When to Suspect HSPB8 Myopathy?

Clinical characteristics: 

  • Difficulty walking in early adulthood. 

  • Muscle weakness affecting distal lower extremities. 

  • Bilateral foot drop. 

  • Foot and ankle pain. 

  • Difficulty raising arms above the head, rising from a chair, or climbing stairs. 

  • Balance issues and frequent falls.  

  • Breathing problems (usually late adulthood). 

 

Neurological examination findings: 

  • Atrophy of tarsal muscles and tibialis anterior (usually bilaterally) 

  • Distal weakness affecting ankle dorsiflexion, eversion, toe extension and flexion.  

  • The weakness might progress over time to involve proximal muscles. 

  • Muscle atrophy in the scapular region with scapular winging (A).  

  • Waddling gait, lumbar lordosis, or scoliosis.  

  • Decreased or absent ankle reflex  

  • Usually intact sensation.  

  • Usually, no facial or bulbar weakness.  

Muscular involvement of the HSPB8 disease, MRI scan showing changes in lower extremities

Al-Tahan S et al. New family with HSPB8-associated autosomal dominant rimmed vacuolar myopathy. Neurol Genet. 2019;5:349.