rs386833649

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000310.4(PPT1):​c.490C>T​(p.Arg164*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000821 in 1,461,874 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 Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. R164R) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 31)
Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

PPT1
NM_000310.4 stop_gained

Scores

4
2
6

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 2.92

Publications

10 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 1-40089456-G-A is Pathogenic according to our data. Variant chr1-40089456-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 56197.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PPT1NM_000310.4 linkc.490C>T p.Arg164* stop_gained Exon 5 of 9 ENST00000642050.2 NP_000301.1
PPT1NM_001363695.2 linkc.490C>T p.Arg164* stop_gained Exon 5 of 8 NP_001350624.1
PPT1NM_001142604.2 linkc.181C>T p.Arg61* stop_gained Exon 2 of 6 NP_001136076.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PPT1ENST00000642050.2 linkc.490C>T p.Arg164* stop_gained Exon 5 of 9 NM_000310.4 ENSP00000493153.1

Frequencies

GnomAD3 genomes
Cov.:
31
GnomAD2 exomes
AF:
0.00000795
AC:
2
AN:
251428
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000821
AC:
12
AN:
1461874
Hom.:
0
Cov.:
32
AF XY:
0.00000688
AC XY:
5
AN XY:
727242
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.000126
AC:
5
AN:
39696
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000540
AC:
6
AN:
1112002
Other (OTH)
AF:
0.00
AC:
0
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
1
2
3
4
5
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
Cov.:
31
Alfa
AF:
0.0000407
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:7
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Neuronal ceroid lipofuscinosis 1 Pathogenic:6
Aug 26, 2014
Counsyl
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

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.

Dec 18, 2017
Genomic Research Center, Shahid Beheshti University of Medical Sciences
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Oct 05, 2023
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
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

Dec 19, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Arg164*) in the PPT1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in PPT1 are known to be pathogenic (PMID: 10679943, 21990111). This variant is present in population databases (rs386833649, gnomAD 0.006%). This premature translational stop signal has been observed in individuals with neuronal ceroid lipofuscinosis (PMID: 9664077, 10649502). ClinVar contains an entry for this variant (Variation ID: 56197). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic.

Jan 25, 2023
Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:curation

The homozygous p.Arg164Ter variant in PPT1 was identified by our study in two siblings with neuronal ceroid lipofuscinosis. The p.Arg164Ter variant in PPT1 has been previously reported in four unrelated individuals with neuronal ceroid lipofuscinosis 1 (PMID: 31741823, PMID: 21990111, PMID: 10649502, PMID: 9664077), but has been identified in 0.005% (1/18394) of East Asian chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP ID: rs386833649). Although this variant has been seen in the general population in a heterozygous state, its frequency is low enough to be consistent with a recessive carrier frequency. Of the four affected individuals previously reported (PMID: 31741823, PMID: 21990111, PMID: 10649502, PMID: 9664077), three were compound heterozygotes who carried pathogenic or likely pathogenic variants in trans (PMID: 31741823, PMID: 21990111, PMID: 9664077, ClinVar Variation ID: 8904), and one was a compound heterozygote who carried a variant of uncertain significance in trans (PMID: 10649502, ClinVar Variation ID: 56217), and the affected siblings identified by our study were homozygotes, which increases the likelihood that the p.Arg164Ter variant is pathogenic. This variant has also been reported in ClinVar (Variation ID: 56197) and has been interpreted as pathogenic by Invitae and the Shahid Beheshti University of Medical Sciences Genomic Research Center and as likely pathogenic by Counsyl. This nonsense variant leads to a premature termination codon at position 164, which is predicted to lead to a truncated or absent protein. Loss of function of the PPT1 gene is an established mechanism of autosomal recessive neuronal ceroid lipofuscinosis 1. In summary, this variant meets criteria to be classified as pathogenic for autosomal recessive neuronal ceroid lipofuscinosis 1. ACMG/AMP Criteria applied: PVS1, PM2_Supporting, PM3_Strong (Richards 2015).

not provided Pathogenic:1
Aug 15, 2023
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 25525159, 28367323, 21990111, 21704547, 24997880, 10649502, 31741823, 9664077)

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.51
D
BayesDel_noAF
Pathogenic
0.58
CADD
Pathogenic
37
DANN
Uncertain
1.0
DEOGEN2
Benign
0.0
.;.;.;.;.;.
Eigen
Uncertain
0.38
Eigen_PC
Benign
0.20
LIST_S2
Benign
0.0
.;.;.;.;.;.
MetaRNN
Benign
0.0
.;.;.;.;.;.
MutationAssessor
Benign
0.0
.;.;.;.;.;.
PhyloP100
2.9
PROVEAN
Benign
0.0
.;.;.;.;.;.
Sift
Pathogenic
0.0
.;.;.;.;.;.
Sift4G
Pathogenic
0.0
.;.;.;.;.;.
Vest4
0.0
GERP RS
2.4
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Mutation Taster
=1/199
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.15
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: rs386833649; hg19: chr1-40555128; COSMIC: COSV107475515; COSMIC: COSV107475515; API