Researchers Find Gene Mutation That Increases Asthma Risk

(Page 2)

Working with the Yale team, Ober found that the Hutterites with asthma or overactive airways had elevated levels of YKL-40. After searching their genetic code, Ober and her colleagues found that one tiny change in the CHI3L1 gene was slightly different in Hutterites with asthma. When the researchers compared these findings to three different groups of people from Chicago; Madison, Wisc.; and Freiberg, Germany, they found an association with changes in CHI3L1 and YKL-40 levels, and the development of asthma. Some children were too young to have developed asthma, but already showed higher levels of YKL-40 if they had the genetic change.

Ober said that not everyone with high levels of YKL-40 develops asthma, but that someone with the CHI3L1 change inherited from both parents "was twice as likely to develop asthma as someone who doesn't have it."

"YKL-40 seems to be involved in many different diseases in which inflammation is a component, and so it is likely to be an important component of the innate immune response, and treatments directed at YKL-40 may be helpful in all of these diseases," said Dr. William Cookson, co-author of an accompanying editorial and a professor of respiratory genetics at the National Heart and Lung Institute at Imperial College in London.

Dickey said the Yale team is currently working on an animal model that doesn't produce YKL-40 to see if the protein is important in other functions in the body.

"If the protein doesn't contribute importantly to any other biological process, it's likely just involved as a parasitic defense, and inhibiting it may not cause any problems, yet could provide substantial benefit [in terms of asthma treatment]," said Dickey.

More information

To learn more about the causes of asthma, visit the National Heart, Lung, and Blood Institute.