rs80357180

Positions:

• chr17-43099859-G-A
• chr17-43099859-G-C
• chr17-43099859-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.463C>T​(p.Gln155Ter) 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. Q155Q) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 31)
• Consequence: BRCA1 NM_007294.4 stop_gained
• Clinical Significance: Pathogenic reviewed by expert panel P:4 O:1
• Conservation: PhyloP100: 1.23

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 17-43099859-G-A is Pathogenic according to our data. Variant chr17-43099859-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 55248.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr17-43099859-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA1	NM_007294.4	c.463C>T	p.Gln155Ter	stop_gained	7/23	ENST00000357654.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA1	ENST00000357654.9	c.463C>T	p.Gln155Ter	stop_gained	7/23	1	NM_007294.4	P4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

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

Pathogenic, criteria provided, single submitter	clinical testing	Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet	May 27, 2024	PVS1; PM2_supporting; PM5_PTC_Strong -
Pathogenic, reviewed by expert panel	curation	Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA)	Dec 15, 2017	Variant allele predicted to encode a truncated non-functional protein. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 23, 2021

The p.Q155* pathogenic mutation (also known as c.463C>T), located in coding exon 6 of the BRCA1 gene, results from a C to T substitution at nucleotide position 463. This changes the amino acid from a glutamine to a stop codon within coding exon 6. This mutation has been reported in several Chinese individuals with breast and or ovarian cancer (Hu Z et al. Hum Mutat. 2003 Jul;22:104; Bhaskaran SP et al. Int J Cancer. 2019 08;145:962-973). Of note, this mutation may be referred to as 582C>T in some literature. 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. -

Hereditary breast ovarian cancer syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 14, 2021

For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 55248). This premature translational stop signal has been observed in individual(s) with breast cancer (PMID: 12815604). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Gln155*) 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). -

Familial cancer of breast Other:1

not provided, no classification provided

literature only

ClinVar Staff, National Center for Biotechnology Information (NCBI)

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Uncertain	0.060
CADD	Pathogenic	34
DANN	Uncertain	1.0
Eigen	Uncertain	0.41
Eigen_PC	Benign	0.088
FATHMM_MKL	Benign	0.13	N
MutationTaster	Benign	1.0	A;A;A;A;A;A;A;A;A;A;N;N;N;N
Vest4		0.89
GERP RS		3.2

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: rs80357180; hg19: chr17-41251876;