Which children will 'grow out' of asthma?
28th June 2013 -- A new study reveals the potential of genetic testing to predict which children will 'grow out' of asthma.
Approximately half of all children with asthma will no longer experience symptoms by the time they reach adolescence or become adults. However, there are no current tests to predict a child's future asthma symptoms.
Researchers have identified 15 locations in the human genome linked to asthma.
US researchers are reporting on a new analysis of data from 40 years of data from New Zealand in the journal Lancet Respiratory Medicine. Asthma risk was calculated for 880 people who were tracked over 38 years.
As part of the study, the amount of disruption to a person's life caused by asthma symptoms was monitored, including time off school or work and admissions to hospital.
Using a risk scoring system, they found children at a higher genetic risk of asthma were 36% more likely to develop serious, life-long asthma than those with a lower risk. The prediction using genes was independent of a person's family history of asthma.
Those with the higher genetic risk were more likely to develop atopic or allergic asthma. Also more common was impaired lung function or airway hyper-responsiveness and incompletely reversible airflow obstruction. The genetic risk also meant more school and work days missed and a greater likelihood of being admitted to hospital with asthma symptoms.
Asthma risk prediction 'still in its infancy'
The research was led by Dan Belsky, a postdoctoral fellow from Duke University Medical Center in the US. In a statement, he says everyday use of accurate genetic testing in asthma is still some way off: "Although our study revealed that genetic risks can help to predict which childhood-onset asthma cases remit and which become life-course-persistent, genetic risk prediction for asthma is still in its infancy."
He says accuracy of the predictions will improve as more asthma risk genes are found.
Commenting on the new research in an emailed statement, Leanne Reynolds, research operations manager at Asthma UK, says: "We know that some children with asthma no longer experience symptoms when they reach adulthood, however it can be misleading to assume they have ‘grown out’ of the condition; the underlying tendency still remains and so symptoms can still return in later life. This study provides valuable insights into this area, although more research is needed before these findings could be used in clinical practice.
"We would welcome further research into this area to expand and confirm these findings. This could mean that in the future we’re able to identify those people whose asthma will put them at greatest risk so we can ensure they get the support they need."