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