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S631C

Category 3/4 — Most DruggableUncertain significanceTransmembrane · predictedSource card
SerineCysteine at position 631 · C-terminal ER-lumenal (calcium binding, calmodulin, chaperone) · WFS1 (Wolframin)

Interactive 3D Structure

Wild-type reference
Wild-type S631 — hydrogen bond to L635
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DynaMut2 mutant · S631C
Mutant C631 — polar contact contact to R629 lost
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Bond changes · DynaMut2 interaction analysis

1 lost1 gained5 preserved
Interaction typeWild-type partnerMutant partnerStatus
Hydrogen bondR629Gained
Hydrogen bondK634K634Preserved
Hydrogen bondL635L635Preserved
Polar contactR629R629Preserved
Polar contactK634K634Preserved
Polar contactL635L635Preserved
Van der WaalsR629Lost

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
-0.44kcal/mol
Destabilising — mild
AlphaMissense
0.588
likely pathogenic
AlphaFold pLDDT
69
model confidence
Schema
Cat 3/4
Category 3/4 — Most Druggable
ΔΔG confidence: Low confidence · Transmembrane
  • transmembrane position; predictor benchmarked on soluble proteins
  • pLDDT 68.5 below 70

This variant sits in the transmembrane band. The stability value was computed with a predictor benchmarked on water-soluble proteins. Published benchmarks of ddG predictors on membrane proteins report correlation below 0.4. Treat the magnitude as unreliable and the sign as weak evidence only.

The underlying AlphaFold model has pLDDT below 70 at this position, so the structure the stability calculation was run on is itself uncertain.

Do not rank this value against a variant from a different region on ΔΔG alone.

Clinical Evidence

ClinVar classificationUncertain significance
Review statuscriteria provided, single submitter
Associated conditionsInborn genetic diseases
Population frequency (gnomAD v4)Ultra-rare · AF 0.00027%
cDNA changec.1892C>G
ClinVar accessionVCV002559474
Last evaluated2023/06/12 00:00

Observed at very low frequency in gnomAD.

Classified for1★ unverified submission

ClinVar classifies this variant as Uncertain significance, but does not state what it is classified for. ClinVar records the condition only as "Inborn genetic diseases". A classification without a phenotype and an inheritance mode cannot be read as a statement about Wolfram syndrome risk or severity.

  • Phenotype scope is interpretation of submitted records. The computed values on this card (AlphaMissense, DynaMut2 ΔΔG, pLDDT) are measurements of the model, not of a patient.
  • Presentation cannot be generalised from neighbouring variants: one nucleotide over can present very differently. Structural similarity supports a mechanistic hypothesis, never a phenotype claim.

Review status: 1★ single submitter. ClinVar "conditions" is the union of all submissions; 0–1★ entries are submitted conditions, not documented phenotypes.

Population frequency
Global (all ancestries)
AF 0.00027% · 4 / 1,461,746 alleles
Homozygotes
0
Highest-frequency population
European (non-Finnish) · AF 0.00036%

Highest in European (non-Finnish): AF 0.00036% (4 of 1,112,010 alleles), in line with the global figure.

No homozygotes reported in gnomAD v4. For a recessive allele this is expected and is not, on its own, evidence either way.

Ancestry groupAllele freq.AC / ANHom.Carrier est.
European (non-Finnish)0.00036%4 / 1,112,0100~1 in 139000

Source: gnomAD r4, retrieved 2026-08-21. Values are allele frequencies. The carrier estimate is derived from the allele frequency (Hardy-Weinberg, ~2·AF) and is an approximation, not a published figure — where a published carrier frequency exists it outranks this column and is cited on the card.

Full Variant Card

WFS1 Wolframin — S631C Variant Card

Molecular Atlas Pilot · RareResearch.AI · Generated by wolfram-variant-card skill

Serine → Cysteine at position 631. C-terminal ER-lumenal (calcium binding. ClinVar Uncertain significance, AlphaMissense 0.588, DynaMut2 ΔΔG -0.44 kcal/mol (destabilising).


Identity

FieldValue
VariantS631C (p.Serine631Cysteine)
DNA changec.1892C>G
Gene · ProteinWFS1 · Wolframin (890 aa)
UniProtO76024 · WFS1_HUMAN
ClinVar accessionVCV002559474
Amino acid changeSerine (S) → Cysteine (C)

Structural Context

FieldValue
AlphaFold modelAF-O76024-F1, v6
pLDDT at residue 63168.50 — confident
DomainC-terminal ER-lumenal (calcium binding, calmodulin, chaperone)
Position contextC-terminal lumenal domain · position 631 projects into the ER lumen
IDR flagNo — pLDDT above 50 threshold

UniProt features at this position:

(none catalogued)

Position 631 sits in the C-terminal lumenal domain (residues 653–869), wolframin's largest soluble region. This domain projects into the ER lumen and is implicated in calcium handling, ER stress sensing, and protein–protein interactions with ATF6 and Na+/K+ ATPase β1. The wild-type residue is small polar (serine — hydroxyl); the mutant is thiol (cysteine — disulfide-capable, free -SH). The chemistry shift implies altered local packing, hydrogen-bonding, and/or electrostatics at this site.


Computational Predictions

AlphaMissense

FieldValue
am_pathogenicity0.5878
am_classlikely pathogenic
InterpretationLikely pathogenic (threshold 0.564)

DynaMut2

FieldValue
ΔΔG (kcal/mol)-0.44 (Destabilising)
Job ID178092133918
Result URLJob 178092133918 · retrieved 2026-06-08 — result self-hosted by RareResearch.AI (Biosig no longer serves this page)

Clinical Evidence

Inheritance and scope

Uncertain significance — phenotype scope not stated in ClinVar

ClinVar classifies this variant as Uncertain significance, but does not state what it is classified for. ClinVar records the condition only as "Inborn genetic diseases". A classification without a phenotype and an inheritance mode cannot be read as a statement about Wolfram syndrome risk or severity.

Phenotype scope is interpretation of submitted records. The computed values on this card (AlphaMissense, DynaMut2 ΔΔG, pLDDT) are measurements of the model, not of a patient. Presentation cannot be generalised from neighbouring variants: one nucleotide over can present very differently. Structural similarity supports a mechanistic hypothesis, never a phenotype claim.

FieldValue
ClassificationUncertain significance
Review statuscriteria provided, single submitter
Last evaluated2023/06/12 00:00
InheritanceInheritance pattern not specified in ClinVar entry; WFS1 has both AD and AR presentations.
WFS1 variant landscapeS631C is 1 of ~326 pathogenic-spectrum variants in WFS1 (out of 2,243 catalogued in ClinVar)
  • Inborn genetic diseases

Research Path Decision Tree

ΔΔG < 2  + binding site affected   →  CATEGORY 3 — docking experiments
ΔΔG 2–4                            →  CATEGORY 2 — pharmacological chaperones
ΔΔG > 4                            →  CATEGORY 1 — gene therapy
pLDDT < 50                         →  CATEGORY 5 — IDR, experimental only
Stable fold + functional site hit  →  CATEGORY 4 — site-specific docking

Final Schema Categorization

Category 3/4 — Most Druggable

<strong>Category 3/4 — Most Druggable</strong><br/><br/>|ΔΔG|=0.44 < 2 kcal/mol (fold intact) + AlphaMissense 0.588 confirms functional impact. Specific local contacts disrupted — priority for docking and pharmacological chaperone screening.

Why this card matters. Wolframin's fold survives this substitution (|ΔΔG|=0.44 kcal/mol). The pathogenic signal is real — AlphaMissense places it at 0.588. Protein still folds, but a specific local site is broken. Pharmacological chaperones and small-molecule binders are the rational therapeutic vector.


Files in this folder

  • AF-O76024-F1-model_v6.pdb — AlphaFold structure
  • S631C_molstar_viewer.html — interactive 3D viewer (auto-highlights position 631 with ball-and-stick + neighbors within 5Å)
  • S631C_variant_card.md — this card (source of truth)
  • S631C_variant_card.html — styled printable card
  • S631C_dynamut2_summary.html — clean offline DynaMut2 result card
  • dynamut2_result.json — structured result data
  • dynamut2_result_page.html — local snapshot of the Biosig result page (asset URLs absolutized)
  • S631C_wildtype_interactions.pse / S631C_mutant_interactions.pse — PyMOL sessions

Generated by wolfram-variant-card skill · RareResearch.AI Molecular Atlas Every assumption documented. Every score sourced.

Therapeutic Strategy Handoff · prediction

Feed this card to Wolfram Intelligence

Download the S631C 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 S631C PDF card ↓Strategies are AI-generated predictions, not validated therapeutics.