rs80357906

chr17-43057062-T-TG

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1 PP5_Very_Strong

The NM_007294.4(BRCA1):c.5266_5267insC(p.Gln1756ProfsTer74) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000675 in 1,613,912 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★★). Synonymous variant affecting the same amino acid position (i.e. Q1756Q) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.000053 (0 hom., cov: 31)
  • Exomes 𝑓: 0.000069 (0 hom.)
• Consequence: BRCA1 NM_007294.4 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:76 U:1 O:3
• Conservation: PhyloP100: 2.46

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 16 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PP5: Variant 17-43057062-T-TG is Pathogenic according to our data. Variant chr17-43057062-T-TG is described in ClinVar as [Pathogenic]. Clinvar id is 17677.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA1	NM_007294.4	c.5266_5267insC	p.Gln1756ProfsTer74	frameshift_variant	19/23	ENST00000357654.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA1	ENST00000357654.9	c.5266_5267insC	p.Gln1756ProfsTer74	frameshift_variant	19/23	1	NM_007294.4	P4

Frequencies

GnomAD3 genomes AF: 0.0000526 AC: 8 AN: 152180 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00115

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000588

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000183 AC: 46 AN: 251494 Hom.: 0 AF XY: 0.000125 AC XY: 17 AN XY: 135922

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00238

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000176

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.0000691 AC: 101 AN: 1461732 Hom.: 0 Cov.: 31 AF XY: 0.0000853 AC XY: 62 AN XY: 727176

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00119

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000540

Gnomad4 OTH exome AF: 0.000149

GnomAD4 genome AF: 0.0000526 AC: 8 AN: 152180 Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1 AN XY: 74344

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00115

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000588

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000400 Hom.: 0

Bravo AF: 0.0000340

EpiCase AF: 0.000164

EpiControl AF: 0.000119

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:76 Uncertain:1 Other:3

Revision: reviewed by expert panel

Submissions by phenotype

Breast-ovarian cancer, familial, susceptibility to, 1 Pathogenic:37

Pathogenic, criteria provided, single submitter	clinical testing	Institute of Immunology and Genetics Kaiserslautern	Feb 02, 2024	ACMG Criteria: PM2_P; Variant was found in heterozygous state -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Mar 17, 2024	- -
Pathogenic, criteria provided, single submitter	clinical testing	Genome Diagnostics Laboratory, University Medical Center Utrecht	Oct 10, 2014	- -
Pathogenic, criteria provided, single submitter	research	HudsonAlpha Institute for Biotechnology, HudsonAlpha Institute for Biotechnology	Dec 10, 2015	- -
Pathogenic, reviewed by expert panel	curation	Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA)	Apr 22, 2016	Variant allele predicted to encode a truncated non-functional protein. -
Pathogenic, criteria provided, single submitter	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	Sep 21, 2015	- -
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, criteria provided, single submitter	clinical testing	Human Genetics Bochum, Ruhr University Bochum	Aug 04, 2022	ACMG criteria used to clasify this variant: PVS1, PM2, PS4 -
Pathogenic, no assertion criteria provided	clinical testing	Pathway Genomics	Jul 24, 2014	- -
Pathogenic, criteria provided, single submitter	clinical testing	Johns Hopkins Genomics, Johns Hopkins University	Oct 29, 2021	This BRCA1 variant (rs80357906) is rare (<0.1%) in a large population dataset (gnomAD: 51/282892 total alleles, 0.018%, no homozygotes) and has been reported in ClinVar. This frameshift variant results in a premature stop codon in exon 19 of 23 likely leading to nonsense-mediated decay and lack of protein production. This variant, also known as 5382insC and 5385insC in the literature, is a common cause of breast and ovarian cancer in the Ashkenazi Jewish population and has been reported in individuals from other ethnicities. This variant has been associated with a 67% to 89% risk of breast cancer by age 70, and a 33% to 42% risk of ovarian cancer by age 70. This variant was also identified in the patient's mother (JHG1740-2). We consider c.5266dupC to be pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	New York Genome Center	Jan 28, 2022	The c.5266dup (p.Gln1756ProfsTer74) variant identified in the BRCA1 gene is the duplication of a single nucleotide resulting in a frameshift at amino acid 1756/1863 (exon 19/23). This variant is predicted to incorporate a premature termination codon at approximately 74 amino acids downstream and result in either loss-of-function via nonsense mediated decay or protein truncation. This variant is found with low frequency in gnomAD(v3.1.2) (8 heterozygotes, 0 homozygotes; allele frequency: 1.972e-5), suggesting it is not a common benign variant in the populations represented in that database. The c.5266dup (p.Gln1756ProfsTer74) variant is reported in ClinVar as Pathogenic by an expert panel (VarID: 17677), and is one of the most frequently reported pathogenic variants in the BRCA1 gene. This variant has been reported in multiple affected individuals in the literature [PMID: 21119707, 24797986, 31706072, others]. Based on the available evidence c.5266dup(p.Gln1756ProfsTer74) variant is reported as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Genetics and Molecular Pathology, SA Pathology	Aug 23, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Michigan Medical Genetics Laboratories, University of Michigan	Nov 03, 2014	- -
Pathogenic, criteria provided, single submitter	clinical testing	Institute of Human Genetics, University of Leipzig Medical Center	Feb 20, 2024	Criteria applied: PVS1,PS4,PM5_STR,PS3_MOD -
Pathogenic, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Pathogenic, criteria provided, single submitter	research	Centre for Mendelian Genomics, University Medical Centre Ljubljana	Dec 09, 2022	PVS1, PS4_STR, BS1 -
Pathogenic, criteria provided, single submitter	clinical testing	Department of Medical Genetics, Oslo University Hospital	Jul 01, 2015	- -
Pathogenic, no assertion criteria provided	research	Medical Genetics, Medical University Pleven	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Human Genome Sequencing Center Clinical Lab, Baylor College of Medicine	May 25, 2017	The c.5266dup (p.Gln1756Profs*74) variant in the BRCA1 gene has been detected multiple patients with breast cancer and/or ovarian cancer [PMID 7894492, 26718727, 20569256, 21503673, 23232912, 26666763, 22430266, 19359128, 20730485, 22032251, 21324516, among others, referred as 5382C in some publications], pancreatic cancer [PMID 24737347, 26440929] and prostate cancer [PMID 27433846 ]. This variant is a founder mutation in the Ashkenazi Jewish population and is found with a high prevalence in Poland and Eastern Europe [PMID 20569256, 20345474, 20507347]. The estimated risk for carriers of this variant was 89% for breast cancer and 42% for ovarian cancer by age 70 [PMID 22430266]. This one bp duplication in exon 19 results in a frameshift and the creation of a premature stop codon. This variant is thus predicted to result in a loss of function of the protein. This variant has been detected in 19 individuals from the ExAC database (http://exac.broadinstitute.org/variant/17-41209079-T-TG). This variant thus classified as pathogenic. -
Pathogenic, no assertion criteria provided	clinical testing	Sharing Clinical Reports Project (SCRP)	Apr 08, 2014	- -
Pathogenic, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA1)	May 29, 2002	- -
Pathogenic, criteria provided, single submitter	clinical testing	Clinical Genomics Laboratory, Washington University in St. Louis	Mar 11, 2024	The BRCA1 c.5266dup (p.Gln1756Profs*74) variant is one of the most common variants reported in Central and Eastern European families with high risk of breast and/or ovarian cancer (Janavicius R, PMID: 23199084). This variant causes a frameshift by inserting one nucleotide, leading to a premature termination codon, which is predicted to lead to nonsense mediated decay. This variant has been reported in the ClinVar database as a germline pathogenic variant by 10 submitters. Based on available information and the ACMG/AMP guidelines for variant interpretation (Richards S et al., PMID: 25741868), this variant is classified as pathogenic. -
Pathogenic, no assertion criteria provided	clinical testing	Genetic Services Laboratory, University of Chicago	Jan 10, 2022	DNA sequence analysis of the BRCA1 gene demonstrated a single base pair duplication in exon 19, c.5266dup. This pathogenic sequence change results in an amino acid frameshift and creates a premature stop codon 74 amino acids downstream of the change, p.Gln1756Profs*74. This pathogenic sequence change is predicted to result in an abnormal transcript, which may be degraded, or may lead to the production of a truncated BRCA1 protein with potentially abnormal function. This sequence change has been described in the gnomAD database with a frequency of 0.23% in the Ashkenazi Jewish subpopulation (dbSNP rs1217805587). This pathogenic sequence change is a well-described pathogenic BRCA1 variant and a known founder mutation in the Ashkenazi Jewish population reported in multiple individuals with hereditary breast and ovarian cancer syndrome (PMID: 12473589, 15131399, 9042909, 22430266, 24764757, 26976419). The c.5266dup sequence change is also referred to as 5382insC in the scientific literature -
Pathogenic, criteria provided, single submitter	clinical testing	Genologica Medica	Jan 01, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Department of Molecular Diagnostics, Institute of Oncology Ljubljana	Apr 02, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	MGZ Medical Genetics Center	Sep 06, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein	Dec 13, 2022	ACMG classification criteria: PVS1 very strong, PS3 supporting, PS4 strong, PP1 strong -
Pathogenic, criteria provided, single submitter	clinical testing	Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet	May 27, 2024	PVS1; PM5_PTC_Strong -
Pathogenic, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	May 18, 2023	The BRCA1 c.5266dup (p.Gln1756ProfsTer74) variant, also referred to as c.5382insC or c.5382_5383insC, causes a shift in the translational reading frame that is predicted to result in premature termination of the protein. Loss of normal protein function through either protein truncation or nonsense-mediated mRNA decay is expected. This variant has been previously identified in individuals with breast cancer, ovarian cancer, pancreatic cancer, and prostate cancer (PMID: 29335925; PMID: 29961768; PMID: 11802209; PMID: 29492181; PMID: 22430266). Further, this variant is one of three well-characterized founder variants in the Ashkenazi Jewish population, accounting for an estimated 26% of pathogenic variants detected in this population (GeneReviews PMID: 20301425). The highest frequency of this allele in the Genome Aggregation Database is 0.002314 in the Ashkenazi Jewish population (v2.1.1). This variant has been classified as pathogenic by >60 submitters in ClinVar, including a BRCA1 expert panel. Based on the available evidence, the c.5266dup (p.Gln1756ProfsTer74) variant is classified as pathogenic for hereditary breast and ovarian cancer. -
Pathogenic, criteria provided, single submitter	clinical testing	Mendelics	May 28, 2019	- -
Pathogenic, no assertion criteria provided	clinical testing	BRCAlab, Lund University	Aug 26, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	DASA	Mar 05, 2022	The c.5266dup;p.(Gln1756Profs*74) is a null frameshift variant (NMD) in the BRCA1 gene and predicts alteration of the nonsense-mediate decay - NMD is present in a relevant exon to the transcript - PVS1_strong. This sequence change has been observed in affected individual(s) and ClinVar contains an entry for this variant (ClinVar ID: 17677; PMID: 15994883; PMID: 22430266) - PS4. The variant is present at low allele frequencies population databases (rs80357906 – gnomAD 0.001803%; ABraOM no frequency - http://abraom.ib.usp.br/) - PM2_supporting. In summary, the currently available evidence indicates that the variant is pathogenic. -
Pathogenic, no assertion criteria provided	literature only	OMIM	Oct 15, 2008	- -
Pathogenic, criteria provided, single submitter	clinical testing	Biomedical Genomics and Oncogenetics Laboratory, Institut Pasteur de Tunis, University Tunis El Manar	-	- -
Pathogenic, no assertion criteria provided	clinical testing	Institute of Human Genetics, Medical University Innsbruck	Feb 11, 2015	- -
Pathogenic, criteria provided, single submitter	literature only	Counsyl	Jul 07, 2014	- -
Pathogenic, criteria provided, single submitter	research	Institute of Genomics, University of Tartu	-	- -

not provided Pathogenic:14 Other:1

Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Sep 01, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Clinical Genetics and Genomics, Karolinska University Hospital	Sep 18, 2014	- -
Pathogenic, criteria provided, single submitter	clinical testing	Institute of Human Genetics, FAU Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg	Jan 17, 2024	This variant has been identified by standard clinical testing. female patient with metastatic breast cancer Selected ACMG criteria: Pathogenic (I):PP5;PS4;PVS1 -
Pathogenic, criteria provided, single submitter	clinical testing	Institute for Clinical Genetics, University Hospital TU Dresden, University Hospital TU Dresden	Nov 03, 2021	- -
not provided, no classification provided	phenotyping only	GenomeConnect, ClinGen	-	GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -
Pathogenic, criteria provided, single submitter	clinical testing	Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen	Oct 23, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Nov 07, 2014	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Feb 12, 2020	Frameshift variant predicted to result in protein truncation 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; Also known as 5382insC or 5385insC; This variant is associated with the following publications: (PMID: 25859162, 25849179, 27160020, 26843898, 26852130, 26833046, 27025497, 27062684, 26681312, 29790872, 26440929, 30067863, 31336956, 32854451, 24372583, 21119707, 26656232, 26083025, 25476495, 24528374, 25195694, 22032251, 7894492, 16168118, 27223485, 26779294, 27433846, 26666763, 26718727, 29478780, 27425403, 22009639, 20569256, 21503673, 23232912, 20345474, 22430266, 29335925, 28285342, 22535016, 29339979, 23954390, 29433453, 29335924, 29492181, 21834074, 24737347, 19359128, 27914478, 28324225, 22666503, 27989354, 29907814, 20730485, 28091860, 28503720, 26556299, 10464624, 28423363, 20507347, 22006311, 25980754, 21324516, 29310832, 30333958, 30159786, 29161300, 30606148, 30152102, 28049106, 28111427, 30186769, 29961768, 30322717, 31090900, 31159747, 30113427, 23199084, 8841191, 30676620, 30489631, 31454914, 12771565, 31528241, 27741520, 29625052, 26689913, 32058061, 31447099, 32039725) -
Pathogenic, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	May 23, 2023	PP5, PS4_moderate, PVS1 -
Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Jun 04, 2023	The BRCA1 c.5266dup (p.Gln1756Profs*74) variant alters the translational reading frame of the BRCA1 mRNA and causes the premature termination of BRCA1 protein synthesis. This variant has been reported in the published literature as a founder mutation in the Ashkenazi Jewish population and has been reported in multiple individuals and families affected with breast and/or ovarian cancer (PMIDs: 18694767 (2008), 19208665 (2009), 21119707 (2011), 30606148 (2019), 32438681 (2020), 35409996 (2022)), as well as prostate cancer (PMID: 36612302 (2023)). This variant has also been reported in affected and control individuals in a large-scale breast cancer association study (PMID: 33471991 (2021), see also LOVD (http://databases.lovd.nl/shared/)). A functional study showed that this variant caused the complete loss of BRCA1 phosphopeptide binding activity (PMID: 15133502 (2004)). Based on the available information, this variant is classified as pathogenic. -
Pathogenic, no assertion criteria provided	clinical testing	Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)	-	- -
Pathogenic, no assertion criteria provided	clinical testing	Clinical Genetics Laboratory, Department of Pathology, Netherlands Cancer Institute	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	May 01, 2024	BRCA1: PVS1, PS4:Moderate -
Pathogenic, criteria provided, single submitter	clinical testing	Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital	Feb 06, 2024	- -
Pathogenic, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Oct 05, 2023	The BRCA1 c.5266dup; p.Gln1756ProfsTer74 variant, also known as 5382insC, has been described in individuals and families with hereditary breast and ovarian cancer, peritoneal cancer, and pancreatic cancer and is a known pathogenic founder variant (Bogdanova 2010, Elsakov 2010, Heidemann 2012, Simard 1994, Uglanitsa 2010, Zhang 2011). This variant is reported as pathogenic in ClinVar (Variation ID: 17677). It is found in the general population with an overall allele frequency of 0.02% (51/282892 alleles) in the Genome Aggregation Database. This variant causes a frameshift by duplicating a single nucleotide, so it is predicted to result in a truncated protein or mRNA subject to nonsense-mediated decay. Based on available information, this variant is considered to be pathogenic. [**Use the AJ BRCA template under BRCA NGS, OR Make sure to add the AJ recommendations from that template "If this individual is of Ashkenazi Jewish ancestry…"**] References: Bogdanova NV et al. High frequency and allele-specific differences of BRCA1 founder mutations in breast cancer and ovarian cancer patients from Belarus. Clin Genet. 2010 78(4):364-72. PMID: 20569256. Elsakov P et al. The contribution of founder mutations in BRCA1 to breast and ovarian cancer in Lithuania. Clin Genet. 2010 78(4):373-6. PMID: 20345474. Heidemann S et al. Double heterozygosity for mutations in BRCA1 and BRCA2 in German breast cancer patients: implications on test strategies and clinical management. Breast Cancer Res Treat. 2012 134(3):1229-39. PMID: 22535016. Simard J et al. Common origins of BRCA1 mutations in Canadian breast and ovarian cancer families. Nat Genet. 1994 8(4):392-8. PMID: 7894492. Uglanitsa N et al. The contribution of founder mutations in BRCA1 to breast cancer in Belarus. Clin Genet. 2010 78(4):377-80. PMID: 20507347. Zhang S et al. Frequencies of BRCA1 and BRCA2 mutations among 1,342 unselected patients with invasive ovarian cancer. Gynecol Oncol. 2011 121(2):353-7. PMID: 21324516. -

Hereditary breast ovarian cancer syndrome Pathogenic:8 Other:1

Pathogenic, criteria provided, single submitter	clinical testing	National Health Laboratory Service, Universitas Academic Hospital and University of the Free State	Nov 16, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Nov 23, 2022	The p.Gln1756ProfsX74 variant in BRCA1 (also referred to as p.Gln1777fs) is a founder variant in the Ashkenazi Jewish population and has been reported in >1000 individuals with BRCA1-associated cancers (Abeliovich 1997 PMID: 9042909, Elwad 2011 PMID: 22185575, Breast Cancer Information Core (BIC) database). This variant has also been identified in 0.2% (24/103702) Ashkenazi Jewish and 0.02% (25/129200) of European chromosomes by gnomAD (http://gnomad.broadinstitute.org). This variant is predicted to cause a frameshift, which alters the protein’s amino acid sequence beginning at position 1756 and leads to a premature termination codon 74 amino acids downstream. This alteration is then predicted to lead to a truncated or absent protein. Heterozygous loss of function of the BRCA1 gene is an established disease mechanism in hereditary breast and ovarian cancer (HBOC). Furthermore, the p.Gln1756ProfsX74 variant was classified as Pathogenic on April 22, 2016 by the ClinGen-approved ENIGMA expert panel (ClinVar ID 17677). In summary, this variant meets criteria to be classified as pathogenic for autosomal dominant HBOC. ACMG/AMP Criteria applied: PS4, PVS1. -
not provided, no classification provided	literature only	GeneReviews	-	Founder variant in Ashkenazi Jews; accounts for 26% of pathogenic variants in this population -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 31, 2024	This sequence change creates a premature translational stop signal (p.Gln1756Profs*74) in the BRCA1 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 108 amino acid(s) of the BRCA1 protein. This variant is present in population databases (rs397507247, gnomAD 0.2%), and has an allele count higher than expected for a pathogenic variant. This premature translational stop signal has been observed in individual(s) with breast and ovarian cancer. It is commonly reported in individuals of Ashkenazi Jewish ancestry (PMID: 9042909, 22185575, 22430266). This variant is also known as 5382insC and 5385insC. ClinVar contains an entry for this variant (Variation ID: 17677). This variant has been associated with a 67% to 89% risk of breast cancer by age 70, and a 33% to 42% risk of ovarian cancer by age 70 (PMID: 15994883, 22430266). This variant disrupts a region of the BRCA1 protein in which other variant(s) (Deletion (Exon 23)) have been determined to be pathogenic (PMID: 18431737, 24825132, 25428789; Invitae). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 22, 2016	Variant summary: The BRCA1 c.5266dupC variant results in a frameshift, which alters the protein's amino acid sequence beginning at position 1756 and leads to a premature termination codon 73 amino acids downstream. It is predicted to cause a truncated or absent BRCA1 protein due to non-sense meditated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory (such as c.5387C>A/p.Ser1796X, c.5417delC/Pro1806fsX28, etc). Mutation Taster predicts a damaging outcome for this variant, and functional studies have shown HR activity is significantly impaired by this variant (Bouwman_BRCA1_Cancer Discovery_2013). BRCA1 c.5266dupC was found in 19/121412 control chromosomes at a frequency of 0.0001565, which does not exceed maximal expected frequency of a pathogenic BRCA1 allele (0.0010005). The variant has been cited in hundreds of HBOC patients and is reported as a known common founder mutation in the literature. Additionally, this variant has been classified by multiple clinical labs and databases as pathogenic. Taken together, this variant was classified as disease variant/pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	GeneKor MSA	Jan 09, 2021	This mutation is an insertion of one nucleotide (cytosine), resulting in a frameshift and the creation of a novel translational termination codon after 74 amino acid residues. The protein product thus produced is truncated and non-functional. This mutation has been described in the international bibliography (http://research.nhgri.nih.gov/projects/bic) and has been shown to be a founder mutation in a number of ethnic groups (PMID: 12142080). This mutation has been described in the mutation database ClinVar (Variation ID:17677). -
Pathogenic, no assertion criteria provided	research	Research Molecular Genetics Laboratory, Women's College Hospital, University of Toronto	Jan 31, 2014	- -
Pathogenic, criteria provided, single submitter	clinical testing	Institute for Biomarker Research, Medical Diagnostic Laboratories, L.L.C.	Feb 14, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario	Feb 02, 2017	- -

Familial cancer of breast Pathogenic:4

Pathogenic, criteria provided, single submitter	clinical testing	Institute of Human Genetics, University of Leipzig Medical Center	Jan 12, 2024	Criteria applied: PVS1,PS4,PM5_STR,PS3_MOD -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Feb 23, 2017	- -
Pathogenic, no assertion criteria provided	clinical testing	Bioscientia Institut fuer Medizinische Diagnostik GmbH, Sonic Healthcare	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Centre for Mendelian Genomics, University Medical Centre Ljubljana	Jun 03, 2019	This variant was classified as: Pathogenic. The following ACMG criteria were applied in classifying this variant: PVS1,PS1. -

Breast and/or ovarian cancer Pathogenic:3

Pathogenic, no assertion criteria provided	clinical testing	Foulkes Cancer Genetics LDI, Lady Davis Institute for Medical Research	Jul 07, 2016	- -
Pathogenic, criteria provided, single submitter	clinical testing	CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario	Mar 24, 2023	- -
Pathogenic, no assertion criteria provided	clinical testing	CZECANCA consortium	Jun 11, 2019	- -

Hereditary cancer-predisposing syndrome Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Mar 20, 2023	This variant (also known as 5382insC and 5385insC) inserts 1 nucleotide in exon 19 of the BRCA1 gene, causing a frameshift and a premature translational stop signal in the last exon. The mutant transcript is expected to escape nonsense-mediated decay and be expressed as a truncated protein that lacks the C-terminal BRCT domain. Experimental studies have shown that variant impacts BRCA1 function in homology-directed repair and subcellular localization assays (PMID: 14729053, 23867111). This variant is a well-known founder mutation in the Ashkenazi Jewish population and occurs at 0.13-0.28% minor allele frequency (PMID: 8841191, 9145676, 11466700, 30152102). This variant has been reported in numerous individuals affected with breast and/or ovarian cancer (PMID: 7545954, 7894492, 8531967, 9042909, 9150153, 17922257, 18334730, 21643751, 22430266, 25418591, 29335925, 30480775, 30606148, 30975216). This variant is the most globally frequent, pathogenic BRCA1 variant and has been reported in diverse populations in Africa, America, Asia and Europe (PMID: 24312913). The risk of female breast cancer among carriers of this mutation is 67-89% by age 70, and the risk of ovarian cancer is 22-42% by age 70 (PMID: 9145676, 15994883, 22430266). A breast cancer case-control meta-analysis has reported this variant in 97/60369 cases and 11/53450 controls with an estimated OR of 7.808 (95%CI 4.185 to 14.567) (PMID: 33471991; Leiden Open Variation Database DB-ID BRCA1_000440). This variant has been identified in 51/282892 chromosomes (24/10370 Ashkenazi Jewish chromosomes and 25/129200 Non-Finnish European chromosomes) in the general population by the Genome Aggregation Database (gnomAD). Loss of BRCA1 function is a known mechanism of disease. Based on the available evidence, this variant is classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	May 24, 2022	The c.5266dupC (p.Q1756Pfs*74) alteration, located in exon 19 (coding exon 18) of the BRCA1 gene, consists of a duplication of C at position 5266, causing a translational frameshift with a predicted alternate stop codon after amino acids. This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. This alteration is one of three well-characterized Ashkenazi Jewish founder mutations, with an overall carrier frequency of nearly 0.5% in this population, but has also been shown to occur at high frequency in many other European populations (Hartge, 1999; Hamel, 2011; Kluz, 2018). Cumulative female breast cancer and ovarian cancer risks (by age 70) associated with this specific mutation have been estimated in the literature at 67% (range: 36-83%) and 33% (range: 8-50%), respectively (Antoniou, 2005). Of note, this mutation is also designated as 5382insC and 5385insC in the published literature. Based on the available evidence, this alteration is classified as pathogenic. -
Pathogenic, no assertion criteria provided	clinical testing	True Health Diagnostics	Apr 27, 2018	- -

Neoplasm of ovary Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Centre for Mendelian Genomics, University Medical Centre Ljubljana	May 29, 2014	- -
Pathogenic, no assertion criteria provided	research	German Consortium for Hereditary Breast and Ovarian Cancer, University Hospital Cologne	Dec 01, 2018	- -

Punctate palmoplantar keratoderma type 2 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Bioinformatics dept., Datar Cancer Genetics Limited, India

Jul 21, 2017

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Breast neoplasm Pathogenic:1

Pathogenic, criteria provided, single submitter

research

A.C.Camargo Cancer Center / LGBM, A.C.Camargo Cancer Center

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Familial cancer of breast;C2676676:Breast-ovarian cancer, familial, susceptibility to, 1;C3280442:Pancreatic cancer, susceptibility to, 4;C4554406:Fanconi anemia, complementation group S Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Nov 22, 2021

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BRCA1-related disorder Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Feb 26, 2024

The BRCA1 c.5266dupC variant is predicted to result in a frameshift and premature protein termination (p.Gln1756Profs*74). This variant, also described as 5382insC, 5385insC, or 5329dupC in the literature, has been associated with autosomal dominant hereditary breast and ovarian cancer syndrome (HBOC) (OMIM #604370; Bogdanova et al. 2010. PubMed ID: 20569256; Alemar et al. 2016. PubMed ID: 27425403; Azzollini et al. 2016. PubMed ID: 27062684; Hamel et al. 2011. PubMed ID: 21119707). This is a founder variant in the Ashkenazi Jewish population, identified in 0.13% of Ashkenazi Jewish individuals unselected for breast cancer (Roa et al. 1996. PubMed ID:8841191). This variant is frequently observed in the Ashkenazi Jewish population in gnomad. This variant is also found in individuals of diverse ancestry at variable frequencies. It is interpreted as pathogenic in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/17677/). Frameshift variants in BRCA1 are expected to be pathogenic. In summary, this variant is interpreted as pathogenic. -

Endometrial carcinoma Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

CZECANCA consortium

Feb 21, 2023

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Malignant tumor of breast Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

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Pancreatic cancer, susceptibility to Other:1

risk factor, no assertion criteria provided

literature only

OMIM

Oct 15, 2008

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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: rs80357906; hg19: chr17-41209079;