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R732H

Category 4 — Stable Fold, Function DisruptedConflictingLumenal · predictedσ-1 candidateEditorial
ArginineHistidine at position 732 · C-terminal lumenal domain (653-869) · WFS1 (Wolframin)

Arginine → Histidine at position 732 in lumenal domain. ClinVar Conflicting including T2D. AlphaMissense 0.386 (below threshold), ΔΔG -0.94. Same position as R732C — second substitution at 732 in the C733-C765 disulfide region.

Interactive 3D Structure

Wild-type reference
Wild-type R732 — ionic bond to D729
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DynaMut2 mutant · R732H
Mutant H732 — ionic bond to D729 lost (4 contacts lost)
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Bond changes · DynaMut2 interaction analysis

4 lost4 gained7 preserved
Interaction typeWild-type partnerMutant partnerStatus
Ionic bondD729Lost
Hydrogen bondI720Gained
Hydrogen bondN721Lost
Hydrogen bondG728G728Preserved
Hydrogen bondD729D729Preserved
Hydrogen bondG736G736Preserved
Polar contactI720Gained
Polar contactN721Lost
Polar contactG728G728Preserved
Polar contactD729D729Preserved
Polar contactW730Gained
Polar contactG736G736Preserved
Van der WaalsG728Gained
HydrophobicI720Lost
HydrophobicC765C765Preserved

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
-0.94kcal/mol
Destabilising — mild
AlphaMissense
0.386
Amb
AlphaFold pLDDT
89
model confidence
Schema
Cat 4
Category 4 — Stable Fold, Function Disrupted
ΔΔG confidence: Standard confidence · Lumenal

This variant is in a water-facing region, which is the regime the stability predictor was built and benchmarked for. Ordinary predictor error still applies.

Clinical Evidence

ClinVar classificationConflicting classifications of pathogenicity
Review statuscriteria provided, conflicting classifications
Associated conditionsType 2 diabetes mellitus
InheritanceT2D documented.
Population frequency (gnomAD v4)Low frequency · AF 0.019%
cDNA changec.2195G>A
ClinVar accessionVCV000215397
Last evaluated2026/01/15 00:00

Observed in the general population.

Classified for1★ unverified submission

ClinVar classifies this variant as Conflicting classifications of pathogenicity for WFS1-related diabetes (autosomal dominant). These are dominant WFS1-related disorders and are clinically distinct from classic recessive Wolfram syndrome. This classification is not a statement about Wolfram syndrome severity.

  • WFS1-related diabetesautosomal dominantsubmitted as: Type 2 diabetes mellitus
  • Submitters conflict on this classification (1★). Treat the conditions above as submitted, not as documented phenotypes.
  • 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★ conflicting classifications. ClinVar "conditions" is the union of all submissions; 0–1★ entries are submitted conditions, not documented phenotypes.

Population frequency
Global (all ancestries)
AF 0.019% · 304 / 1,612,566 alleles
Homozygotes
2
Highest-frequency population
African / African American · AF 0.264%

Highest in African / African American: AF 0.264% (198 of 75,058 alleles), 14.0x the global figure. The global AF describes the general population, not the at-risk group.

2 homozygotes reported in gnomAD v4 (2 African / African American). gnomAD excludes individuals with severe pediatric disease, so homozygotes in this dataset argue against a fully penetrant severe recessive phenotype and belong in the clinical picture. This is interpretive signal, not a classification.

Ancestry groupAllele freq.AC / ANHom.Carrier est.
African / African American0.264%198 / 75,0582~1 in 190
Remaining individuals0.030%19 / 62,4720~1 in 1640
Admixed American0.022%13 / 59,9880~1 in 2310
Middle Eastern · under-sampled0.016%1 / 6,0620
East Asian0.011%5 / 44,8560~1 in 4490
Finnish0.0096%6 / 62,7160~1 in 5230
European (non-Finnish)0.0052%61 / 1,179,8640~1 in 9670
Ashkenazi Jewish · under-sampled0.0034%1 / 29,5860

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.

Structural Context

Position 732 same neighbors as R732C: CYS733 (2.5 Å — C733-C765 disulfide cysteine), MET731 (2.5 Å), ASP729 (3.7 Å), GLY728 (3.8 Å).

R732H is the second substitution at R732. Where R732C eliminated charge + introduced thiol, R732H reduces charge to pH-dependent. The C733 disulfide partner is less perturbed than in R732C (no new aberrant thiol).

|ΔΔG| 0.94 + AM 0.386 under-call + T2D confirm pathogenicity.

Amino-acid chemistry
Arginine (R) → Histidine (H) — long positively-charged amine replaced by small titratable aromatic. Charge reduced (pH-dependent).
Position in the protein
C-terminal lumenal domain · position 732 (pLDDT 89). Same as R732C.

Druggability Assessment

Category 3/4 — Most Druggable (AM under-call). |ΔΔG| 0.94. AlphaMissense 0.386 below threshold and T2D does not resolve it (ClinVar: conflicting submissions).

Mechanism: partial charge loss + perturbation of C733 disulfide region from adjacent position. Therapeutic: same C733-C765 microregion as R732C, C733G, C765R, L734H.

Why this matters

R732H joins R732C at position 732 — both at the C733 disulfide-adjacent position. Five Atlas variants now converge on the 732-734 microregion.
Therapeutic Strategy Handoff · prediction

Feed this card to Wolfram Intelligence

Download the R732H 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 R732H PDF card ↓Strategies are AI-generated predictions, not validated therapeutics.

UniProt Domain Annotation

Chain1890 · Wolframin
Topological domain653869 · Lumenal