Is ALG3 p.Asn397fs (c.1188dup) pathogenic?

ALG3 p.Asn397fs (c.1188dup) is classified Pathogenic in ALG3 (ClinVar, Single submitter, 1 submitter; last evaluated 2024-04-22). Absent from gnomAD; Associated with ALG3-congenital disorder of glycosylation.

What condition is associated with ALG3 p.Asn397fs (c.1188dup)?

ALG3 p.Asn397fs (c.1188dup) is associated with ALG3-congenital disorder of glycosylation (ClinVar).

How common is ALG3 p.Asn397fs (c.1188dup) in the general population?

ALG3 p.Asn397fs (c.1188dup) is absent from gnomAD (gnomAD).

How is ALG3-CDG inherited?

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

ALG3 p.Asn397fs

c.1188dup · rs2473846363 · VCV2000151

Pathogenic Single submitter

Classification

Pathogenic

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

Consequence

frameshift

predicted LoF

gnomAD v4.1

Not reported

no gnomAD frequency available for this variant

Conditions

ALG3-congenital disorder of glycosylation

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Consequence	frameshift	predicted loss-of-function
NMD	escapes	premature termination codon in the last exon (9 of 9) — the truncated protein is likely expressed. PVS1 input, not an applied code
Splicing
SpliceAI	—	not assessed · substitutions only
Constraint at this position
Conservation	phyloP 6.2	GERP 1.7, phastCons 1

Predicted loss-of-function is descriptive, not an applied PVS1 code.

Population frequency

dbSNP / gnomAD

No gnomAD frequency available for this variant. This is missing data, not an absence: the variant may or may not be present in gnomAD. Rarity (ACMG PM2) and BA1/BS1 cannot be assessed for it.

Variant & gene context

Gene: ALG3
Protein: p.Asn397fs
Coding: c.1188dup
MANE Select: NM_005787
dbSNP: rs2473846363
Type: Duplication
Location: chr3:184242642 (GRCh38)
Gene constraint: LOEUF 0.972 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 89.05

Full ALG3 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

ALG3-congenital disorder of glycosylation — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For ALG3-CDG (Orphanet):

Inheritance: Autosomal recessive
Onset: Infancy, Neonatal

Similar variants

ALG3 p.Gln16fs Pathogenic ★ same condition
ALG3 c.444+1G>T Likely pathogenic ★★ same condition
ALG3 p.Arg171Gln Pathogenic/Likely pathogenic ★★ same condition
ALG3 p.Arg266Cys Pathogenic ★★ same condition
ALG3 p.Arg354Cys Likely pathogenic ★★ same condition
ALG3 p.Arg354His Pathogenic/Likely pathogenic ★★ same condition
ALG3 p.Asn174Ser Likely pathogenic ★★ ⚠ same condition
ALG3 p.Gly55= 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/alg3-p-asn397fs (accessed [today's date]).

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