17-43093231-CT-C

Position:

• chr17-43093231-CT-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_007294.4(BRCA1):​c.2299delA​(p.Ser767fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★★). Synonymous variant affecting the same amino acid position (i.e. S767S) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: BRCA1 NM_007294.4 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:11
• Conservation: PhyloP100: 0.439

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 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-43093231-CT-C is Pathogenic according to our data. Variant chr17-43093231-CT-C is described in ClinVar as [Pathogenic]. Clinvar id is 37462.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr17-43093231-CT-C is described in Lovd as [Pathogenic]. Variant chr17-43093231-CT-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.2299delA	p.Ser767fs	frameshift_variant	10/23	ENST00000357654.9	NP_009225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9	c.2299delA	p.Ser767fs	frameshift_variant	10/23	1	NM_007294.4	ENSP00000350283.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 43

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:11

Revision: reviewed by expert panel

Submissions by phenotype

Breast-ovarian cancer, familial, susceptibility to, 1 Pathogenic:6

Pathogenic, criteria provided, single submitter	clinical testing	Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), c/o University of Cambridge	Oct 02, 2015	- -
Pathogenic, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA1)	May 29, 2002	- -
Pathogenic, criteria provided, single submitter	research	Laan Lab, Human Genetics Research Group, University of Tartu	May 01, 2021	- -
Pathogenic, no assertion criteria provided	clinical testing	Sharing Clinical Reports Project (SCRP)	Mar 10, 2010	- -
Pathogenic, reviewed by expert panel	curation	Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA)	Sep 08, 2016	Variant allele predicted to encode a truncated non-functional protein. -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Sep 28, 2022	- -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Oct 03, 2023	Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Truncating variants in this gene are considered pathogenic by a well-established clinical consortium and/or database; Not observed at significant frequency in large population cohorts (gnomAD); Also known as 2418delA; This variant is associated with the following publications: (PMID: 26187060, 10459348, 10686936, 12491487, 17688236, 21614564, 26250392, 21702907, 26269718, 28152038, 16267036, 30702160, 20104584, 29446198, 35535697, 31825140) -
Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Dec 06, 2022	This frameshift variant alters the translational reading frame of the BRCA1 mRNA and causes the premature termination of BRCA1 protein synthesis. This variant has not been reported in large, multi-ethnic general populations (http://gnomad.broadinstitute.org). In the published literature, the variant has been reported in individuals with breast cancer (PMID: 26250392 (2015), 21614564 (2012), 12491487 (2003)), and in individuals with ovarian cancer (PMID: 10686936 (1999), 10459348 (1999)). Based on the available information, this variant is classified as pathogenic. -

Hereditary breast ovarian cancer syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Nov 24, 2020	Variant summary: BRCA1 c.2299delA (p.Ser767AlafsX25) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 251084 control chromosomes (gnomAD). c.2299delA has been reported in the literature in multiple individuals affected with Hereditary Breast and Ovarian Cancer Syndrome. These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Five other submitters, including an expert panel (ENIGMA), have provided clinical-significance assessments for this variant in ClinVar after 2014, and classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 24, 2024	This sequence change creates a premature translational stop signal (p.Ser767Alafs*25) in the BRCA1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in BRCA1 are known to be pathogenic (PMID: 20104584). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with ovarian cancer and breast cancer (PMID: 10686936, 26187060). This variant is also known as 2418delA. ClinVar contains an entry for this variant (Variation ID: 37462). For these reasons, this variant has been classified as Pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 14, 2023

The c.2299delA pathogenic mutation, located in coding exon 9 of the BRCA1 gene, results from a deletion of one nucleotide at nucleotide position 2299, causing a translational frameshift with a predicted alternate stop codon (p.S767Afs*25). This mutation has been reported in multiple individuals with a personal and/or family history consistent with Hereditary Breast and Ovarian Cancer syndrome (HBOC) (Tworek H et al. Cancer Genet. Cytogenet. 1999 Jul;112:105-18; Fetzer S et al. Cancer Genet. Cytogenet. 1999 Aug;113:58-64; Ramus SJ et al. Hum. Mutat. 2007 Dec;28:1207-15; Zhang J et al. Breast Cancer Res. Treat. 2012 Apr;132:421-8; Lynce F et al. Breast Cancer Res. Treat. 2015 Aug;153:201-9; Bhaskaran SP et al. Int. J. Cancer. 2019 Jan). This alteration was also identified in a large, worldwide study of BRCA1/2 mutation positive families (Rebbeck TR et al. Hum. Mutat. 2018 05;39:593-620). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs80357786; hg19: chr17-41245248;