NM_000391.4:c.14C>A

Variant names:

Variant summary

Our verdict is Benign. The variant received -13 ACMG points: 0P and 13B. BP4_StrongBP6BS1BS2

The NM_000391.4(TPP1):c.14C>A(p.Ala5Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00135 in 1,614,190 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A5T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0012 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0014 ( 2 hom. )

Consequence

TPP1
NM_000391.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:7B:6

Conservation

PhyloP100: 0.237

Publications

8 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

TPP1 links:

ENSG00000255680 (HGNC:):

ENSG00000255680 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -13 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.0105650425).

BP6

Variant 11-6619387-G-T is Benign according to our data. Variant chr11-6619387-G-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 92884.

BS1

Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.00121 (185/152304) while in subpopulation NFE AF = 0.00216 (147/68020). AF 95% confidence interval is 0.00188. There are 0 homozygotes in GnomAd4. There are 94 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

BS2

High Homozygotes in GnomAdExome4 at 2 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TPP1	NM_000391.4 link	c.14C>A	p.Ala5Asp	missense_variant	Exon 1 of 13	ENST00000299427.12	NP_000382.3	O14773-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TPP1	ENST00000299427.12 link	c.14C>A	p.Ala5Asp	missense_variant	Exon 1 of 13	1	NM_000391.4	ENSP00000299427.6		O14773-1

Frequencies

GnomAD3 genomes

AF:

0.00122

AC:

185

AN:

152186

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000145

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000262

Gnomad ASJ

AF:

0.000576

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00245

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00216

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00115

AC:

289

AN:

251492

AF XY:

0.00119

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.000116

Gnomad ASJ exome

AF:

0.000694

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00254

Gnomad NFE exome

AF:

0.00185

Gnomad OTH exome

AF:

0.00114

GnomAD4 exome

AF:

0.00137

AC:

2001

AN:

1461886

Hom.:

Cov.:

AF XY:

0.00138

AC XY:

1002

AN XY:

727246

show subpopulations

African (AFR)

AF:

0.000269

AC:

AN:

33480

American (AMR)

AF:

0.000157

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.000803

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.000243

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00286

AC:

153

AN:

53420

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00154

AC:

1716

AN:

1112006

Other (OTH)

AF:

0.00121

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.473

Heterozygous variant carriers

133

266

398

531

664

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

104

156

208

260

<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:

0.00121

AC:

185

AN:

152304

Hom.:

Cov.:

AF XY:

0.00126

AC XY:

AN XY:

74480

show subpopulations

African (AFR)

AF:

0.000144

AC:

AN:

41560

American (AMR)

AF:

0.000261

AC:

AN:

15306

Ashkenazi Jewish (ASJ)

AF:

0.000576

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5184

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00245

AC:

AN:

10618

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00216

AC:

147

AN:

68020

Other (OTH)

AF:

0.00

AC:

AN:

2112

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.492

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.00154

Hom.:

Bravo

AF:

0.000714

TwinsUK

AF:

0.000809

AC:

ALSPAC

AF:

0.00182

AC:

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.000582

AC:

ExAC

AF:

0.00125

AC:

152

EpiCase

AF:

0.000927

EpiControl

AF:

0.000889

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:7Benign:6

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1Benign:4

Oct 25, 2018

Athena Diagnostics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Oct 14, 2016

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jun 01, 2021

CeGaT Center for Human Genetics Tuebingen

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jun 25, 2021

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Has not been previously published as pathogenic or benign to our knowledge -

Jan 28, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Neuronal ceroid lipofuscinosis 2

Uncertain:4

Apr 14, 2020

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

May 22, 2018

Counsyl

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Feb 13, 2018

Baylor Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

not specified

Uncertain:1Benign:1

Apr 28, 2015

Genetic Services Laboratory, University of Chicago

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Apr 09, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: TPP1 c.14C>A (p.Ala5Asp) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.0014 in 1614190 control chromosomes in the gnomAD database, including 2 homozygotes. In addition, the allele frequency of this variant in Finnish population is slightly higher than the expected maximal pathogenic allele frequency of TPP1. c.14C>A has been reported in the literature in individuals affected with epilepsy (e.g., Al Anazi_2022). However, these report(s) do not provide unequivocal conclusions about association of the variant with TPP1-related conditions. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 36539902). ClinVar contains an entry for this variant (Variation ID: 92884). Based on the evidence outlined above, the variant was classified as likely benign. -

Autosomal recessive spinocerebellar ataxia 7;C1876161:Neuronal ceroid lipofuscinosis 2

Uncertain:1

Center for Genomics, Ann and Robert H. Lurie Children's Hospital of Chicago

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

TPP1 NM_000391.3 exon 1 p.Ala5Asp (c.14C>A): This variant has not been reported in the literature but is present in 0.2% (70/25122) of Finnish alleles in the Genome Aggregation Database (https://gnomad.broadinstitute.org/variant/11-6640618-G-T?dataset=gnomad_r2_1). This variant is present in ClinVar (Variation ID:92884). Evolutionary conservation and computational predictive tools suggest that this variant may not impact the protein. In summary, data on this variant is insufficient for disease classification. Therefore, the clinical significance of this variant is uncertain. -

Inborn genetic diseases

Benign:1

Oct 21, 2021

Ambry Genetics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.22

BayesDel_addAF

Benign

-0.19

BayesDel_noAF

Uncertain

-0.040

CADD

Benign

(source)

DANN

Benign

0.94

DEOGEN2

Benign

0.38

T;.;.;.;.

Eigen

Benign

-0.74

Eigen_PC

Benign

-0.65

FATHMM_MKL

Benign

0.080

LIST_S2

Benign

0.63

T;T;T;T;T

M_CAP

Benign

0.039

MetaRNN

Benign

0.011

T;T;T;T;T

MetaSVM

Benign

-0.37

MutationAssessor

Benign

0.69

N;.;.;.;.

PhyloP100

0.24

PrimateAI

Benign

0.33

PROVEAN

Benign

-1.7

N;.;.;.;D

REVEL

Uncertain

0.41

Sift

Benign

0.042

D;.;.;.;D

Sift4G

Benign

0.31

T;.;.;.;D

Polyphen

0.019

B;.;.;.;.

Vest4

0.70

MVP

0.62

MPC

0.29

ClinPred

0.029

GERP RS

1.4

PromoterAI

0.015

Neutral

(source)

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.0

Varity_R

0.39

gMVP

0.55

Mutation Taster

=86/14

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over