Scientists have been invited to create the world's largest asthma database in a bid to discover which genes are responsible for the illness.

With Great Ormond Street Hospital, in London, the researchers at Oxford University will collect genetic information from people suffering from the breathing disorder as well as the skin complaint eczema.

The database will collect DNA make-up samples from severely ill children in hospital and their families, before trying to isolate individual disease-causing genes and studying how they function.

The Medical Research Council-funded research could lead to better treatments for asthma and eczema, which are affecting more and more people every year. One in seven children requires treatment to control symptoms and 1,584 people died after an asthma attack in 1998 alone.

It is estimated that the conditions cost the UK more than 2,000m every year in NHS treatment, absence from work and invalidity benefits.

Prof Bill Cookson, of Oxford University's asthma genetics department, is leading the database study.

He said: "We are delighted to be given the privilege of supervising the national collection of families with asthma and eczema. Our ability to find the genes that cause allergic illnesses depends completely on the study of families with these diseases.

"The MRC national collection will not only help our own research, but will also be of enormous help to many other UK scientists."

The database is one of 14 genetic collections being set up by the MRC.