DMD is a severe type of muscular dystrophy. The symptom of muscle weakness usually begins around the age of four in boys and worsens quickly. Typically muscle loss occurs first in the thighs and pelvis followed by those of the arms. This can result in trouple standing up. Most are unable to walk by the age of 12. Affected muscles may look large due to increased fat content. Scoliosis is also common. Females with a single copy of the defective gene may show mild symptoms. The disorder is X-linked recessive. About two thirds of cases are inherited from a person's mother, while one third of cases are due to a new mutation. It is caused by a mutation in the gene for the protein dystrophin. Dystrophin ist important to maintain the muslce fiber's cell membrane. DMD affects about one in 3'500 males at birth, It is the most common type of muscular dystrophy. The average life expectancy is 26, however, with excellent care, some may live into their 30s or 410s. Gene therapy, as a treatment, is in the early stages of study in humans.
No cure for DMD is known, and on ongoing medical need has been recognized by regulatory authorities.
Treatment is generally aimed at controlling the onset of symtomps to maximize the quality of life which can be measured using specific questionaires, and include:
Early Phase (Up to age 7)
The early phase usually lasts until around age 7, which is a key turning point in normal growth and development. During this phase, parents may notixe their child having trouble with certain activities like sitting, walking or talking. children with Duchenne may be more tired than other children. Since ages 1-7 are a time of rapid growth for all children and child with Duchenne will continue to grow during this time, the onset of these symptoms can be difficutl to recognize.
Transitional Phase (Ages 6 to 9)
During the transitional phase, a child with Duchenne will experience increasing weakness in his muscles. He may also have trouble mobing as easily as a healthy child. The large muscles in the front of the thigh - called the quadriceps - are responsible for many everyday movements like walking, going up stairs, and getting up from a sitting position. As these msucles weaken, you might nitice your child having difficulty walking. He may walk on his toes or have awobbly or abnormal gait and he may start to use what's called the Gower's Maneuver to get up from the floor. Hey ma also begin to have heart problems during this age.
Loss of the Ambulation Phase (Ages 10 to 14)
In this phase, children with Duchenne experience the largest impact on their independence, as they become more and more dependent on a wheelchair. Over time, use of their arms and legs requires assistance, and they may need to rely on a power wheelchair all the time. Most children with Duchenne retain use of their hands an fingers, so they can continue to write or use a computer.
Adult Phase (Age 15+)
In the last phase of Duchenne, there is usually increased difficulty in breathing. Life-threatening heart and lung coditions are more likely. Regular heart and lung monitoring is required, medications are often necessary and breathing support may be needed. Historically, boys with Duchenne typically die in theri late 20's to early 30's due to complications with their heart and lungs.