1-40074165-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1PM2BP4_Moderate

The NM_000310.4(PPT1):​c.817G>A​(p.Glu273Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000186 in 1,614,052 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. E273E) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000019 ( 0 hom. )

Consequence

PPT1
NM_000310.4 missense

Scores

3
16

Clinical Significance

Uncertain significance criteria provided, single submitter U:2

Conservation

PhyloP100: 0.814
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]

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM1
In a chain Palmitoyl-protein thioesterase 1 (size 278) in uniprot entity PPT1_HUMAN there are 88 pathogenic changes around while only 6 benign (94%) in NM_000310.4
PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.14835593).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
PPT1NM_000310.4 linkuse as main transcriptc.817G>A p.Glu273Lys missense_variant 9/9 ENST00000642050.2
PPT1NM_001363695.2 linkuse as main transcriptc.745G>A p.Glu249Lys missense_variant 8/8
PPT1NM_001142604.2 linkuse as main transcriptc.508G>A p.Glu170Lys missense_variant 6/6

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
PPT1ENST00000642050.2 linkuse as main transcriptc.817G>A p.Glu273Lys missense_variant 9/9 NM_000310.4 P1P50897-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152178
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
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
GnomAD3 exomes
AF:
0.00000398
AC:
1
AN:
251434
Hom.:
0
AF XY:
0.00000736
AC XY:
1
AN XY:
135886
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:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000192
AC:
28
AN:
1461874
Hom.:
0
Cov.:
31
AF XY:
0.0000165
AC XY:
12
AN XY:
727238
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:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000243
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152178
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74340
show subpopulations
Gnomad4 AFR
AF:
0.0000241
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000330
Hom.:
0
Bravo
AF:
0.0000113
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Neuronal ceroid lipofuscinosis 1 Uncertain:2
Uncertain significance, no assertion criteria providedclinical testingNatera, Inc.Sep 17, 2021- -
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpDec 11, 2023This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 273 of the PPT1 protein (p.Glu273Lys). This variant is present in population databases (no rsID available, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with PPT1-related conditions. ClinVar contains an entry for this variant (Variation ID: 533955). 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 not expected to disrupt PPT1 protein function with a negative 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.081
BayesDel_addAF
Benign
-0.050
T
BayesDel_noAF
Benign
-0.31
CADD
Benign
16
DANN
Benign
0.61
DEOGEN2
Uncertain
0.64
D;.;.;.;.;.;.
Eigen
Benign
-0.64
Eigen_PC
Benign
-0.54
FATHMM_MKL
Uncertain
0.83
D
LIST_S2
Uncertain
0.89
.;D;D;D;D;D;D
M_CAP
Benign
0.026
D
MetaRNN
Benign
0.15
T;T;T;T;T;T;T
MetaSVM
Benign
-0.36
T
MutationAssessor
Benign
1.1
L;.;.;.;.;.;.
MutationTaster
Benign
0.56
N;N;N
PrimateAI
Benign
0.30
T
PROVEAN
Benign
-0.70
.;.;N;.;.;N;.
REVEL
Benign
0.21
Sift
Benign
0.88
.;.;T;.;.;T;.
Sift4G
Benign
0.83
.;.;T;.;.;T;.
Polyphen
0.0
B;.;.;.;.;B;.
Vest4
0.18, 0.12
MutPred
0.54
Gain of ubiquitination at E273 (P = 0.0289);.;.;.;.;.;.;
MVP
0.90
MPC
0.14
ClinPred
0.037
T
GERP RS
0.15
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.21
gMVP
0.33

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: rs1193191643; hg19: chr1-40539837; API