rs386833659

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_StrongPM2PP5_Very_Strong

The NM_000310.4(PPT1):​c.628-1G>T variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,612,482 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

PPT1
NM_000310.4 splice_acceptor, intron

Scores

4
2
1
Splicing: ADA: 0.9999
2

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 7.62
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.10749186 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.8, offset of -22, new splice context is: tctgatggtaatgaccttAGgtg. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 1-40078659-C-A is Pathogenic according to our data. Variant chr1-40078659-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 56208.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-40078659-C-A is described in Lovd as [Pathogenic]. Variant chr1-40078659-C-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PPT1NM_000310.4 linkc.628-1G>T splice_acceptor_variant, intron_variant Intron 6 of 8 ENST00000642050.2 NP_000301.1 P50897-1
PPT1NM_001363695.2 linkc.628-1G>T splice_acceptor_variant, intron_variant Intron 6 of 7 NP_001350624.1
PPT1NM_001142604.2 linkc.319-1G>T splice_acceptor_variant, intron_variant Intron 3 of 5 NP_001136076.1 P50897-2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PPT1ENST00000642050.2 linkc.628-1G>T splice_acceptor_variant, intron_variant Intron 6 of 8 NM_000310.4 ENSP00000493153.1 P50897-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152118
Hom.:
0
Cov.:
32
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:
0.00
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
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1460364
Hom.:
0
Cov.:
30
AF XY:
0.00000138
AC XY:
1
AN XY:
726588
show subpopulations
Gnomad4 AFR exome
AF:
0.00
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:
0.00000180
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152118
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74330
show subpopulations
Gnomad4 AFR
AF:
0.00
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:
0.0000370
Hom.:
0
Bravo
AF:
0.0000113

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Neuronal ceroid lipofuscinosis 1 Pathogenic:5
Jan 07, 2016
Counsyl
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Oct 03, 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

- -

Oct 21, 2019
Revvity Omics, Revvity
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Mar 08, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change affects an acceptor splice site in intron 6 of the PPT1 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in PPT1 are known to be pathogenic (PMID: 10679943, 21990111). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with infantile neuronal ceroid lipofuscinosis (PMID: 10679943). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is also known as IVS6-1G>T. ClinVar contains an entry for this variant (Variation ID: 56208). 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. -

Neuronal ceroid lipofuscinosis Pathogenic:1
May 06, 2016
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: The c.628-1G>T in a PPT1 gene is a splice-site variant that alters a conserved nucleotide. 5/5 in silico tools in Alamut predict this variant to disrupt a canonical acceptor sequence, however these predictions have yet to be confirmed by functional assay. The variant is absent from ExAC but has been reported in multiple affected patients presented with infantile neuronal ceroid lipofuscinoses. In addition, a reputable database/diagnostic center classified the variant of interest as Likely Pathogenic. Taken together, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Uncertain
0.060
CADD
Pathogenic
33
DANN
Uncertain
0.99
Eigen
Pathogenic
0.98
Eigen_PC
Pathogenic
0.77
FATHMM_MKL
Pathogenic
0.97
D
GERP RS
5.0

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.94
SpliceAI score (max)
0.99
Details are displayed if max score is > 0.2
DS_AG_spliceai
0.26
Position offset: 21
DS_AL_spliceai
0.99
Position offset: -1

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: rs386833659; hg19: chr1-40544331; API