Is IDS p.Ala205Thr (c.613G>A) pathogenic?

IDS p.Ala205Thr (c.613G>A) is classified Pathogenic/Likely pathogenic in IDS (ClinVar, Multiple submitters, 4 submitters; last evaluated 2024-06-07). AlphaMissense: likely benign (0.3061); Very rare (popmax 0.000248%); Associated with mucopolysaccharidosis type 2.

What condition is associated with IDS p.Ala205Thr (c.613G>A)?

IDS p.Ala205Thr (c.613G>A) is associated with mucopolysaccharidosis type 2 (ClinVar).

How common is IDS p.Ala205Thr (c.613G>A) in the general population?

IDS p.Ala205Thr (c.613G>A) is very rare (popmax 0.000248%) (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.Ala205Thr (c.613G>A)?

AlphaMissense predicts likely benign (score 0.3061) — an in-silico prediction, not a clinical call.

IDS p.Ala205Thr

c.613G>A · rs864622779 · VCV816852

Pathogenic/Likely pathogenic Multiple submitters

Classification

Pathogenic/Likely pathogenic

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 4 submitters

AlphaMissense

likely benign

0.3061 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.000248%)

Missense predictors

2/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

mucopolysaccharidosis type 2

Computational evidence

Protein change
AlphaMissense	0.3061	likely benign ⚠ discordant with ClinVar
REVEL	0.858	moderately pathogenic-leaning
SaProt	LLR -10.64	damaging
⇒ REVEL and SaProt call this damaging; AlphaMissense does not.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 7.6	GERP 1.4, phastCons 1
Regional constraint	o/e 0.78	unconstrained · MANE · 21 kb · p 5.6e-05 · regional, not allelic
Overall
CADD	26.2	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

Grpmax group 0.000248%

Overall 0.000248% 3/1,211,550 alleles · very rare exomes 3/1,097,556 · genomes 0/113,994 · joint denominator

Ancestry group	Frequency	1 in
Remaining individualsnot grpmax-eligible	0.0042%	23,820
Finnishnot grpmax-eligible	0.00213%	46,985

Remaining individuals shows a higher raw frequency than the grpmax group above it. gnomAD excludes bottlenecked groups — Finnish, Ashkenazi Jewish, Amish and “Remaining individuals” — from grpmax, because founder effects make their frequencies unrepresentative for filtering. The table is sorted by frequency, so an excluded group can sit above the grpmax row.

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: IDS
Protein: p.Ala205Thr
Coding: c.613G>A
MANE Select: NM_000202
dbSNP: rs864622779
Type: single nucleotide variant
Location: chrX:149498202 (GRCh38)
Structure: AlphaFold pLDDT 93.39 · 2 PDB
Residue 205: an α-helix; a UniProt-annotated variant site (in mps2; intermediate form)

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.Ala205Pro Pathogenic ★★ same residue
IDS p.Ala205Asp 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
IDS c.1007-2A>C Pathogenic/Likely pathogenic ★★ same condition
IDS c.1007-8T>G 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/ids-p-ala205thr (accessed [today's date]).

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