National Institute of Neurosciences, National Center of Neurology and Psychiatry, Tokyo, Japan.
Abstract
PURPOSE OF REVIEW: Distal myopathy with rimmed vacuoles or hereditary inclusion body myopathy is an adult-onset autosomal recessive, slowly progressive and debilitating myopathy due to mutations in the gene that regulates the synthesis of sialic acid. This review aims to update our knowledge of this myopathy and to review studies about pathomechanism and therapeutic strategies.
RECENT FINDINGS: Owing to the mutated gene, it was expected that the pathomechanism of this myopathy would be based on hyposialylation, a highly controversial phenomenon. This concept has been supported by findings in two recently generated animal models. In addition, the intracellular amyloid-beta accumulation in a distal myopathy with rimmed vacuole mouse model is relevant to similar findings in patients.
SUMMARY: Clarifying the role of hyposialylation in distal myopathy with rimmed vacuole/hereditary inclusion body myopathy could potentially lead to a therapeutic strategy for this progressive myopathy. In addition, strategies aimed at preventing amyloid-beta deposition or enhancing its clearance could also be beneficial, as this epiphenomenon is now known to occur early in the course of the disease.