A defective gene appears to contribute to most cases of childhood asthma, a finding that could lead to a better understanding of allergies, U.S. researchers reported on Wednesday.
The gene may control some of the signaling in the immune system, the researchers reported in the New England Journal of Medicine. The defective version causes that system to go awry, producing an overreaction.
The discovery "is very likely to extend beyond asthma and really be a key player in all allergies. Because about 30 percent of the population has allergies, there's a lot of potential here," Dr. Hakon Hakonarson of The Children's Hospital of Philadelphia, who led the study, said in a telephone interview.
"There are a number of genes that have been reported to play a role in asthma. They are either false alarms or their role in asthma is a lot weaker or smaller than we expected them to be, otherwise we would have seen them with this approach," he said.
About one in 15 Americans has asthma, according to the Asthma and Allergy Foundation of America.
Hakonarson said allergies are involved in about 85 percent of childhood asthma cases, and 80 percent to 90 percent of those children have the defective gene.
"The cells that express that gene decide what happens when allergens, viruses and foreign materials come into the body," said Hakonarson.
The team found the gene by evaluating the DNA of 8,881 people from North America, Europe and Africa, some of whom had persistent childhood asthma.
"Other asthma-related genes remain to be discovered, but finding a way to target this common gene variant could benefit large numbers of children," Hakonarson said in a statement.
