rs120074135

Positions:

chr18-23539418-C-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM2PM5PP3_ModeratePP5_Very_Strong

The ENST00000269228.10(NPC1):c.2848G>A(p.Val950Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000211 in 1,613,820 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V950G) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

NPC1
ENST00000269228.10 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:10

Conservation

PhyloP100: 0.430

Variant links:

Genes affected

NPC1 (HGNC:7897): (NPC intracellular cholesterol transporter 1) This gene encodes a large protein that resides in the limiting membrane of endosomes and lysosomes and mediates intracellular cholesterol trafficking via binding of cholesterol to its N-terminal domain. It is predicted to have a cytoplasmic C-terminus, 13 transmembrane domains, and 3 large loops in the lumen of the endosome - the last loop being at the N-terminus. This protein transports low-density lipoproteins to late endosomal/lysosomal compartments where they are hydrolized and released as free cholesterol. Defects in this gene cause Niemann-Pick type C disease, a rare autosomal recessive neurodegenerative disorder characterized by over accumulation of cholesterol and glycosphingolipids in late endosomal/lysosomal compartments.[provided by RefSeq, Aug 2009]

NPC1 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 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in ENST00000269228.10

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr18-23539417-A-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 372774.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Pathogenic=1, Uncertain_significance=1}.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.918

PP5

Variant 18-23539418-C-T is Pathogenic according to our data. Variant chr18-23539418-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2971.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr18-23539418-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NPC1	NM_000271.5 linkuse as main transcript	c.2848G>A	p.Val950Met	missense_variant	19/25	ENST00000269228.10	NP_000262.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NPC1	ENST00000269228.10 linkuse as main transcript	c.2848G>A	p.Val950Met	missense_variant	19/25	1	NM_000271.5	ENSP00000269228	P1	O15118-1
NPC1	ENST00000591051.1 linkuse as main transcript	c.1927G>A	p.Val643Met	missense_variant	12/18	2		ENSP00000467636
NPC1	ENST00000591075.1 linkuse as main transcript	n.481G>A		non_coding_transcript_exon_variant	1/3	4

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152224

Hom.:

Cov.:

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000120

AC:

AN:

250896

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135562

show subpopulations

Gnomad AFR exome

AF:

0.0000621

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:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000226

AC:

AN:

1461596

Hom.:

Cov.:

AF XY:

0.0000234

AC XY:

AN XY:

727058

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:

0.0000288

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152224

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74372

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:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000320

Hom.:

Bravo

AF:

0.00000378

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.00

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:10

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Niemann-Pick disease, type C1

Pathogenic:8

Likely pathogenic, criteria provided, single submitter	literature only	Counsyl	Feb 03, 2015	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Jun 01, 2001	- -
Pathogenic, no assertion criteria provided	clinical testing	Shendure Lab, University of Washington	Aug 01, 2016	patient had late-onset NPC -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Mar 14, 2018	This variant was determined to be pathogenic according to ACMG Guidelines, 2015 [PMID:25741868]. The c.2848G>A (p.V950M) variant has been previously reported in multiple patients with adult-onset Niemann-Pick disease and variant biochemical phenotype [PMID 11333381, 16126423, 26984608, 27900365] -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Aug 03, 2021	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	May 05, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 02, 2023	This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 950 of the NPC1 protein (p.Val950Met). This variant is present in population databases (rs120074135, gnomAD 0.007%). This missense change has been observed in individuals with Niemann-Pick disease type C (PMID: 11333381, 17003072, 26984608, 27900365). ClinVar contains an entry for this variant (Variation ID: 2971). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on NPC1 protein function. Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on NPC1 function (PMID: 28193631, 30923329, 31699992). This variant disrupts the p.Val950 amino acid residue in NPC1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 25236789, 26981555). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Jun 06, 2022	- -

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Aug 06, 2019

Reported previously in association with Niemann-Pick disease, type C (NPC) (Millat et al., 2001; Millat et al., 2005; Sevin et al. 2007; Garver et al. 2010). Two patients with NPC who were apparently homozygous for the V950M variant had adult onset of neurological symptoms (Millat et al., 2001; Sevin et al. 2007); Missense variants in this gene are often considered pathogenic (Stenson et al., 2014); Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 15465421, 26666848, 19744920, 16126423, 26984608, 11333381, 17003072, 27900365) -

NPC1-related disorder

Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Apr 25, 2024

The NPC1 c.2848G>A variant is predicted to result in the amino acid substitution p.Val950Met. This patient is heterozygous in the NPC1 gene for a sequence variant defined as c.2848G>A, which is predicted to result in the amino acid substitution p.Val950Met. This variant has been reported in the homozygous and compound heterozygous states in individuals with adult onset Niemann-Pick disease type C (Patient 22, Millat et al. 2001. PubMed ID: 11333381; Sévin et al. 2007. PubMed ID: 17003072; Dougherty et al. 2016. PubMed ID: 27900365; Sedel et al. 2016. PubMed ID: 26984608). This variant is reported in 0.0062% of alleles in individuals of African descent in gnomAD. Taken together, this variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.15

BayesDel_addAF

Uncertain

0.15

BayesDel_noAF

Pathogenic

0.15

CADD

Benign

DANN

Uncertain

0.98

DEOGEN2

Benign

0.30

Eigen

Benign

-0.52

Eigen_PC

Benign

-0.43

FATHMM_MKL

Uncertain

0.81

LIST_S2

Uncertain

0.97

M_CAP

Uncertain

0.10

MetaRNN

Pathogenic

0.92

MetaSVM

Uncertain

-0.091

MutationAssessor

Benign

1.8

MutationTaster

Benign

1.0

A;A

PrimateAI

Benign

0.38

PROVEAN

Benign

-1.0

REVEL

Uncertain

0.55

Sift

Benign

0.17

Sift4G

Benign

0.29

Polyphen

0.0070

Vest4

0.83

MutPred

0.80

Loss of methylation at K951 (P = 0.0154);

MVP

0.82

MPC

0.32

ClinPred

0.12

GERP RS

0.33

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

2.7

Varity_R

0.14

gMVP

0.76

Splicing

Name

Calibrated prediction

Score

Prediction

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