Experts said in a warning recently that the world's most common inhaler could fail to stop asthma attacks in up to 100,000 British kids.

A genetic mutation present in one out of ten sufferers makes "Salbutamol" the "blue" inhaler less effective. People with this mutation have a 30 percent more chance of getting asthma attacks.

"People are becoming desensitized", said Professor Colin Palmer, of the University of Dundee.

A total of 1 million children are affected by asthma in the UK and one out of ten is affected by this genetic change.

A combined research by University of Dundee and Brighton and Sussex Medical School observed these results.

Every child in the group was taking salbutamol to get relief from asthma attacks but were also on a longer-acting inhaler to control symptoms in the long term.

It was found that a particular genetic flaw increased their risk of asthma by 30 percent and the "blue" inhalers were less effective.

This gene could be detected by conducting a simple saliva test.

Dr Elaine Vickers, research relations manager at Asthma UK, said: "The research did not look at whether a different sort of reliever asthma treatment would be more appropriate for this group of children, so we don't yet know whether they should be given a different treatment.