In Serine deficiency (PHGDH, OMIM 601815), 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 0.4412, γ 1.3285, spinodal 0.5894). 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 Serine deficiency is an R19 double-well emerged from the real proximal-promoter DNA of PHGDH. 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)
1.3285
barrier
0.4412
spinodal
0.5894
s_on / s_off
1.1526 / -1.1526
fragility
0.74
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 0.4412 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).
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 3-phosphoglycerate dehydrogenase serine-biosynthesis enzyme competence lost to the PHGDH LOF defect (raising the switch drive) does NOT move the DOWN [F] switch toward the healthy branch in a PHGDH-deficient model, the h-restore(supply) lever is refuted for this axis.
Falsifier. If a folding-stabiliser/chaperone does NOT re-deepen the healthy well for a residual PHGDH 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: oral L-serine (with glycine) supplementation supplying the serine the deficient PHGDH biosynthetic enzyme can no longer make. 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
oral L-serine (with glycine) supplementation supplying the serine the deficient PHGDH biosynthetic enzyme can no longer make
Sirr 2020 J Inherit Metab Dis 43:758 (A yeast-based complementation assay elucidates the functional impact of 200 missense variants in human PSAT1); Takeichi 2018 J Lipid Res 59:2413 (Reduction of stratum corneum ceramides in Neu-Laxova syndrome caused by phosphoglycerate dehydrogenase deficiency)
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.
Direction-only candidate leads (corpus join)
Each lead is surfaced only because its known mechanism points the same way as the derived lever, and each comes with a source and a falsifier. None is a treatment.
L-serine supplementation [PHGDH Serine deficiency]✓ recovered standarddir: increase · established standard of care
Class. oral L-serine
Mechanism. oral L-serine (with glycine) supplementation supplying the serine the deficient PHGDH biosynthetic enzyme can no longer make Direction: increase the deficient species/competence. Scope: agnostic (downstream).
✓ This is a rediscovery. Oral L-serine (with glycine) supplementation is the established treatment for PHGDH (3-phosphoglycerate dehydrogenase) deficiency; established treatment recovered.
Safety (qualitative; no magnitude). established-use safety profile on record (qualitative; no magnitude)
Falsifier. If L-serine supplementation [PHGDH Serine deficiency] (a gene-specific supply/increase agent) does NOT move the DOWN [F] switch toward the healthy branch in a PHGDH-deficient model, the h-restore(supply) direction is refuted for L-serine supplementation [PHGDH Serine deficiency] here.
Source: Sirr 2020 J Inherit Metab Dis 43:758 (A yeast-based complementation assay elucidates the functional impact of 200 missense variants in human PSAT1)
⚠ 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 PHGDH; 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).