How far would you go to eradicate a disease that impacts millions of lives? Would you cross the ethical line if it meant ending a source of suffering forever? Or would you stop short of playing God?
That’s a question that’s recently been raised as Chinese scientists performed genetic editing on embryonic cells as a way to treat beta thalassemia, a blood disorder that reduces the production of hemoglobin.
People with beta thalassemia have low levels of hemoglobin which leads to a lack of oxygen in many parts of the body. Affected individuals also have a shortage of red blood cells, which can cause pale skin, weakness, fatigue, and more serious complications. They are also at an increased risk of developing abnormal blood clots.
Thousands of infants with beta thalassemia are born each year, according to Genetics Home Reference. It occurs most frequently in people from Mediterranean countries, North Africa, the Middle East, India, Central Asia, and Southeast Asia. Because of this Asian prevalence, researchers at Sun Yat-sen University in China decided to take an aggressive approach to eradicating this disease — at its source!
Since β-Thalassemia is caused by mutations, they decided to correct it in human embryos to prevent the disease being passed on to future generations and cure anemia.
Remarkably, these scientists were able to successfully “edit” the mutation from a tissue sample taken from a patient with β-thalassemia. Data showed that base editor could precisely correct the mutation in the patient’s primary cells! Next, these industrious biologists were able to fuse the edited cells in vitro matured ovum. The gene correction efficiency was over 23.0% in these embryos by base editor.
This study demonstrated the feasibility of curing genetic disease in human somatic (non-embryo) cells and embryos by base editor system. Base editing alters the fundamental building blocks of DNA: the four bases adenine, cytosine, guanine, and thymine. One type of DNA can actually be converted to another using this method, which is also called chemical surgery.
The implications of this experiment are far-reaching. Proponents herald it as a scientific breakthrough with promise for eradicating any number of genetic mutations which lead to a variety of rare (and common) diseases. Conversely, the success of this research is highly controversial among those who question the ethics of using human embryos in scientific testing. (By the way, the genetically altered embryos were not implanted.) China does not currently have the same restraints as many other countries (including the U.S.) for using human embryos in scientific research.