Scientists from the Helmholtz Zentrum München and the Cluster of Excellence "Inflammation at Interfaces" in Kiel in collaboration with researchers and clinicians from 14 different countries have succeeded in identifying ten genomic regions in which common gene variants increase the risk of eczema (atopic dermatitis). The findings of this largest ever genetic study on eczema, in which more than 50,000 patients and 300,000 healthy individuals were examined, have now been published on the website of Nature Genetics.
Eczema, or atopic dermatitis, is a chronic inflammatory skin disease which is characterized by intense itching and recurrent eczematous lesions. It affects up to 20% of children and 10% of adults worldwide, and dramatically impacts the quality of life and psychosocial well-being of patients and their families. Although the precise causes are still insufficiently understood, it is well established that an inherited susceptibility is of utmost importance.
To get insights into the genetic risk factors of the disease, a research team composed of clinicians and scientists from 14 different countries studied the entire genome of more than 50,000 patients and 300,000 healthy individuals. The study was led by Professor Stephan Weidinger, Cluster of Excellence "Inflammation at Interfaces" (Department of Dermatology, Kiel University and Universitätsklinikum Schleswig-Holstein, Kiel Campus), Dr. Marie Standl from the Helmholtz Zentrum München (German Research Center for Environmental Health, Munich) and Dr. Lavinia Paternoster (University of Bristol, UK), within the framework of the "EAGLE" Consortium (EArly Genetics and Lifecourse Epidemiology).
The researchers were able to identify ten new genetic regions in which variations influence the risk for eczema. They also observed differences between ethnic groups. "Through the cooperation with colleagues from Europe, America, Asia and Australia we had access to an extremely high amount of data from diverse populations" says Standl, "and the results are highly robust."
"Inherited susceptibility for inflammatory diseases"
The majority of the genes identified play a role for the balance of the immune system and its response to environmental exposures, and also affect the risk for other inflammatory diseases. Study leader Weidinger: "Our results suggest that many people have an inherited susceptibility for inflammatory diseases in general. In these people, other inherited or environmental exposures are then responsible for this susceptibility to be expressed in the skin."
Understanding gene function to improve diagnostics and therapy
A special challenge will now be to understand in detail the molecular mechanisms through which the identified genes increase the risk for inflammatory diseases and more specifically for eczema. In addition, their interaction with lifestyle and environmental factors has yet to be clarified. "Only then will we be able to develop tests which facilitate the prediction of disease risk and the development of improved strategies for prevention and treatment, or to apply existing treatments in a more targeted fashion", says study leader Weidinger.