18-23539945-C-T

Position:

chr18-23539945-C-T

Variant summary

Our verdict is Benign. Variant got -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2

The NM_000271.5(NPC1):c.2661G>A(p.Pro887=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00117 in 1,614,116 control chromosomes in the GnomAD database, including 19 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0065 ( 9 hom., cov: 33)

Exomes 𝑓: 0.00062 ( 10 hom. )

Consequence

NPC1
NM_000271.5 synonymous

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:7

Conservation

PhyloP100: -2.06

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 Benign. Variant got -21 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.59).

BP6

Variant 18-23539945-C-T is Benign according to our data. Variant chr18-23539945-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 326259.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr18-23539945-C-T is described in Lovd as [Benign].

BP7

Synonymous conserved (PhyloP=-2.06 with no splicing effect.

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00646 (984/152258) while in subpopulation AFR AF= 0.0227 (942/41544). AF 95% confidence interval is 0.0215. There are 9 homozygotes in gnomad4. There are 465 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

BS2

High Homozygotes in GnomAd4 at 9 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NPC1	NM_000271.5 linkuse as main transcript	c.2661G>A	p.Pro887=	synonymous_variant	18/25	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.2661G>A	p.Pro887=	synonymous_variant	18/25	1	NM_000271.5	ENSP00000269228	P1	O15118-1

Frequencies

GnomAD3 genomes

AF:

0.00645

AC:

981

AN:

152140

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0227

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00203

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000192

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000735

Gnomad OTH

AF:

0.00239

GnomAD3 exomes

AF:

0.00151

AC:

380

AN:

251470

Hom.:

AF XY:

0.00104

AC XY:

142

AN XY:

135910

show subpopulations

Gnomad AFR exome

AF:

0.0204

Gnomad AMR exome

AF:

0.00107

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000272

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.000651

GnomAD4 exome

AF:

0.000624

AC:

912

AN:

1461858

Hom.:

Cov.:

AF XY:

0.000472

AC XY:

343

AN XY:

727230

show subpopulations

Gnomad4 AFR exome

AF:

0.0224

Gnomad4 AMR exome

AF:

0.00107

Gnomad4 ASJ exome

AF:

0.0000383

Gnomad4 EAS exome

AF:

0.0000756

Gnomad4 SAS exome

AF:

0.0000812

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000225

Gnomad4 OTH exome

AF:

0.00124

GnomAD4 genome

AF:

0.00646

AC:

984

AN:

152258

Hom.:

Cov.:

AF XY:

0.00624

AC XY:

465

AN XY:

74460

show subpopulations

Gnomad4 AFR

AF:

0.0227

Gnomad4 AMR

AF:

0.00203

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000735

Gnomad4 OTH

AF:

0.00237

Alfa

AF:

0.00314

Hom.:

Bravo

AF:

0.00704

Asia WGS

AF:

0.00173

AC:

AN:

3478

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Niemann-Pick disease, type C1

Benign:4

Likely benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	May 18, 2021	- -
Benign, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 12, 2018	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -
Benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 31, 2024	- -

not provided

Benign:2

Likely benign, criteria provided, single submitter	not provided	Breakthrough Genomics, Breakthrough Genomics	-	- -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Jul 31, 2018	This variant is associated with the following publications: (PMID: 16126423) -

Inborn genetic diseases

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 17, 2022

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.59

CADD

Benign

0.12

DANN

Benign

0.67

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

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