chr17-7687376-C-G

Position:

• chr17-7687376-C-G

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PVS1_Moderate PM2 PP3_Strong PP5

The NM_000546.6(TP53):​c.-29+1G>C variant causes a splice donor change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: TP53 NM_000546.6 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 3.25

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]

WRAP53 (HGNC:25522): (WD repeat containing antisense to TP53) This gene encodes an essential component of the telomerase holoenzyme complex, a ribonucleoprotein complex required for telomere synthesis. This protein is enriched in Cajal bodies, nuclear sites of RNP processing that are important for telomerase function. It interacts with dyskerin, TERT and TERC, other components of active telomerase, and with small Cajal body RNAs (scaRNAs), which are involved in modifying splicing RNAs. This mRNA also functions as a p53 antisense transcript, that regulates endogenous p53 mRNA levels and further induction of p53 protein by targeting the 5' untranslated region of p53 mRNA. Alternatively spliced transcript variants which differ only in the 5' UTR have been found for this gene. [provided by RefSeq, Mar 2011]

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.09560068 fraction of the gene.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 17-7687376-C-G is Pathogenic according to our data. Variant chr17-7687376-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1524222.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TP53	NM_000546.6	c.-29+1G>C		splice_donor_variant		ENST00000269305.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TP53	ENST00000269305.9	c.-29+1G>C		splice_donor_variant		1	NM_000546.6	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 0

GnomAD4 genome Cov.: 32

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

Oct 05, 2023

The c.-29+1G>C intronic variant is located in the 5' untranslated region (5’ UTR) of the TP53 gene. This intronic variant results from a G to C substitution one nucleotide after the first non-coding exon. This alteration has been observed in at least one individual with a personal and/or family history that is consistent with TP53-related disease (Ambry internal data). Another variant impacting the same splice site, TP53 c.-29+1G>T, was identified in a family with Li Fraumeni Syndrome (Verselis SJ et al. Oncogene, 2000 Aug;19:4230-5). Further analyses of this variant did not detect any abnormally spliced transcript; however only transcripts from one allele were observed, suggesting monoallelic expression of the TP53 transcript. This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site. RNA studies did not detect abnormal splicing in the set of samples tested; however additional analyses indicated the presence of transcripts from only one allele, as described for TP53 c.-29+1G>T (Ambry internal data). 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

Labcorp Genetics (formerly Invitae), Labcorp

Jul 26, 2022

ClinVar contains an entry for this variant (Variation ID: 1524222). 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. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This variant has been observed in individual(s) with clinical features of Li-Fraumeni syndrome (Invitae). This variant is not present in population databases (gnomAD no frequency). This variant occurs in a non-coding region of the TP53 gene. It does not change the encoded amino acid sequence of the TP53 protein. It affects a nucleotide within the consensus splice site. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Uncertain	0.090
CADD	Pathogenic	32
DANN	Uncertain	0.99
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.98		Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr17-7590694; COSMIC: COSV53123147; COSMIC: COSV53123147;