Is ALG6 p.Gly227Arg (c.679G>C) pathogenic?

ALG6 p.Gly227Arg (c.679G>C) is classified Uncertain significance in ALG6 (ClinVar, No assertion criteria, 1 submitter; last evaluated 2025-01-28). AlphaMissense: likely pathogenic (0.6893); Absent from gnomAD v4.1; Associated with ALG6-congenital disorder of glycosylation 1C.

What condition is associated with ALG6 p.Gly227Arg (c.679G>C)?

ALG6 p.Gly227Arg (c.679G>C) is associated with ALG6-congenital disorder of glycosylation 1C (ClinVar).

How common is ALG6 p.Gly227Arg (c.679G>C) in the general population?

ALG6 p.Gly227Arg (c.679G>C) is absent from gnomAD v4.1 (gnomAD).

How is ALG6-CDG inherited?

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

What do computational predictors say about ALG6 p.Gly227Arg (c.679G>C)?

AlphaMissense predicts likely pathogenic (score 0.6893) — an in-silico prediction, not a clinical call.

ALG6 p.Gly227Arg

c.679G>C · VCV4057525

Uncertain significance No assertion criteria

Classification

Uncertain significance

ClinVar

Review

No assertion criteria ☆☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely pathogenic

0.6893 · ACMG-weighted

gnomAD v4.1

Absent

absent from gnomAD v4.1

Missense predictors

3/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

ALG6-congenital disorder of glycosylation 1C

Computational evidence

Protein change
AlphaMissense	0.6893	likely pathogenic
REVEL	0.749	pathogenic-leaning
SaProt	LLR -17.96	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 12	GERP 2.1, phastCons 1
Regional constraint	o/e 0.86	unconstrained · MANE · 66 kb · p 0.00074 · regional, not allelic
Overall
CADD	24.7	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean damaging — a triage signal, not a reclassification

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: ALG6
Protein: p.Gly227Arg
Coding: c.679G>C
MANE Select: NM_013339
Type: single nucleotide variant
Location: chr1:63411330 (GRCh38)
Gene constraint: LOEUF 0.892 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 93.08
Residue 227: a UniProt-annotated variant site (in cdg1c)

Full ALG6 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

ALG6-congenital disorder of glycosylation 1C — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For ALG6-CDG (Orphanet):

Inheritance: Autosomal recessive
Onset: Infancy, Neonatal

Similar variants

ALG6 p.Gly227Glu Conflicting classifications of pathogenicity ★ ⚠ same residue
ALG6 c.1128-1G>A Likely pathogenic ★★ same condition
ALG6 c.1128-2A>C Likely pathogenic ★★ same condition
ALG6 c.1326+1G>A Pathogenic/Likely pathogenic ★★ same condition
ALG6 c.257+5G>A Pathogenic/Likely pathogenic ★★ same condition
ALG6 c.429+1G>T Likely pathogenic ★★ same condition
ALG6 c.495-2A>G Likely pathogenic ★★ same condition
ALG6 c.495-2A>T 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/alg6-p-gly227arg (accessed [today's date]).

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