rs1555525353

chr17-7673829-A-Gchr17-7673829-A-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_000546.6(TP53):c.791T>C(p.Leu264Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic 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. L264I) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 31)
• Consequence: TP53 NM_000546.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 9.32

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 8 ACMG points.

• PM1: In a hotspot region, there are 13 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 16 uncertain in NM_000546.6
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.966

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TP53	NM_000546.6	c.791T>C	p.Leu264Pro	missense_variant	8/11	ENST00000269305.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TP53	ENST00000269305.9	c.791T>C	p.Leu264Pro	missense_variant	8/11	1	NM_000546.6	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Jun 18, 2022	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Dec 12, 2016	The p.L264P variant (also known as c.791T>C), located in coding exon 7 of the TP53 gene, results from a T to C substitution at nucleotide position 791. The leucine at codon 264 is replaced by proline, an amino acid with some similar properties. This alteration has been reported as a somatic mutation one time in a larynx tumor, but not as a germline mutation by the IARC TP53 database. This variant is in the DNA binding domain of the TP53 protein and was found to not have an effect on transactivation capacity in yeast based assays (Petitjean A et al. IARC TP53 database [version R17, November 2013]. Hum Mutat. 2007 Jun;28(6):622-9; Kato S et al. Proc Natl Acad Sci USA. 2003 Jul 8;100(14):8424-9). This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Li-Fraumeni syndrome 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Jun 18, 2022

- -

Li-Fraumeni syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 27, 2022

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, 29979965, 30224644). Advanced modeling of experimental studies (such as gene expression, population dynamics, functional pathways, and cell-cycle effects in cell culture) performed at Invitae indicates that this missense variant is not expected to disrupt TP53 protein function. ClinVar contains an entry for this variant (Variation ID: 480759). This variant has not been reported in the literature in individuals affected with TP53-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 264 of the TP53 protein (p.Leu264Pro). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.86
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
Cadd	Benign	23
Dann	Uncertain	0.99
DEOGEN2	Uncertain	0.70	D;.;.;.;.;T;T;.;D;.;.;.;.;.;.;D;.;.;.
Eigen	Uncertain	0.23
Eigen_PC	Uncertain	0.25
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Benign	0.75	T;T;T;T;T;T;T;.;.;.;T;T;.;T;T;T;T;T;T
M_CAP	Pathogenic	0.56	D
MetaRNN	Pathogenic	0.97	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.97	D
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Benign	0.48	T
PROVEAN	Uncertain	-4.1	D;.;.;.;.;.;.;.;D;.;.;D;D;.;.;D;.;.;D
REVEL	Pathogenic	0.83
Sift	Uncertain	0.0010	D;.;.;.;.;.;.;.;D;.;.;D;D;.;.;D;.;.;D
Sift4G	Uncertain	0.0020	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
Polyphen		0.034, 0.049, 0.99	.;.;.;.;.;.;.;.;B;.;B;D;B;.;.;B;.;.;.
Vest4		0.72
MutPred		0.85		Gain of disorder (P = 0.0333);.;.;.;.;.;.;.;Gain of disorder (P = 0.0333);.;Gain of disorder (P = 0.0333);Gain of disorder (P = 0.0333);Gain of disorder (P = 0.0333);.;.;Gain of disorder (P = 0.0333);.;.;.;
MVP		0.98
MPC		0.48
ClinPred		0.99	D
GERP RS		5.1
Varity_R		0.96
gMVP		0.88

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: rs1555525353; hg19: chr17-7577147; COSMIC: COSV53470181; COSMIC: COSV53470181;