Exposure to a farm environment may be stronger than genetic factors in protecting against asthma
Both genetic and environmental factors are known to play roles in asthma. The farming environment has consistently been associated with providing a protection from childhood asthma and allergic sensitization. The full picture of how heredity and genetic variations might contribute to asthma is not yet complete. There is now interest in exploring how the environment and individual genetic make-up may interact to influence the risk for developing asthma.
In a study published in the February 2011 issue of The Journal of Allergy and Clinical Immunology, Ege and colleagues report their findings on this gene-environment interaction in children who are exposed to farming environments. The authors used data from the GABRIEL Advanced Studies surveys, which were conducted in rural regions of Europe and studied the genetic and medical profiles of 1708 children aged 5-13 years. The authors found that common genetic variations are unlikely to modify the protective influence of the farming environment on childhood asthma and allergic sensitivity, although they did find some new rarer gene variants that may have an effect on protection and should be further investigated.
These current findings may indicate that the strong protective effect of a farming environment is due neither to the genetic make-up of the farming population, nor to common genetic variations interacting with exposures on a farm such as contact with cows and straw or drinking raw farm milk. This implies that environmental exposures or the lack of them can be determining factors in the onset of childhood asthma. In a population exposed to farming, some genetic variants may provide additional protection from childhood asthma. Thus, both genetic and environmental components may independently contribute to the mechanisms that underlie asthma.
The Journal of Allergy and Clinical Immunology (JACI) is the official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.