chr18-23533470-C-G

Position:

• chr18-23533470-C-G

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP3_Strong PP5

The NM_000271.5(NPC1):​c.3639G>C​(p.Leu1213Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L1213V) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: NPC1 NM_000271.5 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 2.60

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 11 ACMG points.

• PM1: In a transmembrane_region Helical (size 20) in uniprot entity NPC1_HUMAN there are 5 pathogenic changes around while only 1 benign (83%) 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 chrnull-null-null-null is described in UniProt as null.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.99
• PP5: Variant 18-23533470-C-G is Pathogenic according to our data. Variant chr18-23533470-C-G is described in ClinVar as [Pathogenic]. Clinvar id is 2965.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NPC1	NM_000271.5	c.3639G>C	p.Leu1213Phe	missense_variant	24/25	ENST00000269228.10	NP_000262.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NPC1	ENST00000269228.10	c.3639G>C	p.Leu1213Phe	missense_variant	24/25	1	NM_000271.5	ENSP00000269228	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Niemann-Pick disease, type C1, juvenile form Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Jul 01, 1999

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.93
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.45
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.90	D;D
Eigen	Pathogenic	0.72
Eigen_PC	Uncertain	0.61
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Pathogenic	0.98	D;D
M_CAP	Pathogenic	0.66	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	0.94	D
MutationAssessor	Pathogenic	3.9	.;H
MutationTaster	Benign	1.0	A;A
PrimateAI	Uncertain	0.75	T
PROVEAN	Uncertain	-3.5	.;D
REVEL	Pathogenic	0.82
Sift	Pathogenic	0.0	.;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	.;D
Vest4		0.98
MutPred		0.97		.;Loss of ubiquitination at K1217 (P = 0.0777);
MVP		0.94
MPC		0.95
ClinPred		1.0	D
GERP RS		4.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.92
gMVP		0.79

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs120074131; hg19: chr18-21113434;