Duchenne Muscular Dystrophy
The most severe and most well known type of muscle disease is the duchenne dystrophy. This disease strikes children between the age of 2-6. Progressive disease usually confines it's victims to wheelchairs by their teenage years. This disease is a name for several types of inherited muscular diseases that cause the skeletal muscles to slowly waste away. Ironically, it often appears that the muscles are enlarged. But the enlargement is due to fat deposits. The actual muscle fibers waste away.They are caused by a defect in one or more of the genes that control muscle structure and function. Some types are inherited as a dominant gene abnormality, whil
e others are inherited as a recessive gene abnormality or x linked recessive gene abnormality. The patient may also be given the tensilon test (if a drug that increases the strength of neuromuscular transmission improves the patient's condition, the disease is probaly present). In this case in a x linked abnormality, the gene is on the x chromosome. If they do pass on this disease generally only thier sons will develop the disease because males have only one X chromosome. The early manifestations of Duchenne include: Toe walking Running with excess limb motion and without much foward movement Frequent falls and difficulty rising from the ground Large (hypertrophic) calves Unusually straight postureLater in the course of the disease, muscle wasting, a waddling gait, and curved posture also become evident. Another approach increases the amount of acetylcholine available to muscle receptors with enzyme-inhibiting drugs call anticholinesterases and surgical removal of the thymus gland (thymectomy). The best known enzyme test is the one for creatin kinase. ------------------------------------------------------------------------Bibliography. Diagnosis depends on the distribution of weakness and the patient's medical history, which characteristically includes episodes of weakness during exertion followed by a relatively rapid recovery. This is one of the pairs that determines the person's sex. But in the muscle disease victims tests reveal elevated levels of muscle enzymes in the blood (due to degeneration muscle). The earliest symptoms are usually double vision, drooping eyelids, inability to smile,slurred speech, and difficulting swallowing. The genetic abnormality is located on a segment of the x chromosome called (XP21). But in an X-linked recessecive gene abnormality, women are not affected but may pass on the defective gene to their children.