chr1-40078659-C-A

Position:

chr1-40078659-C-A

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 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

Scores

Splicing: ADA: 0.9999

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]

PPT1 links:

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 0.10640608 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	Effect	MANE	Protein
PPT1	NM_000310.4 linkuse as main transcript	c.628-1G>T	splice_acceptor_variant	ENST00000642050.2	NP_000301.1
PPT1	NM_001142604.2 linkuse as main transcript	c.319-1G>T	splice_acceptor_variant		NP_001136076.1
PPT1	NM_001363695.2 linkuse as main transcript	c.628-1G>T	splice_acceptor_variant		NP_001350624.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PPT1	ENST00000642050.2 linkuse as main transcript	c.628-1G>T		splice_acceptor_variant			NM_000310.4	ENSP00000493153	P1	P50897-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152118

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:

0.00

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:

AN:

1460364

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

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:

AN:

152118

Hom.:

Cov.:

AF XY:

0.00

AC XY:

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.:

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

Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Jan 07, 2016	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Oct 03, 2023	- -
Likely pathogenic, no assertion criteria provided	literature only	Juha Muilu Group; Institute for Molecular Medicine Finland (FIMM)	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	May 30, 2023	For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 56208). This variant is also known as IVS6-1G>T. 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 not present in population databases (gnomAD no frequency). 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). -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Oct 21, 2019	- -

Neuronal ceroid lipofuscinosis

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

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

May 06, 2016

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

BayesDel_noAF

Uncertain

0.060

CADD

Pathogenic

DANN

Uncertain

0.99

Eigen

Pathogenic

0.98

Eigen_PC

Pathogenic

0.77

FATHMM_MKL

Pathogenic

0.97

MutationTaster

Benign

1.0

D;D;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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over