17-43071124-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_007294.4(BRCA1):c.4790C>A(p.Thr1597Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,892 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T1597A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:7
• Conservation: PhyloP100: 0.593

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 Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.28614372).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA1	NM_007294.4	c.4790C>A	p.Thr1597Asn	missense_variant	15/23	ENST00000357654.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA1	ENST00000357654.9	c.4790C>A	p.Thr1597Asn	missense_variant	15/23	1	NM_007294.4	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251412 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135872

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000653

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461892 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 727246

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000464

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Jun 30, 2023	The p.T1597N variant (also known as c.4790C>A), located in coding exon 14 of the BRCA1 gene, results from a C to A substitution at nucleotide position 4790. The threonine at codon 1597 is replaced by asparagine, an amino acid with similar properties. This variant was observed in a study of 1010 unrelated Indian patients with breast and/or ovarian cancer (Singh J et al. Breast Cancer Res Treat, 2018 Jul;170:189-196). This amino acid position is poorly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Uncertain significance, criteria provided, single submitter	curation	Sema4, Sema4	Aug 24, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Nov 29, 2023	This missense variant replaces threonine with asparagine at codon 1597 of the BRCA1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with breast and/or ovarian (PMID: 29470806) and it has been detected in a breast cancer case-control meta-analysis in 1/60466 cases and 0/53461 unaffected individuals (PMID: 33471991; Leiden Open Variation Database DB-ID BRCA1_006201). This variant has been identified in 3/251412 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. -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

May 08, 2023

Variant summary: BRCA1 c.4790C>A (p.Thr1597Asn) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 1.2e-05 in 251412 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.4790C>A has been reported in the literature in an individual affected with Breast/Ovarian cancer and the authors classified the variant as VUS (example: Sing_2018). This report does not provide unequivocal conclusions about association of the variant with Prostate Cancer. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 29470806). Five clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and all classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

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

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Dec 18, 2023

This missense variant replaces threonine with asparagine at codon 1597 of the BRCA1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with breast and/or ovarian (PMID: 29470806) and it has been detected in a breast cancer case-control meta-analysis in 1/60466 cases and 0/53461 unaffected individuals (PMID: 33471991; Leiden Open Variation Database DB-ID BRCA1_006201). This variant has been identified in 3/251412 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. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Revvity Omics, Revvity

Nov 06, 2020

- -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 02, 2024

This sequence change replaces threonine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 1597 of the BRCA1 protein (p.Thr1597Asn). This variant is present in population databases (rs587781623, gnomAD 0.006%). This missense change has been observed in individual(s) with breast and/or ovarian cancer (PMID: 29470806). ClinVar contains an entry for this variant (Variation ID: 141272). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt BRCA1 protein function with a negative predictive value of 95%. 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	Benign	0.10
BayesDel_addAF	Benign	-0.012	T
BayesDel_noAF	Uncertain	-0.070
Cadd	Benign	3.4
Dann	Uncertain	0.98
Eigen	Benign	-0.48
Eigen_PC	Benign	-0.55
FATHMM_MKL	Benign	0.099	N
LIST_S2	Uncertain	0.90	D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.25	D
MetaRNN	Benign	0.29	T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	-0.25	T
MutationTaster	Benign	1.0	N;N;N;N;N;N;N;N;N;N;N;N;N;N
PrimateAI	Benign	0.31	T
PROVEAN	Benign	-1.7	N;N;.;N;.;N;N;N;N;N
REVEL	Uncertain	0.52
Sift	Uncertain	0.013	D;D;.;T;.;D;T;D;D;D
Sift4G	Benign	0.18	T;T;T;T;T;T;T;.;.;T
Polyphen		0.26, 0.72	.;B;.;.;.;.;.;.;P;.
Vest4		0.22
MVP		0.79
MPC		0.094
ClinPred		0.15	T
GERP RS		2.5
Varity_R		0.068
gMVP		0.19

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: rs587781623; hg19: chr17-41223141;