NM_007294.4:c.5334T>A

Variant names:

• chr17-43049193-A-T
• rs754152768
• NM_007294.4:c.5334T>A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PM5

The NM_007294.4(BRCA1):​c.5334T>A​(p.Asp1778Glu) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,692 control chromosomes in the GnomAD database, with no homozygous occurrence. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D1778V) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BRCA1 NM_007294.4 missense, splice_region
• Scores: Splicing: ADA: 0.1253
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 1.17
• Publications: 5 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):

• breast-ovarian cancer, familial, susceptibility to, 1

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

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae), ClinGen, 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: Likely_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 11 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 17 benign, 79 uncertain in NM_007294.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-43051062-CCT-ATGTTG is described in ClinVar as Pathogenic. ClinVar VariationId is 236263.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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BRCA1	NM_007294.4	MANE Select	c.5334T>A	p.Asp1778Glu	missense splice_region	Exon 21 of 23	NP_009225.1
	BRCA1	NM_001407581.1		c.5400T>A	p.Asp1800Glu	missense splice_region	Exon 22 of 24	NP_001394510.1
	BRCA1	NM_001407582.1		c.5400T>A	p.Asp1800Glu	missense splice_region	Exon 22 of 24	NP_001394511.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BRCA1	ENST00000357654.9	TSL:1 MANE Select	c.5334T>A	p.Asp1778Glu	missense splice_region	Exon 21 of 23	ENSP00000350283.3
	BRCA1	ENST00000471181.7	TSL:1	c.5397T>A	p.Asp1799Glu	missense splice_region	Exon 22 of 24	ENSP00000418960.2
	BRCA1	ENST00000470026.6	TSL:1	c.5334T>A	p.Asp1778Glu	missense splice_region	Exon 21 of 23	ENSP00000419274.2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461692 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727162

⚠️ 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: 33478

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

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111824

Other (OTH) AF: 0.00 AC: 0 AN: 60390

⚠️ 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

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary breast ovarian cancer syndrome Uncertain:2

May 01, 2020

Breast Center, Key Laboratory of Carcinogenesis and Translational Research

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Apr 09, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with glutamic acid, which is acidic and polar, at codon 1778 of the BRCA1 protein (p.Asp1778Glu). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with BRCA1-related conditions. ClinVar contains an entry for this variant (Variation ID: 865356). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. Experimental studies have shown that this missense change does not substantially affect BRCA1 function (PMID: 32803532). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.

Breast and/or ovarian cancer Uncertain:1

Feb 23, 2023

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:1

Mar 17, 2024

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Pathogenic	0.18	D
BayesDel_noAF	Uncertain	0.020
CADD	Benign	18
DANN	Uncertain	0.99
DEOGEN2	Benign	0.12	T
Eigen	Benign	0.15
Eigen_PC	Benign	0.20
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Benign	0.81	T
MetaRNN	Uncertain	0.47	T
MetaSVM	Uncertain	0.036	D
MutationAssessor	Benign	1.8	L
PhyloP100		1.2
PrimateAI	Benign	0.40	T
PROVEAN	Uncertain	-2.6	D
REVEL	Uncertain	0.53
Sift	Benign	0.24	T
Sift4G	Benign	0.41	T
Polyphen		0.030	B
Vest4		0.41
MVP		0.74
MPC		0.094
ClinPred		0.80	D
GERP RS		5.5
Varity_R		0.49
gMVP		0.22

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.13
dbscSNV1_RF	Benign	0.32
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

Other links and lift over

dbSNP: rs754152768; hg19: chr17-41201210;