18-23551652-CG-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000271.5(NPC1):​c.1628del​(p.Pro543ArgfsTer20) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,613,704 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (β˜…β˜…). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

NPC1
NM_000271.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 10.0
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]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 18-23551652-CG-C is Pathogenic according to our data. Variant chr18-23551652-CG-C is described in ClinVar as [Pathogenic]. Clinvar id is 556403.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
NPC1NM_000271.5 linkuse as main transcriptc.1628del p.Pro543ArgfsTer20 frameshift_variant 10/25 ENST00000269228.10 NP_000262.2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
NPC1ENST00000269228.10 linkuse as main transcriptc.1628del p.Pro543ArgfsTer20 frameshift_variant 10/251 NM_000271.5 ENSP00000269228 P1O15118-1
NPC1ENST00000591051.1 linkuse as main transcriptc.835+3105del intron_variant 2 ENSP00000467636
NPC1ENST00000540608.5 linkuse as main transcriptn.1542del non_coding_transcript_exon_variant 8/162
NPC1ENST00000590301.1 linkuse as main transcriptn.303del non_coding_transcript_exon_variant 2/22

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152224
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000205
AC:
3
AN:
1461480
Hom.:
0
Cov.:
31
AF XY:
0.00000138
AC XY:
1
AN XY:
727080
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000180
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152224
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74372
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000207
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Niemann-Pick disease, type C1 Pathogenic:3
Pathogenic, criteria provided, single submitterclinical testingCounsylJan 30, 2018- -
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpOct 05, 2023This sequence change creates a premature translational stop signal (p.Pro543Argfs*20) in the NPC1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in NPC1 are known to be pathogenic (PMID: 9211850). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with Niemann-Pick disease type C (PMID: 11349231, 28666962). ClinVar contains an entry for this variant (Variation ID: 556403). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitterclinical testingCentogene AG - the Rare Disease Company-- -
Niemann-Pick disease, type C Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpSep 26, 2021Variant summary: NPC1 c.1628delC (p.Pro543ArgfsX20) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 251230 control chromosomes. c.1628delC has been reported in the literature as a compound heterozygous and homozygous genotype in individuals affected with Niemann-Pick Disease Type C (example, Sun_2001). At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in complete absence of esterification of LDL-derived cholesterol in a homozygous patient derived cell line (example, Sun_2001). Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
not provided Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Oct 11, 2017- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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.

Other links and lift over

dbSNP: rs1555635957; hg19: chr18-21131616; API