Imerslund-Grasbeck (CUBN receptor) OMIM 261100

In Imerslund-Grasbeck (CUBN, OMIM 261100), the master switch sits on the ↓ DOWN branch ([F] forced below); the healthy state is the ON well. The forced corrective direction is to raise s toward ON branch (polarity: supply). Classification: ✓ Recovers an existing standard. Direction only — no dose, no efficacy magnitude.

The disease maps to an R19 double-well whose corrective lever is read straight off the cusp (barrier 0.4079, γ 1.2773, spinodal 0.5556). The corrective direction is forced [F]; the agent names below are direction-concordant labels at grade [O] (no dose, no efficacy or safety magnitude). This is a research hypothesis offered to experts, not medical advice.

The emergence switch

The switch for Imerslund-Grasbeck is an R19 double-well emerged from the real proximal-promoter DNA of CUBN. Its geometry is fixed by measured stiffness γ (never fitted); the numbers below are read directly off that cusp.

emergent axis: ↓ DOWN [F]
healthy branch: ON
lesion: LOF_null
γ (stiffness): 1.2773
barrier: 0.4079
spinodal: 0.5556
s_on / s_off: 1.1302 / -1.1302
fragility: 0.91
corrective polarity: supply
forced direction: raise s toward ON branch

Chemistry feasibility (DIRECTION only [O]). small-molecule recrossing of the fold is geometrically plausible (barrier 0.4079 at neutral drive; lower barrier = smaller drive to supply). [O] -- no affinity/potency/dose/efficacy asserted.

The derived corrective lever

The cusp forces a corrective direction: raise s toward ON branch. This is the load-bearing output of the framework — it is [F] forced, and it is falsifiable. 2 lever families are derived; the lead is h-restore (drive modulator).

h-restore (drive modulator)sign: increasegeometric rank 0.91

Mechanism. supply / restore the positive drive (replace-or-agonise the missing competence)

Applies to. allele-agnostic (downstream/environmental tilt)

favoured when the switch is fragile -- a small drive shift recrosses the fold

Falsifier. If supplying/agonising supply the cobalamin the CUBN cubilin-receptor defect can no longer absorb enterally (raising the switch drive) does NOT move the DOWN [F] switch toward the healthy branch in a CUBN-deficient model, the h-restore(supply) lever is refuted for this axis.

gamma-restore (stabiliser / chaperone)sign: Nonegeometric rank 0.00

Mechanism. N/A

Applies to. none (honest exclusion)

EXCLUDED: null allele -- no product to stiffen

Falsifier. If a folding-stabiliser/chaperone does NOT re-deepen the healthy well for a residual CUBN allele (no rescue that a null allele lacks), the gamma-restore lever is refuted; null alleles are excluded by construction.

Agents mapped onto the lever

✓ Agreement with established practice. The corrective direction derived here (raise s toward ON branch) independently matches an agent already in clinical use for this disease: parenteral cobalamin (hydroxocobalamin) repletion bypassing the cubilin-dependent intestinal B12 absorption defect. The geometry recovered known medicine — this is a validation signal for the logic, not a new treatment claim by this kit.

Existing agents whose known action is direction-concordant with the derived lever (status as pinned in the corpus; no dose, no efficacy magnitude).
agent (class)	dir.	status	phase	map
parenteral cobalamin (hydroxocobalamin) repletion bypassing the cubilin-dependent intestinal B12 absorption defect Kingma 2023 Orphanet J Rare Dis 18:291 (Imerslund-Gräsbeck syndrome: a comprehensive review of reported cases)	increase	established standard of care	0	✓ in use

⚠ Mechanism-direction only — do not self-administer; no dose (unvalidated; set by a physician / national authority); not an approved use.

Evidence & provenance

What is reproduced vs. cited for this page.
element	grade	basis
R19 switch & cusp geometry (this page)	[V] verified	emerged from measured promoter γ of `CUBN`; deterministic, 2×sha256 identical
corrective direction	[F] forced	forced by the cusp sign; falsifiable (see lever falsifiers)
mapped agents / leads	[O] open	direction-concordance only; corpus-pinned (2026-06-21); no dose, no efficacy/safety magnitude

Reading the agent column. VALIDATION SIGNAL -- the agent is already approved / established standard for this disease, so the direction logic recovered known clinical practice. Not a new claim by this kit. GENUINE HYPOTHESIS -- no approved indication for this disease; the direction match is a direction-only, untested [O] lead. Basis field grades the evidence (investigational here / in a related condition / off-label / speculative).