The majority of the female carriers do not have any sign of the condition at all, while a small number of carriers may have a muscular dystrophy that is almost as severe as boys with Duchenne muscular dystrophy. Between these two extremes, there is a variety of signs and symptoms.
Most manifesting carriers experience mild problems with muscle weakness late in adult life. Some get aches and pains in their muscles as their first complaint, and may notice enlargement of their calves and other muscles. Symptoms usually start in the legs but in time may also involve the shoulders and the arms. Muscle weakness may get worse over time, however the progression is usually slow.
Please note: it is important to be aware that some manifesting carriers of Duchenne and Becker muscular dystrophy may have problems with their heart (cardiomyopathy), which are independent of their muscle symptoms.
Heart problems in carriers of Duchenne and Becker muscular dystrophy often do not cause any symptoms, but they can often be treated, so it is important for carriers to be followed up by a specialist for monitoring over time.
The muscles of facial expression, speech and swallowing, and the involuntary muscles (for example those of the bowel and bladder), are not affected.
Some carriers of Duchenne or Becker muscular dystrophy can show learning and/or behavioural difficulties. As learning difficulties are not progressive, it is important they are identified and addressed promptly (e.g. at school), to offer the child the support she will need to reach her full potential to develop her skills. Family support is essential, and specialists may need to be consulted to address specific issues of learning and behaviour.