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).
