ATLANTA - Corn genetically engineered to produce insect-killing proteins may have caused several cases of allergic reaction, but it is too soon to know for sure, according to an investigation by the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia.

The genetically engineered corn, called StarLink, is produced by Aventis Crop Science and was removed from use for human consumption because of concerns about potential allergic reactions. It was, however, later found in taco shells, leading to a recall of more than 300 food products last September.

To assess the health effects of this incident, CDC researchers led by Dr. Brad S. Winterton interviewed 18 individuals who reported symptoms consistent with food allergies after eating corn products--mainly tacos and corn chips.

Of 18 persons interviewed, 12 reported a serious allergic reaction called anaphylaxis, which is characterized by low blood pressure and difficult breathing. Fourteen reported skin allergy, and nine reported stomach problems.

The researchers reported the findings on Thursday at the CDC's 50th Annual Epidemic Intelligence Service Conference meeting here.

According to Winterton, none of the other 60 or so genetically engineered foods on the market have been linked with these types of allergic reactions.

"Just about any crop that we eat has been genetically modified for something," Winterton said. "Other crops have been approved that are insecticidal," he said, "but there's no concern that they might also create an allergic reaction."

The chance of finding the corn's insecticidal protein, called Cry9C, in the current human food supply is slim, Winterton noted.

"The US Department of Agriculture USDA has developed a test...for Cry9C, and the test is being used by many manufacturers of corn products to ensure that their corn has none of the protein in it," he said.

Due to cross-pollination among different plant species, the protein might end up in corn that was non-StarLink, Winterton said, but the USDA test would be able to pick this up also.

"Next, we will be comparing the serum of people who have an allergic reaction to those who we know do not," Winterton added.

"I wish we had the answer to whether the corn caused these allergic reactions," Winterton said, but he pointed out that it is rare for people to have an allergy to corn that has not been genetically modified to produce Cry9C.

** NOTICE: In accordance with Title 17 U.S.C. Section 107, this material is distributed for research and educational purposes only. **