Is ALG9 p.Ile603Val (c.1807A>G) pathogenic?

ALG9 p.Ile603Val (c.1807A>G) is classified Likely benign in ALG9 (ClinVar, Single submitter, 1 submitter; last evaluated 2026-01-30). AlphaMissense: likely benign (0.1317); Ultra-rare (popmax 0.0988%, sas); Associated with ALG9-congenital disorder of glycosylation.

What condition is associated with ALG9 p.Ile603Val (c.1807A>G)?

ALG9 p.Ile603Val (c.1807A>G) is associated with ALG9-congenital disorder of glycosylation (ClinVar).

How common is ALG9 p.Ile603Val (c.1807A>G) in the general population?

ALG9 p.Ile603Val (c.1807A>G) is ultra-rare (popmax 0.0988%, sas) (gnomAD).

How is ALG9-CDG inherited?

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

What do computational predictors say about ALG9 p.Ile603Val (c.1807A>G)?

AlphaMissense predicts likely benign (score 0.1317) — an in-silico prediction, not a clinical call.

ALG9 p.Ile603Val

c.1807A>G · VCV4850542

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.1317 · ACMG-weighted

gnomAD v4.1

Rare

ultra-rare (popmax 0.0988%, sas)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

ALG9-congenital disorder of glycosylation

Computational evidence

Protein change
AlphaMissense	0.1317	likely benign
REVEL	0.073	moderately benign-leaning
SaProt	LLR -7.22	tolerated
⇒ AlphaMissense, REVEL and SaProt all call this tolerated.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 7.9	GERP 2, phastCons 1
Regional constraint	o/e 0.87	unconstrained · MANE · 54 kb · p 0.028 · regional, not allelic
Overall
CADD	22.1	PHRED · no single calibrated threshold — expert panels disagree

AlphaMissense carries the ACMG weight for missense; REVEL and SaProt are independent agreement signals.

⚠ Isoform check: AlphaMissense numbered on a different transcript (AM I596V vs ClinVar I603V) — verify the residue.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0988% South Asian · 90/91,078 alleles

Filtering AF 0.0823% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0761%

Overall 0.00564% 91/1,614,122 alleles · ultra-rare

Ancestry group	Frequency	1 in
South Asiangrpmax	0.0988%	1,012
Remaining individualsnot grpmax-eligible	0.0016%	62,502

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: ALG9
Protein: p.Ile603Val
Coding: c.1807A>G
MANE Select: NM_024740
Type: single nucleotide variant
Location: chr11:111786447 (GRCh38)
Gene constraint: LOEUF 0.853 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 88.35 · 2 PDB

Full ALG9 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

ALG9-congenital disorder of glycosylation — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For ALG9-CDG (Orphanet):

Inheritance: Autosomal recessive
Onset: Antenatal, Infancy, Neonatal

Similar variants

ALG9 c.566-1G>A Pathogenic/Likely pathogenic ★★ same condition
ALG9 c.896-2A>G Likely pathogenic ★★ same condition
ALG9 p.Arg143Ter Pathogenic/Likely pathogenic ★★ same condition
ALG9 p.Trp248Ter Pathogenic/Likely pathogenic ★★ same condition
ALG9 p.Tyr287Cys Pathogenic/Likely pathogenic ★★ same condition
ALG9 c.*1607C>T Uncertain significance ★★ same condition
ALG9 c.*1624A>C Uncertain significance ★★ same condition
ALG9 c.*1722C>T Uncertain significance ★★ 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/alg9-p-ile603val (accessed [today's date]).

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