A genetic variant associated with poor response to a common asthma treatment has been identified in a new study by the Cleveland Clinic. Published in the Proceedings of the National Academy of Sciences, the research team found that a particular gene variant was present in asthmatic patients who were less likely to respond to glucocorticoids and often develop severe asthma.

Asthma is a very common condition where the airways narrow, become inflamed, and produce mucus causing reversible obstruction. All these factors make it difficult for sufferers to breathe. There are more than 1 million cases per year in the UK, and current treatments help to manage the disease but there is no cure. Medications such as glucocorticoids are often prescribed to help reduce inflammation in severe cases, but they do not work for everyone and it’s not known why.

The team from Cleveland Clinic studied more than 500 asthmatic patients and analysed the association between lung function and the patient genomes. The patients either received daily oral glucocorticoid treatment or none.

A gene variant was identified in the HSD3B1 gene – specifically the HSD3B1 (1245A) variant – that was associated with poor lung function and glucocorticoid treatment resistance when compared to those who didn’t have the variant.

The HSD3B1 gene encodes an enzyme that converts weak hormones called androgens into more powerful androgens. The team suggest that the genetic variant could play a role in inhibiting this process and could consequently affect lung function. The team at the Cleveland Clinic have already studied the role of the HSD3B1 gene in prostate cancer, and have discovered that the HSD3B1(1245C) variant is linked to prostate cancer cell survival during androgen deprivation therapy, where cancel cells can produce their own disease-fuelling androgens.

Findings from studies like these show that personalised treatment through genetic testing could help to identify which patients would benefit the most from using different therapies, and ultimately ensure that patients are treated as best as they can.