Gene for asthma revealed

By STEVE CONNOR

Scientists have discovered a gene implicated in asthma, which they believe will help them better understand the breathing illness and find more effective treatments for it.

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 seems to regulate the white blood cells that produce an antibody that helps to trigger the extreme allergies implicated in much 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.

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

The latest gene, called PhF11, is 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."

Asthma cases are growing rapidly in New Zealand, where it affects one in six people and is the most common reason why children are admitted to hospital. Around 155 million people worldwide are diagnosed with asthma.

Although environmental factors, such as house-dust mites, are linked to the condition, there is also a strong genetic component, with some people more susceptible than others.

By studying the role of genes in asthma, scientists hope to understand what triggers the disease and how to treat the symptoms more effectively.

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

New treatments could involve drugs that can turn off the genetic switches involved in producing the immunoglobin E (IgE) antibody, which is heavily implicated in many allergic reactions, including asthma 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 began to locate the genetic traits for asthma more than a decade ago, commentators suggested that it would lead to a cure for asthma within five years, a prediction that has proven hopelessly optimistic.

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

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

Asthma's impact

Asthma affects one in six people in New Zealand.

It is the most common cause of children's hospital admissions.

Worldwide about 155 million people are diagnosed with the respiratory disorder.

- INDEPENDENT AND STAFF REPORTER