In November 2018, the name He Jiankui caused intense controversy for the genetic biology community in China and around the world. He then revealed that he gave birth to two children with genetic modification using CRISPR technology - the most modern and accurate DNA refining method available today.
The two babies were genetically modified then as twins, and He plans to proceed on the third baby born this summer. He said the team planned to remove CCR5 gene, to help the child gain immunity to HIV.
Jiankul's research encountered many objections regarding ethics in science. Within six months of its publication, scientists have searched for hundreds of thousands of medical data, to understand how the genome He changes will affect human health.
And according to a new study published in Nature Medicine, the end is not very positive for He. Experts say that those who carry the genome He has modified will have a 21% risk of dying before the average life expectancy in the world.
Specifically, experts at the University of California, Berkeley tried to study the variants of the CCR5 gene that He inserted into the children. They found that even though the immune system is resistant to HIV, the body is vulnerable to some other viruses - such as the West Nile virus.
"We realize that the mortality rate will increase significantly," - Rasmus Nielsen, the study's author . "The effect is very big. We were quite surprised to find it so serious.
Nielsen's experiment is an encouragement for scientists who have always opposed gene modifications on humans while not fully understanding them.
"This is a lesson for humanity," said George Daley, Dean of Harvard Medical School.
"As soon as we are confident that we understand, genetics can still surprise us. As in this case, eliminating the gene is thought to be harmful but actually causes another problem ."