rs762517273

Positions:

chr18-23534478-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1PM2PM5PP3_Moderate

The NM_000271.5(NPC1):c.3559G>A(p.Ala1187Thr) variant causes a missense change. The variant allele was found at a frequency of 0.0000521 in 1,613,832 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A1187V) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.000092 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000048 ( 0 hom. )

Consequence

NPC1
NM_000271.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:2

Conservation

PhyloP100: 6.12

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 Likely_pathogenic. Variant got 8 ACMG points.

PM1

In a topological_domain Cytoplasmic (size 22) in uniprot entity NPC1_HUMAN there are 6 pathogenic changes around while only 1 benign (86%) 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 chr18-23534477-G-A is described in Lovd as [Pathogenic].

PP3

MetaRNN computational evidence supports a deleterious effect, 0.92

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NPC1	NM_000271.5 linkuse as main transcript	c.3559G>A	p.Ala1187Thr	missense_variant	23/25	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.3559G>A	p.Ala1187Thr	missense_variant	23/25	1	NM_000271.5	ENSP00000269228	P1	O15118-1

Frequencies

GnomAD3 genomes

AF:

0.0000919

AC:

AN:

152260

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000121

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000196

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000637

AC:

AN:

251066

Hom.:

AF XY:

0.0000884

AC XY:

AN XY:

135724

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000174

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000654

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000704

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000479

AC:

AN:

1461572

Hom.:

Cov.:

AF XY:

0.0000495

AC XY:

AN XY:

727112

show subpopulations

Gnomad4 AFR exome

AF:

0.000119

Gnomad4 AMR exome

AF:

0.000179

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000464

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000468

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000919

AC:

AN:

152260

Hom.:

Cov.:

AF XY:

0.0000941

AC XY:

AN XY:

74382

show subpopulations

Gnomad4 AFR

AF:

0.000121

Gnomad4 AMR

AF:

0.000196

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000735

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000659

Hom.:

Bravo

AF:

0.0000793

ExAC

AF:

0.0000494

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Niemann-Pick disease, type C1

Pathogenic:1Uncertain:1

Likely pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 31, 2023	This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 1187 of the NPC1 protein (p.Ala1187Thr). This variant is present in population databases (rs762517273, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with NPC1-related conditions. ClinVar contains an entry for this variant (Variation ID: 499348). 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%. This variant disrupts the p.Ala1187 amino acid residue in NPC1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 26981555). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Uncertain significance, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	May 31, 2022	- -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Eurofins Ntd Llc (ga)

Dec 20, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.18

BayesDel_addAF

Uncertain

0.087

BayesDel_noAF

Pathogenic

0.16

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.78

Eigen

Uncertain

0.61

Eigen_PC

Uncertain

0.51

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Uncertain

0.97

M_CAP

Uncertain

0.26

MetaRNN

Pathogenic

0.92

MetaSVM

Uncertain

0.61

MutationAssessor

Uncertain

2.5

MutationTaster

Benign

1.0

D;D

PrimateAI

Uncertain

0.63

PROVEAN

Uncertain

-3.3

REVEL

Pathogenic

0.68

Sift

Uncertain

0.0040

Sift4G

Uncertain

0.0050

Polyphen

1.0

Vest4

0.85

MVP

0.91

MPC

0.84

ClinPred

0.83

GERP RS

5.8

RBP_binding_hub_radar

0.92

RBP_regulation_power_radar

2.6

Varity_R

0.61

gMVP

0.76

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

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