rs1057519995

Variant names:

• chr17-7674200-T-A
• rs1057519995
• NM_000546.6:c.763A>T

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PM5 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). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I255V) has been classified as Uncertain significance.

• 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
• Publications: 85 publications found

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 Gene-Disease associations (from GenCC):

• breast cancer

  Inheritance: AD Classification: DEFINITIVE Submitted by: Ambry Genetics
• Li-Fraumeni syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, ClinGen, Orphanet
• Li-Fraumeni syndrome 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Genomics England PanelApp
• adrenocortical carcinoma, hereditary

  Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics
• sarcoma

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• bone marrow failure syndrome 5

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
• colorectal cancer

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
• choroid plexus carcinoma

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: In a hotspot region, there are 41 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 8 benign, 29 uncertain in NM_000546.6
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-7674199-A-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 232289.
• 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 VariationId is 376621.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TP53	NM_000546.6	c.763A>T	p.Ile255Phe	missense_variant	Exon 7 of 11	ENST00000269305.9	NP_000537.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TP53	ENST00000269305.9	c.763A>T	p.Ile255Phe	missense_variant	Exon 7 of 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

African (AFR) AF: 0.00 AC: 0 AN: 33464

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86236

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1110994

Other (OTH) AF: 0.0000166 AC: 1 AN: 60356

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

Feb 16, 2024

Myriad Genetics, Inc.

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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

May 13, 2020

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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

Dec 01, 2018

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

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: research

- -

Li-Fraumeni syndrome Uncertain:1

Aug 06, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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

Mar 04, 2025

Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital

Significance: -

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

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;.;.;.
PhyloP100		0.15
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

Other links and lift over

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