Scientists have identified a gene defect that can triple a child’s risk of developing peanut allergy, a discovery which they say can lead to new treatments for the life-threatening condition.
An international team, led by researchers from the University of Dundee, studied defects in the gene, called Filaggrin, and found that children with the defect can be thrice more likely to suffer peanut allergy, than those with normal Filaggrin.
The gene, which is carried by more than 10 per cent of people, has already been shown to be a factor in causing eczema and asthma, the Daily Mail reported.
Peanut allergy, which affects about two per cent of children in the UK alone, can be life-threatening. The number of people affected by the condition has increased dramatically over the past 20 to 30 years, but the causes of the allergy are unknown, the researchers said.
Dr. Sara Brown, a fellow at Dundee University, 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 tell 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.”
According to the researchers, the Filaggrin gene helps build barriers in the skin to protect the body against irritants and allergens.
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 found that one in five of all peanut allergy sufferers has Filaggrin defect. Those with the defect can be three times more likely to suffer peanut allergy than people with normal Filaggrin.
The collaboration looked at 1,300 people in four different population groups in Canada, England, Ireland and the Netherlands.
Scientists said it was the first time that any genetic association with peanut allergy has been demonstrated in more than one population, making it more likely to be a “genuine risk factor”.
Professor Irwin McLean, who is also based at Dundee, said, “The Filaggrin defect is not the cause of peanut allergy but we have established it as a factor in many cases. We don’t yet know enough about the causes of peanut allergy but this is an important step forward.”
The new findings were published in the Journal of Allergy and Clinical Immunology.