Caveolin-3 gene mutation in Japanese with rippling muscle disease.

OBJECTIVES

Rippling muscle disease (RMD) is a rare myopathy characterized by percussion-induced rapid muscle contractions, muscle mounding, and rippling. Recently a caveolin-3 gene (CAV3) mutation was identified in patients with autosomal dominant RMD. The objective of this study was to determine whether a similar mutation was present in two Japanese families with this condition.

PATIENTS AND METHODS

Clinical examination, mutational analysis, and muscle immunohistochemistry were carried out in six patients from two Japanese RMD pedigrees.

RESULTS

Apart from the atrophy of the intrinsic muscles in their hands and a slight muscle weakness in their fingers, the clinical features of our patients were compatible with RMD. Our investigation revealed a CAV3 missense mutation, i.e. Arg26Gln in both families. Immunohistochemistry performed on a muscle biopsy specimen showed reduced caveolin-3 surface expression.

CONCLUSIONS

Japanese RMD also appears to result from a CAV3 mutation.