German researchers report having identified a major gene for allergic diseases.

The newly discovered FCER1A Gene encodes the alpha chain of high affinity IgE receptor, which plays a major role in controlling allergic responses. The team of scientists led by Dr. Stephan Weidinger from the Technische Universität München and Dr. Thomas Illig from the Helmholtz Zentrum München found that certain variations of the FCER1A gene decisively influence the production of immunoglobulin E (IgE) antibodies. IgE antibodies are a particular type of antibody that is normally used to protect against parasites. In Western lifestyle countries with less contact, however, elevated IgE levels are associated with allergic disorders.

In genetically susceptible individuals the immune system becomes biased and produces IgE antibodies against harmless agents such as pollen, dust mites or animal hair. These IgE antibodies then work in conjunction with certain cells to get rid of the allergens, a process that gives rise to the symptoms of allergy such as allergic rhinitis (hay fever), atopic dermatitis or asthma.

Their research, which is based on the genetic scans of 10,000 adults and children in Germany, is published in PLoS Genetics.