NM_000271.5:c.2848G>A

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1PM2PM5PP2PP3_ModeratePP5_Very_Strong

The NM_000271.5(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
NM_000271.5 missense

Scores

2
7
10

Clinical Significance

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

Conservation

PhyloP100: 0.430

Publications

14 publications found
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 Gene-Disease associations (from GenCC):
  • Niemann-Pick disease, type C1
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp, Myriad Women’s Health
  • Niemann-Pick disease type C, adult neurologic onset
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Niemann-Pick disease type C, juvenile neurologic onset
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Niemann-Pick disease type C, late infantile neurologic onset
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Niemann-Pick disease type C, severe early infantile neurologic onset
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Niemann-Pick disease type C, severe perinatal form
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 17 ACMG points.

PM1
In a hotspot region, there are 7 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 chr18-23539417-A-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 372774.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 171 curated pathogenic missense variants (we use a threshold of 10). The gene has 18 curated benign missense variants. Gene score misZ: 1.0917 (below the threshold of 3.09). Trascript score misZ: 1.706 (below the threshold of 3.09). GenCC associations: The gene is linked to Niemann-Pick disease, type C1, Niemann-Pick disease type C, severe early infantile neurologic onset, Niemann-Pick disease type C, late infantile neurologic onset, Niemann-Pick disease type C, adult neurologic onset, Niemann-Pick disease type C, juvenile neurologic onset, Niemann-Pick disease type C, severe perinatal form.
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 Pathogenic/Likely_pathogenic. ClinVar VariationId is 2971.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
NPC1NM_000271.5 linkc.2848G>A p.Val950Met missense_variant Exon 19 of 25 ENST00000269228.10 NP_000262.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
NPC1ENST00000269228.10 linkc.2848G>A p.Val950Met missense_variant Exon 19 of 25 1 NM_000271.5 ENSP00000269228.4 O15118-1
NPC1ENST00000591051.1 linkc.1924G>A p.Val642Met missense_variant Exon 12 of 18 2 ENSP00000467636.1 K7EQ23
NPC1ENST00000591075.1 linkn.481G>A non_coding_transcript_exon_variant Exon 1 of 3 4

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152224
Hom.:
0
Cov.:
33
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
GnomAD2 exomes
AF:
0.0000120
AC:
3
AN:
250896
AF XY:
0.0000221
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000226
AC:
33
AN:
1461596
Hom.:
0
Cov.:
32
AF XY:
0.0000234
AC XY:
17
AN XY:
727058
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44700
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26120
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86146
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000288
AC:
32
AN:
1111880
Other (OTH)
AF:
0.00
AC:
0
AN:
60386
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.472
Heterozygous variant carriers
0
2
4
6
8
10
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152224
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74372
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41454
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68048
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000319
Hom.:
0
Bravo
AF:
0.00000378
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.00
AC:
0

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
Aug 01, 2016
Shendure Lab, University of Washington
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

patient had late-onset NPC -

Jun 01, 2001
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Jun 06, 2022
Revvity Omics, Revvity
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Oct 28, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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). Invitae Evidence 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 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. -

May 05, 2022
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mar 14, 2018
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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] -

Aug 03, 2021
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Feb 03, 2015
Counsyl
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

not provided Pathogenic:1
Aug 06, 2019
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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
Apr 25, 2024
PreventionGenetics, part of Exact Sciences
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

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
D
BayesDel_noAF
Pathogenic
0.15
CADD
Benign
12
DANN
Uncertain
0.98
DEOGEN2
Benign
0.30
T
Eigen
Benign
-0.52
Eigen_PC
Benign
-0.43
FATHMM_MKL
Uncertain
0.81
D
LIST_S2
Uncertain
0.97
D
M_CAP
Uncertain
0.10
D
MetaRNN
Pathogenic
0.92
D
MetaSVM
Uncertain
-0.091
T
MutationAssessor
Benign
1.8
L
PhyloP100
0.43
PrimateAI
Benign
0.38
T
PROVEAN
Benign
-1.0
N
REVEL
Uncertain
0.55
Sift
Benign
0.17
T
Sift4G
Benign
0.29
T
Polyphen
0.0070
B
Vest4
0.83
MutPred
0.80
Loss of methylation at K951 (P = 0.0154);
MVP
0.82
MPC
0.32
ClinPred
0.12
T
GERP RS
0.33
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
2.7
Varity_R
0.14
gMVP
0.76
Mutation Taster
=17/83
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs120074135; hg19: chr18-21119382; API