Nut allergy linked to gene defect

British scientists have helped to identify a gene defect which can triple the risk of a child developing a peanut allergy.

An international collaboration, led by researchers at the University of Dundee, made the discovery after scientists from Canada, Ireland, England and the Netherlands worked on the study.

The team at Dundee had previously found that the gene, called Filaggrin, was a “significant factor” in causing eczema and asthma.

Sara Brown, Wellcome Trust intermediate clinical fellow in the division of molecular medicine at Dundee, said: “It was a logical next step to investigate whether Filaggrin may also be a cause of peanut allergy, since a child may develop all three of these diseases together.

“Allergic conditions often run in families, which tells us that inherited genetic factors are important. In addition to that, changes in the environment and our exposure to peanuts are thought to have been responsible for the recent increase in peanut allergy seen in the Western world in particular.

“Now, for the first time, we have a genetic change that can be firmly linked to peanut allergy.”

The Filaggrin gene helps build barriers in the skin to protect the body against irritants and allergens but changes in the gene decrease the effectiveness of this barrier, allowing substances to enter the body and leading to a range of allergies.

The study, published in the Journal of Allergy and Clinical Immunology, found that one in five of all peanut allergy sufferers has a Filaggrin defect.