rs56335406

chr17-43074501-G-Achr17-43074501-G-Cchr17-43074501-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_007294.4(BRCA1):c.4505C>T(p.Pro1502Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. P1502Q) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 31)
• Consequence: BRCA1 NM_007294.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -0.0330

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 2 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 15 uncertain in NM_007294.4
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.17461303).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA1	NM_007294.4	c.4505C>T	p.Pro1502Leu	missense_variant	14/23	ENST00000357654.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA1	ENST00000357654.9	c.4505C>T	p.Pro1502Leu	missense_variant	14/23	1	NM_007294.4	P4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 21, 2023

The p.P1502L variant (also known as c.4505C>T), located in coding exon 13 of the BRCA1 gene, results from a C to T substitution at nucleotide position 4505. The proline at codon 1502 is replaced by leucine, an amino acid with similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 28, 2018

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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The leucine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with BRCA1-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces proline with leucine at codon 1502 of the BRCA1 protein (p.Pro1502Leu). The proline residue is weakly conserved and there is a moderate physicochemical difference between proline and leucine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.076
BayesDel_addAF	Uncertain	0.038	T
BayesDel_noAF	Benign	-0.18
Cadd	Benign	3.4
Dann	Benign	0.50
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.017	N
LIST_S2	Uncertain	0.91	D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.51	D
MetaRNN	Benign	0.17	T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.51	T
MutationTaster	Benign	1.0	N;N;N;N;N;N;N;N;N;N;N;N;N;N
PrimateAI	Benign	0.22	T
PROVEAN	Uncertain	-2.6	D;N;.;D;N;D;D;N;N
REVEL	Uncertain	0.45
Sift	Benign	0.16	T;T;.;D;T;D;T;T;T
Sift4G	Benign	0.19	T;D;D;T;D;T;.;.;T
Polyphen		0.0, 0.016	.;B;.;.;.;.;.;B;.
Vest4		0.089
MVP		0.46
MPC		0.082
ClinPred		0.042	T
GERP RS		0.095
Varity_R		0.020
gMVP		0.096

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.12		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: rs56335406; hg19: chr17-41226518; COSMIC: COSV58799440; COSMIC: COSV58799440;