18-23556603-G-A

Variant names:

Variant summary

Our verdict is Benign. The variant received -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2

The NM_000271.5(NPC1):c.966C>T(p.Ser322Ser) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00249 in 1,614,068 control chromosomes in the GnomAD database, including 67 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★). Synonymous variant affecting the same amino acid position (i.e. S322S) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.011 ( 24 hom., cov: 32)

Exomes 𝑓: 0.0016 ( 43 hom. )

Consequence

NPC1
NM_000271.5 synonymous

Scores

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:7

Conservation

PhyloP100: -0.347

Publications

1 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 -21 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.53).

BP6

Variant 18-23556603-G-A is Benign according to our data. Variant chr18-23556603-G-A is described in ClinVar as Benign. ClinVar VariationId is 326274.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BP7

Synonymous conserved (PhyloP=-0.347 with no splicing effect.

BS1

Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.0114 (1732/152290) while in subpopulation AFR AF = 0.0387 (1606/41550). AF 95% confidence interval is 0.0371. There are 24 homozygotes in GnomAd4. There are 815 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

BS2

High Homozygotes in GnomAd4 at 24 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NPC1	NM_000271.5 link	c.966C>T	p.Ser322Ser	synonymous_variant	Exon 8 of 25	ENST00000269228.10	NP_000262.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
NPC1	ENST00000269228.10 link	c.966C>T	p.Ser322Ser	synonymous_variant	Exon 8 of 25	1	NM_000271.5	ENSP00000269228.4	O15118-1
NPC1	ENST00000591051.1 link	c.246C>T	p.Ser82Ser	synonymous_variant	Exon 3 of 18	2		ENSP00000467636.1	K7EQ23
NPC1	ENST00000540608.5 link	n.880C>T		non_coding_transcript_exon_variant	Exon 6 of 16	2

Frequencies

GnomAD3 genomes

AF:

0.0113

AC:

1723

AN:

152172

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0386

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00360

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00912

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.0000735

Gnomad OTH

AF:

0.00860

GnomAD2 exomes

AF:

0.00376

AC:

939

AN:

249884

AF XY:

0.00326

show subpopulations

Gnomad AFR exome

AF:

0.0394

Gnomad AMR exome

AF:

0.00174

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000444

Gnomad OTH exome

AF:

0.00181

GnomAD4 exome

AF:

0.00156

AC:

2282

AN:

1461778

Hom.:

Cov.:

AF XY:

0.00163

AC XY:

1188

AN XY:

727190

show subpopulations

African (AFR)

AF:

0.0401

AC:

1344

AN:

33478

American (AMR)

AF:

0.00213

AC:

AN:

44702

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26128

East Asian (EAS)

AF:

0.0000504

AC:

AN:

39696

South Asian (SAS)

AF:

0.00747

AC:

644

AN:

86248

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53406

Middle Eastern (MID)

AF:

0.000693

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000270

AC:

AN:

1111958

Other (OTH)

AF:

0.00270

AC:

163

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.488

Heterozygous variant carriers

140

280

419

559

699

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

100

150

200

250

<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:

0.0114

AC:

1732

AN:

152290

Hom.:

Cov.:

AF XY:

0.0109

AC XY:

815

AN XY:

74474

show subpopulations

African (AFR)

AF:

0.0387

AC:

1606

AN:

41550

American (AMR)

AF:

0.00359

AC:

AN:

15304

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3466

East Asian (EAS)

AF:

0.00

AC:

AN:

5186

South Asian (SAS)

AF:

0.00872

AC:

AN:

4818

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10620

Middle Eastern (MID)

AF:

0.00340

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000735

AC:

AN:

68024

Other (OTH)

AF:

0.0109

AC:

AN:

2116

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.500

Heterozygous variant carriers

163

245

326

408

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Genome 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

Alfa

AF:

0.00237

Hom.:

Bravo

AF:

0.0130

Asia WGS

AF:

0.00462

AC:

AN:

3478

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

Significance: Benign

Submissions summary: Benign:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Benign:3

Genome Diagnostics Laboratory, Amsterdam University Medical Center

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Mar 03, 2015

GeneDx

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Breakthrough Genomics, Breakthrough Genomics

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:not provided

- -

Niemann-Pick disease, type C1

Benign:3

Sep 16, 2020

Natera, Inc.

Significance:Benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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. -

Feb 02, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not specified

Benign:1

Clinical Genetics, Academic Medical Center

Significance:Benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.53

CADD

Benign

6.3

(source)

DANN

Benign

0.74

PhyloP100

-0.35

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Mutation Taster

=100/0

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