NM_007294.4:c.5152+6T>C

Variant names:

• chr17-43063868-A-G
• rs80358074
• NM_007294.4:c.5152+6T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PS3 PVS1_Strong PM2_Supporting

This summary comes from the ClinGen Evidence Repository: The c.5152+6T>C variant is an intronic variant occurring in intron 17(18) of the BRCA1 gene. This variant is absent from gnomAD v2.1 (exomes only, non-cancer subset, read depth ≥25) and gnomAD v3.1 (non-cancer subset, read depth ≥25) (PM2_Supporting met). Intronic variant, functional data considered only from assays that measure effect via mRNA and protein. Reported by one calibrated study incorporating mRNA splicing effects to exhibit protein function similar to pathogenic control variants (PMID:30209399) (PS3 met). This BRCA1 intronic variant is located outside of the native donor and acceptor 1,2 splice sites, and has a SpliceAI score of 0.7, predicting an impact on splicing (score threshold >0.20) (PP3 not applied because a PVS1 code is met). This variant is reported to result in aberrant mRNA splicing. RT-PCR demonstrated that the variant impacts splicing by exon skipping (PMIDs: 32123317, 32761968). The percent reference (full-length) and aberrant transcripts produced from the variant allele is not stated, however assessment of gel electrophoresis shows apparent (near) complete splicing effect. Final code strength determined by the rubric: PVS1_Strong (RNA). Multifactorial likelihood ratio analysis using clinically calibrated data produced a combined LR for this variant of 0.65 (based on Co-occurrence LR=1.07; Family History LR=0.61), which is above the ENIGMA BRCA1/2 VCEP threshold for BP5 (>0.48) and below PP4 (<2.08) (BP5 and PP4 not met; Internal lab contributor). In summary, this variant meets the criteria to be classified as a Likely pathogenic variant for BRCA1-related cancer predisposition based on the ACMG/AMP criteria applied as specified by the ENIGMA BRCA1/2 VCEP (PM2_Supporting, PS3, PVS1_Strong (RNA)). LINK:https://erepo.genome.network/evrepo/ui/classification/CA003291/MONDO:0700268/092

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: BRCA1 NM_007294.4 splice_region, intron
• Scores: Splicing: ADA: 0.9952
• Clinical Significance: Pathogenic reviewed by expert panel P:5 U:2
• Conservation: PhyloP100: 5.73
• Publications: 4 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: Likely_pathogenic. The variant received 9 ACMG points.

• PVS1: For more information check the summary or visit ClinGen Evidence Repository.
• PS3: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.

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.5152+6T>C		splice_region intron	N/A	NP_009225.1	P38398-1
	BRCA1	NM_001407581.1		c.5218+6T>C		splice_region intron	N/A	NP_001394510.1	A0A2R8Y7V5
	BRCA1	NM_001407582.1		c.5218+6T>C		splice_region 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.5152+6T>C		splice_region intron	N/A	ENSP00000350283.3	P38398-1
	BRCA1	ENST00000471181.7	TSL:1	c.5215+6T>C		splice_region intron	N/A	ENSP00000418960.2	P38398-7
	BRCA1	ENST00000470026.6	TSL:1	c.5152+6T>C		splice_region intron	N/A	ENSP00000419274.2	P38398-1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.87e-7 AC: 1 AN: 1456188 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 724888

African (AFR) AF: 0.00 AC: 0 AN: 33342

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

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26108

East Asian (EAS) AF: 0.00 AC: 0 AN: 39656

South Asian (SAS) AF: 0.00 AC: 0 AN: 86156

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53408

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5758

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1106862

Other (OTH) AF: 0.0000166 AC: 1 AN: 60180

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
1	2	-	Breast-ovarian cancer, familial, susceptibility to, 1 (3)
2	-	-	Hereditary cancer-predisposing syndrome (2)
1	-	-	BRCA1-related cancer predisposition (1)
1	-	-	Hereditary breast ovarian cancer syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.29
CADD	Benign	16
DANN	Benign	0.95
PhyloP100		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.96
Splicevardb		3.0
SpliceAI score (max)		0.70		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.70		Position offset: 6

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

Other links and lift over

dbSNP: rs80358074; hg19: chr17-41215885;