17-43063872-A-G

Variant names:

• chr17-43063872-A-G
• rs886040914
• NM_007294.4:c.5152+2T>C

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1_Moderate PM2 PP5_Very_Strong

The NM_007294.4(BRCA1):​c.5152+2T>C variant causes a splice donor, intron change. The variant was absent in control chromosomes in GnomAD project. 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 Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: BRCA1 NM_007294.4 splice_donor, intron
• Scores: Splicing: ADA: 0.9987
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2 O:1
• Conservation: PhyloP100: 5.73

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 Pathogenic. Variant got 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 17-43063872-A-G is Pathogenic according to our data. Variant chr17-43063872-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 491096.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.5152+2T>C		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+2T>C		splice_donor_variant, intron_variant	Intron 17 of 22	1	NM_007294.4	ENSP00000350283.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:2

Apr 06, 2020

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.5152+2T>C intronic variant results from a T to C substitution two nucleotides after coding exon 16 in the BRCA1 gene. 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). This alteration was reported to segregate with disease in a woman with breast cancer diagnosed at age 35-40 and her mother diagnosed with ovarian cancer at age 50-55 (Zuntini R et al. Front Genet, 2018 Sep;9:378). Another BRCA1 alteration, c.5152+2T>G, resulting in the same splice event (in-frame loss of coding exon 16) has been reported in an individual with ovarian cancer from the Middle East (Siraj AK et al. Hum. Mutat., 2019 06;40:729-733). In addition to the clinical data presented in the literature, alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. As such, this alteration is classified as a disease-causing mutation. -

Jan 28, 2022

Color Diagnostics, LLC DBA Color Health

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant causes a T to C nucleotide substitution at the +2 position of intron 17 of the BRCA1 gene. Splice site prediction tools predict that this variant may have a significant impact on RNA splicing. This variant has been reported to be loss-of-function in a haploid cell proliferation assay in human HAP1 cells (PMID: 30209399). This variant has been reported in individuals affected with breast and/or ovarian cancer from high-risk hereditary breast and ovarian cancer families (PMID: 32380732). 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 Likely Pathogenic. -

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

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Brotman Baty Institute, University of Washington

Significance: not provided

Review Status: no classification provided

Collection Method: in vitro

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.33
CADD	Pathogenic	28
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.98
FATHMM_MKL	Pathogenic	0.99	D
GERP RS		6.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.79
SpliceAI score (max)		0.90		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.90		Position offset: 2

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

Publications

LitVar

Other links and lift over

dbSNP: rs886040914; hg19: chr17-41215889;