rs587780076
Variant summary
Our verdict is Likely benign. Variant got -7 ACMG points: 1P and 8B. BS3BS2PM2_Supporting
This summary comes from the ClinGen Evidence Repository: The NM_000546.6:c.877G>T variant in TP53 is a missense variant predicted to cause substitution of glycine by tryptophan at amino acid 293 (p.Gly293Trp). This variant has been observed in 4 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_Moderate; Internal lab contributors: Ambry, SCV000187101.5). This variant has an allele frequency of 0.00003305 (39/1180036 alleles) in the European (Non-Finnish) population in gnomAD v4.1.0 which is lower than the Clingen TP53 VCEP threshold (<0.00004) 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, TP53 c.877G>T (p.Gly293Trp) meets criteria to be classified as likely benign for Li-Fraumeni syndrome. ACMG/AMP criteria applied, as specified by the TP53 Expert Panel: BS2_Moderate, PM2_Supporting, BS3. (Bayesian Points: -5; VCEP specifications version 2.2, 1/16/2025). LINK:https://erepo.genome.network/evrepo/ui/classification/CA000470/MONDO:0018875/009
Frequency
Consequence
NM_000546.6 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -7 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152160Hom.: 0 Cov.: 31
GnomAD3 exomes AF: 0.00000795 AC: 2AN: 251482Hom.: 0 AF XY: 0.0000147 AC XY: 2AN XY: 135916
GnomAD4 exome AF: 0.0000280 AC: 41AN: 1461892Hom.: 0 Cov.: 33 AF XY: 0.0000275 AC XY: 20AN XY: 727248
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152160Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1AN XY: 74330
ClinVar
Submissions by phenotype
Li-Fraumeni syndrome 1 Uncertain:2
This variant is classified as a variant of uncertain significance as there is insufficient evidence to determine its impact on protein function and/or cancer risk. -
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Li-Fraumeni syndrome Uncertain:1Benign:1
The NM_000546.6:c.877G>T variant in TP53 is a missense variant predicted to cause substitution of glycine by tryptophan at amino acid 293 (p.Gly293Trp). This variant has been observed in 4 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_Moderate; Internal lab contributors: Ambry, SCV000187101.5). This variant has an allele frequency of 0.00003305 (39/1180036 alleles) in the European (Non-Finnish) population in gnomAD v4.1.0 which is lower than the Clingen TP53 VCEP threshold (<0.00004) 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, TP53 c.877G>T (p.Gly293Trp) meets criteria to be classified as likely benign for Li-Fraumeni syndrome. ACMG/AMP criteria applied, as specified by the TP53 Expert Panel: BS2_Moderate, PM2_Supporting, BS3. (Bayesian Points: -5; VCEP specifications version 2.2, 1/16/2025). -
This sequence change replaces glycine, which is neutral and non-polar, with tryptophan, which is neutral and slightly polar, at codon 293 of the TP53 protein (p.Gly293Trp). This variant is present in population databases (rs587780076, gnomAD 0.002%). This missense change has been observed in individual(s) with glioblastoma and neurofibromatosis, sarcoma, and breast cancer (PMID: 1686725, 23894400, 26976419). ClinVar contains an entry for this variant (Variation ID: 127826). 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 are conflicting or provide insufficient evidence to determine the effect of this variant on TP53 function (PMID: 12826609, 17606709, 21343334, 30224644, 30840781). 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. -
Hereditary cancer-predisposing syndrome Uncertain:1Benign:1
This missense variant replaces glycine with tryptophan at codon 293 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). Functional studies have shown the mutant protein to be functional in yeast transcription activation assays (IARC database and PMID: 12826609, 17606709, 21343334) and in human cell growth suppression assays (PMID: 30224644). This variant has been reported in a 17 year-old affected with glioblastoma and diagnosed with neurofibromatosis type 1 (PMID: 1686725), individuals affected with adult-onset sarcoma (PMID: 23894400), and individuals affected with breast cancer (PMID: 26976419, 33471991). This variant has been identified in 3/282876 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. -
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. -
not provided Uncertain:1
Not observed at a significant frequency in large population cohorts (Lek 2016); In silico analysis supports that this missense variant does not alter protein structure/function; Published functional studies suggest no damaging effect: retained transactivation activity (Kato 2003, Monti 2011); Observed in individuals with sarcoma, glioblastoma, neurofibromatosis, and/or breast cancer (Chung 1991, Mitchell 2013, Tung 2016); This variant is associated with the following publications: (PMID: 17606709, 26976419, 22045683, 15924253, 30352134, 1686725, 24729566, 25801821, 23894400, 26367797, 26659599, 12826609, 8829653, 26933808, 21343334, 30840781) -
not specified Benign:1
Variant summary: TP53 c.877G>T (p.Gly293Trp) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.6e-05 in 1607056 control chromosomes, predominantly at a frequency of 3.3e-05 within the Non-Finnish European subpopulation in the gnomAD database. This frequency is somewhat lower than the estimated maximum expected for a pathogenic variant in TP53 causing Li-Fraumeni Syndrome (4e-05), allowing no clear conclusions about variant significance. In addition, this variant was also reported in 1/7325 European American women, who were older than age 70, and have never had cancer (in the FLOSSIES database). The variant, c.877G>T, has been reported in the literature in an individual affected with glioblastoma who was diagnosed with neurofibromatosis type 1, however the variant was also found in an unaffected parent (Chung_1991), in addition the variant was reported in patients affected with breast cancer and other tumor phenotypes (e.g. Mitchell_2013, Tung_2016, Dorling_2021), however no supportive evidence for causality was provided. Publications reported experimental evidence evaluating an impact on protein function, and demonstrated that the variant protein was functional based on transcriptional activity in yeast (Kato_2003, Monti_2011), in addition, a loss-of-function saturation mutagenesis screen also indicated that this missense does not substantially affect TP53 function (Giacomelli_2018). The following publications have been ascertained in the context of this evaluation (PMID: 1686725, 3894400, 26976419, 33471991, 12826609, 30224644, 21343334). ClinVar contains an entry for this variant (Variation ID: 127826). Based on the evidence outlined above, the variant was classified as likely benign. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at