The DNA of a diseased patient is mutated, which causes abnormalities in the body. These defective genes alter the body which is non-advantageous to the person effected. Recap: In gene therapy, the mutated DNA is replaced with healthy DNA in the body via germ line gene therapy or somatic gene therapy
How it looks
Feel free to watch the whole video, but if you're only concerned with how the technology works and looks, skip to 7:20 - 10:26