WHAT DID THE CHINESE SCIENTIST DO?
in a way that patients would pass to their own children.
The researcher said he used the gene-editing tool CRISPR to alter a gene named CCR5 in embryos for seven couples during their fertility treatments; one pregnancy resulted. A particular mutation in that CCR5 gene is thought to confer some resistance to HIV by making it harder for that virus to enter cells.
Today’s medications have turned HIV from a death sentence into a manageable disease in much of the world, but He said he chose that gene because HIV remains a big problem in China.
But He’s claims have not been verified by outside scientists, and there are questions about how the work was conducted.
WHY IS MONDAY’S NEWS SO CONTROVERSIAL?
Altering genes in sperm, eggs or embryos means those changes can be passed down to future generations — people who would have no way to consent to those changes. Plus, long-term negative effects might not become apparent for years.
In 2017, the U.S. National Academies of Science, Engineering and Medicine said lab-only research to learn how to alter embryos is ethical — but said it’s not ready for pregnancies yet. The academy said if it is ever allowed, it should be reserved to treat or prevent serious diseases with no good alternatives.
That lab-only research is going on, by Mitalipov and others.
But critics said Monday’s announcement opens the door to “designer babies.”
“If this goes unchallenged, other rogue actors will soon offer wealthy parents purported genetic enhancements for their children,” said Marcy Darnovsky of the Center for Genetics and Society.
WHAT HAPPENED TO THE BABIES?
No independent outsiders know yet, which is partly why scientists are so disturbed.
He, the Chinese researcher, said one twin had both copies of the intended gene altered while the other had just one altered. People with one copy of the mutation can still get HIV.
Scientists who reviewed his claims said the alterations aren’t an exact match to natural CCR5 mutations, and that a big question is whether the gene is altered in every cell.
The particular method used is common in lab research but not precise or controlled enough for embryos, said Columbia University cell biologist Dietrich Egli, who called it “essentially genome vandalism.”
WHAT ARE THE DANGERS?
The biggest concern: That precision, or lack of it. Unintended mutations could harm health rather than help it.
Where you live determines if, or what kind of, research can be performed on human embryos. In the U.S., scientists can perform laboratory embryo research only with private funding, not with federal taxpayer money. Any pregnancy attempt would require permission from the Food and Drug Administration, which is currently prohibited by Congress from even reviewing such a request — a de facto ban.
People undergoing fertility treatments that include IVF can have embryos tested for deadly gene mutations that run in the family, such as Huntington’s disease, and then implant only the embryos that lack such mutations. Also, some so-called mitochondrial disorders can be addressed by using some genetic material from mom and some from a donor egg, along with dad’s sperm.