rs878854957

Positions:

• chr17-43063365-G-A
• chr17-43063365-G-C
• chr17-43063365-G-T

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.5161C>T​(p.Gln1721Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★★). Synonymous variant affecting the same amino acid position (i.e. Q1721Q) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: BRCA1 NM_007294.4 stop_gained
• Clinical Significance: Pathogenic reviewed by expert panel P:8 O:1
• Conservation: PhyloP100: 2.50

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 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 17-43063365-G-A is Pathogenic according to our data. Variant chr17-43063365-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 266529.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr17-43063365-G-A is described in Lovd as [Pathogenic]. Variant chr17-43063365-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA1	NM_007294.4	c.5161C>T	p.Gln1721Ter	stop_gained	18/23	ENST00000357654.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA1	ENST00000357654.9	c.5161C>T	p.Gln1721Ter	stop_gained	18/23	1	NM_007294.4	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:8 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

Hereditary breast ovarian cancer syndrome Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Aug 18, 2023	This sequence change creates a premature translational stop signal (p.Gln1721*) 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 breast and ovarian cancer (PMID: 23175448, 26306726, 29446198, 30333958). This variant is also known as 5280C>T Q1721X and c.5224C>T p.Gln1742*. ClinVar contains an entry for this variant (Variation ID: 266529). 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	Feb 26, 2024	Variant summary: BRCA1 c.5161C>T (p.Gln1721X) 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. The variant was absent in 250974 control chromosomes. c.5161C>T has been reported in the literature in individuals affected with Hereditary Breast and Ovarian Cancer (Muendlein_2015, Nakamura_2013, Minucci_2015, Kechin_2023). These data indicate that the variant is likely to be associated with disease. The following publications have been ascertained in the context of this evaluation (PMID: 24249303, 25971625, 26306726, 36367610). ClinVar contains an entry for this variant (Variation ID: 266529). Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	research	Research Institute, Aichi Cancer Center	Feb 01, 2022	- -

Breast-ovarian cancer, familial, susceptibility to, 1 Pathogenic:2 Other:1

not provided, no classification provided	in vitro	Brotman Baty Institute, University of Washington	-	- -
Pathogenic, reviewed by expert panel	curation	Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA)	Oct 18, 2016	Variant allele predicted to encode a truncated non-functional protein. -
Pathogenic, criteria provided, single submitter	clinical testing	Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), c/o University of Cambridge	Oct 02, 2015	- -

Gastric cancer Pathogenic:1

Pathogenic, no assertion criteria provided

research

Laboratory for Genotyping Development, RIKEN

Jul 01, 2021

- -

Malignant tumor of breast Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

-

The BRCA1 p.Gln1721X variant was identified in 4 of 1314 proband chromosomes (frequency: 0.003) from individuals or families with breast and ovarian cancer (Cao 2013, Cao 2016, Laitman 2011, Minucci 2015); however, control chromosomes were not evaluated in these studies, thus the prevalence of this variant in the general population could not be determined. The variant was also identified in the following databases: ClinVar (3x, pathogenic, reviewed by ENIGMA expert panel), Clinvitae (1x, pathogenic), LOVD 3.0 (1x), UMD-LSDB (3x, causal), and ARUP Laboratories (1x, definitely pathogenic). The variant was not identified in dbSNP, Cosmic, MutDB, BIC Database, or the Zhejiang Colon Cancer Database. The variant was not identified in the control databases: the 1000 Genomes Project, the NHLBI GO Exome Sequencing Project, the Exome Aggregation Consortium (August 8th 2016), or the Genome Aggregation Database (Feb 27, 2017). The c.5161C>T variant leads to a premature stop codon at position 1721 which is predicted to lead to a truncated or absent protein and loss of function. Loss of function variants of the BRCA1 gene are an established mechanism of disease in hereditary breast and ovarian cancer and is the type of variant expected to cause the disorder. In summary, based on the above information this variant meets our laboratory’s criteria to be classified as pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 23, 2021

The p.Q1721* pathogenic mutation (also known as c.5161C>T), located in coding exon 17 of the BRCA1 gene, results from a C to T substitution at nucleotide position 5161. This changes the amino acid from a glutamine to a stop codon within coding exon 17. This mutation has been reported in individuals from various ethnic backgrounds with breast and/or ovarian cancer (Minucci A et al. Expert Rev. Mol. Diagn. 2015 Aug;15:1383-403; Laitman Y et al. Breast Cancer Res. Treat. 2011 Jun;127:489-95; Cao W et al. Anat Rec (Hoboken) 2013 Feb;296:273-8; Bhaskaran SP et al. Int J Cancer. 2019 Aug 15;145(4):962-973.). Of note, this alteration is also designated as 5280C>T in published literature. 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

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	41
DANN	Uncertain	0.99
Eigen	Pathogenic	0.78
Eigen_PC	Uncertain	0.59
FATHMM_MKL	Uncertain	0.84	D
MutationTaster	Benign	1.0	A;A;A;A;A;A;A;A;A;A;A;A;A;D
Vest4		0.94
GERP RS		3.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs878854957; hg19: chr17-41215382;