[Late-onset sarcoglycanopathy: a cause of repeated muscle cramps after exertion]

A 61-year-old man in generally good health had a 2-year history of repetitive episodes of muscle cramps, weakness, numbness and muscle pain of the bilateral limbs after exerting himself. During each episode, his serum creatine kinase level became elevated then recovered only after sufficient hydration had been provided. Bilateral thigh MRI showed abnormal muscular signals, and the patient was subsequently diagnosed by muscle biopsy, immunohistochemistry, and mini-multiplex western blotting analysis as having solitary sarcoglycanopathy. Late-onset sarcoglycanopathy has rarely been described. In the present patient, his mild clinical condition, subclinical cardiomyopathy and possible involvement of polyneuropathy are unique features.