17-7673790-C-T
Variant summary
Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1PM2PP3_StrongPP5
The NM_000546.6(TP53):c.830G>A(p.Cys277Tyr) variant causes a missense change. The variant allele was found at a frequency of 0.00000205 in 1,461,848 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000546.6 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_pathogenic. Variant got 9 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 31
GnomAD4 exome AF: 0.00000205 AC: 3AN: 1461848Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2AN XY: 727224
GnomAD4 genome Cov.: 31
ClinVar
Submissions by phenotype
not provided Pathogenic:1Uncertain:1Other:1
Variant interpretted as Uncertain significance and reported on 12-26-2018 by Lab or GTR ID 500031. GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -
TP53: PS3:Moderate, PM2:Supporting -
Published functional studies demonstrate a damaging effect: loss of transcriptional activation activity with a dominant-negative effect, reduced apoptotic activity (Epstein et al., 1998; Di Como et al., 1998; Kato et al., 2003; Pospisilova et al., 2004; Dearth et al., 2007; Monti et al., 2011); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Observed in individuals with anaplastic thyroid cancer (Garg et al., 2015); This variant is associated with the following publications: (PMID: 10519380, 12759621, 9627118, 27311873, 11406645, 31414729, 30840781, 19336573, 24113472, 22915647, 9482117, 8378080, 21343334, 21232794, 21472523, 19681600, 21197471, 9572492, 16861262, 8633021, 9546439, 23117049, 19671856, 26723900, 11238924, 15192123, 17606709, 16818505, 29979965, 28861920, 30720243, 28884749, 28866070, 27813088, 29922827, 30224644, 32980694, 15510160, 12826609, 25365311, 35050731) -
Li-Fraumeni syndrome Pathogenic:1Uncertain:1
This sequence change replaces cysteine, which is neutral and slightly polar, with tyrosine, which is neutral and polar, at codon 277 of the TP53 protein (p.Cys277Tyr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with anaplastic thyroid cancer, osteosarcoma, and/or prostate cancer (PMID: 12759621, 19671856, 25365311, 27328919; internal data). ClinVar contains an entry for this variant (Variation ID: 185722). Invitae Evidence Modeling incorporating data from in vitro 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%. Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on TP53 function (PMID: 12826609, 29979965). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
This missense variant replaces cysteine with tyrosine at codon 277 of the TP53 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function. Experimental studies have shown that this variant disrupted TP53 function in yeast transactivation assays (PMID: 12826609, 21343334), but did not impact function in a human cell proliferation assays (PMID: 29979965), and showed inconclusive results in human cell growth suppression assays (PMID: 30224644). This variant has been reported in an individual affected with pediatric osteosarcoma (PMID: 12759621), but also in unaffected controls (PMID: 30287823, 32980694, 33309985). This variant has not been identified 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. -
Adrenocortical carcinoma, hereditary Pathogenic:1
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Hereditary cancer-predisposing syndrome Pathogenic:1
The p.C277Y pathogenic mutation (also known as c.830G>A), located in coding exon 7 of the TP53 gene, results from a G to A substitution at nucleotide position 830. The cysteine at codon 277 is replaced by tyrosine, an amino acid with highly dissimilar properties. This variant has been reported in the germline of a child diagnosed with an osteosarcoma at age 14 (Patiño-García A et al. J Pediatr Hematol Oncol. 2003 May;25:362-7). This alteration has also been associated with loss-of-heterozygosity (LOH) in tumor DNA from an individual diagnosed with osteosarcoma at age 22 and is a common somatic mutation detected in Ewing's sarcoma (Patiño-García A et al. Clin. Cancer Res. 2009 Aug;15(16):5082-91; Pospísilová S et al. Mol. Cancer Res. 2004 May; 2(5):296-304). This variant is in the DNA binding domain of the TP53 protein and 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). 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). This alteration is located in the highly conserved DNA binding domain at a residue that has been shown to be directly involved in DNA contact (Martin AC et al. Hum. Mutat. 2002 Feb; 19(2):149-64). This variant has been detected in at least one individual at an allele fraction that is suggestive of clonal hematopoiesis, a predictor of TP53 pathogenicity (Ambry internal data; Fortuno C et al. Genet Med. 2022 03;24:673-680). 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 variant is interpreted as a disease-causing mutation. -
Malignant tumor of breast Uncertain:1
The TP53 p.Cys277Tyr variant was identified in 1 of 14,718 proband chromosomes (frequency: 0.00007) from individuals with anaplastic thyroid and unspecified cancer and was present in 1 of 22,482 control chromosomes (frequency: 0.00004) from healthy individuals (Momozawa 2018, Monti 2007). The variant was identified in dbSNP (rs763098116) as “with likely pathogenic, uncertain significance allele”, in ClinVar (classified as likely pathogenic by GeneDx and Ambry Genetics and uncertain significance by Invitae) and LOVD 3.0 (observed 1x). The variant was not identified in UMD-LSDB. The variant was identified in control databases in 1 of 117,922 chromosomes at a frequency of 0.000008 (Genome Aggregation Database Feb 27, 2017). The variant was observed in the following populations: European in 1 of 65,130 chromosomes (freq: 0.00002), but not in the African, East Asian, Finnish, Latino, Other, and South Asian populations. In a number of yeast-based assays, the variant altered the transactivation activity of p53 exhibiting a dominant negative effect over wild type (Epstein 1998, Flaman 1998, Gagnebin 1998, Di Como 1998). Conversely, in vitro expression of the variant retained p53-mediated apoptosis plus binding and activation of several downstream targets (Pospisilova 2004, Ferrone 2006). Overall, these studies have led to inconclusive findings about the functional effects of the variant. The p.Cys277 residue is conserved across mammals and other organisms, and four out of five computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) suggest that the variant may impact the protein; however, this information is not predictive enough to assume pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -
Neoplasm Other:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at