Safety of a transgenic or genetically modified salmon : the AquAdvantage salmon

4.

The FDA’s Center for Veterinary Medicine (CVM) has evaluated both the direct and indirect food safety impacts of AquAdvantage Salmon and any potential impacts of the rDNA insertion on target animal safety. CVM has also thoroughly evaluated the potential environmental impacts of approving an NADA for AquAdvantage Salmon, and has prepared this draft Environmental Assessment (EA).

In the overall process, FDA’S CVM examines (1) safety of the rDNA construct to the animal; (2) safety of the food from the animal; (3) environmental impact; and (4) the extent to which the producers of GE animals (referred to as “sponsors”) have met the claims made for those GE animals (effectiveness). All of these are based on a thorough analysis of the rDNA construct, its integration into the animal’s DNA, and its stability in the animal over multiple generations. GFI 187 describes this in seven steps that we summarize in the following discussion. Each step is dependent on the results of the analysis performed in the preceding steps, so that the review in effect “rolls up” conclusions as it progresses through the entire process.

The performance of such evaluation is a seven steps process:

1. First, the FDA reviews data and information on how the construct is made, and whether it contains any pieces of DNA from viruses or other organisms that could pose adverse health risks to the animal or people or other animals eating food from the animal. The FDA also looks to see if any pieces of the construct will make new proteins (except for the intended ones) that could possibly cause health concerns.
2. Second, FDA evaluates studies submitted by the producer to determine what happens when the rDNA construct is incorporated into the animal, and how it behaves over multiple generations. This includes analyzing whether the construct remains in the same place over time, and whether animals continue to express the trait (characteristic) that the construct is supposed to introduce.
3. Third, FDA determines whether the rDNA construct is safe for the resulting line of the transgenic animal what is called a the Phenotypic Characterization. They do so by reviewing studies that characterize the actual transgenic animals over several generations. Questions that the agency asks include whether the resulting transgenic animals look like their “regular” counterparts by comparing them to both closely related animals and to animals of the species in general. The agency asks whether the transgenic animals are healthy, including disease resistance, and whether they reach the same developmental milestones that comparison animals do. Another safety question that is evaluated is whether there are any abnormalities that would not be found in other relatives of the transgenic animal which might express similar traits, but via conventional breeding.
   
   In addition, we evaluate the results of necropsies (examinations of the bodies and tissues of animals that have been sacrificed for that purpose) to make sure that cells, tissues, and organs look normal. We also assess the results of the kinds of tests that doctors might perform on people when they get a physical, such as blood cells, blood chemistries, etc., to determine whether the animals not only look healthy, but also that their bodies are functioning appropriately.
4. Fourth, the FDA performs reviews the plan that the sponsor will agree to in order to ensure that the GE animals produced in the future will be equivalent to the GE animals that we evaluate as part of the pre-approval review.
5. Fifth, FDA assesses whether the transgenic animals are safe to eat. This evaluation relies on information gathered in the parts of the application that look at the rDNA construct and the health of the animal. FDA experts in food safety look carefully at the composition of the edible tissues of the transgenic animal to determine whether its meat or milk or eggs differ in any way that affects safety or nutrition from the non-transgenic counterparts that we eat today.
   
   Further, FDA’s food safety experts evaluate data to determine whether the transgenic animal poses any more allergenicity risks than its non-transgenic counterparts currently on the market.
6. Sixth, the agency evaluates the potential for the GE animal to cause significant environmental impacts. We do this by evaluating the results of an EA for the specific proposed conditions of use for a particular application.
7. In the seventh and final step of the process, sponsors submit information and data in support of their claims for the transgenic animal. For an animal that is intended to grow faster, the agency evaluates data to determine if the GE animals do indeed reach some size or weight more rapidly than their conventional counterparts.