Precise” chemical surgery” has been performed on human embryos to remove disease in a world first, reported by Chinese researcher. The team at Sun Yat –sen university used a technique called base editing to correct a single error out of the three billion “letters” of our genetic code. According the researchers, they altered lab-made embryos to remove the disease beta-thalassemia. The embryos were not implanted. The team says this approach may one day treat a range of inherited diseases. Base editing alters the fundamental building blocks of DNA: the four bases adenine, cytosine, guanine and thymine that are known by their respective letters, A, C, G and T. The human body instructions for building and running are encoded in combination of those four bases. Beta-thalassemia is a potentially life-threatening blood disorder caused by a change to a single base in the genetic code- known as a point mutation. This is how the Chines team edited it back. They scanned DNA for the error then converted a G to A, correcting the fault. According to Junjiu Huang, one of the researchers: “We are the first to demonstrate the feasibility of curing genetic disease in human embryos by base editor system.” He also adds that their study opens new avenues for treating patients and preventing babies being born with beta-thalassemia, “and even other inherited diseased”. The following steps were taking to perform the experiments: Tissues taken from a patient with the blood disorder and in human embryos made through cloning. Reported: Prof David Liu, who pioneered base editing at Harvard University, describes the approach as “chemical surgery”. He also says the technique is more efficient and has fewer unwanted side effects than Crispr. BBC reports, he told “ about two –thirds of known human genetic variants associated with disease are point mutations. “So base editing has the potential to directly correct, or reproduce for research purposes, many pathogenic.” There are many positive and negative debates including how these approaches should be regulated, however the latest example shows rapid growing ability of scientists to alter human DNA. Source
