17-43104928-G-A

Position:

• chr17-43104928-G-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.241C>T​(p.Gln81Ter) variant causes a stop gained change. The variant allele was found at a frequency of 0.000000684 in 1,461,552 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BRCA1 NM_007294.4 stop_gained
• Clinical Significance: Pathogenic reviewed by expert panel P:12 O:1
• Conservation: PhyloP100: 4.24

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 17-43104928-G-A is Pathogenic according to our data. Variant chr17-43104928-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 54565.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr17-43104928-G-A is described in Lovd as [Pathogenic]. Variant chr17-43104928-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.241C>T	p.Gln81Ter	stop_gained	5/23	ENST00000357654.9	NP_009225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9	c.241C>T	p.Gln81Ter	stop_gained	5/23	1	NM_007294.4	ENSP00000350283	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461552 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727098

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000594 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:12 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

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

Pathogenic, criteria provided, single submitter	clinical testing	Department of Medical Genetics, Oslo University Hospital	Jul 01, 2015	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Mar 08, 2021	- -
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)	Sep 08, 2016	Variant allele predicted to encode a truncated non-functional protein. -
Pathogenic, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA1)	May 29, 2002	- -
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:2

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	Labcorp Genetics (formerly Invitae), Labcorp	Jul 08, 2021	For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in BRCA1 are known to be pathogenic (PMID: 20104584). This variant has been reported in a family affected with breast cancer or ovarian cancer (PMID: 15382066). This variant is also known as c.360C>T in the literature. ClinVar contains an entry for this variant (Variation ID: 54565). This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Gln81*) in the BRCA1 gene. It is expected to result in an absent or disrupted protein product. -

Breast and/or ovarian cancer Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Foulkes Cancer Genetics LDI, Lady Davis Institute for Medical Research

Sep 06, 2000

- -

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

Oct 31, 2018

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital

Aug 15, 2023

- -

Malignant tumor of breast Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

-

The p.Gln81X variant was identified in 1 of 338 proband chromosomes (frequency: 0.003) from individuals or families with Breast and or Ovarian cancer (Oros, 2004). The variant was also identified in dbSNP (ID: rs80357350) “With pathogenic allele”, HGMD, ClinVar database (sighted by BIC and invitae), the BIC database (3X with class 5 clinical importance), and UMD (5X as a causal variant). The p.Gln81X variant leads to a premature stop codon at position 81, 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

Aug 19, 2022

The p.Q81* pathogenic mutation (also known as c.241C>T), located in coding exon 4 of the BRCA1 gene, results from a C to T substitution at nucleotide position 241. This changes the amino acid from a glutamine to a stop codon within coding exon 4. This mutation has been reported in multiple families with hereditary breast and/or ovarian cancer (Oros KK et al. Int. J. Cancer 2004 Nov;112(3):411-9; Heramb C et al. Hered Cancer Clin Pract 2018 Jan;16:3; Arai M et al. J. Hum. Genet. 2018 Apr;63(4):447-457). Of note, this mutation is also designated as 360C>T in published literature. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). 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	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	37
DANN	Uncertain	1.0
Eigen	Pathogenic	0.95
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Uncertain	0.96	D
MutationTaster	Benign	1.0	A;A;A;A;A;A;A;A;A;A;D;D;D;D
Vest4		0.95
GERP RS		4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.51		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.51		Position offset: 28

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

Publications

LitVar

Other links and lift over

dbSNP: rs80357350; hg19: chr17-41256945;