Is IDS p.Lys227= (c.681G>A) pathogenic?

IDS p.Lys227= (c.681G>A) is classified Likely benign in IDS (ClinVar, Single submitter, 1 submitter; last evaluated 2024-08-05). Very rare (popmax 0.00296%, eas); Associated with mucopolysaccharidosis type 2.

What condition is associated with IDS p.Lys227= (c.681G>A)?

IDS p.Lys227= (c.681G>A) is associated with mucopolysaccharidosis type 2 (ClinVar).

How common is IDS p.Lys227= (c.681G>A) in the general population?

IDS p.Lys227= (c.681G>A) is very rare (popmax 0.00296%, eas) (gnomAD).

How is Mucopolysaccharidosis type 2 inherited?

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

IDS p.Lys227=

c.681G>A · rs1557339514 · VCV1667281

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.00296%, eas)

Conditions

mucopolysaccharidosis type 2

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 1.7	GERP -0.69, phastCons 1
Overall
CADD	11.49	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00296% East Asian · 1/33,760 alleles

Filtering AF 0.000385% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000278%

Overall 0.000909% 11/1,209,493 alleles · very rare exomes 10/1,097,672 · genomes 1/111,821 · joint denominator

Ancestry group	Frequency	1 in
East Asiangrpmax	0.00296%	33,760
Remaining individualsnot grpmax-eligible	0.0021%	47,562
African / African-American	0.00175%	57,077
European (non-Finnish)	0.000894%	111,847

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.Lys227=
Coding: c.681G>A
MANE Select: NM_000202
dbSNP: rs1557339514
Type: single nucleotide variant
Location: chrX:149498134 (GRCh38)
Structure: AlphaFold pLDDT 93.39 · 2 PDB
Residue 227: a UniProt-annotated variant site (in mps2; intermediate form); a UniProt-annotated variant site (in mps2; severe 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.Lys227Gln Likely pathogenic ★ same residue
IDS p.Lys227Glu Conflicting classifications of pathogenicity ★ ⚠ 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-lys227 (accessed [today's date]).

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