The U.S. Food and Drug Administration approved an Intentional genomic alteration (IGA) in a line of domestic pigs, referred to as GalSafe pigs, which may be used for food or human therapeutics.
This is the first Intentional Genomic Alteration in an animal that the FDA has approved for both human food consumption and as a source for potential therapeutic uses.
What is Intentional Genomic Alteration?
Intentional genomic alteration in animals means making specific changes to the genome of the organism using modern molecular technologies that are popularly referred to as “genome editing” or “genetic engineering”.
Such changes in the DNA sequence of an animal may be carried out for research purposes, to produce healthier meat for human consumption and to study disease resistance in animals among other reasons. One example is of using IGAs to make an animal more susceptible to certain diseases such as cancer, which helps researchers get a better understanding of the disease and develop new therapies to treat it.
Genome editing is being performed using, for example, clustered regulatory interspersed short palindromic repeat associated nucleases (CRISPR), zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and oligonucleotide-directed mutagenesis (ODM).
Genome Editing Vs Genetic Engineering:
Genome editing is a much more precise method of making changes to the genome of a plant, animal, or other living organism than methods used previously to make such changes. It also allows for the intentional addition, substitution, or deletion of specific nucleotides (letters in the DNA code) in an organism’s genome. Genetic engineering generally allows for the introduction of new DNA (referred to as a recombinant DNA or rDNA construct) into an organism to alter that organism’s genome, but generally without control of the location in the genome in which the insertion of that rDNA construct would occur.
GalSafe pigs:
The IGA in GalSafe pigs is intended to eliminate alpha-gal sugar on the surface of the pigs’ cells. People with Alpha-gal syndrome (AGS) may have mild to severe allergic reactions to alpha-gal sugar found in red meat (e.g., beef, pork, and lamb).
GalSafe pigs may potentially provide a source of porcine-based materials to produce human medical products that are free of detectable alpha-gal sugar. For example, GalSafe pigs could potentially be used as a source of medical products, such as the blood-thinning drug heparin, free of detectable alpha-gal sugar. Tissues and organs from GalSafe pigs could potentially address the issue of immune rejection in patients receiving xenotransplants, as alpha-gal sugar is believed to be a cause of rejection in patients.
Alpha-gal Syndrome(GalSafe Pigs)
What is alpha-gal?
- Alpha-gal (galactose-α-1,3-galactose) is a sugar molecule found in most mammals.
- Alpha-gal is not normally found in fish, reptiles, birds, or people.
- Alpha-gal can be found in products made from mammals (including some medications, cosmetics, vaccines, gelatin, and milk products).
- There is evidence that the alpha-gal molecule is found in the saliva of certain types of ticks.
What is alpha-gal syndrome (AGS)?
Alpha-gal syndrome (AGS) (also called alpha-gal allergy, red meat allergy, or tick bite meat allergy) is a serious, potentially life-threatening allergic reaction. AGS may occur after people eat red meat or are exposed to other products containing alpha-gal.
What are the symptoms of AGS?
AGS reactions can include:
Rash,Hives,Nausea or vomiting,Difficulty breathing,Drop in blood pressure,Dizziness or faintness,Severe stomach pain
Symptoms commonly appear 3-6 hours after eating meat or exposure to products containing alpha-gal (for example, gelatin-coated medications).
AGS reactions can be different from person-to-person and can range from mild to severe or even life-threatening.
Environmental Implications:
As part of its review, the FDA analyzed the potential impact that the approval of the IGA in GalSafe pigs would have on the U.S. environment and determined it is no greater than from conventional pigs.
- The conditions under which GalSafe pigs will be kept are far more stringent than those for conventionally farmed pigs. Additionally, no animal safety concerns were noted for GalSafe pigs beyond those that would be expected in well-managed, commercial swine operations.
- The FDA also assessed the risk of the IGA to promote the emergence or selection of antimicrobial-resistant bacteria of human health concern in or on GalSafe pigs. The FDA concluded that the microbial food safety risk is low and is mitigated by the low number of GalSafe pigs entering the food supply
The FDA granted approval of the IGA in GalSafe pigs to Revivicor Inc.