GM2 gangliosidosis, AB variant (GM2 activator protein deficiency) OMIM 272750

In GM2 gangliosidosis, AB variant (GM2A, OMIM 272750), 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: — Honest hold (no matched agent). 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 0.4963, γ 1.4090, spinodal 0.6437). 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 GM2 gangliosidosis, AB variant is an R19 double-well emerged from the real proximal-promoter DNA of GM2A. 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): 1.4090
barrier: 0.4963
spinodal: 0.6437
s_on / s_off: 1.1870 / -1.1870
fragility: 0.47
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 0.4963 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 0.47

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 GM2A (raising the switch drive) does NOT move the DOWN [F] switch toward the healthy branch in a GM2A-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 GM2A allele (no rescue that a null allele lacks), the gamma-restore lever is refuted; null alleles are excluded by construction.

Explicitly not levers.

{"agent_class": "substrate-reduction (glucosylceramide-synthase inhibition) -- not established and NOT approved for the AB variant -> a downstream NON-lever, not the corrective", "axis_effect": "DOWN", "lever": "restrain", "source": "Platt 2018 (substrate reduction in gangliosidoses, review)", "status": "investigational", "target": "GM2A", "verdict": "WORSENS"}

Agents mapped onto the lever

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
scAAV9-GM2A in vivo gene therapy (intravenous BBB-crossing / intrathecal) -- DIRECT on the causal gene; PRECLINICAL proof-of-concept (Gm2a-knockout mice), no clinical trial, NOT approved scAAV9-GM2A in Gm2a-/- mice (intrathecal / intravenous proof-of-concept); ASGCT/NTSAD GM2 gene-therapy review 2024 (no AB-variant trial open)	increase	investigational	2	◇ in trials

⚠ 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 `GM2A`; 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).