“Now that science is a big step closer to being able to fiddle with the genes of a human embryo, is it time to panic? Could embryo editing spiral out of control, allowing parents to custom-order a baby with Lin-Manuel Miranda’s imagination or Usain Bolt’s speed?
News that an international team of scientists in Oregon had successfully modified the DNA of human embryos has renewed apprehensions that babies will one day be “designed.” But there are good reasons to think that these fears are closer to science fiction than they are to science.
Here is what the researchers did: repair a single gene mutation on a single gene, a defect known to cause — by its lonesome — a serious, sometimes fatal, heart disease. …”
“ … So are most physical diseases and psychiatric disorders. The genetic message is not carried in a 140-character tweet — it resembles a shelf full of books with chapters, subsections and footnotes.
So embryonic editing is unlikely to prevent most medical problems.
But about 10,000 medical conditions are linked to specific mutations, including Huntington’s disease, cancers caused by BRCA genes, Tay-Sachs disease, cystic fibrosis, sickle cell anemia, and some cases of early-onset Alzheimer’s. Repairing the responsible mutations in theory could eradicate these diseases from the so-called germline, the genetic material passed from one generation to the next. No future family members would inherit them.
But testing editing approaches on each mutation will require scientists to find the right genetic signpost, often an RNA molecule, to guide the gene-snipping tool.
In the study reported this week, it took 10 tries to find the right RNA, said Juan Carlos Izpisua Belmonte, a co-author and geneticist at the Salk Institute.
Dr. Greely noted that while scientists work to get human embryonic editing ready for clinical trials (currently illegal in the United States and many countries), alternate medical treatments for these diseases might be developed. They may be simpler and cheaper. …”