAN	Benign	-0.93	N
REVEL	Pathogenic	0.68
Sift	Benign	0.16	T
Sift4G	Benign	0.39	T
Polyphen		0.47	P
Vest4		0.59
MVP		0.85
MPC		0.44
ClinPred		0.76	D
GERP RS		3.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.80
gMVP		0.36

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: rs372047427; hg19: chr17-41276047;