I came across a BBC article about a Chinese university who have successfully altered a human embryo DNA strand to remove a genetic disease.
They had a DNA strand with a defect that was known to cause the potentially life-threatening blood disorder beta-thalassemia
DNA consists of four different building blocks A, C, G and T strung together in various combinations. Apparently, as I understand it, this disease is caused by a single building block out of place among the millions of blocks that make up a DNA strand.
The Chinese scientists were able to find the incorrect block, a G block, and convert it to the correct block, a “A block”. The expectation is that the DNA would be reintroduced into the embryo and that embryo will not develop the disease as it grows.
At this time the Chinese have not reintroduced the DNA into an embryo. The research is still very early and I’m sure there will be years of experimentation before they get to the point where a human trial will be possible but the process, if proven viable, will be a great advance in medicine for anyone who has a genetic disease in their family tree.
If this interests you, you can read the article on the BBC website at: http://www.bbc.com/news/health-41386849