Inheriting two copies of a genetic variant has been associated with reduced response to steroid inhalers in people with asthma. The finding could explain why around 40 percent of people with asthma do not benefit from inhaled steroids, the most commonly prescribed medication for the condition.
'The study illustrates the importance of research examining the relationship between genetic makeup and response to therapy for asthma, and underscores the need for personalised treatment for those who have it', said Susan Shurin, acting director of the US National Heart, Lung, and Blood Institute, one of the funding bodies of the research.
Researchers at Boston's Brigham and Women's Hospital and Harvard Medical School in the USA carried out a genome-wide association study using data from 1,000 people (including children and their parents), and identified a gene called glucocorticoid-induced transcript 1 gene (GLCCI1). The team, led by Dr Kelan Tantisira, found that treatment with an inhaler produced only one-third of the level of lung improvement in asthma patients with two copies of a variant of the gene compared to those with regular copies of the gene.
The results, published in the New England Journal of Medicine, are 'appreciable but not overwhelming' according the journal's editor Dr Jeffery Drazen, who also noted that the research would be a step towards being able to identify which patients are most likely to respond to inhaled steroids.
'The next step must be to mount clinical trials in which patients are stratified according to their biological signature to determine whether knowledge of this information leads to better clinical outcomes', said Dr Drazen.