Asthma study finds DNA culprit

An international study, published in 'The Lancet' journal, comprised a genome-wide association analysis in 2,669 physician-diagnosed asthmatics and 4,528 control patients from Australia.

Lead author Professor Philip Thompson of Lung Institute of Western Australia says that the study involved comparing DNA of thousands of asthma patients with healthy individuals and combining the results with other international studies.

"Two regions of the DNA were consistently different between asthmatics and non-asthmatics: one in the interleukin-6 receptor (IL6R) gene on chromosome 1, and the other (region) near a gene called GARP on chromosome 11.

"Of these two, the first is particularly interesting because IL6R is a signalling molecule that plays an important role in the immune system and inflammation. It is involved in many diseases, including rheumatoid arthritis," he said.

According to Prof Thompson, results suggest because of this genetic difference asthma patients produce more interleukin-6 receptor in the lung than non-asthmatics which, in turn, contributes to airway inflammation.

The findings raise the possibility for the development of new drug treatments for asthma, say the scientists.

"Medications acting on the IL6R may provide new treatment options. This study has provided key biological insights into the complex mechanisms that cause asthma and illustrate the importance of key scientists combining their expertise to unravel, the molecular pathways involved in asthma," Prof Thompson said.