rs143584882

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM1

The NM_000391.4(TPP1):​c.1252C>T​(p.Arg418Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000446 in 1,614,092 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R418Q) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00018 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000031 ( 0 hom. )

Consequence

TPP1
NM_000391.4 missense

Scores

5
11
3

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 2.56

Publications

1 publications found
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]
TPP1 Gene-Disease associations (from GenCC):
  • neuronal ceroid lipofuscinosis
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • neuronal ceroid lipofuscinosis 2
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Myriad Women’s Health, G2P, Orphanet
  • autosomal recessive spinocerebellar ataxia 7
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_000391.4

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TPP1NM_000391.4 linkc.1252C>T p.Arg418Trp missense_variant Exon 10 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.1252C>T p.Arg418Trp missense_variant Exon 10 of 13 1 NM_000391.4 ENSP00000299427.6 O14773-1

Frequencies

GnomAD3 genomes
AF:
0.000177
AC:
27
AN:
152206
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000627
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:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000636
AC:
16
AN:
251452
AF XY:
0.0000589
show subpopulations
Gnomad AFR exome
AF:
0.000800
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000308
AC:
45
AN:
1461886
Hom.:
0
Cov.:
34
AF XY:
0.0000206
AC XY:
15
AN XY:
727246
show subpopulations
African (AFR)
AF:
0.00102
AC:
34
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.0000348
AC:
3
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000360
AC:
4
AN:
1112010
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.492
Heterozygous variant carriers
0
3
6
8
11
14
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.000177
AC:
27
AN:
152206
Hom.:
0
Cov.:
32
AF XY:
0.000121
AC XY:
9
AN XY:
74362
show subpopulations
African (AFR)
AF:
0.000627
AC:
26
AN:
41452
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68042
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.519
Heterozygous variant carriers
0
2
4
5
7
9
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000690
Hom.:
0
Bravo
AF:
0.000223
ESP6500AA
AF:
0.00159
AC:
7
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000824
AC:
10

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:3
Jan 16, 2018
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 01, 2025
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Nov 27, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 418 of the TPP1 protein (p.Arg418Trp). This variant is present in population databases (rs143584882, gnomAD 0.07%). 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: 576289). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt TPP1 protein function. 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
Feb 15, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1252C>T (p.R418W) alteration is located in exon 10 (coding exon 10) of the TPP1 gene. This alteration results from a C to T substitution at nucleotide position 1252, causing the arginine (R) at amino acid position 418 to be replaced by a tryptophan (W). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Neuronal ceroid lipofuscinosis 2 Uncertain:1
Apr 14, 2020
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
Uncertain
0.46
BayesDel_addAF
Benign
-0.052
T
BayesDel_noAF
Uncertain
0.080
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.87
D;.;.;.;.;.;.
Eigen
Uncertain
0.37
Eigen_PC
Uncertain
0.29
FATHMM_MKL
Uncertain
0.91
D
LIST_S2
Uncertain
0.96
D;.;D;.;D;.;D
M_CAP
Pathogenic
0.46
D
MetaRNN
Uncertain
0.58
D;D;D;D;D;D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
3.5
M;.;.;.;.;.;.
PhyloP100
2.6
PrimateAI
Benign
0.24
T
PROVEAN
Uncertain
-4.2
D;D;.;.;.;.;.
REVEL
Pathogenic
0.72
Sift
Uncertain
0.0070
D;D;.;.;.;.;.
Sift4G
Uncertain
0.023
D;D;.;.;.;.;.
Polyphen
1.0
D;.;.;.;.;.;.
Vest4
0.46
MVP
0.98
MPC
0.64
ClinPred
0.59
D
GERP RS
3.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.22
gMVP
0.87
Mutation Taster
=84/16
polymorphism

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

Other links and lift over

dbSNP: rs143584882; hg19: chr11-6636687; API