rs80358094

Variant names:

• chr17-43063873-C-A
• rs80358094
• NM_007294.4:c.5152+1G>T

Your query was ambiguous. Multiple possible variants found:

• chr17-43063873-C-A
• chr17-43063873-C-G
• chr17-43063873-C-T

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1_Moderate PM2 PP5_Very_Strong

The NM_007294.4(BRCA1):​c.5152+1G>T variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.00000137 in 1,458,892 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: BRCA1 NM_007294.4 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic reviewed by expert panel P:9
• Conservation: PhyloP100: 4.83
• Publications: 21 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: Pathogenic. The variant received 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.013948498 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-43063873-C-A is Pathogenic according to our data. Variant chr17-43063873-C-A is described in ClinVar as Pathogenic. ClinVar VariationId is 55423.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.5152+1G>T		splice_donor_variant, intron_variant	Intron 17 of 22	ENST00000357654.9	NP_009225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9	c.5152+1G>T		splice_donor_variant, intron_variant	Intron 17 of 22	1	NM_007294.4	ENSP00000350283.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1458892 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 726056

African (AFR) AF: 0.00 AC: 0 AN: 33414

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26120

East Asian (EAS) AF: 0.00 AC: 0 AN: 39662

South Asian (SAS) AF: 0.00 AC: 0 AN: 86194

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53410

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

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1109318

Other (OTH) AF: 0.00 AC: 0 AN: 60292

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:9

Revision: reviewed by expert panel

Submissions by phenotype

Breast-ovarian cancer, familial, susceptibility to, 1 Pathogenic:4

May 29, 2002

Breast Cancer Information Core (BIC) (BRCA1)

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Oct 02, 2015

Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), c/o University of Cambridge

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 10, 2015

Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA)

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

IARC class based on posterior probability from multifactorial likelihood analysis, thresholds for class as per Plon et al. 2008 (PMID: 18951446). Class 5 based on posterior probability = 1 -

Mar 02, 2020

BRCAlab, Lund University

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome Pathogenic:2

Apr 15, 2025

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.5152+1G>T intronic pathogenic mutation results from a G to T substitution one nucleotide after coding exon 16 of the BRCA1 gene. This variant, sometimes referred to as IVS18+1G>T and 5271+1G>T in literature, has been reported in a family with multiple members diagnosed with breast cancer before the age of 60 (Gayther SA et al. Nat. Genet. 1995 Dec;11(4):428-33). Additionally, this alteration has been classified as pathogenic by multifactorial analysis, which integrates in silico prediction models, segregation with disease, tumor characteristics, mutation co-occurrence, and functional assay results to determine a likelihood ratio of pathogenicity (Lindor NM et al. Hum. Mutat. 2012 Jan;33(1):8-21). One functional study found that this nucleotide substitution is deleterious in a high throughput genome editing haploid cell survival assay (Findlay GM et al. Nature, 2018 10;562:217-222). RNA studies have demonstrated that this alteration results in abnormal splicing in the set of samples tested (Ambry internal data). In silico splice site analysis predicts that this alteration will weaken the native splice donor site. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). As such, this alteration is classified as a disease-causing mutation. -

Jun 09, 2020

Color Diagnostics, LLC DBA Color Health

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant causes a G to T nucleotide substitution at the +1 position of intron 17 of the BRCA1 gene. This variant is also known as IVS18+1G>T in the literature. RNA study on carrier RNA has reported that this variant resulted in the skipping of exon 17 that partially encodes the BRCT domain (PMID: 30101128), and this variant also is reported to be loss-of-function in a haploid cell proliferation assay (PMID: 30209399). This variant has been reported in at least nine families at-risk for hereditary breast and ovarian cancer (PMID: 7493024, 29446198) and additional individuals who underwent cancer genetic testing (PMID: 18375895). Multifactorial analyses have found this variant to be deleterious with posterior probability of 1.0, based in part on likelihood ratio (deleterious) of 7562 from tumor histopathology (PMID: 18375895, 21990134). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of BRCA1 function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -

Hereditary breast ovarian cancer syndrome Pathogenic:2

Dec 24, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects a donor splice site in intron 17 of the BRCA1 gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in a shortened protein product. This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with breast and/or ovarian cancer (PMID: 7493024, 29446198). This variant is also known as 5271+1G>T and IVS18+1G>T. ClinVar contains an entry for this variant (Variation ID: 55423). Based on a multifactorial likelihood algorithm using genetic, in silico, and/or statistical data, this variant has been determined to have a high probability of being pathogenic (PMID: 21990134). Studies have shown that disruption of this splice site results in skipping of exon 17, but is expected to preserve the integrity of the reading-frame (PMID: 30209399). For these reasons, this variant has been classified as Pathogenic. -

Oct 14, 2019

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.5152+1G>T variant in BRCA1 has been reported in at least 11 probands hereditary breast and/or ovarian cancer (HBOC; Gayther 1995, Brovkina 2018, BIC database). It was absent from large population studies. This variant occurs within the canonical splice site (+/- 1,2) and is predicted to cause altered splicing leading to an abnormal or absent protein. Loss of function of the BRCA1 gene is an established disease mechanism in autosomal dominant HBOC. In vitro functional studies support an impact on protein function (Findlay 2018). This variant was classified as Pathogenic on Oct 18, 2016 by the ClinGen-approved ENIGMA expert panel (Variation ID: 55423). In summary, this variant meets criteria to be classified as pathogenic for autosomal dominant HBOC. ACMG/AMP Criteria applied: PVS1, PM2, PS3_Moderate, PS4_Moderate. -

not provided Pathogenic:1

Sep 12, 2022

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Multifactorial studies suggest this variant is associated with breast and ovarian cancer (Lindor et al., 2012); Observed in individuals with personal and/or family history of BRCA1-related cancers (Gayther et al., 1995; Spurdle et al., 2008; Kim et al., 2012; Brovkina et al., 2018; Nones et al., 2019; Frugtniet et al., 2022); Canonical splice site variant expected to result in aberrant splicing, although in the absence of functional evidence the actual effect of this sequence change is unknown; Not observed at significant frequency in large population cohorts (gnomAD); Also known as 5271+1G>T and IVS18+1G>T; This variant is associated with the following publications: (PMID: 18375895, 8807330, 25525159, 22798144, 7493024, 9699523, 15345110, 30209399, 33087929, 34657373, 21990134, 30333958, 29446198, 31090900) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.41
CADD	Pathogenic	32
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		4.8
GERP RS		6.0
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.90		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.90		Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs80358094; hg19: chr17-41215890;