chr17-43094736-AGAAC-A

Position:

• chr17-43094736-AGAAC-A

Variant summary

Our verdict is Pathogenic. Variant got 19 ACMG points: 19P and 0B. PVS1 PM2 PP3 PP5_Very_Strong

The NM_007294.4(BRCA1):​c.791_794del​(p.Ser264MetfsTer33) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,458,418 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: BRCA1 NM_007294.4 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:12
• Conservation: PhyloP100: 2.27

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 19 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
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 17-43094736-AGAAC-A is Pathogenic according to our data. Variant chr17-43094736-AGAAC-A is described in ClinVar as [Pathogenic]. Clinvar id is 55705.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-43094736-AGAAC-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.791_794del	p.Ser264MetfsTer33	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.791_794del	p.Ser264MetfsTer33	frameshift_variant	10/23	1	NM_007294.4	ENSP00000350283	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000801 AC: 2 AN: 249662 Hom.: 0 AF XY: 0.0000148 AC XY: 2 AN XY: 134968

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000292

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000885

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1458418 Hom.: 0 AF XY: 0.00000276 AC XY: 2 AN XY: 725076

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000226

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.01e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:12

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Breast-ovarian cancer, familial, susceptibility to, 1 Pathogenic:5

Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Nov 10, 2023	- -
Pathogenic, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA1)	Dec 30, 1999	- -
Pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Aug 18, 2017	- -
Pathogenic, no assertion criteria provided	case-control	Molecular Oncology, Hospital Universitario Central de Asturias (HUCA)	May 24, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), c/o University of Cambridge	Oct 02, 2015	- -

Hereditary breast ovarian cancer syndrome Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 22, 2023	For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. ClinVar contains an entry for this variant (Variation ID: 55705). This variant is also known as 910delGTTC, 910del4, and 910_913delGTTC. This premature translational stop signal has been observed in individual(s) with breast and/or ovarian cancer (PMID: 11857748, 12955716, 23683081, 27425403, 27914478, 29907814). This variant is present in population databases (rs80357707, gnomAD 0.003%). This sequence change creates a premature translational stop signal (p.Ser264Metfs*33) 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). -
Pathogenic, criteria provided, single submitter	research	Genetics Program, Instituto Nacional de Cancer	Nov 01, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Oct 28, 2022	Variant summary: BRCA1 c.791_794delGTTC (p.Ser264MetfsX33) 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 allele was found at a frequency of 8e-06 in 249662 control chromosomes. c.791_794delGTTC has been reported in the literature in individuals affected with Hereditary Breast And Ovarian Cancer Syndrome (examples: Rebbeck_2018, Maistro_2016). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Six clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Aug 02, 2022	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; Not observed at significant frequency in large population cohorts (gnomAD); Truncating variants in this gene are considered pathogenic by a well-established clinical consortium and/or database; Also known as 910delGTTC; Observed in individuals with a personal or family history including breast and ovarian cancer (Llort et al., 2002; Alemar et al., 2016; Maistro et al., 2016); This variant is associated with the following publications: (PMID: 27425403, 11857748, 27914478, 29907814, 29161300, 30720243, 31447099) -
Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Nov 09, 2020	This frameshift variant causes the premature termination of BRCA1 protein synthesis. In addition, it has been reported in individuals with breast cancer and ovarian cancer in the published literature (PMID: 29161300 (2017), 27914478 (2016), 23683081 (2013), 12955716 (2003)). Based on the available information, this variant is classified as pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Feb 26, 2021	This variant deletes 4 nucleotides in exon 10 of the BRCA1 gene, creating a frameshift and premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. To our knowledge, functional studies have not been reported for this variant. This variant has been detected in four hereditary breast and ovarian cancer families (PMID: 11857748, 12014998, 23683081, 27425403, 27914478) in which this variant was confirmed present in at least one individual affected with early-onset breast cancer and two individuals affected with ovarian cancer (PMID: 12014998, 27914478). This variant has been identified in 2/249662 chromosomes 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 Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	May 04, 2023	The c.791_794delGTTC pathogenic mutation, located in coding exon 9 of the BRCA1 gene, results from a deletion of 4 nucleotides at nucleotide positions 791 to 794, causing a translational frameshift with a predicted alternate stop codon (p.S264Mfs*33). This alteration has been reported in multiple Spanish and Brazilian HBOC families (Llort G et al. Hum. Mutat. 2002 Mar;19(3):307; Díez O et al. Hum. Mutat. 2003 Oct;22:301-12; Blay P et al. BMC Cancer 2013 May;13:243; Alemar B et al. Cancer Genet. 2016 09;209:417-422; Alemar B et al. PLoS ONE 2017 Nov;12:e0187630; Palmero EI et al. Sci. Rep. 2018 Jun;8:9188). 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)		0.66		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.66		Position offset: 8

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

Publications

LitVar

Other links and lift over

dbSNP: rs80357707; hg19: chr17-41246753;