rs1057519995

Positions:

• chr17-7674200-T-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3 PP5

The NM_000546.6(TP53):​c.763A>T​(p.Ile255Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,780 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 30)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TP53 NM_000546.6 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3 U:1 O:1
• Conservation: PhyloP100: 0.152

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 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, 0.764
• PP5: Variant 17-7674200-T-A is Pathogenic according to our data. Variant chr17-7674200-T-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 376621.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=2, other=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TP53	NM_000546.6	c.763A>T	p.Ile255Phe	missense_variant	7/11	ENST00000269305.9	NP_000537.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TP53	ENST00000269305.9	c.763A>T	p.Ile255Phe	missense_variant	7/11	1	NM_000546.6	ENSP00000269305.4

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460780 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 726792

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: 0.00

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 30

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3 Uncertain:1 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Li-Fraumeni syndrome 1 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Myriad Genetics, Inc.

Feb 16, 2024

This variant is considered likely pathogenic. Functional studies indicate this variant impacts protein function [PMID: 29979965]. This variant is expected to disrupt protein structure [Myriad internal data]. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

May 13, 2020

The p.I255F variant (also known as c.763A>T), located in coding exon 6 of the TP53 gene, results from an A to T substitution at nucleotide position 763. The isoleucine at codon 255 is replaced by phenylalanine, an amino acid with highly similar properties. This variant is in the DNA binding domain of the TP53 protein and is reported to have loss of transactivation in yeast based assays (IARC TP53 database: Kato S et al. Proc. Natl. Acad. Sci. USA 2003 Jul;100:8424-9). Studies conducted in human cell lines indicate this alteration has a dominant negative effect and is deficient at growth suppression (Kotler E et al. Mol. Cell 2018 Jul;71:178-190.e8; Giacomelli AO et al. Nat. Genet. 2018 Oct;50:1381-1387). This alteration has been reported in a cohort of individuals diagnosed with breast cancer (Alsner J et al. Clin. Cancer Res. 2000 Oct;6(10):3923-31), and has numerous somatic observations (cancerhotspots.org; IARCTP53 database). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Ovarian neoplasm Pathogenic:1

Likely pathogenic, no assertion criteria provided

research

German Consortium for Hereditary Breast and Ovarian Cancer, University Hospital Cologne

Dec 01, 2018

- -

Li-Fraumeni syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 06, 2024

This sequence change replaces isoleucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 255 of the TP53 protein (p.Ile255Phe). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TP53-related conditions. ClinVar contains an entry for this variant (Variation ID: 376621). 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 with a positive predictive value of 97.5%. 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. -

Neoplasm Other:1

-, criteria provided, single submitter

clinical testing

Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital

Mar 04, 2025

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.73
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Pathogenic	0.14
CADD	Benign	22
DANN	Benign	0.93
DEOGEN2	Uncertain	0.53	D;T;.;.;.;.;T;T;.;D;.;.;.;.;.;.;D;.;.;.
Eigen	Benign	-0.018
Eigen_PC	Benign	-0.017
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.95	D;D;D;D;D;D;D;D;.;.;.;D;D;.;D;D;D;D;D;D
M_CAP	Pathogenic	0.82	D
MetaRNN	Pathogenic	0.76	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Benign	1.2	.;.;.;.;.;.;.;.;.;L;.;L;L;L;.;.;L;.;.;.
PrimateAI	Uncertain	0.64	T
PROVEAN	Uncertain	-3.0	D;D;.;.;.;.;.;.;.;D;.;.;D;D;.;.;D;.;.;D
REVEL	Pathogenic	0.79
Sift	Benign	0.098	T;T;.;.;.;.;.;.;.;T;.;.;T;T;.;.;T;.;.;T
Sift4G	Uncertain	0.0030	D;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T;T
Polyphen		1.0	D;.;.;.;.;.;.;.;.;D;.;D;B;D;.;.;D;.;.;.
Vest4		0.76
MutPred		0.67		Loss of stability (P = 0.0965);Loss of stability (P = 0.0965);.;.;.;.;.;.;.;Loss of stability (P = 0.0965);.;Loss of stability (P = 0.0965);Loss of stability (P = 0.0965);Loss of stability (P = 0.0965);.;.;Loss of stability (P = 0.0965);.;.;.;
MVP		0.96
MPC		0.47
ClinPred		0.95	D
GERP RS		3.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.86
gMVP		0.60

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: rs1057519995; hg19: chr17-7577518; COSMIC: COSV52663197; COSMIC: COSV52663197;