Is IDS p.Ala85Val (c.254C>T) pathogenic?

IDS p.Ala85Val (c.254C>T) is classified Likely pathogenic in IDS (ClinVar, Single submitter, 1 submitter; last evaluated 2024-06-07). AlphaMissense: likely pathogenic (0.8439); Absent from gnomAD v4.1; Associated with mucopolysaccharidosis type 2.

What condition is associated with IDS p.Ala85Val (c.254C>T)?

IDS p.Ala85Val (c.254C>T) is associated with mucopolysaccharidosis type 2 (ClinVar).

How common is IDS p.Ala85Val (c.254C>T) in the general population?

IDS p.Ala85Val (c.254C>T) is absent from gnomAD v4.1 (gnomAD).

How is Mucopolysaccharidosis type 2 inherited?

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

What do computational predictors say about IDS p.Ala85Val (c.254C>T)?

AlphaMissense predicts likely pathogenic (score 0.8439) — an in-silico prediction, not a clinical call.

IDS p.Ala85Val

c.254C>T · VCV3255634

Likely pathogenic Single submitter

Classification

Likely pathogenic

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely pathogenic

0.8439 · ACMG-weighted

gnomAD v4.1

Absent

absent from gnomAD v4.1

Missense predictors

3/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

mucopolysaccharidosis type 2

Computational evidence

Protein change
AlphaMissense	0.8439	likely pathogenic ✓ concordant with ClinVar
REVEL	0.909	moderately pathogenic-leaning
SaProt	LLR -11.49	damaging
⇒ AlphaMissense, REVEL and SaProt all call this damaging.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 9.6	GERP 1.1, phastCons 1
Regional constraint	o/e 0.07	constrained · MANE · 819 bp · p 6.4e-10 · regional, not allelic
Overall
CADD	25.6	PHRED · no single calibrated threshold — expert panels disagree

AlphaMissense carries the ACMG weight for missense; REVEL and SaProt are independent agreement signals.

Population frequency

gnomAD v4.1 · exomes + genomes

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: IDS
Protein: p.Ala85Val
Coding: c.254C>T
MANE Select: NM_000202
Type: single nucleotide variant
Location: chrX:149503476 (GRCh38)
Structure: AlphaFold pLDDT 93.39 · 2 PDB
Residue 85: an α-helix; a UniProt-annotated variant site (in mps2; severe form); a UniProt-annotated variant site (in mps2; mild to severe forms)

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

Disease context

mucopolysaccharidosis type 2 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Mucopolysaccharidosis type 2 (Orphanet):

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

Similar variants

IDS p.Ala85Asp Pathogenic/Likely pathogenic ★★ same residue
IDS p.Ala85Ser Pathogenic/Likely pathogenic ★★ ⚠ same residue
IDS p.Ala85Thr Pathogenic/Likely pathogenic ★★ ⚠ same residue
IDS p.Ala85Pro Pathogenic ★ same residue
IDS c.1006+1G>C Pathogenic ★★ same condition
IDS c.1006+1G>T Pathogenic ★★ same condition
IDS c.1007-133A>G Likely pathogenic ★★ same condition
IDS c.1007-1G>A 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/ids-p-ala85val (accessed [today's date]).

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