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G674V

Category 3/4 — Most DruggableLikely pathogenicLumenal · predictedσ-1 candidateEditorial
GlycineValine at position 674 · C-terminal lumenal domain (653-869) · WFS1 (Wolframin)

Glycine → Valine at position 674 in wolframin's C-terminal lumenal domain. ClinVar Likely pathogenic, monogenic hearing loss. AlphaMissense 0.983, DynaMut2 ΔΔG -0.24 kcal/mol (destabilising). The FOURTH pathogenic substitution catalogued at position 674 in the Atlas — with G674E, G674R, G674W.

Interactive 3D Structure

Wild-type reference
Wild-type G674 — hydrogen bond to G670
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DynaMut2 mutant · G674V
Mutant V674 — polar contact contact to W678 lost
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Bond changes · DynaMut2 interaction analysis

0 lost4 gained7 preserved
Interaction typeWild-type partnerMutant partnerStatus
Hydrogen bondG670G670Preserved
Hydrogen bondA677A677Preserved
Hydrogen bondW678W678Preserved
Polar contactG670G670Preserved
Polar contactR676R676Preserved
Polar contactA677A677Preserved
Polar contactW678W678Preserved
Van der WaalsG670Gained
Van der WaalsR676Gained
HydrophobicW666Gained
HydrophobicW678Gained

Lost / gained / preserved interatomic contacts at the variant residue, from the DynaMut2 (Arpeggio) interaction analysis of the wild-type and energy-minimized mutant structures.

Computational Predictions

DynaMut2 ΔΔG
-0.24kcal/mol
Destabilising — mild
AlphaMissense
0.983
LPath
AlphaFold pLDDT
84
model confidence
Schema
Cat 3/4
Category 3/4 — Most Druggable

Clinical Evidence

ClinVar classificationLikely pathogenic
Review statuscriteria provided, single submitter
Associated conditionsMonogenic hearing loss
InheritanceMonogenic hearing loss documented.
Population frequency (gnomAD v4)Absent from gnomAD v4
cDNA changec.2021G>T
ClinVar accessionVCV004685574
Last evaluated2025/11/18 00:00

Not observed in ~730k individuals — consistent with a rare allele (ACMG PM2_supporting).

Structural Context

Position 674 sits in wolframin's C-terminal lumenal domain. Same neighbor environment as the G674E/R/W series: CYS673 (2.5 Å), PRO675 (2.5 Å), GLY670 (3.1 Å), TRP678 (4.0 Å), ARG676 (4.5 Å).

Replacing glycine with valine removes the wild-type backbone flexibility but introduces a more conservative side chain than G674E/R/W. The branched aliphatic valine fits the local environment better than charged or bulky alternatives — the |ΔΔG| of 0.24 is the smallest of the G674 series.

Yet AlphaMissense's 0.983 plus monogenic hearing loss clinical evidence confirm severe functional consequence. The mechanism is still loss of glycine's structural flexibility role, even though the variant residue's chemistry is conservative.

G674V is the most chemically conservative substitution at position 674 — and the smallest |ΔΔG| in the series — yet still pathogenic. This confirms the Atlas's hypothesis that the wild-type glycine at this position is structurally irreplaceable regardless of which residue substitutes.

Amino-acid chemistry
Glycine (G) → Valine (V) — smallest amino acid replaced by branched hydrophobic. Loss of backbone flexibility; modest volume increase.
Position in the protein
C-terminal lumenal domain · position 674 in the ER lumen (pLDDT 84). Same environment as the rest of the G674 series.

Druggability Assessment

Category 3/4 — Most Druggable. |ΔΔG| = 0.24 kcal/mol — fold survives. AlphaMissense 0.983 + monogenic hearing loss confirm severe functional consequence.

The mechanism is loss of glycine flexibility at position 674. Therapeutic strategy: same target as G674E/R/W — restore the wild-type backbone geometry at the C673-G674-P675 microregion.

Why this matters

G674V completes the FOUR-substitution series at position 674. Across these variants, the same therapeutic target geometry rescues all of them. The Atlas establishes position 674 as one of the highest-value druggability hotspots in WFS1.
Therapeutic Strategy Handoff · prediction

Feed this card to Wolfram Intelligence

Download the G674V PDF below and upload it to Wolfram Intelligence to generate therapeutic-strategy proposals — guanidinium mimetics, sigma-1 agonist docking, NAC thiol-capping. NAC is already on the bench-testing list.

Download G674V PDF card ↓Strategies are AI-generated predictions, not validated therapeutics.

UniProt Domain Annotation

Chain1890 · Wolframin
Topological domain653869 · Lumenal
Natural variant674674 · in dbSNP:rs200672755