以下是在网上寻找的资料 杜兴氏肌肉营养不良症（Duchenne Muscular Dystrophy ，DMD）
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杜兴氏肌肉萎缩症
杜兴氏肌肉营养不良症（Duchenne Muscular Dystrophy ，DMD），乃遗传性肌肉萎缩病。它的基因（Dystrophin gene）存在于 X 性染色体中（Xp21），因此它是透过性连锁式隐性遗传型态传播的。男性只有一个ｘ性染色体，因此病患者大多为男性；若女性的一对ｘ性染色体中其一个携有异变的Dystrophin 基因，她便成为一个 DMD 的携带者，她的儿子有二分一的机会成为病患者，她的女儿则有二分一机会成为 DMD 基因携带者。
目 录
1Dystrophin 基因
Dystrophin 基因乃现时所知人类基因中体积较大的一种，它的制成品 Dystrophin，与其他相关的蛋白质，是稳定肌肉细胞膜的一个重要部份。它最重要的功能是维持肌肉细胞的稳定性，使它在肌肉收缩的过程中，不会受到破坏，杜兴氏病患者因肌肉中缺少了 Dystrophin ，令到肌肉自出生后，便不断受到破坏和萎缩。 Dystrophin 基因亦会受到另一种较轻微的突变所影响，导致病情较轻的碧加氏肌肉营养不良症（Becker's Muscular Dystrophy ，BMD）。
2杜兴氏肌肉营养不良症病征
杜兴氏肌肉营养不良症的病发率约为每十万名出生男婴中有 20-30 个案。病患者中约三分一有家族病历史，三分一由无症状的 DMD 携带者母亲所获得，三分一相信是经遗传基因突变而致病，患病男婴于初生时并无异样，病情通常初显于婴儿开始学行阶段，患者的活动能力发展较同龄的孩子缓慢，他们通常需用手部支持才可从地上站立起来（ Gower's sign ）。到 4-5 岁时，患者与朋辈一起玩耍，跑步时便感困难，同时跳跃时未能双脚离地。慢慢地患者上楼梯也感有心无力。到 6-7 岁时，患者会肌肉软弱无力而经常跌倒。
虽然杜兴氏患者因肌肉病变而变得四肢无力，但他们的小腿肌肉通常会异常肿大（ Pseudohypertrophy ）。若我们用手轻按这些肌肉，便会发觉它被接触质感不同，由于这些肌肉的正常组织被硬化组织所取代，因此小腿肌肉被接触时有坚实的感觉。
随着年龄增长，患者的肌肉病变和萎缩也变得越来越严重。到 12-13 岁时，患者便需倚助轮椅出入。同时由于肌肉的不正常活动能力，很多关节也有不同程度的畸形变化，因此对患者的照顾造成不便，也会对患者的心肺功能引致一定的影响。患者的心脏肌肉也会因此病而引起变化，导致心肌病。严重的话可发生心律不正，心脏衰竭等病状。
3杜兴氏肌肉营养不良症诊断
杜兴氏患者血液中的肌肉酵素浓度比正常人高出许多，肌电图的检查通常可发现肌肉病的变化，而受影响肌肉的活组织化验也会见到肌肉细胞体积大小不一，不正常肌肉和硬化等病理变化。现代较先进的实验室已可用细胞免疫化学方法，透过电子显微镜直接观察肌肉膜内的成份，从而诊断出杜兴氏病。而遗传学检查中，亦可侦察到某些常见的遗传基因缺失，进而确定此病的存在。可惜这些检查暂时在香港并未引进。
至于杜兴氏病基因携带者的女性，她们在表型（ Phenotype ）上可以有不同程度的病症显现出来。除了临床的检查外，她们在血液肌肉酵素浓度、肌电图和肌肉活动组织检查方面，也会显示出肌肉毛病的存在，从而计算出她们下一代子女受到这疾病影响的机会率。随着遗传学检查的进步，产前的羊水细胞检查和胎毛细胞检查，可以对产前胎儿的诊断给予很大的帮助。
4杜兴氏肌肉营养不良症治疗
由于关节的畸形对患者的活动能力有很大的影响，因此拉筋及各种物理治疗，需于病情早期便开始，以防止挛缩（ contracture ）的出现。适量的运动亦有助于加强儿童的活动能力。适当的辅助器械（如 splint, brace 等）对于关节的强化和防止畸形方面也有一定的帮助。当肢体出现畸形时，部份患者可利用适当的外科手术加以矫正。
药物治疗的成效目前是令人失望的。虽然有研究指出，类固醇的使用可以令到患者在几年的时间内有明显的治疗效果，但效果并不可以持续长久，兼且由于副作用不少，此种治疗只可以在医生的缜密监察下进行。
虽然遗传工程方面不断发展，但由于 Dystrophin 基因 的体积过于庞大，基因治疗如何将如此巨大的 Dystrophin gene 带到肌肉细胞内，还需要经过很多实验发展，新生肌肉细胞（ myoblast ）移植方面，如何令到正常细胞在病态肌肉中健康生长和发挥正常作用，还存在不少困难，目前只可以说还在试验阶段。但随着医疗科学的不断发展，这些技术给杜兴氏患者带来一线曙光，期望将来在治疗上有所突破。
Duchenne muscular dystrophy
Duchenne muscular dystrophy is an inherited disorder that involves muscle weakness, which quickly gets worse.
Causes
Duchenne muscular dystrophy is a form of muscular dystrophy that worsens quickly. Other muscular dystrophies (including Becker's muscular dystrophy) get worse much more slowly.
Duchenne muscular dystrophy is caused by a defective gene for dystrophin (a protein in the muscles). However, it often occurs in people without a known family history of the condition.
Because of the way the disease is inherited, boys are affected, not girls. The sons of females who are carriers of the disease (women with a defective gene but no symptoms themselves) each have a 50% chance of having the disease. The daughters each have a 50% chance of being carriers.
Duchenne muscular dystrophy occurs in about 1 out of every 3,600 male infants. Because this is an inherited disorder, risks include a family history of Duchenne muscular dystrophy.
Symptoms
Symptoms usually appear before age 6 and may appear as early as infancy. They may include:
- Fatigue
- Learning difficulties (the IQ can be below 75)
- Intellectual disability (possible, but does not get worse over time)
- Muscle weakness
- Begins in the legs and pelvis, but also occurs less severely in the arms, neck, and other areas of the body
- Difficulty with motor skills (running, hopping, jumping)
- Frequent falls
- Trouble getting up from a lying position or climbing stairs
- Weakness quickly gets worse
- Progressive difficulty walking
- Ability to walk may be lost by age 12, and the child will have to use a wheelchair
- Breathing difficulties and heart disease usually start by age 20
Exams and Tests
A complete nervous system (neurological), heart, lung, and muscle exam may show:
- Abnormal heart muscle (cardiomyopathy)
- Congestive heart failure or irregular heart rhythm (arrhythmias) -- rare
- Deformities of the chest and back (scoliosis)
- Enlarged muscles of the calves, buttocks, and shoulders (around age 4 or 5). These muscles are eventually replaced by fat and connective tissue (pseudohypertrophy).
- Loss of muscle mass (wasting)
- Muscle contractures in the heels, legs
- Muscle deformities
- Respiratory disorders, including pneumonia and poor swallowing, with food or fluid passing into the lungs (in late stages of the disease)
Tests may include:
- Electromyography (EMG)
- Genetic tests
- Muscle biopsy
- Serum CPK
Treatment
There is no known cure for Duchenne muscular dystrophy. Treatment aims to control symptoms to improve quality of life.
Steroid drugs can slow the loss of muscle strength. They may be started when the child is diagnosed or when muscle strength begins to decline.
Other treatments include:
- Albuteral--a drug used for people with asthma
- Amino acids
- Carnitine
- Coenzyme Q10
- Creatine
- Fish oil
- Green tea extracts
- Vitamin E
However, the effects of these treatments have not been proven. Stem cells and gene therapy may be used in the future.
Activity is encouraged. Inactivity (such as bedrest) can make the muscle disease worse. Physical therapy may be helpful to maintain muscle strength and function. Speech therapy is often needed.
Other treatments may include:
- Assisted ventilation (used during the day or night)
- Drugs to help heart function, such as angiotensin-converting-enzyme inhibitors, beta-blockers, and diuretics
- Orthopedic appliances (such as braces and wheelchairs) to improve mobility
- Proton pump inhibitors (for people with gastroesophageal reflux)
Several new treatments are being studied in trials.
Support Groups
You can ease the stress of illness by joining a support group where members share common experiences and problems. See muscular dystrophy - support group. The Muscular Dystrophy Association is an excellent source of information on this disease.
Outlook (Prognosis)
Duchenne muscular dystrophy leads to quickly worsening disability. Death usually occurs by age 25, typically from lung disorders.
Possible Complications
- Cardiomyopathy
- Congestive heart failure (rare)
- Deformities
- Heart arrhythmias (rare)
- Mental impairment (varies, usually minimal)
- Permanent, progressive disability
- Decreased mobility
- Decreased ability to care for self
- Pneumonia or other respiratory infections
- Respiratory failure
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