Is GBE1 p.Phe257Ser (c.770T>C) pathogenic?

GBE1 p.Phe257Ser (c.770T>C) is classified Likely pathogenic in GBE1 (ClinVar, Single submitter, 1 submitter; last evaluated 2019-05-28). AlphaMissense: likely pathogenic (0.9544); Absent from gnomAD v4.1; Associated with glycogen storage disease due to glycogen branching enzyme deficiency.

What condition is associated with GBE1 p.Phe257Ser (c.770T>C)?

GBE1 p.Phe257Ser (c.770T>C) is associated with glycogen storage disease due to glycogen branching enzyme deficiency (ClinVar).

How common is GBE1 p.Phe257Ser (c.770T>C) in the general population?

GBE1 p.Phe257Ser (c.770T>C) is absent from gnomAD v4.1 (gnomAD).

What do computational predictors say about GBE1 p.Phe257Ser (c.770T>C)?

AlphaMissense predicts likely pathogenic (score 0.9544) — an in-silico prediction, not a clinical call.

GBE1 p.Phe257Ser

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

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

c.770T>C · rs1576183537 · VCV801988

Likely pathogenic Single submitter

Classification

Likely pathogenic

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely pathogenic

0.9544 · ACMG-weighted

gnomAD v4.1

Absent

absent from gnomAD v4.1

Missense predictors

3/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

glycogen storage disease due to glycogen branching enzyme deficiency

Computational evidence

Protein change
AlphaMissense	0.9544	likely pathogenic ✓ concordant with ClinVar
REVEL	0.945	strongly pathogenic-leaning
SaProt	LLR -13.14	damaging
⇒ AlphaMissense, REVEL and SaProt all call this damaging.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 8	GERP 1.9, phastCons 1
Regional constraint	o/e 1.00	unconstrained · MANE · 271 kb · p 0.97 · regional, not allelic
Overall
CADD	27.8	PHRED · no single calibrated threshold — expert panels disagree

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: GBE1
Protein: p.Phe257Ser
Coding: c.770T>C
MANE Select: NM_000158
dbSNP: rs1576183537
Type: single nucleotide variant
Location: chr3:81646404 (GRCh38)
Gene constraint: LOEUF 1.211 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 96.30 · 3 PDB
Residue 257: a UniProt-annotated variant site (in gsd4; loss of activity); a β-strand

Full GBE1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

glycogen storage disease due to glycogen branching enzyme deficiency — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

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

Inheritance: Autosomal recessive
Onset: All ages
Prevalence: 1-9 / 1 000 000 (Worldwide)

Similar variants

GBE1 p.Phe257Leu Conflicting classifications of pathogenicity ★ ⚠ same residue
GBE1 c.1109-1G>T Likely pathogenic ★★ same condition
GBE1 c.1236+1G>A Likely pathogenic ★★ same condition
GBE1 c.1336-1G>A Pathogenic/Likely pathogenic ★★ same condition
GBE1 c.143+1G>A Pathogenic ★★ same condition
GBE1 c.143+2T>C Pathogenic/Likely pathogenic ★★ same condition
GBE1 c.144-1G>C Pathogenic/Likely pathogenic ★★ same condition
GBE1 c.1618+1G>A 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/gbe1-p-phe257ser (accessed [today's date]).

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