NPC1

Chr 18AR

NPC intracellular cholesterol transporter 1

Also known as: NPC, POGZ, SLC65A1

This protein mediates intracellular cholesterol trafficking by transporting low-density lipoproteins to late endosomal/lysosomal compartments where cholesterol is released, residing in the limiting membrane of endosomes and lysosomes with 13 transmembrane domains. Mutations cause Niemann-Pick disease types C1 and D, autosomal recessive neurodegenerative disorders characterized by accumulation of cholesterol and glycosphingolipids in late endosomal/lysosomal compartments. The disease results from loss of protein function leading to defective cholesterol trafficking.

GeneReviewsOMIMResearchSummary from RefSeq, OMIM, UniProt, Mechanism
LOFmechanismARLOEUF 0.494 OMIM phenotypes
Clinical SummaryNPC1
🧬
Gene-Disease Validity (ClinGen)
Niemann-Pick disease, type C1 · ARDefinitive

Definitive — sufficient evidence for diagnostic panels

Population Constraint (gnomAD)
Constrained for loss-of-function variants (OE-LoF 0.34) despite low pLI — interpret in context.
📋
ClinVar Variants
99 unique Pathogenic / Likely Pathogenic· 144 VUS of 399 total submissions
💊
Clinical Trials
1 active or recruiting trial — potential therapeutic options may be available
📖
GeneReview available — NPC1
Authoritative clinical overview · Recommended first read
Open GeneReview ↗

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Moderate LoF intolerance
LoF Constraint
0.49LOEUF
pLI 0.000
Z-score 4.84
OE 0.34 (0.240.49)
Moderately constrained

More LoF-intolerant than ~75% of genes

Missense Constraint
1.09Z-score
OE missense 0.89 (0.830.94)
637 obs / 719.4 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.34 (0.240.49)
00.351.4
Missense OE0.89 (0.830.94)
00.61.4
Synonymous OE1.08
01.21.6
LoF obs/exp: 21 / 62.2Missense obs/exp: 637 / 719.4Syn Z: -1.07
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveNPC1-related Niemann-Pick diseaseLOFAR

Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.

DN
0.77top 25%
GOF
0.76top 25%
LOF
0.1993th %ile

The Badonyi & Marsh prediction model was trained exclusively on dominant disease genes. Predictions are not reliable for genes with autosomal recessive inheritance and are shown at reduced opacity for reference only.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

399 submitted variants in ClinVar

Classification Summary

Pathogenic34
Likely Pathogenic65
VUS144
Likely Benign110
Benign1
34
Pathogenic
65
Likely Pathogenic
144
VUS
110
Likely Benign
1
Benign

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
21
3
10
0
34
Likely Pathogenic
38
24
3
0
65
VUS
2
119
11
12
144
Likely Benign
0
0
53
57
110
Benign
0
0
1
0
1
Total611467869354

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

NPC1 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold
Clinical Literature
Open Research Assistant →
Full-Text Mentions
NLP-detected gene mentions in article bodies · via PubTator3
PubTator3
Top 5 full-text resultsSearch PubTator3 ↗