18-23541154-C-A

Variant names:

Variant summary

Our verdict is Benign. The variant received -8 ACMG points: 1P and 9B. PP2BP4_StrongBS1_SupportingBS2

The NM_000271.5(NPC1):c.2428G>T(p.Val810Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000437 in 1,614,192 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V810I) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00041 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00044 ( 2 hom. )

Consequence

NPC1
NM_000271.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6B:3

Conservation

PhyloP100: -1.83

Publications

8 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: Benign. The variant received -8 ACMG points.

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.

BP4

Computational evidence support a benign effect (MetaRNN=0.0067704916).

BS1

Variant frequency is greater than expected in population amr. GnomAd4 allele frequency = 0.000414 (63/152314) while in subpopulation AMR AF = 0.00203 (31/15288). AF 95% confidence interval is 0.00147. There are 0 homozygotes in GnomAd4. There are 28 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

BS2

High Homozygotes in GnomAdExome4 at 2 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NPC1	NM_000271.5 link	c.2428G>T	p.Val810Phe	missense_variant	Exon 16 of 25	ENST00000269228.10	NP_000262.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein
NPC1	ENST00000269228.10 link	c.2428G>T	p.Val810Phe	missense_variant	Exon 16 of 25	1	NM_000271.5	ENSP00000269228.4
NPC1	ENST00000591051.1 link	c.1504G>T	p.Val502Phe	missense_variant	Exon 9 of 18	2		ENSP00000467636.1
NPC1	ENST00000540608.5 link	n.2342G>T		non_coding_transcript_exon_variant	Exon 14 of 16	2
NPC1	ENST00000586718.1 link	n.219G>T		non_coding_transcript_exon_variant	Exon 1 of 3	3

Frequencies

GnomAD3 genomes

AF:

0.000414

AC:

AN:

152196

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00203

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:

0.000367

Gnomad OTH

AF:

0.00191

GnomAD2 exomes

AF:

0.000541

AC:

136

AN:

251482

AF XY:

0.000515

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.00257

Gnomad ASJ exome

AF:

0.0000992

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000334

Gnomad OTH exome

AF:

0.00114

GnomAD4 exome

AF:

0.000439

AC:

642

AN:

1461878

Hom.:

Cov.:

AF XY:

0.000437

AC XY:

318

AN XY:

727240

show subpopulations

African (AFR)

AF:

0.0000896

AC:

AN:

33480

American (AMR)

AF:

0.00230

AC:

103

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.0000383

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.000458

AC:

509

AN:

1111998

Other (OTH)

AF:

0.000397

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.485

Heterozygous variant carriers

113

151

189

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

110

<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:

0.000414

AC:

AN:

152314

Hom.:

Cov.:

AF XY:

0.000376

AC XY:

AN XY:

74480

show subpopulations

African (AFR)

AF:

0.0000721

AC:

AN:

41582

American (AMR)

AF:

0.00203

AC:

AN:

15288

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5182

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10620

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000368

AC:

AN:

68022

Other (OTH)

AF:

0.00189

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.498

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:

0.000460

Hom.:

Bravo

AF:

0.000703

TwinsUK

AF:

0.000809

AC:

ALSPAC

AF:

0.00104

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000581

AC:

ExAC

AF:

0.000453

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.000296

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6Benign:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Niemann-Pick disease, type C1

Uncertain:4Benign:2

Feb 17, 2022

Department of Pathology and Laboratory Medicine, Sinai Health System

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:research

- -

Apr 11, 2018

Baylor Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -

Sep 16, 2020

Natera, Inc.

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Oct 31, 2018

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 30, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not provided

Uncertain:2

Mar 29, 2018

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jun 01, 2020

CeGaT Center for Human Genetics Tuebingen

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

NPC1-related disorder

Benign:1

Feb 10, 2022

PreventionGenetics, part of Exact Sciences

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.066

BayesDel_addAF

Benign

-0.34

BayesDel_noAF

Benign

-0.27

CADD

Benign

0.23

(source)

DANN

Benign

0.96

DEOGEN2

Benign

0.36

Eigen

Benign

-1.3

Eigen_PC

Benign

-1.4

FATHMM_MKL

Benign

0.17

LIST_S2

Benign

0.70

M_CAP

Uncertain

0.092

MetaRNN

Benign

0.0068

MetaSVM

Benign

-0.37

MutationAssessor

Uncertain

2.0

PhyloP100

-1.8

PrimateAI

Benign

0.27

PROVEAN

Benign

-1.9

REVEL

Benign

0.23

Sift

Benign

0.085

Sift4G

Benign

0.084

Polyphen

0.026

Vest4

0.31

MVP

0.55

MPC

0.34

ClinPred

0.031

GERP RS

-9.3

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.057

gMVP

0.41

Mutation Taster

=86/14

polymorphism

(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