chr11-6616739-C-T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1PM2PP3_Moderate

The NM_000391.4(TPP1):​c.808G>A​(p.Gly270Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000149 in 1,614,034 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Synonymous variant affecting the same amino acid position (i.e. G270G) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

TPP1
NM_000391.4 missense

Scores

15
3
1

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 7.44

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: Likely_pathogenic. The variant received 6 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 10 uncertain in NM_000391.4
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.932

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TPP1NM_000391.4 linkc.808G>A p.Gly270Arg missense_variant Exon 7 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.808G>A p.Gly270Arg missense_variant Exon 7 of 13 1 NM_000391.4 ENSP00000299427.6 O14773-1

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152106
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.0000725
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000318
AC:
8
AN:
251404
AF XY:
0.0000294
show subpopulations
Gnomad AFR exome
AF:
0.000185
Gnomad AMR exome
AF:
0.0000868
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:
0.0000144
AC:
21
AN:
1461810
Hom.:
0
Cov.:
42
AF XY:
0.0000110
AC XY:
8
AN XY:
727218
show subpopulations
African (AFR)
AF:
0.0000896
AC:
3
AN:
33480
American (AMR)
AF:
0.0000671
AC:
3
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000348
AC:
3
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53350
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000989
AC:
11
AN:
1112002
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.470
Heterozygous variant carriers
0
1
2
4
5
6
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:
0.0000197
AC:
3
AN:
152224
Hom.:
0
Cov.:
31
AF XY:
0.0000403
AC XY:
3
AN XY:
74440
show subpopulations
African (AFR)
AF:
0.0000723
AC:
3
AN:
41512
American (AMR)
AF:
0.00
AC:
0
AN:
15298
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5180
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68004
Other (OTH)
AF:
0.00
AC:
0
AN:
2110
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Jun 14, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: TPP1 c.808G>A (p.Gly270Arg) results in a non-conservative amino acid change located in the Sedolisin domain (IPR030400) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 3.2e-05 in 251404 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.808G>A in individuals affected with Neuronal Ceroid-Lipofuscinosis (Batten Disease) and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 527742). Based on the evidence outlined above, the variant was classified as uncertain significance. -

not provided Uncertain:1
Nov 11, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 270 of the TPP1 protein (p.Gly270Arg). This variant is present in population databases (rs561854371, 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: 527742). 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. -

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
Pathogenic
0.86
BayesDel_addAF
Pathogenic
0.35
D
BayesDel_noAF
Pathogenic
0.54
CADD
Pathogenic
29
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.80
D;.;.;.;.;.;.
Eigen
Pathogenic
0.72
Eigen_PC
Uncertain
0.61
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.93
D;.;D;.;D;.;D
M_CAP
Pathogenic
0.79
D
MetaRNN
Pathogenic
0.93
D;D;D;D;D;D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
3.5
M;.;.;.;.;.;.
PhyloP100
7.4
PrimateAI
Pathogenic
0.81
D
PROVEAN
Pathogenic
-7.0
D;D;.;.;.;.;.
REVEL
Pathogenic
0.92
Sift
Pathogenic
0.0
D;D;.;.;.;.;.
Sift4G
Uncertain
0.0040
D;D;.;.;.;.;.
Polyphen
1.0
D;.;.;.;.;.;.
Vest4
0.92
MutPred
0.71
Gain of MoRF binding (P = 0.0099);.;.;.;Gain of MoRF binding (P = 0.0099);.;.;
MVP
0.98
MPC
0.83
ClinPred
0.98
D
GERP RS
4.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.87
gMVP
0.94
Mutation Taster
=48/52
disease causing

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: rs561854371; hg19: chr11-6637970; API