Scientists have discovered a gene involved in the development of asthma, a finding that promises to lead to better treatment and understanding of the respiratory disorder.

A team of medical geneticists led by Professor William Cookson, of Oxford University, announced the discovery of an asthma gene at the weekend after six years of intensive investigation involving more than 20 doctors.

The gene appears to be involved in regulating white blood cells which produce the key antibody that plays a role in triggering the extreme allergies implicated in asthma and childhood eczema, a skin disorder.

"Finding the new gene adds a new dimension to understanding asthma and allergic diseases, but the understanding is still incomplete," Professor Cookson said.

There are about 10 genetic traits that are known to play a role in predisposing someone to asthma and about half of these genes have been identified.

The latest gene, called PhF11, is located on chromosome 13, which has been known for many years to contain a gene for asthma. Its discovery, published in the journal Nature Genetics, may lead to better classification of the disease and to new treatments, Professor Cookson said. "It is very likely that all the important genes will be found in the next three years. Even without knowing all the genes involved in asthma, our ideas about the causes of the disease are changing and we are seeing new ways to treat the illness," the professor said.

Asthma has been one of the fastest-growing disorders in Britain, affecting one in seven children. Worldwide, about 155 million people have been diagnosed with the respiratory disorder. Although environmental factors, such as house-dust mites, are linked with asthma, there is also a strong genetic component, with some people being innately more susceptible than others.

By studying the role of genes in asthma, scientists hope to understand the factors that trigger the disease and how to treat the symptoms at a more fundamental level.

Professor Cookson said that different variations of certain genes were usually associated with severe asthma in adults but added that the PhF11 gene might be involved in milder forms of asthma and eczema in children.

One possible goal for new forms of treatment could be to develop drugs that could turn off the genetic "switches" involved in the production of the immunoglobin E (IgE) antibody, which is heavily implicated in many allergic reactions, including asthmatic attacks. "The challenge of translating genetic findings into new treatments is, however, not trivial and will not be accomplished overnight," Professor Cookson said. "This type of genetic research is expensive and laborious and takes years of work."

When scientists first began to locate the genetic traits for asthma more than a decade ago, commentators suggested that their work would lead to a cure for asthma within five years, a prediction that has proved optimistic.

Donna Covey, representing the National Asthma Campaign, which funded the study with the Wellcome Trust, said that genetics was making an impact on the understanding of the respiratory disorder.

"We already know that developing asthma depends on the balance of genetic factors and environmental factors to which they are exposed," Ms Covey said.