Marked hemiatrophy in carriers of Duchenne muscular dystrophy.

OBJECTIVE To describe the clinical and molecular genetic findings in 2 carriers of Duchenne muscular dystrophy (DMD) who exhibited marked hemiatrophy. Duchenne muscular dystrophy is an X-linked disorder in which affected male patients harbor mutations in the dystrophin gene. Female patients with heterozygous mutations may be manifesting carriers. DESIGN Case study. SETTING Neurology clinic. PATIENTS Two manifesting carriers of DMD. INTERVENTIONS Clinical and radiologic examinations along with histologic and molecular investigations. RESULTS Both patients had marked right-sided hemiatrophy on examination with radiologic evidence of muscle atrophy and fatty replacement on the affected side. In each case, histologic analysis revealed a reduction in dystrophin staining on the right side. Genetic analysis of the dystrophin gene revealed a tandem exonic duplication in patient 1 and a multiexonic deletion in patient 2 with no further point mutations identified on the other chromosome. CONCLUSIONS Marked hemiatrophy can occur in DMD manifesting carriers. This is likely to result from a combination of skewed X-inactivation and somatic mosaicism.