August 2, 2011
New Insights into Asthma
(Ivanhoe Newswire) "“ A team of researchers discovered a novel gene associated with asthma in African-Americans, according to this study. The findings are a promising first step for a new national scientific effort to hunt for the genetic roots of asthma.
"We now have a really good handle on at least five genes that anyone would be comfortable saying are asthma risk loci," Carole Ober, PhD, co-chair of the EVE Consortium, senior author of the study, and Blum-Riese Professor of human genetics and obstetrics/gynecology at the University of Chicago, was quoted as saying. "I think it's an exciting time in asthma genetics."
"Asthma rates have been on the rise in recent years, with the greatest rise among African Americans," Susan B. Shurin, M.D., acting director of the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health, which co-funded the study, was quoted as saying. "Understanding these genetic links is an important first step towards our goal of relieving the increased burden of asthma in this population."
Genome-wide association studies, or GWAS, are a popular method used by geneticists to find genetic variants associated with elevated risk for a particular disease. Genetic data from a group of patients with the target disease are compared to data from a control group without the disease, and researchers look for variants that appear significantly more often in the disease group.
The EVE dataset comprised a more ethnically diverse population than similar efforts in other countries by including European Americans, African Americans/African Caribbeans, and Latinos.
"We believe that this heterogeneity is important," Dr. Ober said. "There are differences in asthma prevalence in these three groups, so it's important to understand whether these are caused by environmental exposures or by differences in genetic risk factors."
Four more gene variants were found significant for asthma risk by the meta-analysis: the 17q21 locus, and IL1RL1, TSLP, and IL33 genes. All four of these sites were concurrently identified in a separate dataset by the GABRIEL Study of more than 40,000 European asthma cases published last year in the New England Journal of Medicine. Confirming these associations in the more diverse EVE population offers additional evidence that the gene variants are significant across ethnicities, the researchers reported.
"We were able to show that almost all of the genes other than PYHIN1 are trans-ethnic and important in all of the groups," Dr. Ober said.
SOURCE: Nature Genetics, published online August 2011