Читать книгу Infants and Children in Context - Tara L. Kuther - Страница 109

We have seen that DNA influences many of our expressed traits. DNA, however, can be changed. Genetic engineering is a technology that permits scientists to change an organism’s DNA. Genetic engineering is commonly used in agriculture and can be applied to modify plants to promote growth, strengthen crop resilience, and improve their nutritional value. In a process known as gene editing, genetic material can be added, removed, or changed at specific places on the genome (National Library of Medicine, 2019). One popular method of gene editing, CRISPR-Cas9 (commonly referred to as CRISPR), has generated a lot of excitement in the scientific community because it is faster, more cost-effective, more accurate, and more efficient than existing genome editing methods (National Library of Medicine, 2019).

Although gene editing is in its infancy, it is an experimental treatment for some genetic illnesses, including cancer and sickle cell anemia. Often referred to as gene therapy, the CRISPR method is used to manipulate the ill person’s genome. At present, gene therapy is generally available only in research settings such as in experimental cancer treatment, for example (Stein, 2019). However, it holds promise. In recent clinical trials, some patients with sickle cell anemia have shown no signs of the disease after gene editing (Kolata, 2019).

Ethical concerns arise when gene editing is used to alter the human genome. Research on gene editing is limited to somatic cells, or body cells, because these changes affect only certain tissues and are not passed from generation to generation. Changes to sperm and egg cells, however, can be passed to future generations, posing ethical dilemmas such as the use of gene editing to enhance normal human traits. Because of these ethical issues as well as safety concerns, gene editing is not permitted on sperm and egg cells or embryos.

In late 2018, Chinese scientist He Jiankui garnered global media attention after using CRISPR to edit the DNA of two embryos. The embryos were implanted and carried to term by their mother. Jiankui’s work was judged as unethical, and he was criticized for using untested, unregulated, and unsafe methods. In addition, the developmental consequences for the infants are unknown and any genetic abnormalities may be passed on to their kin. Jiankui argued that the infants’ genomes were sequenced or mapped after birth, suggesting that only the intended genes were deleted. Nevertheless, the scientific community has condemned Jiankui’s work and Jiankui is facing allegations of scientific misconduct and will also face criminal charges in his home country, China.