Asthma attacks requiring young children to be hospitalized are usually genetically related, according to researchers in the journal Nature Genetics. Their work revealed that, genetically, asthma has many different underlying mechanisms, which need to be individually mapped.

For the study, researchers from the University of Copenhagen studied the genes of 1,200 young children aged between 2 and 6 who were hospitalized several times because of severe asthma attacks. The team compared their findings with data from 2,500 healthy people.

The comparison identified five loci with genome-wide significant association, four of which were previously reported as asthma susceptibility loci, but “the effect sizes for these loci in our cohort were considerably larger than in the previous genome-wide association studies of asthma,” according to the authors.

The team also obtained strong evidence for a new susceptibility gene, CDHR3 (encoding cadherin-related family member 3), which is highly expressed in airway epithelium. These results demonstrate the strength of applying specific phenotyping in the search for asthma susceptibility genes.

“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,” said Klaus B√łnnelykke, MD, PhD, the Copenhagen Studies of Asthma in Childhood (COPSAC), the Danish Pediatric Asthma Center, Copenhagen University Hospital. “In this respect, knowledge about risk genes is an important step in the right direction.”