Certain allergic diseases appear to be associated in certain individuals and families. These are asthma (both allergic and intrinsic), allergic rhinitis, atopic eczema and possibly vasomotor rhinitis, urticaria and bonafide food allergy. Multiple factors, both genetic and environmental are involved in the generation of these diseases.
Recent studies have demonstrated two distinct kinds of genetic controls of IgE antibody formation in inbred mice. One of these has also been shown to exist in man, and appears necessary but not sufficient for the generation of ragweed hay fever. This is the Ir-antigen E gene(s) which permits the individual to recognize low concentrations of antigen E as antigens.
Atopic diseases are based on many genetic and environmental factors. Some factors are unique for individual diseases, and some (one or a small number) are probably common to all. The latter are not clearly appreciated as yet, although mucosal permeability factors and B-adrenergic blockade factors have been suggested.
Understanding of the genetic controls of atopy will require studies on the many individual factors involved in atopy, their function, their genetic transmission and their interplay in the causation of atopic diseases.