4 letters. Different configurations. No punctuation marks. No spaces. YET, it is responsible for encoding all the information needed for all free-living organisms on Earth. Deoxyribonucleic acid or better known as DNA is a molecule that contains the instructions an organism needs to develop, live and reproduce. These instructions are found inside every cell, and are passed down from parents to their children. DNA is made up of molecules called nucleotides. Each nucleotide contains a phosphate group, a sugar group and a nitrogen base. The four types of nitrogen bases are adenine (A), thymine (T), guanine (G) and cytosine (C). The order of these bases is what determines DNA’s instructions, or genetic code. Human DNA has around 3 billion bases, and more than 99 percent of those bases are the same in all people, according to the U.S. National Library of Medicine (NLM).
Genome editing (also called gene editing) is a group of technologies that give scientists the ability to change an organism’s DNA. These technologies allow genetic material to be added, removed, or altered at particular locations in the genome. These technologies allow genetic material to be added, removed, or altered at particular locations in the genome. Several approaches to genome editing have been developed. A recent one is known as CRISPR-Cas9, which is short for clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9. The CRISPR-Cas9 system has generated a lot of excitement in the scientific community because it is faster, cheaper, more accurate, and more efficient than other existing genome editing methods.
Genome editing is of great interest in the prevention and treatment of human diseases. Currently, most research on genome editing is done to understand diseases using cells and animal models. Scientists are still working to determine whether this approach is safe and effective for use in people. It is being explored in research on a wide variety of diseases, including single-gene disorders such as cystic fibrosis, hemophilia, and sickle cell disease. It also holds promise for the treatment and prevention of more complex diseases, such as cancer, heart disease, mental illness, and human immunodeficiency virus (HIV) infection.
Ethical, we’re still trying to figure out if genome editing is something that should be done, using technologies such as CRISPR-Cas9, to alter human genomes. Most of the changes introduced with genome editing are limited to somatic cells, which are cells other than egg and sperm cells. These changes affect only certain tissues and are not passed from one generation to the next, which is good, the consequences will mostly be limited. However, changes made to genes in egg or sperm cells (germline cells) or in the genes of an developing egg could be passed to future generations, meaning, we really don’t know what the consequences are. Germline cell and embryo genome editing bring up a number of ethical challenges, including whether it would be permissible to use this technology to enhance normal human traits (such as height or intelligence). Based on concerns about ethics and safety, germline cell and embryo genome editing are currently illegal in many countries.
Last week, a scientist in China announced that he had created the world’s first genetically edited babies, twin girls who were born this month. The researcher, He Jiankui, said that he had altered a gene in the embryos, before having them implanted in the mother’s womb, with the goal of making the babies resistant to infection with H.I.V. He has not published the research in any journal and did not share any evidence or data that definitively proved he had done it. Dr. He got his Ph.D., from Rice University, in physics and his postdoctoral training, at Stanford, was with Stephen Quake, a professor of bioengineering and applied physics who works on sequencing DNA, not editing it. However, his previous work in gene editing has been highly applauded and supported by a range of investors. According to the South China Morning Post, two of Dr He’s start-up companies received at least $60 million in funding from Chinese and international investors.
He made his groundbreaking announcement on the eve of the Second International Summit on Human Genome Editing in Hong Kong, saying that he had recruited several couples in which the man had H.I.V. and then used in vitro fertilization to create human embryos that were resistant to the virus that causes AIDS. He said he did it by directing Crispr-Cas9 to deliberately disable a gene, known as CCR₅, that is used to make a protein H.I.V. needs to enter cells. Dr. He said the experiment worked for a couple whose twin girls were born in November. He said there were no adverse effects on other genes. He also said the father of the twins has a reason to live now that he has children, and that people with H.I.V. face severe discrimination in China. Dr. Hes announcement was reported earlier by the MIT Technology Review and The Associated Press.
As you can imagine, many were not pleased with the events. Mostly because what he has done is extremely, extremely illegal. Most studies, especially those with human subjects must be reviewed and approved in order to proceed. It is highly unusual for a scientist to announce a groundbreaking development without at least providing data that academic peers can review. Dr. He said he had gotten permission to do the work from the ethics board of the hospital Shenzhen Harmonicare, but the hospital, in interviews with Chinese media, denied being involved. Interestingly enough, after hundreds of scientists, the Chinese Government and even his own university denounced him, Dr He has seemingly disappeared and has not been heard from since last Wednesday. Several attempts to reach him have failed.
What do you think happened to this rogue scientist and what do you think this advancement has done for science? Has it unlocked an entirely new playable area in the game of genes and disease prevention or does it have more sinister implications for humankind? I’d love to hear your thoughts.
Until Next Time,