Makindo Medical Notes

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

About

• Facioscapulohumeral Muscular Dystrophy (FSHD) is a genetic muscle disorder characterized by progressive weakness, primarily affecting the facial muscles, shoulder blades (scapula), and upper arms (humerus).
• Inherited in an autosomal dominant pattern, FSHD is caused by a mutation on Chromosome 4, specifically involving the D4Z4 region.
• FSHD can present in childhood or adulthood, with significant variability in symptom severity among individuals.

Clinical Features

• Facial weakness: Difficulty whistling, smiling, or fully closing the eyes.
• Scapular winging: Prominent shoulder blade protrusion on abduction, due to weakness in stabilizing scapular muscles.
• Humeral muscle weakness: Involvement of upper arm muscles, while sparing the deltoid muscles — a key feature that helps differentiate FSHD from other muscular dystrophies.
• Pelvic girdle weakness: May lead to gait difficulties and balance issues.
• Ocular involvement: Exudative retinopathy, a condition where fluid leaks into the retina, can impair vision.
• Hearing loss: High-frequency sensory hearing loss is common in FSHD.
• No cardiomyopathy: Unlike other muscular dystrophies, FSHD does not typically affect the heart muscle, which helps to distinguish it from other types.

Investigations

• Genetic testing: Confirms diagnosis by identifying the D4Z4 mutation on Chromosome 4.
• Creatine kinase (CK) levels: Mildly elevated, typically 2 to 7 times the normal range, indicating muscle damage.
• Electromyography (EMG): Shows a myopathic pattern, suggesting muscle disease.

Management

• Physiotherapy and occupational therapy: Vital for maintaining muscle function, preventing contractures, and promoting mobility.
• Exudative retinopathy management: Treated with photocoagulation to prevent retinal damage and preserve vision.
• Hearing aids: May be required for those with significant hearing loss.
• Regular monitoring: Assess muscle strength and functional ability regularly to adapt treatment plans as needed.
• Supportive devices: Braces, orthotics, or other mobility aids may assist with walking and posture.