Mapping asthma

Scientists at deCODE genetics (www.decode.com) have mapped the first gene shown to have genomewide links to asthma. A paper, "A Major Susceptibility Gene for Asthma Maps to Chromosome 14q24," was published in the online edition of the American Journal of Human Genetics (www.ajhg.org). The Icelandic study involved approximately 1,000 microsatellite markers, nearly 600 patients, and 550 unaffected relatives.

Glucocorticoids, a widely used treatment for asthma, can have severe side effects, particularly in children. The study generated more than five million data points which led to the identification of key genes responsive to glucocorticoids. deCODE developed an expression-based assay test of seven genes that can predict glucocorticoid responsiveness with nearly 90% accuracy. That may allow doctors to prescribe the medicine that provides the most effective relief with the fewest side-effects. Asthma is the most common chronic disease in children and young adults. Its prevalence in most European and North American countries ranges between 5% and 20% of the population.