Is ALG13 p.Gly9= (c.27G>A) pathogenic?

ALG13 p.Gly9= (c.27G>A) is classified Likely benign in ALG13 (ClinVar, Multiple submitters, 2 submitters; last evaluated 2023-04-22). Very rare (popmax 0.00433%, amr); Associated with developmental and epileptic encephalopathy, 36.

What condition is associated with ALG13 p.Gly9= (c.27G>A)?

ALG13 p.Gly9= (c.27G>A) is associated with developmental and epileptic encephalopathy, 36 (ClinVar).

How common is ALG13 p.Gly9= (c.27G>A) in the general population?

ALG13 p.Gly9= (c.27G>A) is very rare (popmax 0.00433%, amr) (gnomAD).

How is ALG13-CDG inherited?

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

ALG13 p.Gly9=

c.27G>A · rs771955028 · VCV2137628

Likely benign Multiple submitters

Classification

Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

gnomAD v4.1

Rare

very rare (popmax 0.00433%, amr)

Conditions

developmental and epileptic encephalopathy, 36

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 5.9	GERP 1.1, phastCons 1
Overall
CADD	14.04	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00433% Admixed American · 2/46,147 alleles

Filtering AF 0.000718% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000269%

Overall 0.000247% 3/1,212,253 alleles · very rare exomes 3/1,098,129 · genomes 0/114,124 · joint denominator

Ancestry group	Frequency	1 in
Admixed Americangrpmax	0.00433%	23,073
African / African-American	0.00172%	57,986

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: ALG13
Protein: p.Gly9=
Coding: c.27G>A
MANE Select: NM_001099922
dbSNP: rs771955028
Type: single nucleotide variant
Location: chrX:111681245 (GRCh38)
Structure: AlphaFold pLDDT 54.42
Residue 9: the 'glycosyltransferase activity' region

Full ALG13 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

developmental and epileptic encephalopathy, 36 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For ALG13-CDG (Orphanet):

Inheritance: X-linked recessive
Onset: Infancy, Neonatal

Similar variants

ALG13 p.Asn107Ser Pathogenic/Likely pathogenic ★★ ⚠ same condition
ALG13 c.2458-1G>A Uncertain significance ★★ same condition
ALG13 c.2695+4G>A Uncertain significance ★★ same condition
ALG13 c.2932+6T>C Uncertain significance ★★ same condition
ALG13 c.834+3A>G Uncertain significance ★★ same condition
ALG13 c.932+2T>C Uncertain significance ★★ same condition
ALG13 p.Ala1044Thr Uncertain significance ★★ ⚠ same condition
ALG13 p.Ala173Val 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/alg13-p-gly9 (accessed [today's date]).

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