rs1554901523

Positions:

• chr11-6614919-GA-G

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000391.4(TPP1):​c.1497del​(p.Gly501AlafsTer18) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. P499P) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: TPP1 NM_000391.4 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 1.74

Genes affected

TPP1 (HGNC:2073): (tripeptidyl peptidase 1) This gene encodes a member of the sedolisin family of serine proteases. The protease functions in the lysosome to cleave N-terminal tripeptides from substrates, and has weaker endopeptidase activity. It is synthesized as a catalytically-inactive enzyme which is activated and auto-proteolyzed upon acidification. Mutations in this gene result in late-infantile neuronal ceroid lipofuscinosis, which is associated with the failure to degrade specific neuropeptides and a subunit of ATP synthase in the lysosome. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 24 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-6614919-GA-G is Pathogenic according to our data. Variant chr11-6614919-GA-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 522104.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TPP1	NM_000391.4	c.1497del	p.Gly501AlafsTer18	frameshift_variant	12/13	ENST00000299427.12

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TPP1	ENST00000299427.12	c.1497del	p.Gly501AlafsTer18	frameshift_variant	12/13	1	NM_000391.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Jun 16, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Oct 13, 2021	For these reasons, this variant has been classified as Pathogenic. This variant disrupts a region of the TPP1 protein in which other variant(s) (p.Trp542*) have been determined to be pathogenic (Invitae). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. ClinVar contains an entry for this variant (Variation ID: 522104). This premature translational stop signal has been observed in individual(s) with neuronal ceroid lipofuscinosis (PMID: 21990111). This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Gly501Alafs*18) in the TPP1 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 63 amino acid(s) of the TPP1 protein. -

Inborn genetic diseases Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 20, 2017

- -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
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: rs1554901523; hg19: chr11-6636150;