NM_007294.4:c.1391C>T

Variant names:

• chr17-43094140-G-A
• rs62625301
• NM_007294.4:c.1391C>T

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PP3_Moderate BP6

The NM_007294.4(BRCA1):​c.1391C>T​(p.Thr464Ile) variant causes a missense change. The variant allele was found at a frequency of 0.0000041 in 1,461,734 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T464A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:2
• Conservation: PhyloP100: 6.18
• Publications: 7 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: Uncertain_significance. The variant received 1 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.898
• BP6: Variant 17-43094140-G-A is Benign according to our data. Variant chr17-43094140-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 54237.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.1391C>T	p.Thr464Ile	missense_variant	Exon 10 of 23	ENST00000357654.9	NP_009225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9	c.1391C>T	p.Thr464Ile	missense_variant	Exon 10 of 23	1	NM_007294.4	ENSP00000350283.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251096 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000410 AC: 6 AN: 1461734 Hom.: 0 Cov.: 34 AF XY: 0.00000275 AC XY: 2 AN XY: 727170

African (AFR) AF: 0.00 AC: 0 AN: 33460

American (AMR) AF: 0.00 AC: 0 AN: 44714

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39686

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

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53368

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

European-Non Finnish (NFE) AF: 0.00000540 AC: 6 AN: 1111972

Other (OTH) AF: 0.00 AC: 0 AN: 60388

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2 Benign:1

Nov 29, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces threonine with isoleucine at codon 464 of the BRCA1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with BRCA1-related disorders in the literature. This variant has been identified in 1/251096 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Mar 23, 2023

University of Washington Department of Laboratory Medicine, University of Washington

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: curation

Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673). -

May 24, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.T464I variant (also known as c.1391C>T), located in coding exon 9 of the BRCA1 gene, results from a C to T substitution at nucleotide position 1391. The threonine at codon 464 is replaced by isoleucine, an amino acid with similar properties. This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

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

Dec 18, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces threonine with isoleucine at codon 464 of the BRCA1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 1/251096 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Dec 17, 2010

Breast Cancer Information Core (BIC) (BRCA1)

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Hereditary breast ovarian cancer syndrome Uncertain:1 Benign:1

Aug 13, 2024

German Consortium for Hereditary Breast and Ovarian Cancer, University Hospital Cologne

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: curation

According to the ClinGen ENIGMA BRCA1 v1.1.0 criteria we chose this criterion: BP1 (strong benign): silent substitution, missense or in-frame insertion, deletion or delins variants outside a (potentially) clinically important functional domain AND no splicing predicted (SpliceAI <=0.1). -

Oct 01, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 464 of the BRCA1 protein (p.Thr464Ile). This variant is present in population databases (rs62625301, gnomAD 0.0009%). This missense change has been observed in individual(s) with clinical features of BRCA1-related conditions (PMID: 10923033). ClinVar contains an entry for this variant (Variation ID: 54237). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on BRCA1 protein function. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.41
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.37
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.64	D;.;.;.;T;T;.;.;T
Eigen	Pathogenic	0.71
Eigen_PC	Uncertain	0.59
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.91	D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.31	D
MetaRNN	Pathogenic	0.90	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.2	D
MutationAssessor	Pathogenic	3.3	M;M;.;.;.;.;.;.;.
PhyloP100		6.2
PrimateAI	Benign	0.45	T
PROVEAN	Pathogenic	-5.9	D;D;D;D;.;D;D;D;D
REVEL	Pathogenic	0.87
Sift	Pathogenic	0.0	D;D;D;D;.;D;D;D;D
Sift4G	Uncertain	0.0060	D;D;D;D;.;D;.;D;D
Polyphen		1.0	D;.;.;D;.;.;.;.;.
Vest4		0.75
MutPred		0.61		Gain of helix (P = 0.0034);Gain of helix (P = 0.0034);.;Gain of helix (P = 0.0034);.;Gain of helix (P = 0.0034);.;.;Gain of helix (P = 0.0034);
MVP		0.98
MPC		0.47
ClinPred		0.98	D
GERP RS		4.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.6
Varity_R		0.68
gMVP		0.28
Mutation Taster		=72/28	polymorphism

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

Other links and lift over

dbSNP: rs62625301; hg19: chr17-41246157; COSMIC: COSV105177664;