17-43093951-T-C

Position:

• chr17-43093951-T-C

Variant summary

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

The NM_007294.4(BRCA1):​c.1580A>G​(p.Lys527Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,558 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. K527K) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:1
• Conservation: PhyloP100: 1.71

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=0.26952004).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.1580A>G	p.Lys527Arg	missense_variant	10/23	ENST00000357654.9	NP_009225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9	c.1580A>G	p.Lys527Arg	missense_variant	10/23	1	NM_007294.4	ENSP00000350283	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250524 Hom.: 0 AF XY: 0.00000738 AC XY: 1 AN XY: 135430

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000883

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461558 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 727054

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Jan 06, 2021	The p.K527R variant (also known as c.1580A>G), located in coding exon 9 of the BRCA1 gene, results from an A to G substitution at nucleotide position 1580. The lysine at codon 527 is replaced by arginine, an amino acid with highly 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. -
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). -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jul 09, 2015

This variant is denoted BRCA1 c.1580A>G at the cDNA level, p.Lys527Arg (K527R) at the protein level, and results in the change of a Lysine to an Arginine (AAG>AGG). Using alternate nomenclature, this variant would be defined as BRCA1 1699A>G. This variant has not, to our knowledge, been published in the literature as pathogenic or benign. BRCA1 Lys527Arg was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. Since Lysine and Arginine share similar properties, this is considered a conservative amino acid substitution. BRCA1 Lys527Arg occurs at a position that is not conserved and is located in the DNA binding domain (Narod 2004). In silico analyses predict that this variant is unlikely to alter protein structure or function. Based on currently available information, it is unclear whether BRCA1 Lys527Arg is pathogenic or benign. We consider it to be a variant of uncertain significance. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 12, 2021

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: 418567). This missense change has been observed in individual(s) with ovarian cancer (PMID: 32776218). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change replaces lysine, which is basic and polar, with arginine, which is basic and polar, at codon 527 of the BRCA1 protein (p.Lys527Arg). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.16
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.46	T;.;.;.;T;T;.
Eigen	Benign	-0.20
Eigen_PC	Benign	-0.32
FATHMM_MKL	Benign	0.043	N
LIST_S2	Uncertain	0.88	D;D;D;D;D;D;D
M_CAP	Pathogenic	0.41	D
MetaRNN	Benign	0.27	T;T;T;T;T;T;T
MetaSVM	Uncertain	0.56	D
MutationAssessor	Uncertain	2.6	M;M;.;.;.;.;.
MutationTaster	Benign	1.0	N;N;N;N;N;N;N;N;N;N;N;N;N;N
PrimateAI	Benign	0.33	T
PROVEAN	Uncertain	-2.5	N;D;N;D;.;D;D
REVEL	Pathogenic	0.67
Sift	Benign	0.21	T;T;T;T;.;T;T
Sift4G	Benign	0.30	T;T;T;T;.;T;.
Polyphen		0.97	D;.;.;P;.;.;.
Vest4		0.36
MutPred		0.50		Loss of methylation at K527 (P = 0.0098);Loss of methylation at K527 (P = 0.0098);.;Loss of methylation at K527 (P = 0.0098);.;Loss of methylation at K527 (P = 0.0098);.;
MVP		0.92
MPC		0.35
ClinPred		0.29	T
GERP RS		3.3
Varity_R		0.090
gMVP		0.054

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: rs774959350; hg19: chr17-41245968;