18-23539447-G-A

Position:

chr18-23539447-G-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong

The NM_000271.5(NPC1):c.2819C>T(p.Ser940Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000198 in 1,613,258 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. S940P) has been classified as Likely pathogenic.

Frequency

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

Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

NPC1
NM_000271.5 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 9.79

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 18 ACMG points.

PM1

In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_000271.5

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr18-23539448-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2810311.Status of the report is criteria_provided_single_submitter, 1 stars.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.948

PP5

Variant 18-23539447-G-A is Pathogenic according to our data. Variant chr18-23539447-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 188716.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr18-23539447-G-A is described in Lovd as [Pathogenic]. Variant chr18-23539447-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NPC1	NM_000271.5 linkuse as main transcript	c.2819C>T	p.Ser940Leu	missense_variant	19/25	ENST00000269228.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NPC1	ENST00000269228.10 linkuse as main transcript	c.2819C>T	p.Ser940Leu	missense_variant	19/25	1	NM_000271.5	P1	O15118-1
NPC1	ENST00000591051.1 linkuse as main transcript	c.1898C>T	p.Ser633Leu	missense_variant	12/18	2
NPC1	ENST00000591075.1 linkuse as main transcript	n.452C>T		non_coding_transcript_exon_variant	1/3	4

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152196

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

GnomAD3 exomes

AF:

0.0000160

AC:

AN:

250088

Hom.:

AF XY:

0.0000148

AC XY:

AN XY:

135046

show subpopulations

Gnomad AFR exome

AF:

0.0000625

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:

0.0000265

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000212

AC:

AN:

1461062

Hom.:

Cov.:

AF XY:

0.0000220

AC XY:

AN XY:

726710

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000504

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.0000187

Gnomad4 NFE exome

AF:

0.0000243

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152196

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74358

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:

0.0000922

Hom.:

Bravo

AF:

0.0000264

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000330

AC:

EpiCase

AF:

0.000164

EpiControl

AF:

0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Niemann-Pick disease, type C1

Pathogenic:4

Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Centre for Mendelian Genomics, University Medical Centre Ljubljana	Oct 22, 2019	This variant was classified as: Pathogenic. The following ACMG criteria were applied in classifying this variant: PM2,PM3,PP3,PP5. -
Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Nov 11, 2021	NM_000271.4(NPC1):c.2819C>T(S940L) is a missense variant classified as pathogenic in the context of Niemann-Pick disease type C1. S940L has been observed in cases with relevant disease (PMID: 26981555, 11349231, 25425405, 21245028, 16126423, 23146215, 16720792, 30285904, 26790753). Functional assessments of this variant are not available in the literature. S940L has been observed in population frequency databases (gnomAD: AFR 0.01%). In summary, NM_000271.4(NPC1):c.2819C>T(S940L) is a missense variant that has been observed more frequently in cases with the relevant disease than in healthy populations. Please note: this variant was assessed in the context of healthy population screening. -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 11, 2024	This sequence change replaces serine, which is neutral and polar, with leucine, which is neutral and non-polar, at codon 940 of the NPC1 protein (p.Ser940Leu). This variant is present in population databases (rs143124972, gnomAD 0.003%). This missense change has been observed in individual(s) with Niemann-Pick disease type C (PMID: 26790753, 28105569, 28710748, 32138288). ClinVar contains an entry for this variant (Variation ID: 188716). 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) performed at Invitae indicates that this missense variant is expected to disrupt NPC1 protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -

not provided

Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	May 03, 2022	PP1, PP3, PM2, PM3_very_strong -
Pathogenic, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Aug 18, 2017	- -

Niemann-Pick disease, type C

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

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

Dec 29, 2017

Variant summary: The NPC1 c.2819C>T (p.Ser940Leu) variant involves the alteration of a conserved nucleotide and 5/5 in silico tools predict a damaging outcome for this variant. This variant was found in 3/244918 control chromosomes (gnomAD) at a frequency of 0.0000122, which does not exceed the estimated maximal expected allele frequency of a pathogenic NPC1 variant (0.0027735). Multiple publications have cited the variant in affected homozygote and compound heterozygote individuals. In addition, a clinical diagnostic laboratory classified this variant as likely pathogenic. Taken together, this variant is classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.35

BayesDel_addAF

Pathogenic

0.47

BayesDel_noAF

Pathogenic

0.50

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.78

Eigen

Pathogenic

0.90

Eigen_PC

Pathogenic

0.83

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

0.98

M_CAP

Pathogenic

0.51

MetaRNN

Pathogenic

0.95

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

3.7

MutationTaster

Benign

1.0

D;D

PrimateAI

Uncertain

0.62

PROVEAN

Uncertain

-4.1

REVEL

Pathogenic

0.92

Sift

Uncertain

0.0050

Sift4G

Uncertain

0.014

Polyphen

1.0

Vest4

0.94

MVP

0.97

MPC

0.82

ClinPred

0.98

GERP RS

5.3

Varity_R

0.55

gMVP

0.91

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