Genetic Variant NPC1:c.1947+13_1947+14insC (chr18-23544946-C-CG) – ACMG Classification: Likely_benign (-6 pts)

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP6_ModerateBS2

The NM_000271.5(NPC1):c.1947+13_1947+14insC variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000384 in 1,329,706 control chromosomes in the GnomAD database, including 4 homozygotes. Variant has been reported in ClinVar as Likely benign (★).

Frequency

Genomes: 𝑓 0.000052 ( 1 hom., cov: 27)

Exomes 𝑓: 0.000037 ( 3 hom. )

Consequence

NPC1
NM_000271.5 intron

Scores

Not classified

Clinical Significance

Likely benign criteria provided, single submitter B:2

Conservation

PhyloP100: -0.996

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:

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -6 ACMG points.

BP6

Variant 18-23544946-C-CG is Benign according to our data. Variant chr18-23544946-C-CG is described in ClinVar as [Likely_benign]. Clinvar id is 1575142.Status of the report is criteria_provided_single_submitter, 1 stars.

BS2

High Homozygotes in GnomAdExome4 at 3 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NPC1	NM_000271.5 link	c.1947+13_1947+14insC		intron_variant	Intron 12 of 24	ENST00000269228.10	NP_000262.2

Ensembl

Gene	Transcript	HGVSc	Effect	Exon rank	TSL	MANE	Protein	UniProt
NPC1	ENST00000269228.10 link	c.1947+13_1947+14insC	intron_variant	Intron 12 of 24	1	NM_000271.5	ENSP00000269228.4	O15118-1
NPC1	ENST00000591051.1 link	c.1023+13_1023+14insC	intron_variant	Intron 5 of 17	2		ENSP00000467636.1	K7EQ23
NPC1	ENST00000540608.5 link	n.1861+13_1861+14insC	intron_variant	Intron 10 of 15	2

Frequencies

GnomAD3 genomes

AF:

0.0000515

AC:

AN:

135902

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000217

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:

0.0000657

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.0000369

AC:

AN:

1193804

Hom.:

Cov.:

AF XY:

0.0000265

AC XY:

AN XY:

602958

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000553

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000126

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000215

Gnomad4 OTH exome

AF:

0.0000197

GnomAD4 genome

AF:

0.0000515

AC:

AN:

135902

Hom.:

Cov.:

AF XY:

0.0000752

AC XY:

AN XY:

66464

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000217

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000657

Gnomad4 OTH

AF:

0.00

ClinVar

Significance: Likely benign

Submissions summary: Benign:2

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

NPC1-related disorder

Benign:1

Sep 23, 2021

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). -

Niemann-Pick disease, type C1

Benign:1

Jan 22, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

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