The U.S. Food and Drug Administration (FDA) has written a letter to the manufacturers and developers of new plant varieties, urging them to fully consider the potential ramifications of transferring the genes of allergens to new plant varieties used for food.

In a letter dated April 13, Kristi Muldoon-Jacobs, Acting Director of the Office of Food Additive Safety, said the agency is aware that some companies are exploring the transfer of genes for proteins that are food allergens—including major food allergens—into new plant varieties used for foods.

For example, she said a developer could add the gene for an allergenic animal protein to a new plant variety to provide a non-animal source of protein for use as an ingredient in another food. Muldoon-Jacobs said this could result in the presence of an unexpected allergen in the food and other consequences for food producers, such as the need to recall affected products. FDA is not aware of any foods currently in the U.S. market from these types of new plant varieties, she said.

The agency warned that stewardship practices for such plant varieties are likely to be more challenging and complicated than with other crops, and said that when developing risk management plans, they will likely have to significantly bolster standard mitigation strategies and practices to prevent inadvertent mixing of foods containing a transferred allergen with other foods.

“We urge developers of products involving transfer of a gene for an allergen to a new plant variety used for food to fully consider the potential allergenicity issues related to these products,” Muldoon-Jacobs said. “We believe it is critically important to consider whether you and your partners throughout the supply chain can reliably establish and maintain conditions, from farm to processing to consumption, under which such new plant varieties, and protein-containing materials from such varieties, do not inadvertently enter the food supply, and are properly labeled when they are intentionally part of the food supply.”