Is GNPTAB p.Ser55= (c.165C>T) pathogenic?

GNPTAB p.Ser55= (c.165C>T) is classified Likely benign in GNPTAB (ClinVar, Single submitter, 1 submitter; last evaluated 2026-01-21). Very rare (popmax 0.000424%, nfe); Associated with mucolipidosis type II.

What condition is associated with GNPTAB p.Ser55= (c.165C>T)?

GNPTAB p.Ser55= (c.165C>T) is associated with mucolipidosis type II, mucolipidosis type III, alpha/beta (ClinVar).

How common is GNPTAB p.Ser55= (c.165C>T) in the general population?

GNPTAB p.Ser55= (c.165C>T) is very rare (popmax 0.000424%, nfe) (gnomAD).

How is Mucolipidosis type II inherited?

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

GNPTAB p.Ser55=

c.165C>T · rs2547975388 · VCV2185602

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.000424%, nfe)

Conditions

mucolipidosis type II

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 1.8	GERP -0.064, phastCons 1
Overall
CADD	10.76	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.000424% European (non-Finnish) · 5/1,178,994 alleles

Filtering AF 0.000124% ClinGen BA1/BS1 input FAF95, joint · FAF99 9e-05%

Overall 0.00031% 5/1,612,640 alleles · very rare exomes 5/1,460,514 · genomes 0/152,126 · joint denominator

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: GNPTAB
Protein: p.Ser55=
Coding: c.165C>T
MANE Select: NM_024312
dbSNP: rs2547975388
Type: single nucleotide variant
Location: chr12:101796715 (GRCh38)
Gene constraint: LOEUF 0.8 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 72.15 · 5 PDB
Residue 55: an α-helix

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

Disease context

mucolipidosis type II — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: mucolipidosis type III, alpha/beta

For Mucolipidosis type II (Orphanet):

Inheritance: Autosomal recessive
Onset: Antenatal, Neonatal
Prevalence: 1-9 / 1 000 000 (Europe)

Similar variants

GNPTAB p.Ser55fs Likely pathogenic ★ same residue
GNPTAB c.118-1G>A Pathogenic/Likely pathogenic ★★ same condition
GNPTAB c.118-2A>G Pathogenic/Likely pathogenic ★★ same condition
GNPTAB c.1284+1G>T Pathogenic/Likely pathogenic ★★ same condition
GNPTAB c.1408+1G>T Pathogenic/Likely pathogenic ★★ same condition
GNPTAB c.1409-2A>G Pathogenic/Likely pathogenic ★★ same condition
GNPTAB c.2715+1G>A Pathogenic ★★ same condition
GNPTAB c.2715+2T>G 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/gnptab-p-ser55 (accessed [today's date]).

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