Makindo Medical Notes

Related Subjects: |Autosomal Dominant |Autosomal Recessive |X Linked Recessive

🧬 About

• Facioscapulohumeral Muscular Dystrophy (FSHD) is a genetic muscle disorder with progressive weakness affecting the face 😶, shoulder blades 🦴, and upper arms 💪.
• Inheritance is autosomal dominant 📈, caused by mutations in the D4Z4 region on Chromosome 4.
• Onset can be in childhood 👦 or adulthood 👩, and severity varies widely between patients—even within the same family.

🩺 Clinical Features

• Facial weakness: Difficulty whistling, smiling, puffing cheeks, or fully closing eyes.
• Scapular winging 🪽: Shoulder blades stick out when arms are raised, due to weak stabilisers.
• Humeral sparing pattern: Weakness of upper arm muscles, but deltoids are spared ➝ key diagnostic clue against other muscular dystrophies.
• Pelvic girdle weakness: Gait disturbance, waddling, balance issues 🚶.
• Ocular: Exudative retinopathy 👁️ (fluid leakage in retina) may threaten vision.
• Hearing: High-frequency sensorineural hearing loss 👂 is relatively common.
• No cardiomyopathy ❤️❌: Unlike Duchenne/Becker MD, the heart is spared—an important differentiator.

🧪 Investigations

• Genetic testing: Confirms D4Z4 mutation on chromosome 4.
• Creatine kinase (CK): Mildly elevated (≈2–7× normal), much lower than Duchenne/Becker MD.
• Electromyography (EMG): Myopathic pattern ⚡.

🛠️ Management

• Physio & OT: Maintain mobility, prevent contractures, support independence.
• Ocular care: Exudative retinopathy ➝ laser photocoagulation to preserve vision 👁️.
• Hearing aids: For significant sensorineural hearing loss.
• Monitoring: Regular review of muscle function, posture, and activities of daily living.
• Supportive devices: Braces, orthoses, or walking aids may be helpful.

📚 Clinical Pearls

• Pattern of weakness is diagnostic: FSHD affects face + scapula + humerus with deltoid sparing ➝ classic for exams.
• Heart and respiratory function usually normal, unlike other muscular dystrophies ➝ helps distinguish FSHD in clinic.
• Highly variable penetrance: Some family members may remain only mildly affected well into late adulthood.

Cases — Facioscapulohumeral Muscular Dystrophy (FSHD)

• Case 1 — Facial Weakness in a Teenager 🙂: A 16-year-old boy is brought in because he cannot fully close his eyes when sleeping and struggles to whistle or puff his cheeks. Exam: facial weakness with sparing of extraocular muscles; asymmetric scapular winging when raising arms. Diagnosis: FSHD. Management: Supportive — physiotherapy, orthotics, genetic counselling.
• Case 2 — Shoulder Girdle Weakness 🎒: A 22-year-old woman complains of progressive difficulty lifting her arms overhead. On exam: bilateral scapular winging, reduced deltoid and biceps bulk, preserved distal limb strength. Family history: father with similar shoulder weakness. Diagnosis: FSHD with autosomal dominant inheritance. Management: Multidisciplinary care — physiotherapy, orthopaedics for scapular fixation surgery if functionally severe.
• Case 3 — Adult with Asymmetric Weakness + Hearing Loss 👂: A 30-year-old man presents with progressive left-sided shoulder weakness and difficulty smiling symmetrically. He also has mild high-frequency sensorineural hearing loss. Diagnosis: FSHD (notable for asymmetry and extra-muscular features such as hearing loss and retinal changes). Management: Supportive care, audiology follow-up, rehabilitation planning.

Teaching Commentary 🧠

FSHD is an autosomal dominant muscular dystrophy, usually presenting in adolescence or young adulthood. Hallmarks: - Weakness of facial, scapular, and humeral muscles (hence the name). - Often asymmetric compared to other dystrophies. - Extra-muscular features: sensorineural hearing loss, retinal telangiectasia. - CK is normal or mildly raised; genetic testing confirms diagnosis. Progression is usually slow, and life expectancy is near normal. Management: multidisciplinary supportive care (physio, OT, orthopaedics, hearing/vision checks, genetic counselling).