Muscular dystrophy (MD) is a group of over 30 diseases that are genetically inherited.1 All these diseases cause a progressive weakening and degeneration of the muscles that are responsible for controlling the movements in our body. Muscular dystrophy is classified majorly in 9 types. All the types are characterized according to the age at which they start, the extent to which they progress and the inheritance pattern that they follow.
Is Muscular Dystrophy Inherited?
Muscular dystrophy is a genetically inherited group of disorders. The causes and the inheritance pattern of muscular dystrophy include:
Muscular dystrophy occurs as a result of mutation in some specific genes. The type of the disease is determined according the gene that is involved in mutation. Some genetic defects have been established which are responsible for some types of the disease. However, researches are still going on to find out the genetic problems that are responsible for other types of muscular dystrophy.
Most of the types of muscular dystrophy are a resultant of inherited disease called X-linked disorders. These disorders are transmitted by a mother to her male child even if the mother isn’t suffering from the disorder.
It can be explained as follows. There are two chromosomes in men- one X and one Y. Similarly, there are two chromosomes in women- both X. Hence, if a girl must be affected by muscular dystrophy, both the X chromosomes-one from each parent should carry the defective gene. This is extremely rare, as the mother must be a carrier in this and the father must have muscular dystrophy.
A woman who carries a defective X- chromosome can transmit it to her male child, who has a Y chromosome from his father.
Some types of muscular dystrophies are not inherited, and they result as there is a new genetic mutation or abnormality
Diagnosis Of Muscular Dystrophy
The physician will ask for your detailed medical history and perform a detailed physical examination. He may recommend some tests to diagnose muscular dystrophy, which include but are not limited to-
Electromyography:
- This is performed by injecting an electrode needle into the muscle that is to be tested 2
- The electrical activity is then noted as you relax and tighten the muscles gently
- Deviation in the normal patterns of the electrical activity can indicate a problem with the muscles
Enzyme tests:
- If a muscle is damaged, it releases certain enzymes like creatine kinase into the blood
- This can happen when there is a trauma or injury to the muscles
- However, if there is no history of injury or trauma and the blood tests still show these enzymes in high levels, it might be suggestive of a muscle disorder like muscular dystrophy
Genetic testing:
- Blood tests can be done to identify genetic mutations3
- These can be confirmatory as well as helpful in determining the type of the muscular dystrophy
Biopsy of muscles:
Biopsy of muscles performed by removing a small sample of muscle and studying under a microscope, can help in differentiating muscular dystrophy from other muscle diseases
ECG and Echo:
- Both these tests are useful in determining whether the heart is functioning normally or not
- This can be considered a supportive test in those already diagnosed with muscular dystrophy, to ascertain the functioning of the heart, especially in myotonic muscular dystrophy
Lung tests:
- Lung functioning tests are performed to check the functioning of the lungs, as respiration can get affected in many typed of muscular dystrophy, especially the ones in which the spine gets deformed
- In such cases, unsatisfactory lung function tests can indicate a need for corrective bone surgery, for better breathing in the affected person
Muscular dystrophy refers to a group of over 30 diseases, that are genetically inherited. They are characterized by causing a progressive and degenerative muscle weakness in the muscles that control the body movements- the skeletal muscles. Muscular dystrophy is not curable, neither can it be reversed. However, a prompt and efficient treatment can help in reducing the severity of symptoms and slowing down the progression of the disease.
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