17-7674184-G-T

Variant names:

• chr17-7674184-G-T
• rs876658916
• NM_000546.6:c.779C>A

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 1P and 5B. PM2_Supporting BS2_Supporting BS3

This summary comes from the ClinGen Evidence Repository: The NM_000546.6: c.779C>A variant in TP53 is a missense variant predicted to cause substitution of serine by tyrosine at amino acid 260 (p.Ser260Tyr). This variant has been observed in 2-3 heterozygous unrelated females from the same data source with no personal history of cancer prior to age 60 years and no personal history of sarcoma at any age (BS2_Supporting; ClinVar SCV000830817.4, Internal lab contributors). This variant has an allele frequency of 0.000001864 (3/1609760 alleles) across gnomAD v4.1.0 which is lower than the Clingen TP53 VCEP threshold (<0.00003) for PM2_Supporting, and therefore meets this criterion (PM2_Supporting). In vitro assays performed in yeast and/or human cell lines showed functional transactivation and retained growth suppression activity indicating that this variant does not impact protein function (BS3; PMIDs: 12826609, 29979965, 30224644). In summary, this variant meets the criteria to be classified as likely benign for Li Fraumeni syndrome based on the ACMG/AMP criteria applied, as specified by the ClinGen TP53 VCEP: BS2_Supporting, PM2_Supporting, BS3. (Bayesian Points: -4; VCEP specifications version 2.2; 1/16/2025). LINK:https://erepo.genome.network/evrepo/ui/classification/CA10580921/MONDO:0018875/009

• Frequency:
  • Genomes: not found (cov: 30)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: TP53 NM_000546.6 missense
• Clinical Significance: Likely benign reviewed by expert panel U:2 B:2
• Conservation: PhyloP100: 2.66
• Publications: 23 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_benign. The variant received -4 ACMG points.

• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• BS2: For more information check the summary or visit ClinGen Evidence Repository.
• BS3: For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TP53	NM_000546.6	c.779C>A	p.Ser260Tyr	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.779C>A	p.Ser260Tyr	missense_variant	Exon 7 of 11	1	NM_000546.6	ENSP00000269305.4

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251436 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1457658 Hom.: 0 Cov.: 31 AF XY: 0.00000276 AC XY: 2 AN XY: 725448

African (AFR) AF: 0.00 AC: 0 AN: 33406

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

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26102

East Asian (EAS) AF: 0.00 AC: 0 AN: 39678

South Asian (SAS) AF: 0.0000348 AC: 3 AN: 86194

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53412

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5758

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1108118

Other (OTH) AF: 0.00 AC: 0 AN: 60268

GnomAD4 genome Cov.: 30

ClinVar

Significance: Likely benign

Submissions summary: Uncertain:2 Benign:2

Revision: reviewed by expert panel

Submissions by phenotype

Li-Fraumeni syndrome Uncertain:1 Benign:1

Jan 12, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces serine, which is neutral and polar, with tyrosine, which is neutral and polar, at codon 260 of the TP53 protein (p.Ser260Tyr). 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: 231033). Invitae Evidence Modeling incorporating data from in vitro experimental studies (PMID: 12826609, 29979965, 30224644) indicates that this missense variant is not expected to disrupt TP53 function with a negative predictive value of 97.5%. Experimental studies have shown that this missense change does not substantially affect TP53 function (PMID: 12826609). 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. -

Jan 16, 2025

ClinGen TP53 Variant Curation Expert Panel, ClinGen

Significance: Likely benign

Review Status: reviewed by expert panel

Collection Method: curation

The NM_000546.6: c.779C>A variant in TP53 is a missense variant predicted to cause substitution of serine by tyrosine at amino acid 260 (p.Ser260Tyr). This variant has been observed in 2-3 heterozygous unrelated females from the same data source with no personal history of cancer prior to age 60 years and no personal history of sarcoma at any age (BS2_Supporting; ClinVar SCV000830817.4, Internal lab contributors). This variant has an allele frequency of 0.000001864 (3/1609760 alleles) across gnomAD v4.1.0 which is lower than the Clingen TP53 VCEP threshold (<0.00003) for PM2_Supporting, and therefore meets this criterion (PM2_Supporting). In vitro assays performed in yeast and/or human cell lines showed functional transactivation and retained growth suppression activity indicating that this variant does not impact protein function (BS3; PMIDs: 12826609, 29979965, 30224644). In summary, this variant meets the criteria to be classified as likely benign for Li Fraumeni syndrome based on the ACMG/AMP criteria applied, as specified by the ClinGen TP53 VCEP: BS2_Supporting, PM2_Supporting, BS3. (Bayesian Points: -4; VCEP specifications version 2.2; 1/16/2025). -

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Dec 30, 2021

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Feb 06, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces serine with tyrosine at codon 260 of the TP53 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). Experimental studies have shown that this variant did not impact function in yeast transactivation assays (PMID: 12826609), human cell proliferation assays (PMID: 29979965), and human cell growth suppression assays (PMID: 30224644). To our knowledge, this variant has not been reported in individuals affected with TP53-related disorders in the literature. This variant has been identified in 1/251436 chromosomes 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.20
BayesDel_addAF	Pathogenic	0.33	D
BayesDel_noAF	Pathogenic	0.23
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.59	D;D;.;.;.;.;T;T;.;D;.;.;.;.;.;.;D;.;.;.
Eigen	Uncertain	0.35
Eigen_PC	Uncertain	0.31
FATHMM_MKL	Benign	0.62	D
LIST_S2	Benign	0.42	T;D;D;D;D;D;D;D;.;.;.;D;D;.;D;D;D;D;D;D
M_CAP	Pathogenic	0.37	D
MetaRNN	Uncertain	0.56	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.0	.;.;.;.;.;.;.;.;.;M;.;M;M;M;.;.;M;.;.;.
PhyloP100		2.7
PrimateAI	Benign	0.46	T
PROVEAN	Benign	-1.7	N;N;.;.;.;.;.;.;.;N;.;.;N;N;.;.;N;.;.;N
REVEL	Pathogenic	0.67
Sift	Pathogenic	0.0	D;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;D
Polyphen		0.95	P;.;.;.;.;.;.;.;.;P;.;P;P;P;.;.;P;.;.;.
Vest4		0.57
MutPred		0.40		Loss of disorder (P = 0.0088);Loss of disorder (P = 0.0088);.;.;.;.;.;.;.;Loss of disorder (P = 0.0088);.;Loss of disorder (P = 0.0088);Loss of disorder (P = 0.0088);Loss of disorder (P = 0.0088);.;.;Loss of disorder (P = 0.0088);.;.;.;
MVP		0.92
MPC		0.37
ClinPred		0.90	D
GERP RS		4.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.76
gMVP		0.33

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: rs876658916; hg19: chr17-7577502; COSMIC: COSV52978505;