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S626F

Category 4 — Stable Fold, Function DisruptedUncertain significanceTransmembrane · predictedSource card
SerinePhenylalanine at position 626 · C-terminal ER-lumenal (calcium binding, calmodulin, chaperone) · WFS1 (Wolframin)

Interactive 3D Structure

Wild-type reference
Wild-type S626 — hydrogen bond to G622
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DynaMut2 mutant · S626F
Mutant F626 — hydrogen bond contact to M623 lost
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Bond changes · DynaMut2 interaction analysis

0 lost0 gained12 preserved
Interaction typeWild-type partnerMutant partnerStatus
Hydrogen bondG622G622Preserved
Hydrogen bondM623M623Preserved
Hydrogen bondR629R629Preserved
Polar contactG622G622Preserved
Polar contactM623M623Preserved
Polar contactV624V624Preserved
Polar contactT628T628Preserved
Polar contactR629R629Preserved
Polar contactM632M632Preserved
Van der WaalsV624V624Preserved
Van der WaalsT628T628Preserved
Van der WaalsM632M632Preserved

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
-0.66kcal/mol
Destabilising — mild
AlphaMissense
0.365
ambiguous
AlphaFold pLDDT
51
model confidence
Schema
Cat 4
Category 4 — Stable Fold, Function Disrupted
ΔΔG confidence: Low confidence · Transmembrane
  • transmembrane position; predictor benchmarked on soluble proteins
  • pLDDT 51.03 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, multiple submitters, no conflicts
Associated conditions
Population frequency (gnomAD v4)Ultra-rare · AF 0.00043%
cDNA changec.1877C>T
ClinVar accessionVCV002438603
Last evaluated2023/01/09 00:00

Observed at very low frequency in gnomAD.

Classified for2★ documented assertion

ClinVar classifies this variant as Uncertain significance, but does not state what it is classified for. ClinVar records no condition for this variant. 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: 2★ multiple submitters, no conflicts. ClinVar "conditions" is the union of all submissions; 0–1★ entries are submitted conditions, not documented phenotypes.

Population frequency
Global (all ancestries)
AF 0.00043% · 7 / 1,614,084 alleles
Homozygotes
0
Highest-frequency population
South Asian · AF 0.0077%

Highest in South Asian: AF 0.0077% (7 of 91,082 alleles), 17.7x the global figure. The global AF describes the general population, not the at-risk group.

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.
South Asian0.0077%7 / 91,0820~1 in 6510

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 — S626F Variant Card

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

Serine → Phenylalanine at position 626. C-terminal ER-lumenal (calcium binding. ClinVar Uncertain significance, AlphaMissense 0.365, DynaMut2 ΔΔG -0.66 kcal/mol (destabilising).


Identity

FieldValue
VariantS626F (p.Serine626Phenylalanine)
DNA changec.1877C>T
Gene · ProteinWFS1 · Wolframin (890 aa)
UniProtO76024 · WFS1_HUMAN
ClinVar accessionVCV002438603
Amino acid changeSerine (S) → Phenylalanine (F)

Structural Context

FieldValue
AlphaFold modelAF-O76024-F1, v6
pLDDT at residue 62651.03 — confident
DomainC-terminal ER-lumenal (calcium binding, calmodulin, chaperone)
Position contextC-terminal lumenal domain · position 626 projects into the ER lumen
IDR flagNo — pLDDT above 50 threshold

UniProt features at this position:

(none catalogued)

Position 626 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 large aromatic hydrophobic (phenylalanine). The chemistry shift implies altered local packing, hydrogen-bonding, and/or electrostatics at this site.


Computational Predictions

AlphaMissense

FieldValue
am_pathogenicity0.3651
am_classambiguous
InterpretationLikely benign (threshold 0.564)

DynaMut2

FieldValue
ΔΔG (kcal/mol)-0.66 (Destabilising)
Job ID178094718718
Result URLJob 178094718718 · 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 no condition for this variant. 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, multiple submitters, no conflicts
Last evaluated2023/01/09 00:00
InheritanceInheritance pattern not specified in ClinVar entry; WFS1 has both AD and AR presentations.
WFS1 variant landscapeS626F is 1 of ~326 pathogenic-spectrum variants in WFS1 (out of 2,243 catalogued in ClinVar)

(no conditions catalogued)


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 4 — Stable Fold, Function Disrupted

<strong>Category 4 — Stable Fold, Function Disrupted</strong><br/><br/>|ΔΔG|=0.66 negligible. Likely site-specific functional disruption — docking strategy.

Why this card matters. Wolframin's fold survives this substitution (|ΔΔG|=0.66 kcal/mol). The pathogenic signal is real — AlphaMissense places it at 0.365. 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
  • S626F_molstar_viewer.html — interactive 3D viewer (auto-highlights position 626 with ball-and-stick + neighbors within 5Å)
  • S626F_variant_card.md — this card (source of truth)
  • S626F_variant_card.html — styled printable card
  • S626F_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)
  • S626F_wildtype_interactions.pse / S626F_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 S626F 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 S626F PDF card ↓Strategies are AI-generated predictions, not validated therapeutics.