chr1-40092135-T-G

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1PM2PM5PP3_StrongPP5

The NM_000310.4(PPT1):c.272A>C(p.Gln91Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,994 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

PPT1
NM_000310.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:3

Conservation

PhyloP100: 7.86

Publications

4 publications found

Variant links:

Genes affected

PPT1 (HGNC:9325): (palmitoyl-protein thioesterase 1) The protein encoded by this gene is a small glycoprotein involved in the catabolism of lipid-modified proteins during lysosomal degradation. The encoded enzyme removes thioester-linked fatty acyl groups such as palmitate from cysteine residues. Defects in this gene are a cause of infantile neuronal ceroid lipofuscinosis 1 (CLN1, or INCL) and neuronal ceroid lipofuscinosis 4 (CLN4). Two transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Dec 2008]

PPT1 Gene-Disease associations (from GenCC):

neuronal ceroid lipofuscinosis
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
neuronal ceroid lipofuscinosis 1
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), ClinGen, G2P, Orphanet, Myriad Women’s Health

PPT1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 11 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_000310.4

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr1-40092120-CACACTGTTGTTACTTG-AA is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 56186.Status of the report is no_assertion_criteria_provided, 0 stars.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.981

PP5

Variant 1-40092135-T-G is Pathogenic according to our data. Variant chr1-40092135-T-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 56187.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PPT1	NM_000310.4 link	c.272A>C	p.Gln91Pro	missense_variant	Exon 3 of 9	ENST00000642050.2	NP_000301.1	P50897-1
PPT1	NM_001363695.2 link	c.272A>C	p.Gln91Pro	missense_variant	Exon 3 of 8		NP_001350624.1
PPT1	NM_001142604.2 link	c.125-2623A>C		intron_variant	Intron 1 of 5		NP_001136076.1	P50897-2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PPT1	ENST00000642050.2 link	c.272A>C	p.Gln91Pro	missense_variant	Exon 3 of 9		NM_000310.4	ENSP00000493153.1		P50897-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152200

Hom.:

Cov.:

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:

0.000385

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:

0.0000119

AC:

AN:

251460

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000163

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000205

AC:

AN:

1461794

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727214

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.0000504

AC:

AN:

39694

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111926

Other (OTH)

AF:

0.0000166

AC:

AN:

60390

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

Exome 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

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152200

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74356

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41456

American (AMR)

AF:

0.00

AC:

AN:

15276

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.000385

AC:

AN:

5190

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68034

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

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:

0.00000632

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2Uncertain:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Neuronal ceroid lipofuscinosis 1

Pathogenic:2Uncertain:2

Apr 17, 2020

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Juha Muilu Group; Institute for Molecular Medicine Finland (FIMM)

Significance:Likely pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

- -

May 13, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces glutamine, which is neutral and polar, with proline, which is neutral and non-polar, at codon 91 of the PPT1 protein (p.Gln91Pro). This variant is present in population databases (rs386833639, gnomAD 0.02%). This missense change has been observed in individual(s) with neuronal ceroid lipofuscinosis (PMID: 17044973; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 56187). 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 PPT1 protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -

Apr 25, 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. -

not specified

Uncertain:1

Jun 11, 2025

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: PPT1 c.272A>C (p.Gln91Pro) results in a non-conservative amino acid change in the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function all suggest that this variant is likely to be disruptive. The variant allele was found at a frequency of 1.2e-05 in 251460 control chromosomes. c.272A>C has been observed in individuals affected with Neuronal Ceroid-Lipofuscinosis (e.g., Bi_2006, internal data). These data indicate that the variant may be associated with disease. 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: 17044973). ClinVar contains an entry for this variant (Variation ID: 56187). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.95

BayesDel_addAF

Pathogenic

0.36

BayesDel_noAF

Pathogenic

0.55

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.99

D;.;.;.;.

Eigen

Pathogenic

0.88

Eigen_PC

Pathogenic

0.76

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.95

.;D;D;D;D

M_CAP

Uncertain

0.28

MetaRNN

Pathogenic

0.98

D;D;D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

4.0

H;.;.;.;.

PhyloP100

7.9

PrimateAI

Benign

0.47

REVEL

Pathogenic

0.99

Polyphen

1.0

D;.;.;.;.

MutPred

0.95

Loss of catalytic residue at Q91 (P = 0.0916);.;.;Loss of catalytic residue at Q91 (P = 0.0916);Loss of catalytic residue at Q91 (P = 0.0916);

MVP

1.0

MPC

0.64

ClinPred

0.88

GERP RS

5.4

Varity_R

0.99

gMVP

0.98

Mutation Taster

=2/98

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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