chr17-43045704-G-T

Position:

• chr17-43045704-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 4P and 3B. PM1 PM2 BP4_Moderate BP6

The ENST00000357654.9(BRCA1):​c.5566C>A​(p.Pro1856Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,613,814 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 variant affecting the same amino acid position, but resulting in a different missense (i.e. P1856S) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: BRCA1 ENST00000357654.9 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:1
• Conservation: PhyloP100: 1.37

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.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 8 benign, 15 uncertain in ENST00000357654.9
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.22467476).
• BP6: Variant 17-43045704-G-T is Benign according to our data. Variant chr17-43045704-G-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 409334.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA1	NM_007294.4	c.5566C>A	p.Pro1856Thr	missense_variant	23/23	ENST00000357654.9	NP_009225.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA1	ENST00000357654.9	c.5566C>A	p.Pro1856Thr	missense_variant	23/23	1	NM_007294.4	ENSP00000350283	P4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152096 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461600 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727094

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

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 AF: 0.00000657 AC: 1 AN: 152214 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 74408

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000193

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Apr 11, 2024	The p.P1856T variant (also known as c.5566C>A), located in coding exon 22 of the BRCA1 gene, results from a C to A substitution at nucleotide position 5566. The proline at codon 1856 is replaced by threonine, an amino acid with highly similar properties. This amino acid position is poorly conserved in available vertebrate species. In one study, this variant (designated as P1856T (5685C>A)) exhibited loss of function when studied by a termperature sensitive transcriptional activation assay (Carvalho MA et al. Cancer Biol.Ther. 2002 Sep;1(5):502-8). This variant was functional in a homology directed repair and cisplatin resistance protein functional assay (Adamovich AI et al. Am J Hum Genet, 2022 Apr;109:618-630). In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	May 30, 2019	- -

Hereditary breast ovarian cancer syndrome Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 11, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Uncertain	0.15	D
BayesDel_noAF	Uncertain	-0.020
CADD	Benign	13
DANN	Uncertain	0.99
DEOGEN2	Benign	0.13	.;T;.;T;T;T;.;.
Eigen	Benign	-0.36
Eigen_PC	Benign	-0.34
FATHMM_MKL	Benign	0.31	N
LIST_S2	Benign	0.81	T;T;T;T;T;T;T;T
M_CAP	Uncertain	0.21	D
MetaRNN	Benign	0.22	T;T;T;T;T;T;T;T
MetaSVM	Uncertain	-0.23	T
MutationAssessor	Benign	1.8	.;L;.;.;.;.;.;.
MutationTaster	Benign	1.0	N;N;N;N;N;N;N;N;N;N;N;N;N;N
PrimateAI	Benign	0.30	T
PROVEAN	Benign	-1.9	N;N;.;.;.;.;N;N
REVEL	Uncertain	0.47
Sift	Uncertain	0.016	D;D;.;.;.;.;D;D
Sift4G	Uncertain	0.045	D;D;D;D;T;T;D;D
Polyphen		0.41, 0.24	.;B;.;.;.;B;.;.
Vest4		0.098
MVP		0.82
MPC		0.18
ClinPred		0.42	T
GERP RS		1.9
Varity_R		0.15
gMVP		0.21

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: rs80357274; hg19: chr17-41197721;