Y291*
NonsenseN1PathogenicCytoplasmic · predictedN1 — NMD-targeted — null allele
Wild-type vs Translated Product
Left: full-length wild-type wolframin (890 aa) with the truncation point at residue 291 marked. Right: the same model with the lost region (residues 291–890) marked — what the nonsense transcript fails to produce as native protein.
Structural / NMD Prediction
Stop codon at position 291 is more than 50 nt upstream of the last exon-exon junction (~aa 413). The 50-nt rule predicts the transcript is degraded by nonsense-mediated decay. No truncated protein is produced; functionally a null allele.
Therapeutic Implication · N1
Protein Domains
- Transmembrane helix 1311–331
- Cytoplasmic loop 1332–340
- Transmembrane helix 2341–361
- Lumenal loop 1362–370
- Transmembrane helix 3371–391
- Cytoplasmic loop 2392–400
- Transmembrane helix 4401–421
- Lumenal loop 2422–431
- Transmembrane helix 5432–452
- Cytoplasmic loop 3453–461
- Transmembrane helix 6462–482
- Lumenal loop 3483–496
- Transmembrane helix 7497–517
- Cytoplasmic loop 4518–532
- Transmembrane helix 8533–553
- Lumenal loop 4554–573
- Transmembrane helix 9574–594
- Cytoplasmic loop 5 / pre-lumenal595–599
- C-terminal ER-lumenal (calcium binding, calmodulin, chaperone)600–890
Clinical Evidence
Observed at very low frequency in gnomAD.
ClinVar classifies this variant as Pathogenic for Wolfram syndrome (classic) (autosomal recessive, OMIM 222300). Classic Wolfram syndrome is recessive: a single copy does not produce it, and this classification says nothing about a carrier's own risk.
- Wolfram syndrome (classic)autosomal recessive · OMIM 222300submitted as: Wolfram syndrome
- 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.
Every ancestry group with observed alleles falls below the reporting threshold (min 2 alleles, min 500 sampled) — too sparse to name a highest-frequency population.
No homozygotes reported in gnomAD v4. For a recessive allele this is expected and is not, on its own, evidence either way.
| Ancestry group | Allele freq. | AC / AN | Hom. | Carrier est. |
|---|---|---|---|---|
| European (non-Finnish) · under-sampled | 0.000090% | 1 / 1,111,950 | 0 | — |
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.
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Full Variant Card
Y291* — WFS1 Molecular Atlas Card
Variant type: Nonsense (premature stop codon) Position: 291 Wild-type residue: Tyrosine (Y) Domain context (where the stop falls): N-terminal cytoplasmic (intrinsically disordered)
Schema category: N1 — NMD-targeted — null allele
Transcript degraded by NMD; no truncated protein produced. Therapeutic options: (a) translational readthrough drugs — Ataluren/PTC124, gentamicin-class aminoglycosides — may rescue partial readthrough; (b) gene therapy — allele replacement is the higher-yield long-term path. Pharmacological chaperones do not apply since no protein is made.
NMD prediction
- Status: NMD-targeted
- Confidence: high
- Reasoning: Stop codon at position 291 is more than 50 nt upstream of the last exon-exon junction (~aa 413). The 50-nt rule predicts the transcript is degraded by nonsense-mediated decay. No truncated protein is produced; functionally a null allele.
Truncation analysis
- Residues retained: 1 – 290 (32.6% of full-length protein)
- Residues lost: 291 – 890 (67.4% of full-length protein)
Retained domains
(no domains fully retained)
Partially retained at truncation point
- N-terminal cytoplasmic (intrinsically disordered) — partial: aa 1–290 retained, aa 291–310 lost
Lost domains
- Transmembrane helix 1 (aa 311–331)
- Cytoplasmic loop 1 (aa 332–340)
- Transmembrane helix 2 (aa 341–361)
- Lumenal loop 1 (aa 362–370)
- Transmembrane helix 3 (aa 371–391)
- Cytoplasmic loop 2 (aa 392–400)
- Transmembrane helix 4 (aa 401–421)
- Lumenal loop 2 (aa 422–431)
- Transmembrane helix 5 (aa 432–452)
- Cytoplasmic loop 3 (aa 453–461)
- Transmembrane helix 6 (aa 462–482)
- Lumenal loop 3 (aa 483–496)
- Transmembrane helix 7 (aa 497–517)
- Cytoplasmic loop 4 (aa 518–532)
- Transmembrane helix 8 (aa 533–553)
- Lumenal loop 4 (aa 554–573)
- Transmembrane helix 9 (aa 574–594)
- Cytoplasmic loop 5 / pre-lumenal (aa 595–599)
- C-terminal ER-lumenal (calcium binding, calmodulin, chaperone) (aa 600–890)
Clinical evidence
Inheritance and scope
Pathogenic — for Wolfram syndrome (classic) (autosomal recessive, OMIM 222300)
ClinVar classifies this variant as Pathogenic for Wolfram syndrome (classic) (autosomal recessive, OMIM 222300). Classic Wolfram syndrome is recessive: a single copy does not produce it, and this classification says nothing about a carrier's own risk.
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.
- Classification: Pathogenic
- Review status: criteria provided, multiple submitters, no conflicts
- Associated conditions: Wolfram syndrome
- cDNA change: c.873C>G
- ClinVar accession: VCV000212616
- Last evaluated: 2025/02/17 00:00
- Submissions: 1
Population frequency
- Frequency: Ultra-rare · AF 0.0001%
- Allele count: 1 of 1,461,786 alleles (~730,893 individuals)
- gnomAD variant ID:
4-6300668-C-G - Interpretation: Observed at very low frequency in gnomAD.
Source: gnomAD v4 joint exome + genome callset, cached locally. Frequency is population evidence only — it does not by itself establish or exclude pathogenicity.
Why this variant matters
This variant is biologically silent — the transcript is degraded before any truncated protein can be made. From a therapeutic standpoint, that simplifies the problem (one null allele) and points toward two specific paths: readthrough compounds that exploit the ribosome's natural ability to bypass premature stops, or gene-level replacement therapy. The atlas surfaces this clarity directly.
Card generated by wolfram-atlas-batch skill (v1) on 2026-07-31T21:01:26.978596Z.
NMD rule and schema definitions: reference/nmd_rules.md, reference/card_schema_extension.md.
WFS1 reference: UniProt O76024, AlphaFold model v6.