Study: Gene variant increases asthma risk

CHICAGO, April 15 (UPI) -- U.S. scientists say they've determined a tiny variation in a gene known as CHI3L1 increases one's susceptibility to asthma and related medical conditions.

University of Chicago Medical Center researchers said the gene variant causes increased blood levels of YKL-40, a biomarker for asthma. A slightly different genetic variation lowers YKL-40 levels and protects against asthma, bronchial hyperresponsiveness and declines in lung function.

Although the original discovery came from a study of a genetically isolated population, the Hutterites of South Dakota, the researchers were able to confirm the same connections between the CHI3L1 variations, YKL-40 levels and asthma susceptibility in three genetically diverse Caucasian populations from Chicago, Madison, Wis., and Freiberg, Germany.

"This is exciting because it connects asthma susceptibility to a whole new pathway at the protein and the genetic levels," said Professor Carole Ober, the study's author. "There is a good deal more we need to find out about this connection, but now we know where to look."

The findings are reported in the early online edition of the New England Journal of Medicine in advance of the journal's April 17 issue.