NM_000546.6:c.376T>G

Variant names:

• chr17-7675236-A-C
• rs886039483
• NM_000546.6:c.376T>G

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.376T>G​(p.Tyr126Asp) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. 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. Y126H) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: TP53 NM_000546.6 missense, splice_region
• Scores: Splicing: ADA: 0.8129
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4 U:1
• Conservation: PhyloP100: 9.28
• Publications: 80 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 31 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 8 benign, 32 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 chr17-7675236-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1734755.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.975
• PP5: Variant 17-7675236-A-C is Pathogenic according to our data. Variant chr17-7675236-A-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 265333.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TP53	NM_000546.6	c.376T>G	p.Tyr126Asp	missense_variant, splice_region_variant	Exon 5 of 11	ENST00000269305.9	NP_000537.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TP53	ENST00000269305.9	c.376T>G	p.Tyr126Asp	missense_variant, splice_region_variant	Exon 5 of 11	1	NM_000546.6	ENSP00000269305.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:4 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Li-Fraumeni syndrome Pathogenic:1

Jan 06, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces tyrosine, which is neutral and polar, with aspartic acid, which is acidic and polar, at codon 126 of the TP53 protein (p.Tyr126Asp). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with clinical features of Li-Fraumeni syndrome (internal data). ClinVar contains an entry for this variant (Variation ID: 265333). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. Experimental studies have shown that this missense change affects TP53 function (PMID: 11229518, 11429705, 12826609, 29979965, 30224644). This variant disrupts the p.Tyr126 amino acid residue in TP53. Other variant(s) that disrupt this residue have been observed in individuals with TP53-related conditions (PMID: 14965603), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. -

Li-Fraumeni syndrome 1 Pathogenic:1

Feb 13, 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: 29979965]. This variant is expected to disrupt protein structure [Myriad internal data]. -

not provided Pathogenic:1

Jun 03, 2019

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 29979965, 11896595, 20668451, 21343334, 22006311, 28234344, 27189670, 14559903, 12826609, 11429705, 11229518, 21796119, 23525077, 23297126, 23103869) -

Ovarian neoplasm Pathogenic:1

Dec 01, 2018

German Consortium for Hereditary Breast and Ovarian Cancer, University Hospital Cologne

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: research

- -

Hereditary cancer-predisposing syndrome Uncertain:1

Feb 10, 2017

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Y126D variant (also known as c.376T>G) is located in coding exon 4 of the TP53 gene. The tyrosine at codon 126 is replaced by aspartic acid, an amino acid with highly dissimilar properties. This change occurs in the first base pair of coding exon 4. This alteration has been reported in an individual with a personal history of both breast and peritoneal cancer and a family history of breast or ovarian cancer (Walsh T et al. Proc. Natl. Acad. Sci. U.S.A., 2011 Nov;108:18032-7). This variant is located in the DNA binding domain of the TP53 protein and is reported to exhibit loss of transactivation capacity in yeast-based functional studies. (IARC TP53 database; Kato S et al. Proc Natl Acad Sci USA. 2003 Jul 8;100(14):8424-9; Campomenosi P et al. Oncogene, 2001 Jun;20:3573-9). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.88	D;D;.;D;.;.;.;.;.;.;D;.;.;D;D;.
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	0.98	D;D;.;.;.;D;D;.;D;D;D;D;D;T;D;D
M_CAP	Pathogenic	0.82	D
MetaRNN	Pathogenic	0.97	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.93	D
MutationAssessor	Pathogenic	3.3	.;.;.;M;.;M;M;M;.;.;M;.;.;.;.;.
PhyloP100		9.3
PrimateAI	Uncertain	0.76	T
PROVEAN	Pathogenic	-8.5	D;D;.;D;.;.;D;D;.;.;D;.;.;D;D;D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D;D;.;D;.;.;D;D;.;.;D;.;.;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D;D;D;D;D;D;D;D;.;.;.
Polyphen		1.0	D;.;.;D;.;D;D;D;.;.;D;.;.;D;.;.
Vest4		0.94
MutPred		0.84		Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);.;Loss of sheet (P = 0.0457);.;Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);.;.;Loss of sheet (P = 0.0457);.;.;.;Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);
MVP		1.0
MPC		2.2
ClinPred		1.0	D
GERP RS		5.5
PromoterAI		0.018	Neutral
Varity_R		0.99
gMVP		0.89
Mutation Taster		=3/97	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.81
dbscSNV1_RF	Benign	0.69
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: rs886039483; hg19: chr17-7578554; COSMIC: COSV52661802; COSMIC: COSV52661802;