18-23544484-C-T

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM2PM5PP2PP3_StrongPP5_Very_Strong

The NM_000271.5(NPC1):c.1990G>A(p.Val664Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000136 in 1,614,092 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 Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V664L) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

NPC1
NM_000271.5 missense

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 7.90

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

NPC1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr18-23544484-C-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 1468673.Status of the report is criteria_provided_single_submitter, 1 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, 0.953

PP5

Variant 18-23544484-C-T is Pathogenic according to our data. Variant chr18-23544484-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 370601.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
NPC1	NM_000271.5 link	c.1990G>A	p.Val664Met	missense_variant	Exon 13 of 25	ENST00000269228.10	NP_000262.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
NPC1	ENST00000269228.10 link	c.1990G>A	p.Val664Met	missense_variant	Exon 13 of 25	1	NM_000271.5	ENSP00000269228.4	O15118-1
NPC1	ENST00000591051.1 link	c.1066G>A	p.Val356Met	missense_variant	Exon 6 of 18	2		ENSP00000467636.1	K7EQ23
NPC1	ENST00000540608.5 link	n.1904G>A		non_coding_transcript_exon_variant	Exon 11 of 16	2

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152204

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000796

AC:

AN:

251294

AF XY:

0.00

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 FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000137

AC:

AN:

1461888

Hom.:

Cov.:

AF XY:

0.0000138

AC XY:

AN XY:

727244

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53418

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.0000153

AC:

AN:

1112010

Other (OTH)

AF:

0.0000331

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.490

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.0000131

AC:

AN:

152204

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74354

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41454

American (AMR)

AF:

0.00

AC:

AN:

15280

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5206

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10612

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68036

Other (OTH)

AF:

0.00

AC:

AN:

2086

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000540

Hom.:

Bravo

AF:

0.0000302

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Niemann-Pick disease, type C1

Pathogenic:4

Jun 01, 2022

Solve-RD Consortium

Significance:Likely pathogenic

Review Status:no assertion criteria provided

Collection Method:provider interpretation

Variant confirmed as disease-causing by referring clinical team -

Mar 08, 2016

Counsyl

Significance:Likely pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

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. -

Jun 14, 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 664 of the NPC1 protein (p.Val664Met). This variant is present in population databases (rs376213990, gnomAD 0.004%). This missense change has been observed in individual(s) with Niemann-Pick type C (PMID: 20718790, 25236789, 26937389, 28222799). ClinVar contains an entry for this variant (Variation ID: 370601). 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. -

Sep 16, 2020

Natera, Inc.

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Niemann-Pick disease, type C

Pathogenic:1

Nov 17, 2022

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

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: NPC1 c.1990G>A (p.Val664Met) results in a conservative amino acid change located in the Sterol-sensing domain (IPR000731) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 251294 control chromosomes. c.1990G>A has been reported in the literature as a biallelic compound heterozygous genotyppe in multiple individuals affected with Niemann-Pick Disease Type C (example, Macias-Vidal_2011, Takamura_2013, Greenberg_2015, Reunert_2016, Guan_2020). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

NPC1-related disorder

Pathogenic:1

Mar 20, 2023

PreventionGenetics, part of Exact Sciences

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The NPC1 c.1990G>A variant is predicted to result in the amino acid substitution p.Val664Met. This variant was reported in numerous individuals with Niemann-Pick disease, type C (Park et al. 2003. PubMed ID: 12955717; Macías-Vidal et al. 2011. PubMed ID: 20718790; Takamura et al. 2013. PubMed ID: 24001525; Jahnova et al. 2014. PubMed ID: 25236789; Greenberg et al. 2015. PubMed ID: 26937389; Table S1, Reunert et al. 2016. PubMed ID: 26981555; de Castro-Orós et al. 2017. PubMed ID: 28222799; Abtahi et al. 2022. PubMed ID: 35086560). This variant is reported in 0.0040% of alleles in individuals of African descent in gnomAD (http://gnomad.broadinstitute.org/variant/18-21124448-C-T). This variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.91

BayesDel_addAF

Pathogenic

0.49

BayesDel_noAF

Pathogenic

0.49

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.92

Eigen

Pathogenic

0.86

Eigen_PC

Pathogenic

0.76

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.99

M_CAP

Pathogenic

0.45

MetaRNN

Pathogenic

0.95

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

3.3

PhyloP100

7.9

PrimateAI

Uncertain

0.69

PROVEAN

Uncertain

-2.9

REVEL

Pathogenic

0.86

Sift

Uncertain

0.0010

Sift4G

Uncertain

0.0020

Polyphen

1.0

Vest4

0.97

MVP

0.94

MPC

0.92

ClinPred

0.97

GERP RS

5.8

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.81

gMVP

0.86

Mutation Taster

=10/90

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over