rs746067447

chr17-43094763-C-Achr17-43094763-C-Gchr17-43094763-C-T

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP6

The NM_007294.4(BRCA1):c.768G>T(p.Arg256Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,458,962 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). Another nucleotide change resulting in same amino acid change has been previously reported as Likely benignin ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R256K) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 0.0920

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.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.123312294).
• BP6: Variant 17-43094763-C-A is Benign according to our data. Variant chr17-43094763-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1760148.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA1	NM_007294.4	c.768G>T	p.Arg256Ser	missense_variant	10/23	ENST00000357654.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA1	ENST00000357654.9	c.768G>T	p.Arg256Ser	missense_variant	10/23	1	NM_007294.4	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000401 AC: 1 AN: 249322 Hom.: 0 AF XY: 0.00000742 AC XY: 1 AN XY: 134784

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000545

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: 0.00000137 AC: 2 AN: 1458962 Hom.: 0 Cov.: 33 AF XY: 0.00000276 AC XY: 2 AN XY: 725592

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000504

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

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

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	Jun 29, 2022	The p.R256S variant (also known as c.768G>T), located in coding exon 9 of the BRCA1 gene, results from a G to T substitution at nucleotide position 768. The arginine at codon 256 is replaced by serine, an amino acid with dissimilar properties. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.27
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Pathogenic	0.20
Cadd	Benign	17
Dann	Uncertain	0.99
DEOGEN2	Benign	0.23	T;.;.;.;.;.;T;.;T;.;T;T;.;T
Eigen	Benign	-0.25
Eigen_PC	Benign	-0.14
FATHMM_MKL	Benign	0.17	N
LIST_S2	Uncertain	0.95	D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.23	D
MetaRNN	Benign	0.12	T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	0.48	D
MutationAssessor	Benign	1.7	L;L;L;.;L;.;.;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;N;N;N;N;N;N;N;N
PrimateAI	Benign	0.21	T
PROVEAN	Benign	-0.87	N;N;N;N;N;N;N;N;N;N;.;N;N;N
REVEL	Uncertain	0.49
Sift	Uncertain	0.0060	D;D;D;D;D;D;D;D;D;D;.;D;D;D
Sift4G	Benign	0.40	T;T;T;T;T;.;.;T;.;T;.;T;.;D
Polyphen		0.18	B;.;.;.;B;.;B;.;.;B;.;.;.;.
Vest4		0.34
MutPred		0.17		Gain of phosphorylation at R256 (P = 0.0404);Gain of phosphorylation at R256 (P = 0.0404);Gain of phosphorylation at R256 (P = 0.0404);.;Gain of phosphorylation at R256 (P = 0.0404);.;.;.;.;Gain of phosphorylation at R256 (P = 0.0404);.;Gain of phosphorylation at R256 (P = 0.0404);.;Gain of phosphorylation at R256 (P = 0.0404);
MVP		0.84
MPC		0.15
ClinPred		0.20	T
GERP RS		4.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.16
gMVP		0.22

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs746067447; hg19: chr17-41246780;