Do genes play a role in peanut allergies? New study suggests - YES

Researchers have pinpointed a region in the human genome associated with peanut allergy in U.S. children, offering strong evidence that genes can play a role in the development of food allergies.

But in an additional finding that suggests genes are not the only players in food allergies, the Johns Hopkins Bloomberg School of Public Health-led research team found there may be other molecular mechanisms that may contribute to whether those who are genetically predisposed to peanut allergies actually develop them.

The findings are published online Feb. 24 in the journal Nature Communications.

"We always suspected it, but this is the first genome-wide association study (GWAS) that identified a genetic link to well-defined peanut allergy," says the study's principal investigator, Xiaobin Wang, MD, ScD, MPH, the Zanvyl Krieger Professor and Director of the Center on the Early Life Origins of Disease at the Johns Hopkins Bloomberg School of Public Health.

Food allergies have been rising rapidly in the U.S. and around the world over the past 20 years and now affect an estimated two to 10 percent of children in the United States. Food allergies have become a major clinical and public health problem due to their increasing prevalence, their potential to be life threatening and their enormous medical and economic impact. Peanut allergy is among the most fatal food allergies and is often a lifelong allergy, unlike milk or egg allergies which most children will grow out of.

There is currently no effective prevention or treatment approved by the U.S. Food and Drug Administration, except for emergency treatment given after accidental exposure. The only effective prevention strategy is to avoid the food that triggers a reaction. This can be a challenging task given the three most common allergies in American children are peanut, egg and milk, items that are widely found in processed foods.

Peanut Allergy Prevalence

- Peanut and tree nut (pecans, walnuts, almonds, etc.) allergy can be a serious condition that affects approximately three million Americans, or 1.1 percent of the population.

- Peanuts are the leading cause of severe food allergic reactions, followed by shellfish, fish, tree nuts and eggs. (Food Allergy Network)

Peanut Allergy Characteristics

Peanut allergy can be characterized by more severe symptoms, such as gastrointestinal, skin and respiratory symptoms, than other food allergies and by a high rate of symptoms on minimal contact. ("Clinical characteristics of peanut allergy," Clin. Exp. Allergy, 1997; "An evaluation of the sensitivity of subjects with peanut allergy to very low doses of peanut protein," J. Allergy Clin. Immunol., 1997)

Severe sufferers also may experience potentially life-threatening anaphylactic shock in response to ingestion of peanuts. Anaphylactic shock is an allergic reaction in which the release of histamine causes swelling, difficulty in breathing, heart failure, circulatory collapse, and sometimes death.