Basics of Duchenne/Becker Muscular Dystrophy
About 400 – 600 boys are affected by the most common form of muscular dystrophy every year in the U.S. Muscular dystrophy is usually diagnosed when the child is between 3 to 6 years of age.
The most common form of muscular dystrophy is Duchenne Muscular Dystrophy (DMD). A milder form is Becker Muscular Dystrophy (BMD). Together, they are referred to as Duchenne/Becker Muscular Dystrophy (DBMD).
DBMD is found almost exclusively in boys. Girls rarely get DBMD, though they might display symptoms later in life.
What happens in DBMD?
In Duchenne Muscular Dystrophy, muscles in the body weaken, resulting in restriction of movement. This is due to the body’s inability to produce dystrophin, which is required for muscle growth. Symptoms in childhood include delay in walking, frequent falling, inability to get up from a sitting position etc.
By the time the child is 12 years of age, he will be unable to walk. He will require a wheelchair to move around. Complications arise in the teens or early 20s, usually respiratory and heart problems. DMD patients rarely live beyond their 30s.
Becker Muscular Dystrophy is a milder form of DMD. Some dystrophin is produced, so muscles are not completely weakened. Patients can live into old age with proper care.
Cause of DBMD
Duchenne/Becker Muscular Dystrophy is caused by a genetic disorder. In 1986, researchers found the gene which, when it is flawed or mutated, causes DBMD.
The proper functioning of that particular gene is required to produce dystrophin. Dystrophin is needed by the body to strengthen and protect muscles. A flawed gene means decreased or abnormal dystrophin, which in turn results in weak muscles.
Why females don’t get DBMD
The gene that causes DBMD is found in the X chromosome. Males have one X chromosome and one Y chromosome. If they have a flawed dystrophin related gene, they will get DBMD.
Females have two X chromosomes. So even if the gene in one chromosome is flawed, the gene in the other chromosome can compensate for it. That is why females seldom get DBMD. But if they are so unlucky that in most of their cells the flawed X chromosome is active, they might get DBMD. But this is very rare.
When females do get DBMD, they get affected by it only later in life. They will experience heart problems, which if left untreated may be fatal.
Heredity of DBMD
Even though females do not get DBMD, they can act as carriers. That is, they pass on the mutated gene to their offspring.
2/3rd of the patients who have DBMD inherited it from their mother. In 1/3rd of the patients the mutation of the gene has happened in the egg.
Treatment of DBMD
There is no treatment for DBMD. Though some steroids can reduce the intensity of symptoms, DBMD cannot be cured.
Research is going on to develop a cure for DBMD.
What to do if your child exhibits DBMD symptoms
Consult a doctor immediately. Tests will be done to confirm if it is DBMD.
If it is DBMD, your son and your family may be facing challenging times. Contact DBMD societies for support. Find out about other families who dealt with a DBMS child to learn how they coped with it.