rs28934578

Positions:

• chr17-7675088-C-A
• chr17-7675088-C-G
• chr17-7675088-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 10P and 1B. PP3_Moderate PP4 PM2_Supporting BS3_Supporting PM1 PM5 PS4_Moderate

This summary comes from the ClinGen Evidence Repository: The NM_000546.6: c.524G>T variant in TP53 is a missense variant predicted to cause substitution of arginine by leucine at amino acid 175 (p.Arg175Leu). This variant is absent from gnomAD v4.1.0 (PM2_Supporting). This variant has been reported in 4 unrelated probands meeting Revised Chompret criteria. Based on this evidence, this variant scores 2 total points meeting the TP53 VCEP phenotype scoring criteria of 2-3.5 points. (PS4_Moderate; PMID:16707427; Internal lab contributors: Invitae, Ambry). In vitro assays performed in yeast and/or human cell lines showed partially functional transactivation, and retained growth suppression activity indicating that this variant does not impact protein function (BS3_Supporting; PMIDs: 12826609, 29979965, 30224644).Computational predictor scores (BayesDel = 0.57303; Align GVGD = Class C65) are above recommended thresholds (BayesDel > 0.16 and an Align GVGD Class of 65), evidence that correlates with impact to TP53 via protein change (PP3_Moderate). At least one individual with this variant was found to have a variant allele fraction of ≤35%, which is a significant predictor of variant pathogenicity (PP4_Moderate, PMID:34906512, Internal lab contributor: Invitae). This variant resides within a codon (NM_00546.4: 175, 245, 248, 249, 273, 282) of TP53 that is defined as a mutational hotspot by the ClinGen TP53 VCEP (PM1; PMID:8023157). Another missense variant(c.524G>A, p.Arg175His) (ClinVar Variation ID: 12374), in the same codon has been classified as pathogenic for Li-Fraumeni syndrome by the ClinGen TP53 VCEP’s specifications. (PM5). In summary, this variant meets the criteria to be classified as Likely Pathogenic for Li Fraumeni syndrome based on the ACMG/AMP criteria applied, as specified by the ClinGen TP53 VCEP: PS4_Moderate, PM2_Supporting, BS3_Supporting, PP3_Moderate, PP4, PM1, PM5 (Bayesian Points: 9; VCEP specifications version 2.0; 9/6/2024) LINK:https://erepo.genome.network/evrepo/ui/classification/CA000252/MONDO:0018875/009

• Frequency: Genomes: not found (cov: 33)
• Consequence: TP53 NM_000546.6 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 6.16

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 9 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TP53	NM_000546.6	c.524G>T	p.Arg175Leu	missense_variant	5/11	ENST00000269305.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TP53	ENST00000269305.9	c.524G>T	p.Arg175Leu	missense_variant	5/11	1	NM_000546.6	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Jun 18, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Sep 17, 2020	The p.R175L pathogenic mutation (also known as c.524G>T), located in coding exon 4 of the TP53 gene, results from a G to T substitution at nucleotide position 524. The arginine at codon 175 is replaced by leucine, an amino acid with dissimilar properties. This alteration has been identified in pediatric patients with adrenal cortical carcinoma and in families meeting Chompret criteria for Li-Fraumeni syndrome (West AN et al. Cancer Res. 2006 May; 66(10):5056-62; Ambry internal data). This alteration is located in the DNA binding domain and has shown a partial loss of transactivation activity, and temperature sensitivity in yeast and mammalian cell in vitro assays (Kato S et al. Proc Natl Acad Sci USA. 2003 Jul 8;100(14):8424-9; Shiraishi K et al. J. Biol. Chem. 2004 Jan; 279(1):348-55; Dearth LR et al. Carcinogenesis 2007 Feb; 28(2):289-98). More extensive evaluation of this variant showed that it was able to suppress cell growth similar to wild type p53, yet was deficient in apoptotic activity (West AN et al. Cancer Res. 2006 May; 66(10):5056-62). Structural modeling by this same group determined that the leucine substitution may destabilize the native structure, yet not necessarily disrupt the overall conformation of the DNA binding domain. Studies conducted in human cell lines are equivocal about this variant's ability to suppress cell growth (Kotler E et al. Mol.Cell. 2018 Jul;71:178-190.e8; Giacomelli AO et al. Nat. Genet. 2018 Oct;50:1381-1387). Another alteration at this same position, p.R175H, is a well-characterized mutation hotspot known to be associated with classic Li-Fraumeni syndrome (McIntyre et al. J Clin Oncol. 1994. 12(5):925-930; Melhem-Bertrandt et al. Cancer. 2012. 118(4):908-13; Choong et al. Clin Genet. 2012. 82(6):564-8; Varley et al. J Med Genet. 1995. 32:942-945). This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). 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 the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Li-Fraumeni syndrome 1 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Jun 18, 2022

- -

Li-Fraumeni syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Aug 16, 2022

For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Arg175 amino acid residue in TP53. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 8164043, 8825920, 11370630, 21761402, 22006311, 25927356). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on TP53 function (PMID: 12826609, 16707427, 16861262). 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 expected to disrupt TP53 protein function. ClinVar contains an entry for this variant (Variation ID: 182963). This missense change has been observed in individuals with Li-Fraumeni syndrome (PMID: 16707427; Invitae). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 175 of the TP53 protein (p.Arg175Leu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.88	D;D;.;.;.;.;T;T;.;D;.;.;.;.;.;.;D;.;.;.;D
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D;D;D;D;D;D;D;D;.;.;.;D;D;.;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.70	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.92	D
MutationAssessor	Pathogenic	3.3	.;.;.;.;.;.;.;.;.;M;.;M;M;M;.;.;M;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Uncertain	0.66	T
PROVEAN	Pathogenic	-6.8	D;D;.;.;.;.;.;.;.;D;.;.;D;D;.;.;D;.;.;D;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D;.;.;.;.;.;.;.;D;.;.;D;D;.;.;D;.;.;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;.
Polyphen		1.0	D;.;.;.;.;.;.;.;.;D;.;D;D;D;.;.;D;.;.;.;D
Vest4		0.97
MutPred		0.99		Loss of disorder (P = 0.0191);Loss of disorder (P = 0.0191);.;.;.;.;.;.;.;Loss of disorder (P = 0.0191);.;Loss of disorder (P = 0.0191);Loss of disorder (P = 0.0191);Loss of disorder (P = 0.0191);.;.;Loss of disorder (P = 0.0191);.;.;.;.;
MVP		1.0
MPC		1.8
ClinPred		1.0	D
GERP RS		5.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.99
gMVP		0.85

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs28934578; hg19: chr17-7578406; COSMIC: COSV52731306; COSMIC: COSV52731306;