In what looks to be a true medical breakthrough, a team of researchers from Children's Hospital of Philadelphia believe they have pinpointed the underlying cause of most cases of childhood asthma: a defective gene that triggers the body's immune system to overreact to certain allergens.
The study, published December 23, 2009, in the New England Journal of Medicine, tested DNA samples from more than 8,000 people from North America, Europe, and Africa, some of whom had persistent childhood asthma. Allergies were involved in about 85 percent of childhood asthma cases and between 80 to 90 percent of those children had the defective gene.
"The cells that express that gene decide what happens when allergens, viruses, and foreign materials come into the body," said Dr. Hakon Hakonarson, study lead author, in an interview with ABC News. In children with the gene defect, Hakonarson speculates, immune system cells go awry and chronically produce asthmatic reactions.
Researchers believe their finding may go a long way towards developing a better understanding of why some children develop asthma—and one day creating a gene-based treatment for the condition.
"Other asthma-related genes remain to be discovered, but finding a way to target this common gene variant could benefit large numbers of children," noted Hakonarson.
According to the Asthma and Allergy Foundation of America, about 20 million Americans have asthma—a disease of the lungs in which the airways become blocked or narrowed causing breathing difficulty.