Technical Abstract: Crops with significant food allergen issues, include legumes, peanut and soybean, cereal grains, such as wheat and maize, and tree nuts (walnut, Brazil nut, among other phylogenetically diverse species) (Teuber et al. 2006). Officially recognized allergenic proteins may include one or multiple proteins per species (www.allergen.org; www.allergome.org) and fall into a variety of functional/biochemical classes (Ozias-Akins et al. 2006). These classes include seed storage proteins (e.g., globulins, albumins), metabolic proteins, such as profilin (an actin binding protein), and certain proteins with protective functions, such as insect or fungal resistance (agglutinin, protease inhibitors, lipid transfer proteins, etc.). Natural genetic variation results in multiple isoforms for one allergen, and these isoforms can be officially recognized as distinct if sufficient evidence for allergenicity is provided to the Allergen Nomenclature Sub-Committee of the International Union of Immunological Societies (I.U.I.S.). The committee considers submissions that meet the following criteria: reactivity with IgE of more than 5% prevalence, and a minimum of five patients that show IgE reactivity. There is no formal nomenclature system for isoforms that are highly similar in amino acid sequence, but show minimal reactivity with human sera. We are exploring molecular variation for allergens in peanut (Arachis hypogaea L.) with the goal of using genetic resources to reduce allergenicity of the food product.