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.

抗肌萎缩蛋白基因是X染色体上一庞大基因，含有79显子，全长超过2000kbp（书上通常缩写为bp，碱基对）。

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

DMDBMD都是由于同一抗肌萎缩蛋白基因突变引起，着二者是“等位基因疾病”。

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）Becker型肌营养不良（BMD）；这二者都是由抗肌萎缩蛋白基因突变导致。

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，其它基因突变导致了其它几十种肌营养不良，其中一些基因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基因是正常，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，如果机体中有该基因缺陷细胞更多，而正常基因更少，这一类人群就是“显性携带者”，着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，因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心律失常。

Mutations in the dystrophin gene that lead to a loss of dystrophin leads to duchenne muscular dystrophy, whereas mutations in the dystrophin gene that leads to misshapen dystrophin leads to Becker muscular dystrophy.

基因突变导致抗肌萎缩蛋白丢失会引发DMD；而突变导致畸形蛋白则会引发BMD。