A muscular dystrophy is a group of rare inherited disorders characterized by the progressive damage of all the muscles in the body, engaging muscles weakness, and disability. Muscular dystrophy is translated by progressive weakening of the muscles, especially skeletal muscles, which are voluntarily controlled by the brain. Being a mom with muscular dystrophy is hard and you must be aware that there is a high risk of transmitting this disease to your baby.
This disease act by replacing the normal muscles fibers with connective tissues and fats. In some forms of muscular dystrophy, there are also affected the myocardium muscles and other organs. Each of its forms differs in terms of symptoms and the mode of hereditary transmission. The most common types are Duchenne muscular dystrophy and Becker muscular dystrophy that affects only male subjects. They are caused by the genetical deficiency of a protein called dystrophin. There is no cure for muscular dystrophy.
Muscular dystrophy is a rare condition, among babies, only 0.02% – 0.03% will suffer from Duchenne muscular dystrophy, while 0.003% suffer from Becker muscular dystrophy.
Duchenne Muscular Dystrophy
Duchenne muscular dystrophy is the most prevalent form of muscular dystrophy, affecting about 3 out of 1000. It is a hereditary disease with autosomal recessive linked to chromosome X. Therefore, Duchenne myopathy only affects male infants. The disease is caused by a faulty gene that causes the deficiency of a protein called dystrophin. The absence of dystrophin causes damages to the membranes covering the muscle cells (myocytes), engaging muscle fiber degeneration and myocytes necrosis.
In some cases, the disease manifests itself in the embryonic stage, but in others, it occurs after the age of 3 or 4 years. Affected children require more time to learn how to walk than normal. They have difficulties climbing stairs, running or lifting off the ground. The tendency is to fall.
After the first symptoms, the disease progresses rapidly. Despite the weakness, muscle hypertrophy seems lost due to the replacement of muscle fibers with connective tissue and fats. At the age of 12, children lose the ability to walk and are confined to wheelchairs. In 1/3 of the cases, intellectual impairment occurs, especially on verbal skills. In general, death occurs by the age of 20 years as a result of respiratory complications and heart failure.
Becker Muscular Dystrophy
Becker muscular dystrophy is also a hereditary disease, with the same transmission like the Duchenne muscular dystrophy, but considerably clinically softer in its symptoms and effects than the Duchenne muscular dystrophy.
If in the Duchenne dystrophy case, the protein called dystrophin is totally absent, in the case of Becker muscular dystrophy, dystrophin is only insufficient, but present and partially fulfilling its function to protect the membrane that surrounds the muscles fibers.
Becker muscular dystrophy symptoms are generally milder than in the case of the Duchenne myopathy. Their onset is variable from 2 to 45 years of age, and the average age of developing its symptoms is around 12 years of age. The ability of walking is not affected by the age of 16 years, and deformations of the spine are rare. Respiratory failure is not occurring before 40 or even 50 years of age and intellectual functions are not altered.
Becker dystrophy is 10 times rarer than the Duchenne disease, affecting about 3 out of 10,000 boys and most patients live up to 50-60 years of age. The causes of death are the same as for Duchenne myopathy: lung infections and heart failure.
Myotonic Muscular Dystrophy
Myotonic muscular dystrophy is the most common form of muscular dystrophy in adults, affecting about 30 out of 100,000 newborns. Both sexes are equally affected.
The first signs and symptoms of myotonic muscular dystrophy occur in adolescence or later, in adulthood and consists of myotonia (abnormal slowness and weakness in muscular contraction), weakness, limb muscles (especially hand muscles), and cardiomyopathy (heart’s muscle damage). Myotonic muscular dystrophy may be accompanied by cataracts, mental retardation, and hormonal disorders (disorders of virility, testicular atrophy in men, menstrual disorders, recurrent miscarriage in women).
Landouzy-Dejerine dystrophy is an autosomal dominant inherited disease, characterized by the weakness of the facial, arms, shoulders, pectoral and upper-back muscles. Landouzy-Dejerine dystrophy occurs in both sexes and often affects several members of the same family The first signs of Landouzy-Dejerine dystrophy occur between 7 and 40 years of age, but most often before 20 years of age. There is an infantile form of this disease which is rapidly progressive.
The classical form debuts in adolescence, it is slowly progressive and affects the muscles of the face, arms, and shoulders. The patient can not perform gestures with the facial muscles, has difficulty in lifting his arms, and even has difficulties in closing his eyes. Life expectancy is normal and occurs relatively late. Landouzy-Dejerine dystrophy effects can be reduced by physiotherapy.
Causes of Dystrophy
All types of muscular dystrophy are hereditary. The gene responsible for Duchenne and Becker dystrophy is transmitted through the mother’s X chromosome.
Women have two X chromosomes, while males have one X chromosome and one Y chromosome. Pregnant women can transmit the disease only to male newborns because boys inherit only one X chromosome, they do not benefit from a normal gene to counteract the damage, so the gene mutation on the X chromosome occurs and the disease is transmitted. Dystrophin is a protein produced by muscle that helps muscle cells keep their shape. The faulty gene that is the cause of Duchenne muscular dystrophy prevents dystrophin production, resulting in muscular membrane damage and necrosis of the muscular fibers.
For women diagnosed with myotonic dystrophy, there is a 50% risk of transmitting the myotonic dystrophy to their newborns. The dystrophy has an autosomal dominant transmission, so if one parent carries the gene responsible for myotonic dystrophy, there appears the 50% risk to transmit the disease to the newborns.
Treatment of Dystrophy
Currently, there is no permanent cure for muscular dystrophy, but there are some methods to care these disorders and improve the patient’s life quality and life expectancy. Existing treatments are designed to prevent or reduce the joints or the spine deformations. Muscular dystrophy treatments include physiotherapy, physical therapy, medication, and surgery.
The goal of physiotherapy is to maintain the flexibility of the joints, to prevent contractions, to delay or reduce the spinal deformation.
– Myotonic muscular dystrophy: mexiletine, phenytoin, carbamazepine, and procainamide.
– Duchenne muscular dystrophy: inflammatory corticosteroids are sometimes prescribed to delay the disease.
If damages of the respiratory muscles occur, take steps to prevent respiratory disorders. Considering that lung infections are common in the advanced stages of muscular dystrophy, vaccines against pneumonia and influenza are important. To regulate the heartbeat, a pacemaker can be used. Other methods include gene therapies (replacing the faulty genes with normal genes) and transfer of myoblasts (transplantation of healthy muscles cells in a patient with muscular dystrophy).
Being a Mom with Muscular Dystrophy
To prevent these disorders transmission, couples in which the woman is suffering from muscular dystrophy or has a family history of muscular dystrophy can call for a genetic counseling, to determine the risk of occurrence of the muscular dystrophy in children.
If doctors give their OK to the couple, then the couple will conceive, taking their risks. If the woman is suffering from muscular dystrophy, a special care during pregnancy will be mandatory. Special physiotherapy sessions are a great help for any mom with muscular dystrophy. Physiotherapy will prepare the future mom’s body for the extra pounds she will gain during pregnancy. Medication may be prescribed in order to reduce muscular dystrophy negative effects, without hurting the fetus. A mom with muscular dystrophy must be aware of the fact that she’ll be giving birth through a C-section, and the recovery will be hard.
Being a mom with muscular dystrophy is not at all an easy task. You’ll always have to work on your body in order to diminish the dystrophy’s negative effects, and you’ll always have to keep in touch with your doctor to know your disease’s evolution, during pregnancy but also after you gave birth.