Child- and adult-onset asthma have some faulty genes in common, but there are also important differences, meaning optimal treatment could differ between the two, US researchers say.

The study of more than 356,000 Caucasian individuals shows that while 37 genetic variants were common to both child- and adult-onset disease, 23 were unique in child-onset disease and one to adult-onset.

Clinical differences between early- and late-onset asthma were well known: adult-onset disease was more common in women, had a worse prognosis, a poorer response to corticosteroids and was less allergic, say the authors of an associated editorial in the Lancet Respiratory Medicine.

The study added to this as it revealed the genes associated with child-onset disease were predominantly expressed in the skin, while those found in adult-onset patients were expressed in the lung and spleen, say the researchers from the University of Chicago.