17-43093601-A-T

Position:

• chr17-43093601-A-T

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 0P and 1B. BP4

The NM_007294.4(BRCA1):​c.1930T>A​(p.Cys644Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000547 in 1,461,778 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in same amino acid change has been previously reported as Uncertain significancein ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C644F) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000055 (1 hom.)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4 B:1
• Conservation: PhyloP100: 3.05

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 Likely_benign. Variant got -1 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.39817703).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA1	NM_007294.4	c.1930T>A	p.Cys644Ser	missense_variant	10/23	ENST00000357654.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA1	ENST00000357654.9	c.1930T>A	p.Cys644Ser	missense_variant	10/23	1	NM_007294.4	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250856 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135560

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461778 Hom.: 1 Cov.: 34 AF XY: 0.00000550 AC XY: 4 AN XY: 727184

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000202

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Feb 25, 2020	This missense variant replaces cysteine with serine at codon 644 of the BRCA1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 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 reported for this variant. This variant has been reported in individuals affected with breast and/or ovarian cancer (PMID: 19656164, 28111427). This variant has also been identified in 1/250856 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. -
Likely benign, criteria provided, single submitter	curation	University of Washington Department of Laboratory Medicine, University of Washington	Mar 23, 2023	Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673). -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Nov 14, 2023	The p.C644S variant (also known as c.1930T>A), located in coding exon 9 of the BRCA1 gene, results from a T to A substitution at nucleotide position 1930. The cysteine at codon 644 is replaced by serine, an amino acid with dissimilar properties. This alteration has been reported in 1/206 breast cancer cases and 0/171 controls in a Korean study (Seong MW et al. Clin. Genet., 2009 Aug;76:152-60) as well as in 3/7051 unselected breast cancer patients and 3/11241 controls in a Japanese study (Momozawa Y et al. Nat Commun, 2018 Oct;9:4083). This amino acid position is not 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:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 21, 2023

This sequence change replaces cysteine, which is neutral and slightly polar, with serine, which is neutral and polar, at codon 644 of the BRCA1 protein (p.Cys644Ser). 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. 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. ClinVar contains an entry for this variant (Variation ID: 409347). This missense change has been observed in individual(s) with personal and/or family history of breast and/or ovarian cancer (PMID: 19656164, 28111427, 30287823). This variant is present in population databases (rs753521391, gnomAD 0.006%). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Uncertain	0.16	D
BayesDel_noAF	Pathogenic	0.16
CADD	Benign	16
DANN	Benign	0.95
DEOGEN2	Uncertain	0.49	T;.;.;.;T;T;.
Eigen	Benign	-0.058
Eigen_PC	Benign	-0.054
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Benign	0.85	T;T;T;T;T;T;D
M_CAP	Pathogenic	0.41	D
MetaRNN	Benign	0.40	T;T;T;T;T;T;T
MetaSVM	Uncertain	0.55	D
MutationAssessor	Uncertain	2.7	M;M;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;N;N;N;N;N;N
PrimateAI	Benign	0.24	T
PROVEAN	Pathogenic	-7.2	D;D;D;D;.;D;D
REVEL	Uncertain	0.55
Sift	Benign	0.15	T;T;T;T;.;T;T
Sift4G	Benign	0.21	T;T;T;T;.;T;.
Polyphen		0.66	P;.;.;D;.;.;.
Vest4		0.38
MutPred		0.54		Gain of phosphorylation at C644 (P = 0.021);Gain of phosphorylation at C644 (P = 0.021);.;Gain of phosphorylation at C644 (P = 0.021);.;Gain of phosphorylation at C644 (P = 0.021);.;
MVP		0.96
MPC		0.22
ClinPred		0.22	T
GERP RS		2.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Varity_R		0.22
gMVP		0.096

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: rs753521391; hg19: chr17-41245618;