Is ALG9 p.His339Tyr (c.1015C>T) pathogenic?

ALG9 p.His339Tyr (c.1015C>T) is classified Uncertain significance in ALG9 (ClinVar, Single submitter, 1 submitter; last evaluated 2022-08-03). AlphaMissense: likely benign (0.2415); Very rare (popmax 0.00381%, nfe); Associated with ALG9-congenital disorder of glycosylation.

What condition is associated with ALG9 p.His339Tyr (c.1015C>T)?

ALG9 p.His339Tyr (c.1015C>T) is associated with ALG9-congenital disorder of glycosylation (ClinVar).

How common is ALG9 p.His339Tyr (c.1015C>T) in the general population?

ALG9 p.His339Tyr (c.1015C>T) is very rare (popmax 0.00381%, nfe) (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.His339Tyr (c.1015C>T)?

AlphaMissense predicts likely benign (score 0.2415) — an in-silico prediction, not a clinical call.

ALG9 p.His339Tyr

c.1015C>T · rs782528335 · VCV1949385

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.2415 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00381%, nfe)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

ALG9-congenital disorder of glycosylation

Computational evidence

Protein change
AlphaMissense	0.2415	likely benign
REVEL	0.102	moderately benign-leaning
SaProt	LLR -8.74	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 8.7	GERP 1.9, phastCons 1
Regional constraint	o/e 0.40	unconstrained · MANE · 3,925 bp · p 1.5e-05 · regional, not allelic
Overall
CADD	23.0	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean tolerated — 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

Grpmax group 0.00381% European (non-Finnish) · 45/1,179,958 alleles

Filtering AF 0.00291% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0026%

Overall 0.00285% 46/1,613,820 alleles · very rare

Ancestry group	Frequency	1 in
European (non-Finnish)grpmax	0.00381%	26,221
African / African-American	0.00134%	74,886

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.His339Tyr
Coding: c.1015C>T
MANE Select: NM_024740
dbSNP: rs782528335
Type: single nucleotide variant
Location: chr11:111844604 (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-his339tyr (accessed [today's date]).

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