An international team has pin-pointed the genes responsible for an increased chance of severe asthma in children, which could one day lead to much more effective treatments.

Asthma is a very common and dangerous childhood disease, one of the major reasons for children being admitted to hospital and a source of high cost and concern for parents.

Doctors have typically faced a lack of concrete knowledge on the causes of attacks – making it extraordinarily difficult to counteract.

New research may change this, with the identification of the genes putting some children at a higher risk of experiencing severe attacks. The results have been published in the journal ‘Nature Genetics’.

“Our results show that asthma attacks requiring young children to be hospitalised are usually genetically related. Genes play a far greater role in children with asthma than in adults,” says researcher Klaus Bønnelykke, MD, PhD.

“By screening children's DNA we've discovered that a gene called CDHR3, which was previously unassociated with the disease, plays a key role for the development of asthma, particularly in the very early years of life. Our study supports the theory that asthma is not just a single disease, but a complex of several sub-types that should be genetically mapped and understood individually if we are to prevent and treat the disease properly in future,” Dr Bønnelykke said.

The genes of 1,200 children aged between two and six who had been hospitalised several times because of severe asthma attacks were compared them with 2,500 healthy people.

CDHR3 is known to impact the lungs directly.

The new research results indicate that it plays a particularly important role in the lungs of young children with severe asthma. Over time the researchers hope to be able to map the precise mechanisms the gene is involved in, as well as the environmental factors that trigger activation of the gene in some children.

The researchers say typically the same medications are used for asthma virtually regardless of the different types and degrees of the disease. They say that an improved understanding of the sub-types of asthma will hopefully clear the way for individualised treatment in future.

“Although good asthma medication is available today, it doesn't work for everyone. Specifically we need effective medicine to prevent very young children from being hospitalised and to treat them once they have been admitted. That's why we started looking at this particular group,” Bønnelykke said.

“Because asthma symptoms are fairly similar in all children, doctors tend to approach the condition in the same way. However, in reality asthma has many different underlying mechanisms, which need to be individually mapped,” he says.

Dr Bønnelykke explains that to date, researchers have focused on various theories about asthma attack prevention in young children, for example, recommending breastfeeding and avoiding pets and dust mites in the home.

“We know that children exposed to smoking have a higher risk of asthma attacks, but beyond that, none of our advice has really helped, and we won't make any progress until we understand the individual sub-types of asthma and their underlying mechanisms. In this respect knowledge about risk genes is an important step in the right direction,” he also pointed out.