rs751951695

chr18-23554764-C-Achr18-23554764-C-T

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_000271.5(NPC1):c.1547G>T(p.Cys516Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,156 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C516Y) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: NPC1 NM_000271.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.64

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]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 4 uncertain in NM_000271.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr18-23554764-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 268186.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.944

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NPC1	NM_000271.5	c.1547G>T	p.Cys516Phe	missense_variant	9/25	ENST00000269228.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NPC1	ENST00000269228.10	c.1547G>T	p.Cys516Phe	missense_variant	9/25	1	NM_000271.5	P1
NPC1	ENST00000591051.1	c.830G>T	p.Cys277Phe	missense_variant	4/18	2
NPC1	ENST00000540608.5	n.1461G>T		non_coding_transcript_exon_variant	7/16	2
NPC1	ENST00000590301.1	n.222G>T		non_coding_transcript_exon_variant	1/2	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251226 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135784

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460156 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726556

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.53
Cadd	Pathogenic	27
Dann	Uncertain	0.99
DEOGEN2	Pathogenic	0.87	D
Eigen	Pathogenic	0.82
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D
M_CAP	Pathogenic	0.65	D
MetaRNN	Pathogenic	0.94	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.2	H
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.76	T
PROVEAN	Pathogenic	-10	D
REVEL	Pathogenic	0.91
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0050	D
Polyphen		0.99	D
Vest4		0.96
MutPred		0.66		Gain of helix (P = 0.132);
MVP		0.97
MPC		0.94
ClinPred		1.0	D
GERP RS		4.6
Varity_R		0.97
gMVP		0.99

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

Other links and lift over

dbSNP: rs751951695; hg19: chr18-21134728;