LONDON: Genetic tests to identify children at risk of eczema and asthma and improve treatments are a step closer, thanks to a study of the conditions’ genetic basis. Scientists have discovered 15 different mutations within a gene called filaggrin that is known to be involved in the debilitating conditions when it malfunctions.

The data from eczema patients in the UK and Ireland suggest that genetic slip-ups in the gene are responsible for around half of the most serious eczema cases.

“Once we cracked this exceptionally difficult gene, we were surprised to learn how many different defects in filaggrin were waiting to be discovered, not only in European people, but other populations worldwide,” said Irwin McLean at the College of Medicine, Dentistry and Nursing at the University of Dundee in Scotland.

The study is a follow-up to the team’s breakthrough research published in March last year which showed that eczema and related asthma cases were caused by mutations in the gene. The protein coded by the gene is an important component of the skin’s outer protective layer. The study offered the opportunity for scientists to really understand what is going wrong in eczema, and a more serious skin condition called ichthyosis vulgaris, which causes flaky and scaly skin.

Eczema affects around one in five UK children. Knowing which mutations to look for could allow doctors to identify individuals at risk of the disease early on. It might also allow scientists to develop treatments.

Until filaggrin’s role was identified, researchers had mostly assumed that problems with the immune system were responsible for the condition.

Now, though, research is focusing on drugs that can boost production of the filaggrin protein in skin.

To identify what the genetic errors are that cause the diseases, the team looked closely at filaggrin sequences from 23 sufferers of ichthyosis vulgaris from Ireland, Scotland, the Netherlands and Austria. This search threw up 12 changes to the normal sequence that prevented or reduced protein production from the gene. A further study of five Irish children with severe eczema identified three more mutations. The study, carried out with researchers at Trinity College Dublin, is published in the journal Nature Genetics.

The team speculate that lacking the filaggrin protein might confer advantages that balance the risks from eczema. —Dawn/The Guardian News Service