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Prevalence is unknown: DMD and BMD primarily affect males and only a small percentage of female carriers have been reported to manifest these diseases (24% of female carriers from families with DMD and 19% of female carriers from families with BMD).

Symptomatic female carriers usually present later in life (with onset generally occurring in adulthood). The muscle weakness is generally mild to moderate and is usually proximal and asymmetric; often the upper limbs are weaker than the lower limbs. Myalgia and cramps have also been reported. Some patients present with cardiac manifestations alone.

DMD and BMD are both X-linked recessive diseases and are caused by dystrophin deficiency in skeletal and heart muscles due to deletions/mutations in the DMD gene (Xp21.2). Females with clinical features of DMD and BMD are usually carriers of X-chromosome rearrangements, display skewed X-inactivation or have Turner syndrome (complete or partial absence of an X chromosome; see this term).

Diagnosis can be confirmed by molecular testing which is available on a clinical basis.

As for male DMD and BMD patients, management should be multidisciplinary and female carriers of BMD and DMD should undergo regular cardiac evaluations.

The prognosis for symptomatic female carriers is variable, but the disease course tends to be milder in females than in males and progression is slow.