Mitochondrial Disease
A 30-slide clinical learning module · Energy metabolism, maternal inheritance, and multisystem disease
Slide 1 of 303% complete
Module Outline
⚡ Part 1
🔬 Part 2
🏥 Part 3
📋 Part 4
💊 Part 5
🧩 Part 6
Slide 1/30
⚡ Part 1: The Mitochondrial Patient
Why Mitochondria Matter
The organelle at the center of energy, disease, and evolution
- 1Mitochondria produce ~90% of cellular ATP via oxidative phosphorylation (OXPHOS). Every cell contains hundreds to thousands of mitochondria, each with 2–10 copies of its own 16,569 bp circular genome (mtDNA).
- 2High-energy organs are hit first and hardest: brain (20% of body O2), heart, skeletal muscle, retina, cochlea, liver, kidneys. This explains why mitochondrial disease is fundamentally MULTISYSTEM — if a child has unexplained disease in ≥2 unrelated organ systems, mitochondria should be on your differential.
- 3Incidence: ~1 in 4,300 (one of the most common inherited metabolic disorders). mtDNA mutations alone affect ~1 in 5,000 adults. Nuclear-encoded mitochondrial disease adds substantially to this number.
- 4The clinical challenge: mitochondrial disease is a great mimicker. The same mutation can cause different phenotypes (phenotypic heterogeneity), and the same phenotype can result from different mutations (genetic heterogeneity). This makes pattern recognition essential.
- 5Key concept: "any symptom, any organ, any age, any inheritance pattern" — the unofficial motto of mitochondrial medicine. While this is an overstatement, it captures the diagnostic challenge.
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Clinical Pearl
The classic teaching is "think mitochondria when nothing else fits." But the modern approach is more proactive: think mitochondria early when you see unexplained multisystem disease, especially involving brain + muscle + eye + endocrine. Early genetic testing has replaced the old "diagnose by exclusion" paradigm.
Gorman et al., Nat Rev Dis Primers 2016; Chinnery, GeneReviews 2021