By comparison, most genes have only about 10 exons and are 50 thousand base pairs in length.

相对来说，大多数基因只有10个外显50kbp。

Most of these gene mutations are deletions or duplications of one or more exons, and a small amount are point mutations.

基因突变大多数为一个或多个外显的缺或重复，小部分点突变。

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X体上一个庞大的基因，含有79个外显，全超过2000kbp（书上通常缩写为bp，碱基对）。

More base pairs and more exons mean that there are more chances for mistakes during meiosis, which is when the egg or sperm are being created.

更多的碱基对外显意味着减数分裂时有更多出错的可能，导致生成X体上有错误编码序列的卵细胞或者精。