Is ALG6 p.Leu260Val (c.778C>G) pathogenic?

ALG6 p.Leu260Val (c.778C>G) is classified Uncertain significance in ALG6 (ClinVar, Single submitter, 1 submitter; last evaluated 2022-03-29). AlphaMissense: likely benign (0.0953); Absent from gnomAD v4.1; Associated with ALG6-congenital disorder of glycosylation 1C.

What condition is associated with ALG6 p.Leu260Val (c.778C>G)?

ALG6 p.Leu260Val (c.778C>G) is associated with ALG6-congenital disorder of glycosylation 1C (ClinVar).

How common is ALG6 p.Leu260Val (c.778C>G) in the general population?

ALG6 p.Leu260Val (c.778C>G) is absent from gnomAD v4.1 (gnomAD).

How is ALG6-CDG inherited?

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

What do computational predictors say about ALG6 p.Leu260Val (c.778C>G)?

AlphaMissense predicts likely benign (score 0.0953) — an in-silico prediction, not a clinical call.

ALG6 p.Leu260Val

c.778C>G · rs12733227 · VCV2168888

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.0953 · ACMG-weighted

gnomAD v4.1

Absent

absent from gnomAD v4.1

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

ALG6-congenital disorder of glycosylation 1C

Computational evidence

Protein change
AlphaMissense	0.0953	likely benign
REVEL	0.143	moderately benign-leaning
SaProt	LLR -6.71	tolerated
⇒ AlphaMissense, REVEL and SaProt all call this tolerated.
Splicing
SpliceAI	<0.2	no splice effect predicted · four deltas, not one · how we know
Constraint at this position
Conservation	phyloP 0.64	GERP -0.57, phastCons 0.14
Regional constraint	o/e 0.86	unconstrained · MANE · 66 kb · p 0.00074 · regional, not allelic
Overall
CADD	15.28	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

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: ALG6
Protein: p.Leu260Val
Coding: c.778C>G
MANE Select: NM_013339
dbSNP: rs12733227
Type: single nucleotide variant
Location: chr1:63412023 (GRCh38)
Gene constraint: LOEUF 0.892 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 93.08

Full ALG6 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

ALG6-congenital disorder of glycosylation 1C — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For ALG6-CDG (Orphanet):

Inheritance: Autosomal recessive
Onset: Infancy, Neonatal

Similar variants

ALG6 p.Leu260= Likely benign ★ same residue
ALG6 c.1128-1G>A Likely pathogenic ★★ same condition
ALG6 c.1128-2A>C Likely pathogenic ★★ same condition
ALG6 c.1326+1G>A Pathogenic/Likely pathogenic ★★ same condition
ALG6 c.257+5G>A Pathogenic/Likely pathogenic ★★ same condition
ALG6 c.429+1G>T Likely pathogenic ★★ same condition
ALG6 c.495-2A>G Likely pathogenic ★★ same condition
ALG6 c.495-2A>T 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/alg6-p-leu260val (accessed [today's date]).

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