18-23544401-C-T

Position:

chr18-23544401-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.2073G>A(p.Pro691=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00649 in 1,614,158 control chromosomes in the GnomAD database, including 51 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0049 ( 2 hom., cov: 32)

Exomes 𝑓: 0.0067 ( 49 hom. )

Consequence

NPC1
NM_000271.5 synonymous

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:16

Conservation

PhyloP100: -4.85

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=-0.64).

BP6

Variant 18-23544401-C-T is Benign according to our data. Variant chr18-23544401-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 194158.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr18-23544401-C-T is described in Lovd as [Likely_benign]. Variant chr18-23544401-C-T is described in Lovd as [Benign].

BP7

Synonymous conserved (PhyloP=-4.85 with no splicing effect.

BS1

Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.00488 (743/152286) while in subpopulation SAS AF= 0.0116 (56/4828). AF 95% confidence interval is 0.00917. There are 2 homozygotes in gnomad4. There are 348 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

BS2

High Homozygotes in GnomAd4 at 2 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NPC1	NM_000271.5 linkuse as main transcript	c.2073G>A	p.Pro691=	synonymous_variant	13/25	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.2073G>A	p.Pro691=	synonymous_variant	13/25	1	NM_000271.5	ENSP00000269228	P1	O15118-1
NPC1	ENST00000591051.1 linkuse as main transcript	c.1152G>A	p.Pro384=	synonymous_variant	6/18	2		ENSP00000467636
NPC1	ENST00000540608.5 linkuse as main transcript	n.1987G>A		non_coding_transcript_exon_variant	11/16	2

Frequencies

GnomAD3 genomes

AF:

0.00489

AC:

744

AN:

152168

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00106

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00249

Gnomad ASJ

AF:

0.0104

Gnomad EAS

AF:

0.000192

Gnomad SAS

AF:

0.0118

Gnomad FIN

AF:

0.00273

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.00775

Gnomad OTH

AF:

0.00527

GnomAD3 exomes

AF:

0.00536

AC:

1347

AN:

251440

Hom.:

AF XY:

0.00578

AC XY:

786

AN XY:

135900

show subpopulations

Gnomad AFR exome

AF:

0.000800

Gnomad AMR exome

AF:

0.00280

Gnomad ASJ exome

AF:

0.00843

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00990

Gnomad FIN exome

AF:

0.00365

Gnomad NFE exome

AF:

0.00650

Gnomad OTH exome

AF:

0.00505

GnomAD4 exome

AF:

0.00666

AC:

9731

AN:

1461872

Hom.:

Cov.:

AF XY:

0.00674

AC XY:

4905

AN XY:

727236

show subpopulations

Gnomad4 AFR exome

AF:

0.000597

Gnomad4 AMR exome

AF:

0.00282

Gnomad4 ASJ exome

AF:

0.0103

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0105

Gnomad4 FIN exome

AF:

0.00352

Gnomad4 NFE exome

AF:

0.00699

Gnomad4 OTH exome

AF:

0.00631

GnomAD4 genome

AF:

0.00488

AC:

743

AN:

152286

Hom.:

Cov.:

AF XY:

0.00467

AC XY:

348

AN XY:

74462

show subpopulations

Gnomad4 AFR

AF:

0.00106

Gnomad4 AMR

AF:

0.00248

Gnomad4 ASJ

AF:

0.0104

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.0116

Gnomad4 FIN

AF:

0.00273

Gnomad4 NFE

AF:

0.00775

Gnomad4 OTH

AF:

0.00521

Alfa

AF:

0.00592

Hom.:

Bravo

AF:

0.00437

Asia WGS

AF:

0.00751

AC:

AN:

3478

EpiCase

AF:

0.00851

EpiControl

AF:

0.00860

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:16

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Niemann-Pick disease, type C1

Benign:7

Likely benign, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, Amsterdam University Medical Center	Aug 07, 2017	- -
Benign, no assertion criteria provided	clinical testing	Natera, Inc.	Dec 06, 2019	- -
Benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Feb 01, 2024	- -
Benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Jun 10, 2021	- -
Likely 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 likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -
Likely benign, criteria provided, single submitter	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	Jun 28, 2017	- -
Likely benign, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -

not provided

Benign:4

Benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jul 01, 2024	NPC1: BP4, BP7, BS1, BS2 -
Likely benign, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, University Medical Center Utrecht	-	- -
Likely benign, no assertion criteria provided	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	Apr 25, 2017	- -
Likely benign, criteria provided, single submitter	not provided	Breakthrough Genomics, Breakthrough Genomics	-	- -

not specified

Benign:3

Benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	May 20, 2015	- -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Sep 24, 2015	This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -
Likely benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Mar 28, 2016	Variant identified in a genome or exome case(s) and assessed due to predicted null impact of the variant or pathogenic assertions in the literature or databases. Disclaimer: This variant has not undergone full assessment. The following are preliminary notes: MAF, Silent variant. -

Inborn genetic diseases

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 20, 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. -

NPC1-related disorder

Benign:1

Benign, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Jun 22, 2023

This variant is classified as 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

BayesDel_noAF

Benign

-0.64

CADD

Benign

0.39

DANN

Benign

0.53

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