1-40092171-T-C

Position:

chr1-40092171-T-C

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM2PP3_StrongPP5_Very_Strong

The NM_000310.4(PPT1):c.236A>G(p.Asp79Gly) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,848 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 predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D79E) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

PPT1
NM_000310.4 missense, splice_region

Scores

Splicing: ADA: 0.7265

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 7.86

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:

PPT1 (HGNC:):

PPT1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 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, 5 uncertain in NM_000310.4

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.99

PP5

Variant 1-40092171-T-C is Pathogenic according to our data. Variant chr1-40092171-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 8901.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-40092171-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PPT1	NM_000310.4 linkuse as main transcript	c.236A>G	p.Asp79Gly	missense_variant, splice_region_variant	3/9	ENST00000642050.2	NP_000301.1	P50897-1
PPT1	NM_001363695.2 linkuse as main transcript	c.236A>G	p.Asp79Gly	missense_variant, splice_region_variant	3/8		NP_001350624.1
PPT1	NM_001142604.2 linkuse as main transcript	c.125-2659A>G		intron_variant			NP_001136076.1	P50897-2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PPT1	ENST00000642050.2 linkuse as main transcript	c.236A>G	p.Asp79Gly	missense_variant, splice_region_variant	3/9		NM_000310.4	ENSP00000493153.1		P50897-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251388

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135854

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:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000274

AC:

AN:

1461848

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

727224

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:

0.00000360

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Neuronal ceroid lipofuscinosis 1

Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Aug 14, 2023	ClinVar contains an entry for this variant (Variation ID: 8901). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. RNA analysis performed to evaluate the impact of this missense change on mRNA splicing indicates it does not significantly alter splicing (PMID: 9425237). Experimental studies have shown that this missense change affects PPT1 function (PMID: 10191107, 11440996). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. This missense change has been observed in individual(s) with neuronal ceroid lipofuscinosis (PMID: 9425237). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is present in population databases (rs137852697, gnomAD 0.0009%). This sequence change replaces aspartic acid, which is acidic and polar, with glycine, which is neutral and non-polar, at codon 79 of the PPT1 protein (p.Asp79Gly). -
Pathogenic, no assertion criteria provided	literature only	OMIM	Feb 01, 1998	- -

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Jul 01, 2021

Published functional studies demonstrate a damaging effect as palmitoyl-CoA hydrolase activity is reduced by ~90% as compared to wild type (Bellizzi et al., 2000); Not observed at a significant frequency in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: 9425237, 10781062, 27535533, 21228398, 9664077, 11440996, 29576218) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.90

BayesDel_addAF

Pathogenic

0.58

BayesDel_noAF

Pathogenic

0.60

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.97

D;.;.;.;.

Eigen

Pathogenic

0.87

Eigen_PC

Pathogenic

0.77

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Benign

0.80

.;T;T;T;T

M_CAP

Uncertain

0.20

MetaRNN

Pathogenic

0.99

D;D;D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.9

H;.;.;.;.

PrimateAI

Uncertain

0.49

REVEL

Pathogenic

0.97

Polyphen

1.0

D;.;.;.;.

MutPred

0.97

Loss of helix (P = 0.0376);.;.;Loss of helix (P = 0.0376);Loss of helix (P = 0.0376);

MVP

1.0

MPC

0.66

ClinPred

1.0

GERP RS

5.3

Varity_R

0.94

gMVP

0.85

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.73

dbscSNV1_RF

Benign

0.71

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

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