Is NPC2 p.Tyr55= (c.165C>T) pathogenic?

NPC2 p.Tyr55= (c.165C>T) is classified Likely benign in NPC2 (ClinVar, Single submitter, 2 submitters; last evaluated 2023-03-08). No allele count reported in gnomAD v4.1 (AN 1,602,576); Associated with Niemann-Pick disease, type C2.

What condition is associated with NPC2 p.Tyr55= (c.165C>T)?

NPC2 p.Tyr55= (c.165C>T) is associated with Niemann-Pick disease, type C2 (ClinVar).

How common is NPC2 p.Tyr55= (c.165C>T) in the general population?

NPC2 p.Tyr55= (c.165C>T) is no allele count reported in gnomAD v4.1 (AN 1,602,576) (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.Tyr55=

c.165C>T · rs2086712268 · VCV990179

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 2 submitters

gnomAD v4.1

Not reported

no allele count reported in gnomAD v4.1 (AN 1,602,576)

Conditions

Niemann-Pick disease, type C2

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
REVEL	0.255	benign-leaning
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 0.82	GERP -0.23, phastCons 1
Overall
CADD	5.262	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

No allele count reported in gnomAD v4.1 (AN 1,602,576). This is missing data, not an absence: the variant may or may not be present in gnomAD. Rarity (ACMG PM2) and BA1/BS1 cannot be assessed for it.

Variant & gene context

Gene: NPC2
Protein: p.Tyr55=
Coding: c.165C>T
MANE Select: NM_006432
dbSNP: rs2086712268
Type: single nucleotide variant
Location: chr14:74486354 (GRCh38)
Gene constraint: LOEUF 1.422 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 92.88 · 2 PDB
Residue 55: a β-strand

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.Tyr55Ter 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-tyr55 (accessed [today's date]).

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