[Value of muscle studies in the early diagnosis of Schwartz-Jampel syndrome]. / Intérêt du bilan musculaire dans le diagnostic précoce du syndrome de Schwartz-Jampel.

The authors report a case of Schwartz-Jampel syndrome (osteo-chondro muscular dystrophy with myotonia). The diagnosis was made when the child was 3 1/2 year old. Then, there were no clinical symptoms; however, the electromyographic and histologic patterns of the disease were found. Two years later, the clinical status provided confirmation of the diagnosis. The discussion focuses on the difficulty of the diagnosis and the relevance of electrophysiological studies and muscular biopsy in order to distinguish this disease from others with similar clinical pattern (as Freeman-Sheldon, or Marden Walker syndromes).