IDC10-Code = E74.4
Enzyme Commission Number = EC#1.1.1.27
Genomic coordinate (human 12:21,635,342 LDHB).
Cytoband (human 12p12.1 LDHB).
Intraband %= 12.0% LDHB
OMIM’ genes @ 12p12.1 = 24 genes.
Polymorphs = 83 LDHB variants in ClinVar.
Hyperbolic Umbilic Chromosome-12 is 1,200 genes.
Here I 🎁 present: “Lactate Dehydrogenase Deficiency-B“, Victor McKusick, Mendelian Inheritance in Man’, 1966. (LDHB)
CORE CONCEPT.
Lactate Dehydrogenase-B (LDHB) Deficiency elevates the energy barrier for converting lactate to pyruvate in oxidative tissues without completely blocking the reaction’s reversibility.
Visual Landscape Breakdown
- Green Basin: Lactate, representing the glycolytic state.
- Red Basin: Pyruvate, representing the oxidative state.
- Height: Relative free energy cost to transition between metabolic states.
- Critical Point: The saddle region governing net flux based on enzyme capacity.
Impact of Reduced LDHB Activity
- Higher Barrier: Increases the activation energy needed for lactate-to-pyruvate conversion.
- Reduced Capacity: Lowers overall metabolic flux through this pathway.
- Maintained Reversibility: Pyruvate can still convert back to lactate depending on cellular conditions.
Clinical & Physiological Impact
- Target Tissues: Affects oxidative tissues like the heart, red blood cells, and kidneys.
- Efficiency Drop: Reduces the tissue’s ability to utilize lactate as an energy substrate.
- Mild Phenotype: Often presents as mild hemolysis or exercise intolerance. Severe rhabdomyolysis is rare.
