rs879254224

Variant names:

• chr17-43099892-GGTAAAGAACA-G
• rs879254224
• NM_007294.4:c.442-22_442-13delTGTTCTTTAC

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1_Strong PP1_Strong PP4_Moderate

This summary comes from the ClinGen Evidence Repository: The c.442-22_442-13del variant is an intronic variant occurring in intron 6 of the BRCA1 gene. This deletion variant was not observed in gnomAD v2.1 (exomes only, non-cancer subset) or gnomAD v3.1 (non-cancer subset), but PM2_Supporting was not applied since recall is suboptimal for this type of variant (PM2_Supporting not met). This variant is reported to result in aberrant mRNA splicing. RT-PCR and qPCR assays demonstrated that the variant impacts splicing by activation of a cryptic acceptor site, resulting in a 59nt intron retention of intron 6. Combination of non-allele specific assay results (PMIDs: 10323242, 32745242) and assessment of full-length transcript quantification by real-time PCR in carriers (personal communication) suggests a near complete splicing effect. Appropriate code strength determined by comparison of results to PVS1 decision tree and assessment of mRNA splicing data (PVS1_Strong (RNA) met). Cosegregation analysis of family(ies) carrying this variant provided evidence towards pathogenicity, and has a Bayes Score of 48.83, within the thresholds for strong pathogenic evidence (LR >18.7 & ≤350) (PP1_Strong met; PMID:32745242, Internal lab contributors). Multifactorial likelihood ratio analysis using clinically calibrated data produced a combined LR for this variant of 4.83 (based on Pathology LR=4.83), within the thresholds for Moderate evidence towards pathogenicity (LR >4.3 & ≤18.7) (PP4_Moderate met; 32745242, Internal lab contributors). In summary, this variant meets the criteria to be classified as a Pathogenic variant for BRCA1-related cancer predisposition based on the ACMG/AMP criteria applied as specified by the ENIGMA BRCA1/2 VCEP (PVS1_Strong (RNA), PP1_Strong, PP4_Moderate). LINK:https://erepo.genome.network/evrepo/ui/classification/CA10584575/MONDO:0011450/092

• Frequency: Genomes: not found (cov: 31)
• Consequence: BRCA1 NM_007294.4 intron
• Clinical Significance: Pathogenic reviewed by expert panel P:8
• Conservation: PhyloP100: 3.57
• Publications: 1 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 10 ACMG points.

• PVS1: For more information check the summary or visit ClinGen Evidence Repository.
• PP1: For more information check the summary or visit ClinGen Evidence Repository.
• PP4: 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.442-22_442-13delTGTTCTTTAC		intron	N/A	NP_009225.1
	BRCA1	NM_001407581.1		c.442-22_442-13delTGTTCTTTAC		intron	N/A	NP_001394510.1
	BRCA1	NM_001407582.1		c.442-22_442-13delTGTTCTTTAC		intron	N/A	NP_001394511.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BRCA1	ENST00000357654.9	TSL:1 MANE Select	c.442-22_442-13delTGTTCTTTAC		intron	N/A	ENSP00000350283.3
	BRCA1	ENST00000471181.7	TSL:1	c.442-22_442-13delTGTTCTTTAC		intron	N/A	ENSP00000418960.2
	BRCA1	ENST00000470026.6	TSL:1	c.442-22_442-13delTGTTCTTTAC		intron	N/A	ENSP00000419274.2

Frequencies

GnomAD3 genomes Cov.: 31

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 31

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
2	-	-	Hereditary breast ovarian cancer syndrome (2)
2	-	-	Hereditary cancer-predisposing syndrome (2)
1	-	-	BRCA1-related cancer predisposition (1)
1	-	-	Familial cancer of breast;C2676676:Breast-ovarian cancer, familial, susceptibility to, 1;C4554406:Fanconi anemia, complementation group S (1)
1	-	-	Inherited ovarian cancer (without breast cancer) (1)
1	-	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		3.6
Mutation Taster		=3/97	disease causing (ClinVar)

Splicing

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

Other links and lift over

dbSNP: rs879254224; hg19: chr17-41251909;