Is EXT2 p.Arg223= (c.669G>A) pathogenic?

EXT2 p.Arg223= (c.669G>A) is classified Likely benign in EXT2 (ClinVar, Single submitter, 1 submitter; last evaluated 2025-03-31). Absent from gnomAD v4.1; Associated with exostoses, multiple, type 2.

What condition is associated with EXT2 p.Arg223= (c.669G>A)?

EXT2 p.Arg223= (c.669G>A) is associated with exostoses, multiple, type 2 (ClinVar).

How common is EXT2 p.Arg223= (c.669G>A) in the general population?

EXT2 p.Arg223= (c.669G>A) is absent from gnomAD v4.1 (gnomAD).

How is Multiple osteochondromas inherited?

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

EXT2 p.Arg223=

c.669G>A · rs141410374 · VCV1540734

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Absent

absent from gnomAD v4.1

Conditions

exostoses, multiple, 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 1.1	GERP -5.2, phastCons 1
Overall
CADD	8.729	PHRED · no single calibrated threshold — expert panels disagree

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: EXT2
Protein: p.Arg223=
Coding: c.669G>A
MANE Select: NM_207122
dbSNP: rs141410374
Type: single nucleotide variant
Location: chr11:44114227 (GRCh38)
Gene constraint: LOEUF 0.775 · pLI <0.01 · ClinGen HI 3/3 (gnomAD)
Structure: AlphaFold pLDDT 87.59 · 6 PDB
Residue 223: a UniProt-annotated variant site (in ext2)

Full EXT2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

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

For Multiple osteochondromas (Orphanet):

Inheritance: Autosomal dominant
Onset: Childhood
Prevalence: >1 / 1000 (Specific population)

Similar variants

EXT2 p.Arg223Gln Uncertain significance ★★ ⚠ same residue
EXT2 p.Arg223Trp Uncertain significance ★★ ⚠ same residue
EXT2 p.Arg223Pro Pathogenic ★ same residue
EXT2 c.1079+1G>A Pathogenic ★★ same condition
EXT2 c.1079+1G>T Pathogenic ★★ same condition
EXT2 c.1173+1G>A Pathogenic ★★ same condition
EXT2 c.1662+1G>C Likely pathogenic ★★ same condition
EXT2 c.536+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/ext2-p-arg223 (accessed [today's date]).

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