OBJECTIVETo investigate the clinical features of female Duchenne muscular dystrophy(DMD), and find out the onset mechanism.

METHODSThe clinical manifestations of a female DMD family were followed; the immunofluorescence studies on muscle system and the genetic analysis were carried out.

RESULTSThe clinical manifestations and results of relevant examinations on the DMD woman in this family were in accordance with the typical characteristics of DMD. The 39-year-old mother of this proband was noted to have a clinical feature resembling that of Becker muscular dystrophy (BMD), and the immunofluorescence analysis revealed that dystrophin positive fibers and negative fibers co-existed in her muscle. The dystrophy genetic analysis of the family indicated non-deletions. The mother's karyotype was found to be normal.

CONCLUSIONThe 39-year-old female patient's clinical manifestations were similar to BMD, and only one third of her fibers were dystrophin-positive. The present authors assume that the skewed pattern of X inactivation is the likely mechanism, because the karyotype is normal.