Is ALG8 p.Gly226= (c.678G>T) pathogenic?

ALG8 p.Gly226= (c.678G>T) is classified Uncertain significance in ALG8 (ClinVar, Single submitter, 1 submitter; last evaluated 2018-01-13). Ultra-rare (popmax 0.0109%, nfe); Associated with ALG8-congenital disorder of glycosylation.

What condition is associated with ALG8 p.Gly226= (c.678G>T)?

ALG8 p.Gly226= (c.678G>T) is associated with ALG8-congenital disorder of glycosylation (ClinVar).

How common is ALG8 p.Gly226= (c.678G>T) in the general population?

ALG8 p.Gly226= (c.678G>T) is ultra-rare (popmax 0.0109%, nfe) (gnomAD).

How is ALG8-CDG inherited?

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

ALG8 p.Gly226=

c.678G>T · rs754476593 · VCV881121

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

ultra-rare (popmax 0.0109%, nfe)

Conditions

ALG8-congenital disorder of glycosylation

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
REVEL	0.492	indeterminate
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -2.6	GERP -4.3
Overall
CADD	1.748	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0109% European (non-Finnish) · 128/1,172,606 alleles

Filtering AF 0.00933% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00877%

Overall 0.00825% 132/1,599,526 alleles · ultra-rare

Ancestry group	Frequency	1 in
European (non-Finnish)grpmax	0.0109%	9,161
Remaining individualsnot grpmax-eligible	0.00322%	31,030
African / African-American	0.00134%	74,568
South Asian	0.00113%	88,552

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: ALG8
Protein: p.Gly226=
Coding: c.678G>T
MANE Select: NM_024079
dbSNP: rs754476593
Type: single nucleotide variant
Location: chr11:78113985 (GRCh38)
Gene constraint: LOEUF 0.909 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 92.07
Residue 226: a UniProt-annotated variant site (in pcld3)

Full ALG8 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

ALG8-congenital disorder of glycosylation — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For ALG8-CDG (Orphanet):

Inheritance: Autosomal recessive
Onset: Antenatal, Infancy, Neonatal

Similar variants

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ALG8 c.674-2A>G Likely pathogenic ★★ same condition
ALG8 c.777+1G>A Likely pathogenic ★★ same condition
ALG8 c.95+1G>A Likely pathogenic ★★ same condition
ALG8 p.Arg179Ter Pathogenic/Likely pathogenic ★★ same condition
ALG8 p.Arg229Ter Pathogenic/Likely pathogenic ★★ same condition
ALG8 p.Arg268Ter Pathogenic/Likely pathogenic ★★ same condition
ALG8 p.Arg364Ter 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/alg8-p-gly226 (accessed [today's date]).

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