For Clinicians

HSPB8 Myopathy, or Myofibrillar Myopathy Type 13 with Rimmed Vacuoles is an ultra-rare, slowly progressing autosomal dominanant. Mutations in HSPB8 gene, which have previously been associated with Charcot-Marie-Tooth type 2L and distal hereditary motor neuronopathy type IIa, have more recently also been reported to cause Myopathy with Rimmed Vacuoles. Affected patients have distal and proximal limb girdle myopathy. Muscle biopsy displays histologic features of myofibrillar myopathy with aggregates and rimmed vacuoles. 

HSPB8 Myopathy typically manifests in the second, third, or fourth decade of life. It is characterized by progressive muscle weakness, which may initially appear either proximally or distally. The condition predominantly affects the lower limbs and gradually spreads to the truncal muscles and upper limbs. Due to its progressive nature, individuals experience increasing difficulty with muscle strength and mobility over time.