Asthma genetic risk research could lead to future test

Asthma in some children becomes more serious in adulthood

Research into the genetic risks for asthma could lead to a test which predicts which children will never grow out of it, says a study in The Lancet.

Scientists found that those at higher genetic risk of asthma were 36% more likely to develop serious, life-long asthma than those with lower risk.

But they said it was too soon to be used as a reliable clinical test.

Asthma UK says the findings could help identify people whose asthma could become severe.

Earlier studies had linked several genes to small increases in asthma risk.

This study, led by researchers from Duke University in North Carolina, identified 15 separate locations in the human genome which are associated with asthma.

Using this knowledge combined with data from a major New Zealand health study of more than 1,000 people since birth, the researchers were able to calculate the genetic risk score for 880 individuals.

They then tracked the development and progression of their asthma from early childhood through to their late 30s.

Those with higher genetic risk scores were more likely to have severe asthma which continued into adulthood, and they more often developed problems with lung function.

They were also more likely to miss school or work and to be admitted to hospital because of their asthma.

At present, there are no tests that can predict which children will recover as they grow older.

'Long way'

Dr Daniel Belsky, a post-doctoral fellow at the Duke Institute for Genome Sciences and Policy, said it was too early to talk about a predictive test for severe asthma.

"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.

"As additional risk genes are discovered, the value of genetic assessments is likely to improve."

He said there was still a long way to go before genetic risk scores could be used routinely in medical practice.

But the study could lead to a better understanding of asthma and how to treat it, he said.

Leanne Reynolds, from the charity Asthma UK, said it was misleading to assume that some children 'grow out' of the condition.

"We know that some children with asthma no longer experience symptoms when they reach adulthood, however... the underlying tendency still remains and so symptoms can still return in later life."

However, she said further research in this area would be welcomed.

"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."