Is AGL p.Pro474= (c.1422G>A) pathogenic?

AGL p.Pro474= (c.1422G>A) is classified Uncertain significance in AGL (ClinVar, Single submitter, 1 submitter; last evaluated 2022-03-23). Very rare (popmax 0.00769%, sas); Associated with glycogen storage disease III.

What condition is associated with AGL p.Pro474= (c.1422G>A)?

AGL p.Pro474= (c.1422G>A) is associated with glycogen storage disease III (ClinVar).

How common is AGL p.Pro474= (c.1422G>A) in the general population?

AGL p.Pro474= (c.1422G>A) is very rare (popmax 0.00769%, sas) (gnomAD).

AGL p.Pro474=

Q: How is Glycogen storage disease due to glycogen debranching enzyme deficiency inherited?

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

c.1422G>A · rs144714696 · VCV1404892

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.00769%, sas)

Conditions

glycogen storage disease III

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 2.7	GERP 0.51, phastCons 1
Overall
CADD	13.05	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00769% South Asian · 7/91,070 alleles

Filtering AF 0.00359% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00255%

Overall 0.00136% 22/1,613,894 alleles · very rare

Ancestry group	Frequency	1 in
South Asiangrpmax	0.00769%	13,010
Remaining individualsnot grpmax-eligible	0.0016%	62,496
Finnishnot grpmax-eligible	0.00156%	64,020
European (non-Finnish)	0.0011%	90,763

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: AGL
Protein: p.Pro474=
Coding: c.1422G>A
MANE Select: NM_000642
dbSNP: rs144714696
Type: single nucleotide variant
Location: chr1:99876596 (GRCh38)
Gene constraint: LOEUF 0.72 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 92.88 · 1 PDB
Residue 474: the 'amylo-1,6-glucosidase' region; a β-strand

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

Disease context

glycogen storage disease III — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Glycogen storage disease due to glycogen debranching enzyme deficiency (Orphanet):

Inheritance: Autosomal recessive
Onset: Childhood, Infancy
Prevalence: 1-9 / 100 000 (United States)

Similar variants

AGL p.Pro474Arg Uncertain significance ★★ ⚠ same residue
AGL p.Pro474Leu Uncertain significance ★ ⚠ same residue
AGL c.1283+2T>C Likely pathogenic ★★ same condition
AGL c.1284-1G>A Likely pathogenic ★★ same condition
AGL c.1284-2A>G Likely pathogenic ★★ same condition
AGL c.1423+1G>A Pathogenic ★★ same condition
AGL c.1423+1G>C Pathogenic ★★ same condition
AGL c.1423+1G>T 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/agl-p-pro474 (accessed [today's date]).

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