In all, more than 500,000 tests were performed on the genes of 10,000 children and adults with the condition, and 16,000 non-asthmatics.
The Imperial College-led research, published in the New England Journal of Medicine, could point to new targets for drugs.
Experts said gene testing could not predict who would get the condition.
One in seven children in the UK suffers from asthma, which causes the airways to become irritated and narrow, making it harder for them to breathe.
The reasons why people develop the disease are not yet fully clear, although scientists suspect a roughly equal mixture of genetic susceptibility and environmental factors.
The latest genetic variants discovered by the international research appeared in more than a third of children with asthma.
However, the gene with the strongest impact on children did not affect people who developed asthma in adulthood, suggesting that the two versions of asthma may differ biologically. Read Full Story from the Publisher