Gene therapy is a medical technology that aims to produce a therapeutic effect through the manipulation of gene expression or through altering the biological properties of living cells.
The term modifications in genetics refers to both naturally occurring and engineered changes in DNA. Incidental, or natural mutations occur through errors during replication and repair, either spontaneously or due to environmental stressors. Intentional modifications are done in a laboratory for various purposes, developing hardier seeds and plants, and increasingly to treat human disease. The use of gene editing technology remains controversial.
A germline mutation, or germinal mutation, is any detectable variation within germ cells. Mutations in these cells are the only mutations that can be passed on to offspring, when either a mutated sperm or oocyte come together to form a zygote. After this fertilization event occurs, germ cells divide rapidly to produce all of the cells in the body, causing this mutation to be present in every somatic and germline cell in the offspring; this is also known as a constitutional mutation. Germline mutation is distinct from somatic mutation.
A designer baby is a baby whose genetic makeup has been selected or altered, often to exclude a particular gene or to remove genes associated with disease. This process usually involves analysing a wide range of human embryos to identify genes associated with particular diseases and characteristics, and selecting embryos that have the desired genetic makeup; a process known as preimplantation genetic diagnosis. Screening for single genes is commonly practiced, and polygenic screening is offered by a few companies. Other methods by which a baby's genetic information can be altered involve directly editing the genome before birth, which is not routinely performed and only one instance of this is known to have occurred as of 2019, where Chinese twins Lulu and Nana were edited as embryos, causing widespread criticism.
CRISPR is a family of DNA sequences found in the genomes of prokaryotic organisms such as bacteria and archaea. These sequences are derived from DNA fragments of bacteriophages that had previously infected the prokaryote. They are used to detect and destroy DNA from similar bacteriophages during subsequent infections. Hence these sequences play a key role in the antiviral defense system of prokaryotes and provide a form of acquired immunity. CRISPR is found in approximately 50% of sequenced bacterial genomes and nearly 90% of sequenced archaea.
Medical genetics is the branch of medicine that involves the diagnosis and management of hereditary disorders. Medical genetics differs from human genetics in that human genetics is a field of scientific research that may or may not apply to medicine, while medical genetics refers to the application of genetics to medical care. For example, research on the causes and inheritance of genetic disorders would be considered within both human genetics and medical genetics, while the diagnosis, management, and counselling people with genetic disorders would be considered part of medical genetics.
Gene targeting is a biotechnological tool used to change the DNA sequence of an organism. It is based on the natural DNA-repair mechanism of Homology Directed Repair (HDR), including Homologous Recombination. Gene targeting can be used to make a range of sizes of DNA edits, from larger DNA edits such as inserting entire new genes into an organism, through to much smaller changes to the existing DNA such as a single base-pair change. Gene targeting relies on the presence of a repair template to introduce the user-defined edits to the DNA. The user will design the repair template to contain the desired edit, flanked by DNA sequence corresponding (homologous) to the region of DNA that the user wants to edit; hence the edit is targeted to a particular genomic region. In this way Gene Targeting is distinct from natural homology-directed repair, during which the ‘natural’ DNA repair template of the sister chromatid is used to repair broken DNA. The alteration of DNA sequence in an organism can be useful in both a research context – for example to understand the biological role of a gene – and in biotechnology, for example to alter the traits of an organism.
James Van Gundia Neel was an American geneticist who played a key role in the development of human genetics as a field of research in the United States. He made important contributions to the emergence of genetic epidemiology and pursued an understanding of the influence of environment on genes. In his early work, he studied sickle-cell disease and acatalasia. conducted research on the effects of radiation on survivors of the Hiroshima atomic bombing.
Transcription activator-like effector nucleases (TALEN) are restriction enzymes that can be engineered to cut specific sequences of DNA. They are made by fusing a TAL effector DNA-binding domain to a DNA cleavage domain. Transcription activator-like effectors (TALEs) can be engineered to bind to practically any desired DNA sequence, so when combined with a nuclease, DNA can be cut at specific locations. The restriction enzymes can be introduced into cells, for use in gene editing or for genome editing in situ, a technique known as genome editing with engineered nucleases. Alongside zinc finger nucleases and CRISPR/Cas9, TALEN is a prominent tool in the field of genome editing.
Genome editing, or genome engineering, or gene editing, is a type of genetic engineering in which DNA is inserted, deleted, modified or replaced in the genome of a living organism. Unlike early genetic engineering techniques that randomly inserts genetic material into a host genome, genome editing targets the insertions to site-specific locations. The basic mechanism involved in genetic manipulations through programmable nucleases is the recognition of target genomic loci and binding of effector DNA-binding domain (DBD), double-strand breaks (DSBs) in target DNA by the restriction endonucleases, and the repair of DSBs through homology-directed recombination (HDR) or non-homologous end joining (NHEJ).
Editas Medicine, Inc.,, is a clinical-stage biotechnology company which is developing therapies for rare diseases based on CRISPR gene editing technology. Editas headquarters is located in Cambridge, Massachusetts and has facilities in Boulder, Colorado.
Human germline engineering is the process by which the genome of an individual is edited in such a way that the change is heritable. This is achieved by altering the genes of the germ cells, which then mature into genetically modified eggs and sperm. For safety, ethical, and social reasons, there is broad agreement among the scientific community and the public that germline editing for reproduction is a red line that should not be crossed at this point in time. There are differing public sentiments, however, on whether it may be performed in the future depending on whether the intent would be therapeutic or non-therapeutic.
The He Jiankui affair is a scientific and bioethical controversy concerning the use of genome editing following its first use on humans by Chinese scientist He Jiankui, who edited the genomes of human embryos in 2018. He became widely known on 26 November 2018 after he announced that he had created the first human genetically edited babies. He was listed in Time magazine's 100 most influential people of 2019. The affair led to ethical and legal controversies, resulting in the indictment of He and two of his collaborators, Zhang Renli and Qin Jinzhou. He eventually received widespread international condemnation.
He Jiankui is a Chinese biophysicist who was an associate professor in the Department of Biology of the Southern University of Science and Technology (SUSTech) in Shenzhen, China. Earning his Ph.D. from Rice University in Texas on protein evolution, including that of CRISPR, He learned gene-editing techniques (CRISPR/Cas9) as a postdoctoral researcher at Stanford University in California.
CRISPR gene editing standing for "Clustered Regularly Interspaced Short Palindromic Repeats" is a genetic engineering technique in molecular biology by which the genomes of living organisms may be modified. It is based on a simplified version of the bacterial CRISPR-Cas9 antiviral defense system. By delivering the Cas9 nuclease complexed with a synthetic guide RNA (gRNA) into a cell, the cell's genome can be cut at a desired location, allowing existing genes to be removed and/or new ones added in vivo.
Unnatural Selection is a 2019 American documentary television series. It presents an overview of genetic engineering, particularly the DNA-editing technology of CRISPR, from the perspective of scientists, corporations and biohackers working from their home. The series was released on Netflix on October 18, 2019.
CRISPR Therapeutics AG is a Swiss–American biotechnology company headquartered in Zug, Switzerland. It was one of the first companies formed to utilize the CRISPR gene editing platform to develop medicines for the treatment of various rare and common diseases. The company has approximately 500 employees and has offices in Zug, Switzerland, Boston, Massachusetts, San Francisco, California and London, United Kingdom. Its manufacturing facility in Framingham, Massachusetts won the Facilities of the Year Award (FOYA) award in 2022. The company’s lead program, exagamglogene autotemcel, or exa-cel, was granted regulatory approval by the US Food and Drug Administration (FDA) in December 2023.
Vence L. Bonham Jr. is an American lawyer who is the acting Deputy Director of the National Human Genome Research Institute (NHGRI) of the U. S. National Institutes of Health, and is the leader of the NHGRI Health Disparities Unit. His research focuses on social determinants of health, particularly with regard to the social implications of new genomic knowledge and technologies.
Matthew Hebden Porteus is Sutardja Chuk Professor of Definitive and Curative Medicine at Stanford University. In 2003, as a postdoctoral fellow in David Baltimore's lab at the California Institute of Technology, Porteus was the first to demonstrate precise gene editing in human cells using chimeric nucleases.
The Innovative Genomics Institute (IGI) is a nonprofit scientific research institute founded by Nobel laureate and CRISPR gene editing pioneer Jennifer Doudna and biophysicist Jonathan Weissman. The institute is based at the University of California, Berkeley, and also has member researchers at the University of California, San Francisco, UC Davis, UCLA, Lawrence Berkeley National Laboratory, Lawrence Livermore National Laboratory, Gladstone Institutes, and other collaborating research institutions. The IGI focuses on developing real-world applications of genome editing to address problems in human health, agriculture and climate change.
