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Genetic testing may be able to determine which children with asthma are likely to grow out of the condition and which will continue having symptoms as they grow older, a new study suggests.

New research published in The Lancet Respiratory Medicine, analyzed data from a 40-year longitudinal study.  Researchers found that children with asthma and higher risk scores comprising of multiple genetic variants linked to asthma were over 36 percent more likely to develop life-long-persistent asthma that those with a lower genetic risk.

Around half of all children with asthma will grow out of it by the time they reach adolescent or adulthood.  However, there are no tests that can predict which children will grow out of the chronic lung disease.

However, recent genetic studies have identified several variants (single nucleotide polymorphisms; SNPs), which carry a small increased risk of asthma. Researchers in the current study wanted to see whether these known genetic risks are related to the onset, persistence and severity of asthma, and with disruptions to daily life.

In the latest study, researchers constructed a genetic risk score based on 15 variants identified by previous genome-wide association studies and tested associations between the scores and asthma phenotypes in 880 participants.  The findings revealed that boys and girls with higher risk scores had a greater likelihood of developing asthma over the 38 years of follow-up than those with a lower genetic risk.  Children with asthma and higher risk scores also developed the condition earlier in life.

The findings revealed that individuals with higher genetic risk scores were also more likely to develop atopic (allergic) asthma and impaired lung function (airway hyper-responsiveness and incompletely reversible airflow obstruction), and to miss school or work and to be hospitalized because of asthma than those with a lower genetic risk.

Researchers stressed that the predictive value of the genotype score was independent of family history.

"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," lead researcher Daniel Belsky from Duke University Medical Center noted.

"As additional risk genes are discovered, the value of genetic assessments is likely to improve. But our predictions are not sufficiently sensitive or specific to support their use in routine clinical practice," he added.