Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000546.6(TP53):c.917_919+10delGAGGTAAGCAAGC(p.Arg306_Ala307delinsPro) variant causes a splice donor, disruptive inframe deletion, splice region, intron change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★).
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]
Verdict is Pathogenic. Variant got 18 ACMG points.
PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 17-7673690-TGCTTGCTTACCTC-T is Pathogenic according to our data. Variant chr17-7673690-TGCTTGCTTACCTC-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 528253.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with TP53-related disease. Donor and acceptor splice site variants typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in TP53 are known to be pathogenic (PMID: 20522432). This sequence change removes the last 3 nucleotides of exon 8, and affects a donor splice site in intron 8 of the TP53 gene. It is expected to disrupt RNA splicing and/or create a premature translational stop signal, and likely results in an absent or disrupted protein product. For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. -
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The c.917_919+10DEL13 alteration is a deletion beginning in exon 8 of the TP53 gene and extending 10 nucleotides into intron 8. This results in the deletion of a total of 13 nucleotides, including the last 3 nucleotides of exon 8 and the first ten nucleotides of the splice donor site of intron 8. This deletion may cause a disruption of normal RNA splicing; however, direct evidence is unavailable. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -