17-7675236-A-G

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP3_Strong PP5

The NM_000546.6(TP53):c.376T>C(p.Tyr126His) 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. 2/3 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. Y126C) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: TP53 NM_000546.6 missense, splice_region
• Scores: Splicing: ADA: 0.8934
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 9.28

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]

ACMG classification

Verdict is Pathogenic. Variant got 11 ACMG points.

• PM1: In a hotspot region, there are 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 16 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 chr17-7675235-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 458541.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=4, Pathogenic=1}.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.97
• PP5: Variant 17-7675236-A-G is Pathogenic according to our data. Variant chr17-7675236-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1734755.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TP53	NM_000546.6	c.376T>C	p.Tyr126His	missense_variant, splice_region_variant	5/11	ENST00000269305.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TP53	ENST00000269305.9	c.376T>C	p.Tyr126His	missense_variant, splice_region_variant	5/11	1	NM_000546.6	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 03, 2020

The p.Y126H variant (also known as c.376T>C) is located in coding exon 4 of the TP53 gene. The tyrosine at codon 126 is replaced by histidine, an amino acid with similar properties. This change occurs in the first base pair of coding exon 4. This variant is in the DNA binding domain of the TP53 protein and is reported to have loss of transactivation in yeast based assays (IARC TP53 database: Kato S et al. Proc. Natl. Acad. Sci. USA 2003 Jul;100:8424-9). Additional studies conducted in human cell lines indicate this alteration has a dominant negative effect and is deficient at growth suppression (Kotler E et al. Mol. Cell. 2018 Jul;71:178-190.e8; Giacomelli AO et al. Nat. Genet. 2018 Oct;50:1381-1387). 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 majority of available evidence to date, this variant is likely to be pathogenic. -

Li-Fraumeni syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jun 13, 2022

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. Experimental studies have shown that this missense change affects TP53 function (PMID: 12826609, 29979965, 30224644). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. This variant has not been reported in the literature in individuals affected with TP53-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces tyrosine, which is neutral and polar, with histidine, which is basic and polar, at codon 126 of the TP53 protein (p.Tyr126His). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.94
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
Cadd	Pathogenic	26
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.88	D;D;.;D;.;.;.;.;.;.;D;.;.;D;D;.
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	0.99	D;D;.;.;.;D;D;.;D;D;D;D;D;T;D;D
M_CAP	Pathogenic	0.85	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
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Uncertain	0.77	T
PROVEAN	Uncertain	-4.3	D;D;.;D;.;.;D;D;.;.;D;.;.;D;D;D
REVEL	Pathogenic	0.96
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;.;.;P;.;.
Vest4		0.93
MutPred		0.84		Gain of disorder (P = 0.0305);Gain of disorder (P = 0.0305);.;Gain of disorder (P = 0.0305);.;Gain of disorder (P = 0.0305);Gain of disorder (P = 0.0305);Gain of disorder (P = 0.0305);.;.;Gain of disorder (P = 0.0305);.;.;.;Gain of disorder (P = 0.0305);Gain of disorder (P = 0.0305);
MVP		0.99
MPC		1.9
ClinPred		1.0	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.98
gMVP		0.75

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.89
dbscSNV1_RF	Pathogenic	0.74
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

Publications

LitVar

Other links and lift over

dbSNP: rs886039483; hg19: chr17-7578554; COSMIC: COSV53031989; COSMIC: COSV53031989;