Makindo Medical Notes

A positive Gowers' sign reflects proximal lower limb weakness. The child uses their upper limbs to rise: first pushing up onto hands and knees, then “walking” their hands up their thighs to stand. This is classic for Duchenne Muscular Dystrophy (DMD).

📖 About

• 💀 Lethal X-linked recessive disorder, belonging to the muscular dystrophies.
• 🧬 These conditions cause progressive muscle weakness and loss of muscle mass due to absent or defective dystrophin protein.

🧬 Aetiology

• X-linked recessive inheritance – mutation in the DMD gene on Xp21.
• Female carriers may show mild muscle fatigue and are at increased risk of cardiomyopathy.

🩺 Clinical Features

• 👦 Onset age 3–6 years: progressive weakness of proximal limb-girdle muscles.
• ❤️ Cardiac involvement is almost universal.
• 🐂 Calf pseudohypertrophy due to fat and connective tissue replacement.
• 🚶‍♂️ Progressive difficulty walking; wheelchair use by early adolescence.
• 🫁 Death typically by age 30 from respiratory failure or cardiomyopathy.
• 🦴 Contractures, scoliosis, intellectual impairment, and reduced night vision may also develop.

🔍 Differentials

• Other muscular dystrophies (e.g. Becker MD, Limb-girdle MD)
• Cerebral palsy

🧪 Investigations

• 📈 Serum CK-MM markedly elevated (often >10,000 IU/L).
• 🧬 Genetic testing: exon deletion/duplication in ~65% cases.
• 💉 Muscle biopsy & EMG (show muscle fibre necrosis and myopathic changes).
• 🫀 ECG, CXR & Echocardiogram for cardiomyopathy assessment.

💊 Management

• Supportive and multidisciplinary care is key.
• 💊 Corticosteroids (prednisolone/deflazacort) may slow progression.
• 🧾 Genetic counselling: sons of affected men are unaffected, but all daughters are obligate carriers.
• 🏊‍♂️ Exercise such as swimming can preserve function.
• 🦽 Good OT/PT input → wheelchairs, home adaptations, splints.
• 🫁 Respiratory support (NIV, cough assist devices) as disease advances.

📚 References

• Royal College of Paediatrics and Child Health – Neuromuscular Disorders guidance.
• BNF for Children, NICE Clinical Knowledge Summaries.
• Emery AE. Duchenne Muscular Dystrophy. Oxford University Press.