Genetic Variant NM_007294.4:c.5251C>T (chr17-43057078-G-A) – ACMG Classification: Pathogenic (21 pts)

Variant summary

Our verdict is The variant received 21 classification points (ACMG Germline Pathogenicity v2019): 21P and 0B. PVS1PS3PM2_SupportingPP5_Very_Strong

The NM_007294.4(BRCA1):c.5251C>T (p.Arg1751*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant is predicted to lead to nonsense-mediated mRNA decay (NMD). The variant allele was found at a cumulative frequency of 0.00000274 (AC=4) in the gnomAD database across 1,461,802 control chromosomes (no homozygotes observed). The grpmax filtering allele frequency (95% CI) is 0.0000241. Note: a gnomAD entry for this variant shows a statistical allele-bias signature, consistent with mosaic/somatic contamination (e.g. age-related clonal hematopoiesis) rather than true inherited population frequency — this frequency should not be read as evidence of a common, benign germline variant. In-silico predictor (BayesDel (addAF)) classifies this variant as likely damaging/oncogenic. Splicing prediction tools (SpliceAI) predict no significant impact on normal splicing. Variant has been reported in ClinVar as Pathogenic/Likely Pathogenic (★★★). ClinVar reports functional evidence for this variant: "SCV000108685: Published functional studies demonstrate a damaging effect: unable to support viability in a haploid cell line (Findlay 2018)" and additional evidence is available in ClinVar. This exact variant is curated in the UniProt human variants database as Uncertain Significance, associated with Adenomas and Adenocarcinomas; it is also listed as a COSMIC curated somatic variant.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 31)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

BRCA1
NM_007294.4 stop_gained

Scores

Clinical Significance

Pathogenic reviewed by expert panel P:47O:1

Conservation

PhyloP100: 2.15

Publications

125 publications found

Variant links:

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):

BRCA1-related cancer predisposition
Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
breast-ovarian cancer, familial, susceptibility to, 1
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Genomics England PanelApp
Fanconi anemia, complementation group S
Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P, ClinGen
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

BRCA1 links:

Genome browser will be placed here

new If you want to explore the variant's impact on the transcript NM_007294.4, check out the Mutation Effect Viewer. This is especially useful for frameshift variants or if you want to visualize the effect of exon loss / intron retention.

Classification according to ACMG Germline Pathogenicity v2019

Specifications for BRCA1 are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Classification was made for transcript

Our verdict: Pathogenic. The variant received 21 points.

PVS1

Frameshift/stop-gained, NMD predicted, LoF disease mechanism — very strong (PVS1); Stop-gained (exon 19 of 23) at amino acid 1751 of 1863, predicted to trigger nonsense-mediated mRNA decay. Loss of function is a known disease mechanism for this gene.

PS3

Well-established functional study supports damaging effect (PS3); SCV000108685: Published functional studies demonstrate a damaging effect: unable to support viability in a haploid cell line (Findlay 2018); SCV000213371: "One functional study found that this nucleotide substitution is non-functional in a high-throughput, genome editing, haploid cell survival assay (Findlay GM et al. Nature, 2018 10;562:217-222)."; SCV000683276: A functional study reported that this variant impacts BRCA1 function in a haploid human cell proliferation assay (PMID: 30209399).

PM2

Rare in gnomAD for AD/XL gene (popmax AF below threshold) — PM2 Supporting; GnomAD popmax AF = 0.0000241 — borderline rare for AD+AR gene (base 0.0001, raised to 0.000118 by highest known P/LP ClinVar AF 0.000118) — PM2 supporting.

PP5

ClinVar ≥3 stars pathogenic — very strong (PP5); ClinVar submissions overwhelmingly pathogenic (≥10 total, ≥80% P/LP, <10% B/LB) — strong (PP5, count-based); ClinVar germline classification: Pathogenic/Likely Pathogenic, 3 star(s). ClinVar submissions strongly and reliably favor pathogenicity (47/47 total P/LP).

Variant Effect in Transcripts

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

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
BRCA1	NM_007294.4	MANE Select	c.5251C>T	p.Arg1751*	stop_gained	Exon 19 of 23	NP_009225.1	P38398-1
BRCA1	NM_001407581.1		c.5317C>T	p.Arg1773*	stop_gained	Exon 20 of 24	NP_001394510.1	A0A2R8Y7V5
BRCA1	NM_001407582.1		c.5317C>T	p.Arg1773*	stop_gained	Exon 20 of 24	NP_001394511.1	A0A2R8Y7V5

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
BRCA1	ENST00000357654.9	TSL:1 MANE Select	c.5251C>T	p.Arg1751*	stop_gained	Exon 19 of 23	ENSP00000350283.3	P38398-1
BRCA1	ENST00000471181.7	TSL:1	c.5314C>T	p.Arg1772*	stop_gained	Exon 20 of 24	ENSP00000418960.2	P38398-7
BRCA1	ENST00000470026.6	TSL:1	c.5251C>T	p.Arg1751*	stop_gained	Exon 19 of 23	ENSP00000419274.2	P38398-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152116

Hom.:

Cov.:

show subpopulations

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000119

AC:

AN:

251492

AF XY:

0.0000147

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad FIN exome

AF:

0.0000462

Gnomad NFE exome

AF:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000274

AC:

AN:

1461802

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

727206

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33476

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26128

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39698

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.0000187

AC:

AN:

53416

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5762

European-Non Finnish (NFE)

AF:

0.00000180

AC:

AN:

1111948

Other (OTH)

AF:

0.00

AC:

AN:

60392

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.463

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152116

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74302

show subpopulations

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

African (AFR)

AF:

0.0000241

AC:

AN:

41428

American (AMR)

AF:

0.00

AC:

AN:

15256

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5190

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10606

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68016

Other (OTH)

AF:

0.00

AC:

AN:

2090

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.00000037155), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.325

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00000456

Hom.:

Bravo

AF:

0.00000756

ClinVar

ClinVar submissions

Significance:Pathogenic

Revision:reviewed by expert panel

View on ClinVar

Pathogenic

VUS

Benign

Condition

Breast-ovarian cancer, familial, susceptibility to, 1 (22)

not provided (11)

Hereditary breast ovarian cancer syndrome (6)

Hereditary cancer-predisposing syndrome (4)

Breast and/or ovarian cancer (1)

Breast neoplasm (1)

Familial cancer of breast (1)

Familial cancer of breast;C2676676:Breast-ovarian cancer, familial, susceptibility to, 1;C3280442:Pancreatic cancer, susceptibility to, 4;C4554406:Fanconi anemia, complementation group S (1)

Inherited ovarian cancer (without breast cancer) (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.43

BayesDel_noAF

Pathogenic

0.55

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

Eigen

Uncertain

0.54

Eigen_PC

Uncertain

0.36

FATHMM_MKL

Uncertain

0.77

PhyloP100

2.2

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Mutation Taster

=0/200

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

Splicevardb

2.0

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

Classification according to ACMG Germline Pathogenicity v2019

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over