NM_000391.4:c.1466A>G

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1PM2PP3_Strong

The NM_000391.4(TPP1):​c.1466A>G​(p.Asn489Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000266 in 1,613,954 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000026 ( 0 hom. )

Consequence

TPP1
NM_000391.4 missense

Scores

13
3
3

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 7.30
Variant links:
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]

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

PM1
In a helix (size 20) in uniprot entity TPP1_HUMAN there are 6 pathogenic changes around while only 0 benign (100%) in NM_000391.4
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.94

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TPP1NM_000391.4 linkc.1466A>G p.Asn489Ser missense_variant Exon 12 of 13 ENST00000299427.12 NP_000382.3 O14773-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TPP1ENST00000299427.12 linkc.1466A>G p.Asn489Ser missense_variant Exon 12 of 13 1 NM_000391.4 ENSP00000299427.6 O14773-1

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152070
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.000377
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000239
AC:
6
AN:
251488
Hom.:
0
AF XY:
0.0000294
AC XY:
4
AN XY:
135920
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.000185
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000260
AC:
38
AN:
1461884
Hom.:
0
Cov.:
33
AF XY:
0.0000289
AC XY:
21
AN XY:
727248
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.000206
Gnomad4 NFE exome
AF:
0.0000207
Gnomad4 OTH exome
AF:
0.0000331
GnomAD4 genome
AF:
0.0000329
AC:
5
AN:
152070
Hom.:
0
Cov.:
32
AF XY:
0.0000538
AC XY:
4
AN XY:
74292
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.000377
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000282
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.0000330
AC:
4

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:2
Mar 30, 2022
Revvity Omics, Revvity
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Dec 15, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces asparagine, which is neutral and polar, with serine, which is neutral and polar, at codon 489 of the TPP1 protein (p.Asn489Ser). This variant is present in population databases (rs751645191, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with TPP1-related conditions. ClinVar contains an entry for this variant (Variation ID: 408909). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt TPP1 protein function with a positive predictive value of 95%. 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. -

Inborn genetic diseases Uncertain:1
Jan 21, 2025
Ambry Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The c.1466A>G (p.N489S) alteration is located in exon 12 (coding exon 12) of the TPP1 gene. This alteration results from a A to G substitution at nucleotide position 1466, causing the asparagine (N) at amino acid position 489 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Neuronal ceroid lipofuscinosis 2 Uncertain:1
Nov 11, 2019
Natera, Inc.
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.27
BayesDel_addAF
Pathogenic
0.20
D
BayesDel_noAF
Uncertain
0.070
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.86
D;.;.;.;.;.;.
Eigen
Pathogenic
0.86
Eigen_PC
Pathogenic
0.76
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.92
D;.;D;.;D;.;D
M_CAP
Pathogenic
0.33
D
MetaRNN
Pathogenic
0.94
D;D;D;D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.8
H;.;.;.;.;.;.
PrimateAI
Benign
0.40
T
PROVEAN
Pathogenic
-4.5
D;D;.;.;.;.;.
REVEL
Pathogenic
0.89
Sift
Pathogenic
0.0
D;D;.;.;.;.;.
Sift4G
Pathogenic
0.0
D;D;.;.;.;.;.
Polyphen
1.0
D;.;.;.;.;.;.
Vest4
0.88
MutPred
0.77
Gain of disorder (P = 0.0704);.;.;.;.;.;.;
MVP
0.98
MPC
0.67
ClinPred
1.0
D
GERP RS
4.9
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.80
gMVP
0.97

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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs751645191; hg19: chr11-6636182; COSMIC: COSV100196442; COSMIC: COSV100196442; API