Is GNPTAB p.Ala522= (c.1566A>G) pathogenic?

GNPTAB p.Ala522= (c.1566A>G) is classified Likely benign in GNPTAB (ClinVar, Single submitter, 1 submitter; last evaluated 2023-01-18). Ultra-rare (popmax 0.0165%, mid); Associated with mucolipidosis type III, alpha/beta.

What condition is associated with GNPTAB p.Ala522= (c.1566A>G)?

GNPTAB p.Ala522= (c.1566A>G) is associated with mucolipidosis type III, alpha/beta, mucolipidosis type II (ClinVar).

How common is GNPTAB p.Ala522= (c.1566A>G) in the general population?

GNPTAB p.Ala522= (c.1566A>G) is ultra-rare (popmax 0.0165%, mid) (gnomAD).

How is Mucolipidosis type III inherited?

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

GNPTAB p.Ala522=

c.1566A>G · rs1953089573 · VCV1604606

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

ultra-rare (popmax 0.0165%, mid)

Conditions

mucolipidosis type III, alpha/beta

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 0.6	GERP -0.94, phastCons 1
Overall
CADD	11.45	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0165% Middle Eastern · 1/6,060 alleles

Overall 0.000137% 2/1,461,868 alleles · ultra-rare

Ancestry group	Frequency	1 in
Middle Easterngrpmax	0.0165%	6,060
European (non-Finnish)	8.47e-05%	1,180,022

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.Ala522=
Coding: c.1566A>G
MANE Select: NM_024312
dbSNP: rs1953089573
Type: single nucleotide variant
Location: chr12:101766137 (GRCh38)
Gene constraint: LOEUF 0.8 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 72.15 · 5 PDB
Residue 522: a disulfide bond; a UniProt-annotated variant site (in mliiia)

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

Disease context

mucolipidosis type III, alpha/beta — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: mucolipidosis type II

For Mucolipidosis type III (Orphanet):

Inheritance: Autosomal recessive
Onset: Childhood
Prevalence: 1-9 / 1 000 000 (Europe)

Similar variants

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
GNPTAB c.324-2A>G 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/gnptab-p-ala522 (accessed [today's date]).

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