chr17-43049192-G-A

Variant names:

• chr17-43049192-G-A
• rs397509267
• NM_007294.4:c.5335C>T

Variant summary

Our verdict is Pathogenic. The variant received 22 ACMG points: 22P and 0B. PVS1 PS3 PM2 PP5_Very_Strong

The NM_007294.4(BRCA1):​c.5335C>T​(p.Gln1779*) variant causes a stop gained, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,554 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Pathogenic (★★★). ClinVar reports functional evidence for this variant: "SCV000661070: One functional study found that this nucleotide substitution is deleterious in a high throughput genome editing haploid cell survival assay (Findlay, 2018).; SCV000779357: Published functional studies demonstrate a damaging effect: variant classified as non-functional based on a saturation genome editing (SGE) assay measuring cell survival (Findlay et al., 2018).; SCV004847910: "In vitro functional studies support an impact on protein function (Findlay 2018)."". Synonymous variant affecting the same amino acid position (i.e. Q1779Q) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BRCA1 NM_007294.4 stop_gained, splice_region
• Clinical Significance: Pathogenic reviewed by expert panel P:6
• Conservation: PhyloP100: 1.86
• Publications: 11 publications found

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]

BRCA1 Gene-Disease associations (from GenCC):

• BRCA1-related cancer predisposition

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• breast-ovarian cancer, familial, susceptibility to, 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics
• Fanconi anemia, complementation group S

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, LIMITED Submitted by: G2P, ClinGen, Labcorp Genetics (formerly Invitae), Ambry Genetics
• pancreatic cancer, susceptibility to, 4

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• hereditary breast ovarian cancer syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Fanconi anemia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 22 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PS3: PS3 evidence extracted from ClinVar submissions: SCV000661070: One functional study found that this nucleotide substitution is deleterious in a high throughput genome editing haploid cell survival assay (Findlay, 2018).; SCV000779357: Published functional studies demonstrate a damaging effect: variant classified as non-functional based on a saturation genome editing (SGE) assay measuring cell survival (Findlay et al., 2018).; SCV004847910: "In vitro functional studies support an impact on protein function (Findlay 2018)."
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-43049192-G-A is Pathogenic according to our data. Variant chr17-43049192-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 55540.Status of the report is reviewed_by_expert_panel, 3 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_007294.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BRCA1	NM_007294.4	MANE Select	c.5335C>T	p.Gln1779*	stop_gained splice_region	Exon 21 of 23	NP_009225.1	P38398-1
	BRCA1	NM_001407581.1		c.5401C>T	p.Gln1801*	stop_gained splice_region	Exon 22 of 24	NP_001394510.1	A0A2R8Y7V5
	BRCA1	NM_001407582.1		c.5401C>T	p.Gln1801*	stop_gained splice_region	Exon 22 of 24	NP_001394511.1	A0A2R8Y7V5

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BRCA1	ENST00000357654.9	TSL:1 MANE Select	c.5335C>T	p.Gln1779*	stop_gained splice_region	Exon 21 of 23	ENSP00000350283.3	P38398-1
	BRCA1	ENST00000471181.7	TSL:1	c.5398C>T	p.Gln1800*	stop_gained splice_region	Exon 22 of 24	ENSP00000418960.2	P38398-7
	BRCA1	ENST00000470026.6	TSL:1	c.5335C>T	p.Gln1779*	stop_gained splice_region	Exon 21 of 23	ENSP00000419274.2	P38398-1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461554 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727116

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86246

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111714

Other (OTH) AF: 0.00 AC: 0 AN: 60382

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 31

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
2	-	-	Breast-ovarian cancer, familial, susceptibility to, 1 (2)
2	-	-	Hereditary breast ovarian cancer syndrome (2)
1	-	-	Hereditary cancer-predisposing syndrome (1)
1	-	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	38
DANN	Uncertain	0.99
Eigen	Pathogenic	0.81
Eigen_PC	Uncertain	0.60
FATHMM_MKL	Uncertain	0.86	D
PhyloP100		1.9
Vest4		0.93
GERP RS		4.5
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs397509267; hg19: chr17-41201209; COSMIC: COSV104621668;