Without the support of dystrophin in place, the sarcolemma essentially wilts and becomes unstable.

没有抗肌萎缩蛋白支撑，肌膜塌缩变得不稳定。

Okay, so as a quick recap: the protein dystrophin is super important for stabilizing the muscle cell membrane.

抗肌萎缩蛋白对肌纤维稳定性维持极其重要。

Alright, so the dystrophin gene is a huge gene on the X-chromosome, that has 79 exons and is over 2 million base pairs in length.

抗肌萎缩蛋白是X染色体上一个庞大，含有79个外显子，全长超过2000kbp（书上通常缩写为bp，碱对）。

Now, the fact that both Duchenne and Becker muscular dystrophy result from mutations in the same dystrophin gene means that they are " allelic disorders, "

DMD和BMD都是由于同一抗肌萎缩蛋白突变引起，意者是“等位疾病”。

Within that group, dystrophinopathies are the most common, which includes Duchenne muscular dystrophy, or DMD, and Becker muscular dystrophy, both of which result from mutations in the dystrophin gene.

这些功能紊乱中，营养不良疾病是最常见，包括Duchenne型肌营养不良（DMD）和Becker型肌营养不良（BMD）；这者都是由抗肌萎缩蛋白突变导致。

In addition to those two, genetic mutations in other genes are responsible for several dozen other muscular dystrophies, some of which code for proteins that form a protein complex with dystrophin protein.

除了这两种疾病，其它突变导致了其它几十种肌营养不良，其中一些编码形成抗肌萎缩蛋白相关蛋白复合体蛋白质。

Now if this inactivation's random, you'd expect about half of the female's cells to have a functional dystrophin gene and the other half to have a defective dystrophin gene, and these people are typically asymptomatic.

如果失活是随机，可以预料到女性一半细胞中抗肌萎缩蛋白是正常，另一半是有缺陷，通常这些人无临床症状。

Having said that, if more cells end up with the defective dystrophin gene, and less with the functional one, they can end up being " manifesting carriers, " meaning that they manifest or show some symptoms.

话虽如此，如果机体中有该缺陷细胞更多，而正常更少，这一类人群就是“显性携带者”，意他们也会有部分症状表现。

Later symptoms include needing a wheelchair because of severe weakness, developing respiratory failure because of a weak diaphragm, scoliosis, and developing dilated cardiomyopathy and arrhythmias since the dystrophin protein is also expressed in heart muscle.

后期症状包括，由于严重肌无力需坐轮椅，由于膈肌无力会发生呼吸衰竭、脊柱侧凸，为抗肌萎缩蛋白也表达于心肌纤维，还会引发扩张型心肌病和心律失常。