17-7673582-G-T
Variant summary
Our verdict is Likely benign. The variant received -1 ACMG points: 1P and 2B. BP4PM2_SupportingBS2_Supporting
This summary comes from the ClinGen Evidence Repository: The NM_000546.6:c.946C>A variant in TP53 is a missense variant predicted to cause substitution of proline by threonine at amino acid 316 (p.Pro316Thr). Although this variant has been observed in germline cases, to our knowledge, this variant has not been reported in individuals meeting classical LFS or Chompret criteria (PS4 not met; Internal lab contributors). 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; Internal lab contributor). This variant has an allele frequency of 0.000003098 (5/1614040 alleles) across gnomAD v4.1.0 which is lower than the Clingen TP53 VCEP threshold (<0.00003) for PM2_Supporting and has a subpopulation allele frequency of <0.00004 in all non-bottleneck populations with 2 or more alleles present (PM2_Supporting). In vitro assays performed in yeast and/or human cell lines showed conflicting results with respect to transactivation, growth suppression activity, and/or tetramer formation (PS3/BS3 not met; PMIDs: 12826609, 16007150, 29979965, 30224644). Computational predictor scores (BayesDel = -0.0226052; Align GVGD Class C0) are below the recommended thresholds (BayesDel ≤ -0.008 and an Align GVGD Class ≤ 55), evidence that does not predict a damaging effect on TP53 via protein change. SpliceAI predicts that the variant has no impact on splicing. (BP4_Moderate). 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, BP4_Moderate. (Bayesian Points: -2; VCEP specifications version 2.3) LINK:https://erepo.genome.network/evrepo/ui/classification/CA001212/MONDO:0018875/009
Frequency
Consequence
NM_000546.6 missense
Scores
Clinical Significance
Conservation
Publications
- breast cancerInheritance: AD Classification: DEFINITIVE Submitted by: Ambry Genetics
- Li-Fraumeni syndromeInheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, ClinGen, Orphanet
- Li-Fraumeni syndrome 1Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Genomics England PanelApp
- adrenocortical carcinoma, hereditaryInheritance: AD Classification: STRONG Submitted by: Ambry Genetics
- sarcomaInheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
- bone marrow failure syndrome 5Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
- colorectal cancerInheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
- choroid plexus carcinomaInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Likely_benign. The variant received -1 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152154Hom.: 0 Cov.: 31 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251478 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 0.00000274 AC: 4AN: 1461886Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2AN XY: 727242 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152154Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1AN XY: 74324 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Li-Fraumeni syndrome Uncertain:2Benign:1
This sequence change replaces proline, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 316 of the TP53 protein (p.Pro316Thr). This variant is present in population databases (rs772773208, gnomAD 0.0009%). 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: 230382). 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%. Studies have shown that this missense change alters TP53 gene expression (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. -
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The NM_000546.6:c.946C>A variant in TP53 is a missense variant predicted to cause substitution of proline by threonine at amino acid 316 (p.Pro316Thr). Although this variant has been observed in germline cases, to our knowledge, this variant has not been reported in individuals meeting classical LFS or Chompret criteria (PS4 not met; Internal lab contributors). 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; Internal lab contributor). This variant has an allele frequency of 0.000003098 (5/1614040 alleles) across gnomAD v4.1.0 which is lower than the Clingen TP53 VCEP threshold (<0.00003) for PM2_Supporting and has a subpopulation allele frequency of <0.00004 in all non-bottleneck populations with 2 or more alleles present (PM2_Supporting). In vitro assays performed in yeast and/or human cell lines showed conflicting results with respect to transactivation, growth suppression activity, and/or tetramer formation (PS3/BS3 not met; PMIDs: 12826609, 16007150, 29979965, 30224644). Computational predictor scores (BayesDel = -0.0226052; Align GVGD Class C0) are below the recommended thresholds (BayesDel ≤ -0.008 and an Align GVGD Class ≤ 55), evidence that does not predict a damaging effect on TP53 via protein change. SpliceAI predicts that the variant has no impact on splicing. (BP4_Moderate). 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, BP4_Moderate. (Bayesian Points: -2; VCEP specifications version 2.3) -
Hereditary cancer-predisposing syndrome Uncertain:2Benign:1
The p.P316T variant (also known as c.946C>A), located in coding exon 8 of the TP53 gene, results from a C to A substitution at nucleotide position 946. The proline at codon 316 is replaced by threonine, an amino acid with highly similar properties. This variant is reported to have non-functional transactivation in yeast based assays (Kato S et al. Proc. Natl. Acad. Sci. USA. 2003 Jul;100:8424-9). However, studies conducted in human cell lines indicate this alteration is proficient at growth suppression and has no dominant negative effect (Giacomelli AO et al. Nat Genet, 2018 Oct;50:1381-1387). This amino acid position is not well conserved in available vertebrate species, and threonine is the reference amino acid in other vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -
Each variant was annotated with functional scores from MAVE data which was translated into functional evidence codes. All other evidence codes and combining criteria were adhered to as closely as possible based on the ClinGen VCEP (Variant Curation Expert Panel) gene-specific recommendations. See Supplemental Figure 34 of final paper (Supp Fig. 28 in preprint: doi:10.1101/2024.04.11.24305690) for a table to see which lines of evidence we did not have data for. The ClinGen VCEPs are highly regarded as the gold-standard for gene-specific variant curation and are developed after extensive evaluation of the evidence by clinical and scientific experts for the particular gene to classify genomic variants on a spectrum from pathogenic to benign using the 2015 ACMG/AMP Variant Interpretation Guidelines as a backbone (PMID: 25741868). Reclassification of these VUS variants from gnomAD or All of Us focused only on variants originally prescribed as VUS in ClinVar. To ensure reproducibility, transparency, and increased throughput, all the procedures for annotating variants and assigning evidence codes were codified using Python. All code has been made freely available and is linked in the Code Availability section and all reclassified variants with evidence codes used can be found in Tables S18-19 (preprint: doi:10.1101/2024.04.11.24305690). For the MAVE data, the clinical curation and clinical strength assignment as per the ClinGen recommendations in Brnich et al. (2020) (PMID: 31892348) for or against pathogenicity or benignity of each of these MAVE datasets utilized in this study were previously published in Fayer et al. (2021) (PMID: 34793697).For TP53, we used the output of the Naïve Bayes classifier that synthesized data from four different TP53 MAVEs in Fayer et al. (2021) (PMID: 34793697). If the classifier predicted a variant to be "Functionally abnormal," the variant was assigned PS3 evidence and no BS3 evidence. If a variant was predicted to be "Functionally normal," BS3_moderate evidence was used with no PS3 evidence. This variant GRCh37:17:7576900:G>T was assigned evidence codes ['BS3_Moderate', 'BP4'] and an overall classification of Likely Benign -
This missense variant replaces proline with threonine at codon 316 of the TP53 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). Functional studies have reported this variant as defective in yeast based gene expression assays but functional in human cell growth suppression assays (PMID: 12826609, 30224644). This variant has not been reported in individuals affected with TP53-related disorders in the literature. This variant has been identified in 1/251478 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. -
not provided Uncertain:1
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Published functional studies are conflicting: a yeast-based assay demonstrates non-functional transactivation, while an assay in human cell lines exhibits no dominant negative effect over wildtype p53 (Kato et al., 2003; Giacomelli et al., 2018); This variant is associated with the following publications: (PMID: 12826609, 30224644, Pessoa2014[Chapter], 2247074, 30661751) -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at