Duchenne muscular dystrophy (DMD) is due to the absence of dystrophin, which is in itself linked to abnormalities in the DMD gene. However, traces of residual dystrophin and revertant muscle fibres can be found in more or less large numbers in muscle biopsies of patients. In this paper, a British team has demonstrated that of 63 biopsies from DMD patients, 47% were revertant fibres, 32% showed residual traces of dystrophin, 15% were revertant fibres and showed traces of residual dystrophin and 36% did not contain any dystrophin. No correlation between the presence of revertant fibres or residual dystrophin was identified with the performance of patients (assessed by the Motor Ability Score) or their response to corticosteroids. Finally, a second biopsy performed in nine patients, approximately eight years after the first biopsy, showed no increase in the number of revertant fibres or residual dystrophin in contrast to that commonly observed in mdx mice. These results should facilitate the implementation and evaluation of clinical trials based on the restoration of dystrophin expression.

Références : Arechavala-Gomeza V, Kinali M, Feng L, Guglieri M, Edge G, Main M, Hunt D, Lehovsky J, Straub V, Bushby K, Sewry CA, Morgan JE, Muntoni F. Revertant fibres and dystrophin traces in Duchenne muscular dystrophy: implication for clinical trials. Neuromuscul Disord. 2010 May;20(5):295-301. Epub 2010 Apr 14.