Is NPC2 p.Gln23= (c.69G>A) pathogenic?

NPC2 p.Gln23= (c.69G>A) is classified Likely benign in NPC2 (ClinVar, Single submitter, 1 submitter; last evaluated 2026-01-20). Very rare (popmax 0.00167%, amr); Associated with Niemann-Pick disease, type C2.

What condition is associated with NPC2 p.Gln23= (c.69G>A)?

NPC2 p.Gln23= (c.69G>A) is associated with Niemann-Pick disease, type C2 (ClinVar).

How common is NPC2 p.Gln23= (c.69G>A) in the general population?

NPC2 p.Gln23= (c.69G>A) is very rare (popmax 0.00167%, amr) (gnomAD).

How is Niemann-Pick disease type C inherited?

Typically Autosomal recessive (Orphanet). A genetic counselor can assess individual risk for a family.

NPC2 p.Gln23=

c.69G>A · rs760160779 · VCV1581631

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.00167%, amr)

Conditions

Niemann-Pick disease, type C2

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -1.4	GERP -3.8
Overall
CADD	1.559	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00167% Admixed American · 1/59,766 alleles

Overall 0.000124% 2/1,611,380 alleles · very rare exomes 0/1,459,138 · genomes 2/152,242 · joint denominator

Ancestry group	Frequency	1 in
Admixed Americangrpmax	0.00167%	59,766
African / African-American	0.00133%	74,916

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: NPC2
Protein: p.Gln23=
Coding: c.69G>A
MANE Select: NM_006432
dbSNP: rs760160779
Type: single nucleotide variant
Location: chr14:74493206 (GRCh38)
Gene constraint: LOEUF 1.422 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 92.88 · 2 PDB

Full NPC2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

Niemann-Pick disease, type C2 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Niemann-Pick disease type C (Orphanet):

Inheritance: Autosomal recessive
Onset: All ages
Prevalence: 1-9 / 100 000 (Europe)

Similar variants

NPC2 p.Gln23Ter Likely pathogenic ★ same residue
NPC2 c.190+5G>A Pathogenic/Likely pathogenic ★★ same condition
NPC2 p.Cys47Ter Pathogenic ★★ same condition
NPC2 p.Cys99Arg Pathogenic ★★ same condition
NPC2 p.Gln45Ter Pathogenic/Likely pathogenic ★★ same condition
NPC2 p.Glu118Ter Pathogenic ★★ same condition
NPC2 p.Glu20Ter Pathogenic ★★ same condition
NPC2 p.Met1Ile Pathogenic/Likely pathogenic ★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/npc2-p-gln23 (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown