NM_007294.4:c.547+2T>A

Variant names:

• chr17-43099773-A-T
• rs80358047
• NM_007294.4:c.547+2T>A

Variant summary

Our verdict is Pathogenic. The variant received 22 ACMG points: 22P and 0B. PVS1 PS3 PM2 PP5_Very_Strong

The NM_007294.4(BRCA1):​c.547+2T>A 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 Pathogenic (★★★). ClinVar reports functional evidence for this variant: "SCV000282246: Allele-specific assay on patient-derived mRNA demonstrated that the variant allele produces only predicted non-functional transcripts. Variant allele produces r.442_547del transcript (encoding predicted non-functional protein)." and additional evidence is available in ClinVar. The gene BRCA1 is included in the ClinGen Criteria Specification Registry.

• Frequency: Genomes: not found (cov: 31)
• Consequence: BRCA1 NM_007294.4 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic reviewed by expert panel P:18
• Conservation: PhyloP100: 3.92
• 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):

• 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: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics
• Fanconi anemia, complementation group S

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, LIMITED Submitted by: G2P, ClinGen, Labcorp Genetics (formerly Invitae), 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

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

Our verdict: Pathogenic. The variant received 22 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PS3: PS3 evidence extracted from ClinVar submissions: SCV000282246: Allele-specific assay on patient-derived mRNA demonstrated that the variant allele produces only predicted non-functional transcripts. Variant allele produces r.442_547del transcript (encoding predicted non-functional protein).; SCV002556781: Functional studies confirm BRCA1:c.547+2T>A results in skipping of exon 8 generating a frameshift transcript (BRCA1:r.442_547) that encodes premature termination of the protein synthesis (BRCA1:p.Gln148AspfsTer51) (Houdayer et al., 2012, PMID:22505045, Colombo et al., 2013, PMID:23451180).; SCV000077022: Studies have shown that disruption of this splice site alters mRNA splicing and is expected to lead to the loss of protein expression (PMID: 24667779).; SCV006086295: At least one publication reports experimental evidence that this variant affects mRNA splicing (Steffensen_2014).; SCV000296429: Published functional studies show that this variant causes aberrant mRNA splicing that result in skipping of exon 8 (PMID: 10479726 (1999), 22505045 (2012), 23451180 (2013), 24667779 (2014)).; SCV000665799: RNA studies have demonstrated that this alteration causes coding exon 6 skipping (total exon 8 in the literature), which results in a transcript that is subject to nonsense-mediated mRNA decay (Ambry internal data; Pyne MT et al. Mutat. Res. 1999 Aug;406:101-7; Houdayer C et al. Hum. Mutat. 2012 Aug;33:1228-38; Colombo M et al. PLoS ONE 2013 Feb;8:e57173).; SCV000905208: RNA studies have reported that the variant causes the out-of-frame skipping of exon 7, resulting in premature termination, in RNA derived from carriers and in a minigene splicing assay (PMID: 10479726, 22505045, 23451180, 24667779).
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-43099773-A-T is Pathogenic according to our data. Variant chr17-43099773-A-T is described in ClinVar as Pathogenic. ClinVar VariationId is 37674.Status of the report is reviewed_by_expert_panel, 3 stars.

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BRCA1	NM_007294.4	MANE Select	c.547+2T>A		splice_donor intron	N/A	NP_009225.1	P38398-1
	BRCA1	NM_001407581.1		c.547+2T>A		splice_donor intron	N/A	NP_001394510.1	A0A2R8Y7V5
	BRCA1	NM_001407582.1		c.547+2T>A		splice_donor intron	N/A	NP_001394511.1	A0A2R8Y7V5

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BRCA1	ENST00000357654.9	TSL:1 MANE Select	c.547+2T>A		splice_donor intron	N/A	ENSP00000350283.3	P38398-1
	BRCA1	ENST00000471181.7	TSL:1	c.547+2T>A		splice_donor intron	N/A	ENSP00000418960.2	P38398-7
	BRCA1	ENST00000470026.6	TSL:1	c.547+2T>A		splice_donor intron	N/A	ENSP00000419274.2	P38398-1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 31

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
8	-	-	Breast-ovarian cancer, familial, susceptibility to, 1 (8)
4	-	-	Hereditary breast ovarian cancer syndrome (4)
3	-	-	Hereditary cancer-predisposing syndrome (3)
2	-	-	not provided (2)
1	-	-	Breast and/or ovarian cancer (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.18	D
BayesDel_noAF	Uncertain	0.020
CADD	Pathogenic	27
DANN	Benign	0.97
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Uncertain	0.90	D
PhyloP100		3.9
GERP RS		5.2
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.90
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.99		Position offset: 2

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

Other links and lift over

dbSNP: rs80358047; hg19: chr17-41251790; COSMIC: COSV58804428;