NM_000546.6:c.830G>T

Variant names:

• chr17-7673790-C-A
• rs763098116
• NM_000546.6:c.830G>T

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP3_Strong PP5

The NM_000546.6(TP53):​c.830G>T​(p.Cys277Phe) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,856 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). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C277R) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TP53 NM_000546.6 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3 U:3
• Conservation: PhyloP100: 6.08
• Publications: 216 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: Pathogenic. The variant received 11 ACMG points.

• PM1: In a hotspot region, there are 66 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 6 benign, 26 uncertain in NM_000546.6
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-7673791-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 421804.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991
• PP5: Variant 17-7673790-C-A is Pathogenic according to our data. Variant chr17-7673790-C-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 458567.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TP53	NM_000546.6	c.830G>T	p.Cys277Phe	missense_variant	Exon 8 of 11	ENST00000269305.9	NP_000537.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TP53	ENST00000269305.9	c.830G>T	p.Cys277Phe	missense_variant	Exon 8 of 11	1	NM_000546.6	ENSP00000269305.4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251308 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: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461856 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727230

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111996

Other (OTH) AF: 0.00 AC: 0 AN: 60396

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 31

Alfa AF: 0.00 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3 Uncertain:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:2

Feb 25, 2025

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.C277F pathogenic mutation (also known as c.830G>T), located in coding exon 7 of the TP53 gene, results from a G to T substitution at nucleotide position 830. The cysteine at codon 277 is replaced by phenylalanine, an amino acid with highly dissimilar properties. This alteration has been shown to have a loss of transactivation activity in yeast based functional studies (IARC TP53 database: Kato S et al. Proc. Natl. Acad. Sci. U.S.A., 2003 Jul;100:8424-9; Kucab JE et al. DNA Repair (Amst.), 2016 Mar;39:21-33; Paget V et al. PLoS ONE, 2012 Feb;7:e30921). Studies conducted in human cell lines indicate this alteration is deficient at growth suppression and has a dominant negative effect (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 the same codon, p.C277R (c.829T>C), has been detected an individual with a personal history of adrenocortical carcinoma and shown to segregate with disease in three affected family members in one family with early-onset breast cancer tested by our laboratory (Ambry internal data). This amino acid position is well conserved in available vertebrate species. The p.C277F alteration has been observed numerous times as a somatic mutation in the cancerhotspots.org database (Chang MT et al. Cancer Discov. 2018 02;8:174-183). 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 is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD) non-cancer dataset. 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. -

Apr 12, 2024

Lupski Lab, Baylor-Hopkins CMG, Baylor College of Medicine

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

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 GRCh38:17:7673790:C>A was assigned evidence codes ['PS3', 'PP3_Moderate'] and an overall classification of Likely pathogenic -

Li-Fraumeni syndrome Uncertain:2

Mar 04, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Oct 13, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces cysteine, which is neutral and slightly polar, with phenylalanine, which is neutral and non-polar, at codon 277 of the TP53 protein (p.Cys277Phe). This variant is present in population databases (rs763098116, 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: 458567). 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. Experimental studies have shown that this missense change affects TP53 function (PMID: 9407971, 12826609, 19850740, 26070072, 29979965, 30224644). 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. -

Li-Fraumeni syndrome 1 Pathogenic:1

Feb 20, 2024

Myriad Genetics, Inc.

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely pathogenic. Functional studies indicate this variant impacts protein function [PMID: 18524770, 27813088, 29979965]. This variant is expected to disrupt protein structure [Myriad internal data]. -

TP53-related disorder Uncertain:1

Jun 23, 2023

PreventionGenetics, part of Exact Sciences

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The TP53 c.830G>T variant is predicted to result in the amino acid substitution p.Cys277Phe. To our knowledge, this variant has not been reported in the literature in association with TP53-related disease. Functional studies in vitro indicate that this variant affects protein function (see for example, Kato et al. 2003. PubMed ID: 12826609; Malcikova et al. 2009. PubMed ID: 19850740; Giacomelli AO et al. 2018. PMID: 30224644). This variant is reported in 0.00088% of alleles in individuals of European (Non-Finnish) descent in gnomAD (http://gnomad.broadinstitute.org/variant/17-7577108-C-A). In ClinVar, it is classified as a variant of uncertain significance (https://www.ncbi.nlm.nih.gov/clinvar/variation/458567/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.88	D;.;.;.;.;T;T;.;D;.;.;.;.;.;.;D;.;.;.
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D;D;D;D;D;D;D;.;.;.;D;D;.;D;D;D;D;D;D
M_CAP	Pathogenic	0.52	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.93	D
MutationAssessor	Pathogenic	3.2	.;.;.;.;.;.;.;.;M;.;M;M;M;.;.;M;.;.;.
PhyloP100		6.1
PrimateAI	Uncertain	0.68	T
PROVEAN	Pathogenic	-10	D;.;.;.;.;.;.;.;D;.;.;D;D;.;.;D;.;.;D
REVEL	Pathogenic	0.93
Sift	Pathogenic	0.0	D;.;.;.;.;.;.;.;D;.;.;D;D;.;.;D;.;.;D
Sift4G	Pathogenic	0.0010	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
Polyphen		1.0, 1.0	.;.;.;.;.;.;.;.;D;.;D;D;D;.;.;D;.;.;.
Vest4		0.92
MutPred		0.94		Loss of sheet (P = 0.1158);.;.;.;.;.;.;.;Loss of sheet (P = 0.1158);.;Loss of sheet (P = 0.1158);Loss of sheet (P = 0.1158);Loss of sheet (P = 0.1158);.;.;Loss of sheet (P = 0.1158);.;.;.;
MVP		0.99
MPC		0.44
ClinPred		1.0	D
GERP RS		5.1
PromoterAI		0.022	Neutral
Varity_R		1.0
gMVP		0.91
Mutation Taster		=3/97	disease causing

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

Other links and lift over

dbSNP: rs763098116; hg19: chr17-7577108; COSMIC: COSV52693726; COSMIC: COSV52693726;