17-7674197-T-C

Position:

chr17-7674197-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1PM2PP3_Strong

The NM_000546.6(TP53):c.766A>G(p.Thr256Ala) variant causes a missense change. The variant allele was found at a frequency of 0.000000685 in 1,460,386 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: not found (cov: 30)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

TP53
NM_000546.6 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 6.24

Variant links:

Genes affected

TP53 (HGNC:11998): (tumor protein p53) This gene encodes a tumor suppressor protein containing transcriptional activation, DNA binding, and oligomerization domains. The encoded protein responds to diverse cellular stresses to regulate expression of target genes, thereby inducing cell cycle arrest, apoptosis, senescence, DNA repair, or changes in metabolism. Mutations in this gene are associated with a variety of human cancers, including hereditary cancers such as Li-Fraumeni syndrome. Alternative splicing of this gene and the use of alternate promoters result in multiple transcript variants and isoforms. Additional isoforms have also been shown to result from the use of alternate translation initiation codons from identical transcript variants (PMIDs: 12032546, 20937277). [provided by RefSeq, Dec 2016]

TP53 links:

TP53 (HGNC:):

TP53 links:

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

PM1

In a region_of_interest Interaction with AXIN1 (size 176) in uniprot entity P53_HUMAN there are 53 pathogenic changes around while only 3 benign (95%) in NM_000546.6

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.99

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TP53	NM_000546.6 linkuse as main transcript	c.766A>G	p.Thr256Ala	missense_variant	7/11	ENST00000269305.9	NP_000537.3	P04637-1K7PPA8Q53GA5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TP53	ENST00000269305.9 linkuse as main transcript	c.766A>G	p.Thr256Ala	missense_variant	7/11	1	NM_000546.6	ENSP00000269305.4		P04637-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.85e-7

AC:

AN:

1460386

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

726586

show subpopulations

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:

9.00e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Jan 04, 2023	The p.T256A variant (also known as c.766A>G) is located in coding exon 6 of the TP53 gene. This alteration results from an A to G substitution at nucleotide position 766. The threonine at codon 256 is replaced by alanine, an amino acid with similar properties. This has been identified in a patient reported to have Li-Fraumeni syndrome; however clinical details were not provided (Morgan JE et al. Hum Mutat. 2010 Apr;31(4):484-91). This alteration has been observed in at least one individual with a personal and/or family history that is consistent with TP53-related disease; however, it has also been seen in individuals with cancer diagnoses at later age of onset than expected for TP53-related disease (Ambry internal data, personal communication). This variant is in the DNA binding domain of the TP53 protein and is reported to have partially functional transactivation in yeast based assays (Kato S et al. Proc. Natl. Acad. Sci. USA. 2003 Jul;100:8424-9). However, studies conducted in human cell lines indicate this alteration is proficient at growth suppression and has no dominant negative effect (Kotler E et al. Mol.Cell. 2018 Jul;71:178-190.e8; Giacomelli AO et al. Nat. Genet. 2018 Oct;50:1381-1387). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on current evidence, this alteration may be a moderate risk allele that leads to increased risk of developing a TP53-related cancer; however, since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Sep 20, 2021	This missense variant replaces threonine with alanine at codon 256 of the TP53 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). Functional analysis in yeast reported transcriptional activity for this variant (PMID: 16861262) with reduced activity in one study (PMID: 12826609). This variant has been reported in an individual affected with Li-Fraumeni syndrome (PMID: 20127978). This variant has not been identified 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. -

Li-Fraumeni syndrome 1

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Pathway Genomics

Oct 30, 2014

- -

Li-Fraumeni syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 14, 2023

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. Experimental studies have shown that this missense change does not substantially affect TP53 function (PMID: 12826609, 16861262, 29979965, 30224644). Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (PMID: 12826609, 29979965, 30224644) indicates that this missense variant is expected to disrupt TP53 function. ClinVar contains an entry for this variant (Variation ID: 141011). This missense change has been observed in individual(s) with clinical features of Li-Fraumeni syndrome (PMID: 20127978). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 256 of the TP53 protein (p.Thr256Ala). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.87

BayesDel_addAF

Pathogenic

0.55

BayesDel_noAF

Pathogenic

0.55

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.87

D;D;.;.;.;.;T;T;.;D;.;.;.;.;.;.;D;.;.;.

Eigen

Uncertain

0.47

Eigen_PC

Uncertain

0.36

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

0.99

D;D;D;D;D;D;D;D;.;.;.;D;D;.;D;D;D;D;D;D

M_CAP

Pathogenic

0.83

MetaRNN

Pathogenic

0.99

D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

2.9

.;.;.;.;.;.;.;.;.;M;.;M;M;M;.;.;M;.;.;.

PrimateAI

Uncertain

0.66

PROVEAN

Uncertain

-4.4

D;D;.;.;.;.;.;.;.;D;.;.;D;D;.;.;D;.;.;D

REVEL

Pathogenic

0.91

Sift

Uncertain

0.0010

D;D;.;.;.;.;.;.;.;D;.;.;D;D;.;.;D;.;.;D

Sift4G

Uncertain

0.0030

D;D;T;T;T;T;T;T;D;D;D;D;D;D;D;D;D;D;D;T

Polyphen

1.0

D;.;.;.;.;.;.;.;.;D;.;D;P;D;.;.;D;.;.;.

Vest4

0.94

MutPred

0.96

Loss of disorder (P = 0.1333);Loss of disorder (P = 0.1333);.;.;.;.;.;.;.;Loss of disorder (P = 0.1333);.;Loss of disorder (P = 0.1333);Loss of disorder (P = 0.1333);Loss of disorder (P = 0.1333);.;.;Loss of disorder (P = 0.1333);.;.;.;

MVP

1.0

MPC

0.36

ClinPred

1.0

GERP RS

3.5

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.98

gMVP

0.79

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over